Symposium Organizers
Richard M. Laine University of Michigan
Clement Sanchez Universite Pierre et Marie Curie
Christophe Barbe Ceramisphere, ANSTO
Ulrich Schubert Vienna University of Technology
S2: Mesoporous Materials I
Session Chairs
Kazuki Nakanishi
Bernd Smarsly
Tuesday AM, April 10, 2007
Room 2004 (Moscone West)
9:15 AM - **S5.1
Mesoporous Hybrid Thin Films: Building Blocks for Complex Materials with Spatial Organization.
Galo Soler-Illia 1 2 , Paula Angelome 1 , M. Cecilia Fuertes 1 , Alejandro Wolosiuk 1 , Sara Bilmes 2 , Javier Lopez-Alcaraz 3 , Hernan Miguez 3
1 Unidad de Actividad Química, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires, Argentina, 2 INQUIMAE-DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires Argentina, 3 Instituto de Ciencia de Materiales de Sevilla, Consejo Superior de Investigaciones Científicas, Sevilla Spain
Show Abstract9:45 AM - **S5.2
Inorganic and Hybrid Thin Layers with Specific Designs.
Vincent Rouessac 1 , Andre Ayral 1
1 Institut Européen des Membranes UMR n° 5635 CNRS-ENSCM-UM2, CC047, Université Montpellier 2, F34095 Montpellier cedex 5 France
Show Abstract10:15 AM - **S5.3
Dynamic Supramolecular Hybrid Membranes
Mihai Barboiu 1
1 Adaptative Supramolecular Nanosystems, Institut Europeen des Membranes, Montpellier France
Show AbstractThe chemistry of membrane transport systems of interest for molecular information transfer has been extensively developed during the last twenty years. Our interest focus on hybrid solid membranes in which the molecular recognition-driven transport function could be ensured by a dynamic incorporation of specific organic receptors covalently and non-covalently linked in a dense and mesoporous siloxane inorganic matrix. Of particular interest is the potential ability of such solid membranes to combine functional properties such as solute molecular recognition, generation by self-assembling of the directional conduction pathways and target-constitutional evolution at the supramolecular level.From the mechanistic point of view, we use heteroditopic carriers which self-assemble in functional aggregates which would present combined (hybrid) intermediate features between the former carrier-monomers and the resulted pseudo-channel-forming superstructures. Thus, we therefore studied the membrane transport properties of such supramolecular systems resulted by the dynamic self-assembly of the hydrogen-bonded urea-crown ethers or bioorganic molecules in solid dense or mesoporous hybrid membranes. The crown-ether self-organized systems can be “frozen” in a polymeric hybrid matrix, opening the door to the design of a novel class of organic-inorganic nanomembranes. New self-organized hybrid membrane materials have been prepared from heteropolysiloxane superstructures chemically fixed in a silica matrix by sol-gel process. They have been employed to design the solid dense membranes, functioning as an ion-powered ATP pump.The selective recognition functions and self organization can be transferred inside regular mesoporous nanochannels. The MCM41-type mesostructured powders and membranes were used as hydrophobic or hydrophilic host matrix for physically or chemically entrapped 15-crown-5 and 18-crown-6 self-organized receptors. The combined features of structural adaptation in a specific hybrid nanospace and of dynamic supramolecular selection process make the membranes presented here of general interest for the development of a specific approach toward nanomembranes of increasing constitutional selectivity. 1.Barboiu, M.; Guizard, C.; Hovnanian, N.; Palmeri, J.; Reibel, C.; Luca, C.; Cot, L. J. Membrane Sci. 2000, 172, 91-103. 2.Barboiu, M.; Guizard, C.; Hovnanian, N.; Cot, L. Sep. Tech. Pur., 2001, 25, 211-218. 3.Barboiu, M.; Vaughan, G.; van der Lee A., Org. Lett., 2003, 5 (17), 3073-3076. 4.Barboiu, M., J. Incl. Phenom. Mol Rec. 2004, 49 133-137. 5.Barboiu, M.; Cerneaux, S.; Vaughan, G.; van der Lee, A.. J. Am. Chem. Soc., 2004, 126, 3545-3550. 6. Cazacu,A.; Tong,C.; van der Lee A., Fyles, T.; Barboiu,M. J. Am. Chem. Soc. 2006, 128, 9541-9548.
10:45 AM - S2:Meso 1
BREAK
11:15 AM - S5.4
Hybrid Organic-Inorganic Membranes with Long-Term Stability for Pervaporation.
Hessel Castricum 1 2 , Ashima Sah 1 , Jaap Vente 3 , Johan ten Elshof 1
1 Inorganic Materials Science, MESA+ Institute for Nanotechnology, Universiteit Twente, Enschede Netherlands, 2 Van ‘t Hoff Institute for Molecular Sciences, Universiteit van Amsterdam, Amsterdam Netherlands, 3 Molecular Separation Technology, Energy research Centre of the Netherlands, Petten Netherlands
Show AbstractMolecular separation processes are responsible for an estimated 40% of the total energy consumption in the (petro)chemical industry worldwide, i.e. more than 10 billion barrels of oil equivalent per year. These separations are currently performed using (cryogenic) distillation or adsorption-based techniques. The energy efficiency of these techniques is in general as low as 10%. Molecular separations based on membrane technology are generally accepted as one of the possible alternatives thanks to their inherently low energy consumption. Thermal, mechanical and chemical (solvent) stability are poor for polymeric membranes, while improvement of the hydrothermal stability is the main challenge for ceramic membranes in order to be able to work under humid conditions. As a consequence, the state-of-the-art membranes, i.e. PVA-based materials and methylated silca, have a application temperatures below ~100°C with minor associated benefit. In order to be cost-efficient, a membrane should be able to function at temperatures up to at least 150°C for several years.Mechanical stresses built-up during the sol-gel preparation of silica-based membranes are responsible for promoting hydrolysis of siloxane network bonds, resulting in the destruction of the microstructure in water. We have succeeded in preparing an organic/inorganic network material with a truly hybrid character by the application of a bis-silyl precursor. While this precursor suffers from extensive autocondensation and di-/trimerisation, resulting in the formation of non-reactive complexes and the development of a dense solid structure, we have been able to successfully suppress this mechanism by mixing with silane co-reactants and ensuring very gradual hydrolysis and condensation. This resulted in a microporous structure with a high organic fraction. Through the careful control over the coating procedure, a supported defect-free thin layer (< 100 nm) with a high hydrothermal stability has been obtained. The organic linking groups provide a ‘core network’ of unhydrolysable moieties and provide flexibility, which limits strain in the siloxane bonds. This leads to a high stability in water-containing media at increased temperatures. Moreover, they promote stress relaxation of the thin coated film during the preparation procedure and perseverance of the structure against thermal and pressure gradients. Consequently, the material is highly resistant to cracking. As a result, a membrane has been produced that can be applied in the dehydration of n-butanol up to at least 150°C for more than one year, bringing industrial application within close reach.
11:30 AM - S5.5
Nanoparticle Assembly of Ordered Multicomponent Mesostructured Metal Oxides via a Versatile Sol-gel Process
Jie Fan 1 , Shannon Boettcher 1 , Galen Stucky 1
1 Chemistry and Biochemistry, University of California, Santa Barbara, California, United States
Show AbstractMulti-component metal oxides have attracted attention for their potential use in electronic, (photo)catalytic, photovoltaic, and energy storage applications. The ability to simultaneously control the nanoscale structure and composition of such materials using simple and inexpensive routes is important for that potential to be realized. Here we introduce a simple and widely-applicable methodology for the synthesis of multicomponent mesostructured metal oxides (MMMOs) from the combination of inexpensive and commercially available polymers with metal alkoxides solubilized in a sol-gel solution consisting of acetic acid, hydrochloric acid and ethanol (AcHE). MMMOs obtained utilizing the AcHE system have tunable pore structures, a high degree homogeneity, and in certain cases thermal stability above 1000 oC. The ability to easily process these diverse MMMOs in the form of thin films, free standing membranes, and monoliths provides distinct advantages over previously reported MMO synthesis procedures—especially when large quantities of material are required, for instance, in heterogeneous catalyst development. Most importantly, we demonstrate that using this method, the diverse condensation kinetics of a variety of metal oxide materials can be homogenized—which allows for the fabrication of complicated and novel MMMO compositions (e.g. rare earth and transition metal oxides). The development of such simple and widely-applicable methodologies are extremely important for the practical implementation of porous metal oxides.
11:45 AM - S5.6
Inorganic/organic Polymer Films Formed via Plasma Enhanced Chemical Vapor Deposition.
Jesse Enlow 1 , Hao Jiang 1 , Kurt Eyink 1 , Mark Foster 2 , Somesh Peri 2 , John Grant 3 , Timothy Bunning 1
1 , Air Force Research Laboratory, WpAFB, Ohio, United States, 2 , U. Akron, Akron, Ohio, United States, 3 , UDRI, Dayton, Ohio, United States
Show Abstract12:00 PM - **S5.7
Mesoporous Carbon Nitrides: a First Step towards Metal-Free Heterogeneous Catalysis.
Frederic Goettmann 1 , Anna Fisher 1 , Philippe Makovski 1 , Markus Antonietti 1 , Arne Thomas 1
1 Colloid Chemistry, Max-Planck-Institut for Colloids and Interfaces, Potsdam Germany
Show AbstractThe use of transition metals in catalysis is considered as the great chemical success story of the XXth century.[1] Nevertheless, increasing noble metals prices and evidence of large amounts of metals in soil or polar ices rose concerns about the sustainability of industrial process relying on such metal. Therefore, homogeneous organic catalysis attracted increased attention in recent years.[2; 3] An additional step towards more sustainable industrial process would be the development of a whole class of heterogeneous organic catalysts. Besides graphite,[4] carbon nitrides are a very promising class of material for this purpose. Graphitic C3N4 is easily available through thermal condensation of cyanamide.[5] This C3N4 material features graphene like layers of tris-s-triazine units and is especially interesting for its electronic properties. In order to investigate the potential catalytic performances of this material, increased surface was obtained by a nanocasting approach relying on the use of silica nanospheres as a hard template. The resulting powders exhibited surface area up to 400 m2.g-1. This mesoporous graphitic C3N4 (mpgC3N4) was then successfully used as a catalyst in various reactions:- The Friedel-Crafst acylation of benzene relying on an activation of the aromatic ring through electron transfer from the solid to the ring.[6; 7]- The cyclotrimerization of substituted nitriles and alkynes.[8]- The activation of CO2 and benzene to form Phenol and CO.[9]- The synthesis of various organic carbonates starting with CO and the corresponding alcohols.These very promising results drove us to investigate the synthesis and properties of other carbon nitrides like C3N3, N=N double bonds doped graphite…[1] W. A. Herrmann and B. Cornils, Angew. Chem.-Int. Edit. Engl. 36, 1997, 1049-1067.[2] P. I. Dalko and L. Moisan, Angew. Chem.-Int. Edit. 43, 2004, 5138-5175.[3] B. List, Accounts Chem. Res. 37, 2004, 548-557.[4] D. S. Su, N. Maksimova, J. J. Delgado, N. Keller, G. Mestl, M. J. Ledoux and R. Schlogl, Catal. Today 102, 2005, 110-114.[5] B. Jurgens, E. Irran, J. Senker, P. Kroll, H. Muller and W. Schnick, J. Am. Chem. Soc. 125, 2003, 10288-10300.[6] F. Goettmann, A. Fischer, M. Antonietti and A. Thomas, Angew. Chem. Int. Ed. 45, 2006, 4467 –4471.[7] F. Goettmann, A. Fischer, M. Antonietti and A. Thomas, Chem. Commun.2006, DOI: 10.1039/b608532f.[8] F. Goettmann, A. Fischer, M. Antonietti and A. Thomas, New. J. Chem.2006, Submitted.[9] F. Goettmann, A. Thomas and M. Antonietti, Angew. Chem. Int. Ed.2006, accepted.
12:30 PM - **S5.8
From Polymeric to Particulate Inorganic Macrocellular Foams:Some Integrative Chemistry Synthetic Pathways
Florent Carn 1 , Renal Backov 1
1 , CNRS-Universite Bordeaux-I, Pessac France
Show AbstractDesigning new porous materials in a monolithic state with a framework involving hierarchical porous systems while tuning the macroscopic void spaces is an emerging area of technological interests dedicated toward several applications as for instance heterogeneous catalysis, separations, artificial bone structure, thermal and/or acoustic insulation, ion-exchange operation and so forth. Recently a new concept of “Integrative Chemistry” has been postulated and can be defined as a transversal tool box, ranging from chemistry, physical chemistry and biology, where researchers might find the entire ingredients to compose complex architectures (porous or not) in order to reach the desired specific function or polyfunctionalities.[1] First we will discussed the syntheses of polymeric foams based on SiO2[2] , TiO2[3] scaffolds and the design of the macroporous networks while maintaining a good mesoporosity, as for instance a specific surface area of 400 m2.g-1 can be reached when generating Anatase titanium dioxide macrocellular foams.[4] Secondly we will show how macrocellular foams might be generated playing with nano-building blocks where the nanoparticles intrinsic aspect ratio can be switched from one dimensional vanadium oxide ribbons,[5] zirconium phosphate exfoliated sheets,[6] and silica monodisperse spherical nanoparticles.[7] In this later case, the as synthesized opal-like skeleton provide a tunable surface roughness by using different size of silica colloidal particles while the macropore morphology (i.e. pore wall thickness, pore wall length) can be tune by a continuous control over the foam’s liquid fraction and the gas bubble size during the mineralization process. Moreover open or closed pore structure can be reached upon the foam’s liquid fraction and the colloidal particle size involved during the foaming process. 1- R. Backov, Soft Matter, 2006, 2, 452.2- F. Carn, A. Colin, M.-F. Achard, H. Deleuze, R. Backov Adv. Mater., 2004, 6, 140.3- F. Carn, A. Colin, M.-F. Achard, H. Deleuze, C. Sanchez, R. Backov, Adv. Mater., 2005, 17, 62.4- F. Carn, M-F. Achard, O. Babot, H. Deleuze, S. Reculusa and R. Backov, J. Mater. Chem., 5- F. Carn, N. Steunou , A. Colin, J. Livage, R. Backov Chem. Mater. 2005, 17, 644. 6- F. Carn, A. Derré, W. Neri, O. Babot, H. Deleuze, R. Backov, New J. Chem., 2005, 29, 13467- F. Carn, P. Massé, S. Ravaine, H. Deleuze, C. Sanchez, B. Julian, D.R. Talham, R. Backov Langmuir, 2006, 22, 5469.
S4: Poster Session: Organic/Inorganic Materials I
Session Chairs
Chris Barbe
Richard Laine
Wednesday AM, April 11, 2007
Salon Level (Marriott)
9:00 PM - S4.1
Phase Separation in Alkoxy-Derived Silica System Containing Polyacrylamide
Kousuke Kawamoto 1 , Kazuki Nakanishi 1 , Teiichi Hanada 1
1 Department of Chemistry, Graduated School of Sience, Kyoto University, Kyoto Japan
Show AbstractBy inducing phase separation parallel to the sol-gel transition of alkoxy-derived silica systems, we can obtain gels having both co-continuous macropores and mesopores. The tendency of phase separation induced by polymerization of alkoxysilane can be controlled by the starting composition and reaction temperature. Relation between the parallel dynamics, formation of phase domains and sol-gel transition, determines the final morphologies frozen in the gel network. Tetramethoxysilane (TMOS) as a silica source, polyacrylamide (average MW=10,000) and aqueous nitric acid solution were mixed for hydrolysis, and kept closed at constant temperature. Polyacrylamide(PAAm), which exhibits a strong hydrogen-bonding interaction with silica, was used as a phase-separation inducer. Gels thus prepared were evaporation-dried after solvent exchange by ethanol or water/ethanol. Some of the dried gels were heat-treated. From limited starting compositions, we obtained silica gels having hierarchical macro/mesoporous structure. At higher PAAm concentrations, after vigorous ethanol washing, pores measured by the nitrogen adsorption distributed in significantly large pore size regime (10-50nm). Characterization of the dried or heat-treated samples was carried out using a scanning electron microscope (SEM), nitrogen adsorption and TG-DTA. Depending on not only the initial concentration of PAAm but on the post-gelation treatment on wet-gels, the mesopore structure of dried gels exhibited dramatic change. Solvent exchange by water/ethanol will influence the swelling-deswelling state of PAAm strongly associated with silica, and may have resulted in the final mesopore structure of smaller pore size (3-10nm) and sharper pore size distribution.
9:00 PM - S4.10
Structural and Photoluminescence Features of Eu3+ Based Amorphous and Lamellar Bridged Silsesquioxanes
Sonia Nobre 1 2 , Rute Ferreira 1 , Carole Carcel 2 , Michel Man 2 , Joel Moreau 2 , Luis Carlos 1
1 Physics and CICECO, University of Aveiro, Aveiro Portugal, 2 Laboratoire Hétérochimie Moléculaire et Macromoléculaire (UMR-CNRS 5076), Ecole Nationale Supérieure de Chimie de Montpellier, Montpellier France
Show AbstractOrgano-bridged silsesquioxanes are hybrid materials with potential technological applications owing to the myriad of properties that can be introduced through the organic fragments. Recently, the introduction of urea as self associative groups in the organic fragment and also under the acid-catalysed hydrolytic condensation allowed a good control of the organisation of these solids at various scale lengths [1,2]. Here we report the synthesis, structural and photoluminescence features of a bis- (trialkoxysilylated) organic molecule capable of self-assembly associating urea functional groups and alkylidene chains incorporating the EuCl3.6H2O salt. The fluoride ion catalysed hydrolysis in ethanol in the presence of a stoichiometric amount of water produces a amorphous hybrid while the acid-catalysed hydrolysis in an excess of water gave rise to the formation of crystalline lamellar hybrid material through a self-organisation process. A recent work reports preliminary results on the effects of the self-assembling of the nanobuild blocks (in this case a aromatic ring) on the photoluminescence properties of the hybrids without Eu3+ [3]. The emission in these materials arises from a mixture of components related with the aromatic rings and the urea bridges [4]. Here we will study the lamellar and the amorphous hybrids without and incorporating EuCl3.6H2O in order to understand the effects of the self-assembling of the nanobuild block on the structural and photoluminescence features. The hybrid-to-Eu3+ energy transfer will be also addressed. The materials are fully characterized by X-ray diffraction, infrared and Raman spectroscopies, 29Si and 13C nuclear magnetic resonance, scanning and transmission electron microscopy, elemental analysis and photoluminescence (emission, excitation and time-resolved modes) techniques.References[1] J. J. E. Moreau, L. Vellutini, M.Wong Chi Man, C. Bied, J.-L. Bantignies, P. Dieudonné, and J.-L. Sauvajol, J. Am. Chem. Soc., 123, 7957-7958,2001. [2] J. J. E. Moreau, B. P. Pichon, M. Wong Chi Man, C. Bied, H. Pritzkow, J-L. Bantignies, P. Dieudonné, J-L. Sauvajol, Angew. Chem. Int. Ed., 43, 203-206, 2004. [3] L. D. Carlos, R. A. Sá Ferreira, S. S. Nobre, M. Wong Chi Man, J. J. E. Moreau, C. Bied, B. Pichon, Mater. Sci. Forum (Advanced Materials Forum III), 514-516, 118-122, 2006. [4] L. D. Carlos, R. A. Sá Ferreira, R. N. Pereira, M. Assunção, V. de Zea Bermudez, J. Phys. Chem. B, 108, 14924 -14932, 2004.
9:00 PM - S4.11
Preparation of Ordered Mesoporous Metal Oxides with Crystalline Framewrork by Nano-replication using Ordered Mesoporous Silicas.
Jeong Kuk Shon 1 , Sung Soo Kim 1 , Byung Guk So 1 , Jiae Yu 1 , Hyung Ik Lee 1 , Jin Hoe Kim 1 , Ji Man Kim 1
1 chemistry, Sungkyunkwan University, Suwon Korea (the Republic of)
Show Abstract9:00 PM - S4.12
Mesostructured Silica Films With Metal Oxide Doped Pore Walls
Nicola Huesing 1 , Joachim Koehler 1
1 Inorganic Chemistry, Ulm University, Ulm Germany
Show AbstractSince the development of periodically arranged mesoporous silica materials by Kresge and Beck in 1992, the investigation of this new class of materials found an enormous improvement with respect to the variability of the pore size and pore structure. The great research effort in this field resulted in a large variety of different compositions and morphologies, ranging from silica to mixed metal oxides and from powders to monoliths and thin films. A wide field of possible applications, which range from chromatography, catalysis, sensors to optics, is of interest for these materials.The main goal of this work is the preparation of mixed-metal oxide mesostructured films by a combination of evaporation-induced self-assembly and ligand-assisted templating applying the spin-coating technique. The focus lies on Ge-, Ti-, Fe-, Al-oxide modified silica, with M to Si ratios of 1 : 10 and higher. The ligand-assisted templating allows a selective positioning of the metal species in the silica wall which is advantageous for many catalytic applications with respect to activity and efficiency.For the synthesis of these metal doped silica films, a non-ionic polyether-based surfactant (Brij56) was simultaneously used as the structure-directing agent and ligand for the respective metal-alkoxide, such as titanium isopropoxide, germanium isopropoxide, iron ethoxide and aluminum isopropoxide. These modified surfactants were mixed with a prehydrolyzed silica-solution based on tetraethoxysilane and ethanol. To get different pore arrangements the concentration of the surfactant was varied as well as the spin-coating rotation speed as the main control for the film thickness.To characterize the metal-surfactant-complexes, NMR and UV/vis-spectroscopy were used. The final films were characterized by XRD, XPS, nitrogen porosimetry and TEM.
9:00 PM - S4.13
Glycol-Modified Precursors in the Synthesis of Mesoporous, Monodisperse Particles:Synthesis, Characterization and Catalytic Applications
Jasmin Geserick 1 , Nicola Huesing 1 , Katharina Landfester 2 , Renate Rossmanith 2 , Juergen Behm 3 , Yvonne Denkwitz 3 , Ute Kaiser 4 , Ute Hoermann 4
1 Inorganic Chemistry, Ulm University, Ulm Germany, 2 Organic Chemistry III, Ulm University, Ulm Germany, 3 Physical Chemistry II, Ulm University, Ulm Germany, 4 Electron Microscopy, Ulm University, Ulm Germany
Show AbstractThe focus of this work lies on the synthesis of mesoporous, high surface area SiO2- and TiO2-particles employing ethylene glycol modified precursors (EGMS and EGMT, respectively) and their application as catalyst support. Ethylene glycol modified precursors, such as tetrakis(2-hydroxyethyl)orthosilicate (EGMS) as well as bis(2-hydroxyethyl)titanate (EGMT), have distinct advantages in the synthesis of mesoporous materials compared to commercially available tetraalkoxide precursors, since they have proven to be compatible with lyotropic surfactant mesophases and they allow for a processing in purely aqueous conditions. The latter point additionally gives access to the controlled formation of particles by applying the miniemulsion technique.For a typical synthesis protocol, a dilute hydrochloric acid solution containing an amphiphilic molecule (CTAB, Brij56, P123) and the respective precursor was homogenized with a lipophilic solvent (e.g. Isopar M, a mixture of alkanes) using ultrasonics. The resulting droplets act as minireactors in which the cooperative self assembly process of the surfactant and condensable precursor proceeds. The hybrid inorganic-organic particles were either calcined or treated by solvent extraction for a complete template removal. The combination of cooperative self-assembly and miniemulsion processing allowed to obtain monodisperse mesoporous and in some cases even mesostructured particles with high specific surface areas. The samples were characterized by XRD, electron microscopy (REM, TEM) and nitrogen porosimetry. The potential of these materials for catalytic applications was tested in the low temperature CO oxidation reaction, using Au/TiO2 catalysts. The catalysts were prepared by deposition precipitation. Measurements of the CO oxidation kinetics, both in dilute CO:O2 = 1:1 mixtures and in H2-rich gas mixtures (CO:O2:H2 = 1:1:75) indeed show a high Au-normalized activity and a higher stability (lower tendency for deactivation) of the mesoporous TiO2 based catalysts compared to Au/TiO2 catalysts based on commercial TiO2 (P25, Degussa).
9:00 PM - S4.14
Synthesis and Characterization of Hierarchical Porous Gold Materials.
Gregory Nyce 1 , Joel Hayes 1 , Alex Hamza 1 , Joe Satcher, Jr 1
1 , Lawrence Livermore National Lab, Livermore, California, United States
Show AbstractHierarchical porous gold materials were prepared using templating and dealloying techniques. Polystyrene Ag/Au core shell particles were prepared by sequential electroless deposition of gold and silver onto polystyrene microspheres. The core shell particles were cast into a monolith and heat treated at 400 C to form hollow Ag/Au alloy spherical shells. Dealloying the Ag/Au shells selectively removes the silver leaving a shell wall comprised of a nanoporous gold network. Combining templating and dealloying techniques, ultra-low density gold monoliths (0.28 mg/cc, 1.5 % relative density) have been prepared.
9:00 PM - S4.15
Mesoporous Carbon Monoliths from Mesophase Pitch for Electrochemical Applications
Philipp Adelhelm 1 , Bernd Smarsly 1 , Yongsheng Hu 2
1 , Max-Planck-Institute for Colloids and Interfaces, Potsdam Germany, 2 , Max-Planck-Institute for Solid State Research, Stuttgart Germany
Show AbstractMesoporous carbon is a favorable material for forthcoming technologies such as supercapacitors, high performance electrodes or catalysis. Until now, most mesoporous carbons are powders made by infiltration of porous templates (usually silica) with a carbon precursor, followed by carbonization and removal of silica. Previously used precursors such as furfuryl alcohol lead to a quite amorphous carbon microstructure, while a higher order of the graphene (i.e. the building blocks of such carbons) structure would be advantageous for such applications due to better chemical stability and higher conductivity. Also, the microporosity (pores < 2nm) should be as low as possible, because it traps and immobilizes molecules. Mesophase pitches (MP) are favorable precursors, since they already exhibit a pre-organized graphitic structure before carbonization, but so far porous carbons based on MP usually were powders. By contrast, a monolithic material shows several advantages. For instance, binder gets redundant, which is normally necessary to form an electrode out of carbon powder.We developed a simple replica process using preformed hierarchically porous silica monoliths prepared by the Nakanishi process [1], infiltrated by MP as carbon precursor, leading to carbon monoliths (cylinders/plates) up to a length of 10 cm with a 3-dimensional network of macro- (1-5 µm) and uniform mesopores (6 nm, BJH). We studied the carbon microstructure in detail by wide-angle X-ray scattering (WAXS), XPS and EELS. A new WAXS-model [2] was applied to analyze the graphene microstructure of different carbonization temperatures (700°C-2500°C) and its effect on electrochemical properties. Compared to sugar-based precursors, the MP-based carbon microstructure shows a higher order in terms of the graphene size and arrangement. The produced monoliths are mechanically stable and exhibit negligible micropore content (BET surface area of 300 m2/g and a pore volume of 0.4 -0.6 cc/g). High reversible capacity and superior high rate performance were achieved when the material was used as an anode material in rechargeable lithium batteries. For carbon treated at 700 °C, we measured a capacity of 900 mAh/g at a C-Rate of C/5, which is more than 3 times higher than the value for graphite. The material is also stable under faster cycling and shows 145 mA h g-1 at 30C, and 70 mA h g-1 at 60C. This superior rate performance possibly results from the favorable transport advantages of this hierarchically porous structure and the higher ordered carbon microstructure. The high surface area leads to a high electrode/electrolyte contact area, providing a large number of active sites for charge-transfer reactions. The well-interconnected wall structure reduces the solid-state transport lengths for Li diffusion which is assumed to determine the overall rate performance in these nanostructures. [1] Smarsly et al. Phys. Chem. Chem. Phys. 2006, 8[2] Ruland, W.; Smarsly, B. J. Appl. Cryst. 2002, 35
9:00 PM - S4.18
Simple Fabrication of Mesoporous Silica with Remarkable High Temperature Stability at Neutral pH and Ambient Conditions from TEOS
David Hess 1 , Radha Vippagunta 2 , James Watkins 2
1 Chemical Engineering, University of Massachusetts-Amherst, Amherst, Massachusetts, United States, 2 Polymer Science and Engineering, University of Massachusetts-Amherst, Amherst, Massachusetts, United States
Show AbstractSince their discovery mesoporous silicas prepared using cooperative assembly techniques have been the subject of considerable research. These materials are prepared from tetraethylorthosilicate (TEOS) in aqueous media containing structure directing surfactants or block copolymers at extreme pH. Such processesyield well ordered materials, but the synthesis conditions lead to incomplete condensation of the silica network, which results in significant structural contraction upon calcination and limited thermal, hydrothermal and mechanical stability. Here we report a simple synthesis procedure that, surprisingly, yields nearly complete condensation of the silica network (virtually all Q4 linkages) using cysteamine as the catalyst and polyoxyethylene surfactants as the structure directing agents in buffered solution at neutral pH and ambient temperature. The fully condensed silica network has exceptional structural and thermal stability to the mesoporous material.Marine organisms produce highly ordered hierarchal silica structures at ambient conditions through polypeptide-mediated silica condensation within spatially defined regions delimited by a biomacromolecule template. Much work has been directed towards the study of laboratory mimics of these naturally occurring processes. Recently, small molecule bifunctional amines, including cysteamine, were evaluated at neutral pH conditions as small molecule mimics of the natural catalyst systems and shown to be effective for silica condensation.We combine the cysteamine catalyst system with structure-directing block copolymer surfactants at neutral pH and ambient temperature to produce mesoporous silica. For example, the addition of TEOS to a solution of containing cysteamine, citrate buffer (pH 7.2) and 5wt% Brij amphiphilic block copolymer (polyethylene oxide-polyethylene) in de-ionized water yields mesoporous silica. The resulting mesoporous silica powder was analyzed using XRD, TGA, FTIR, TEM, and NMR. The materials exhibited stability under extreme temperature calcinations (up to 800C) in the presence of water. SAXS shows that 1.0% shrinkage upon calcination up to 800C. The virtual absence of shrinkage is attributed to the high degree of silica condensation mediated by the cysteamine catalyst. 29Si NMR analysis supports this observation. Silica linkages in the as-prepared samples are primarily Q4, indicating a fully developed network structure, despite the ambient temperature and neutral pH conditions used for the synthesis.The preparation of fully condensed mesoporous silica at neutral pH and ambient conditions resolves two limiting issues related to the implementation of these materials in a broad range of applications. High thermal, hydrothermal and mechanical stability is often essential for use in catalysis, separations and device applications while neutral synthesis conditions enables the encapsulation of biomolecules or thermally labile therapeutics for drug delivery and sensor applications.
9:00 PM - S4.19
Synthesis and Applications of Nanostrucured Metal Nitride.
Anna Fischer 1 , Frederic Goettmann 1 , Markus Antonietti 1 , Arne Thomas 1
1 , Max-Placnk-Institute for Colloids and Interfaces, Potsdam Germany
Show Abstract9:00 PM - S4.20
Polymer Composite Reinforced With Nanodiamonds And Clay.
Valery Karbushev 1 , Ivan Konstantinov 1 , Alexander Semakov 1 , Irina Parsamyan 1 , Valery Kulichikhin 1 , Vladimir Popov 2
1 , A.V.Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences , Moscow Russian Federation, 2 , Moscow Institute of Steel and Alloys , Moscow Russian Federation
Show AbstractThree different polymers have been used as matrices: LC hydroxypropylcellulose (HPC), amorphous polysulfone (PSF) and styrene-acrylonitrile copolymer (SAN). Composites have been prepared on laboratory mixer Minilab (ThermoHaake) and hand-made mixer of rotor-plunger type. For estimation of particles distribution in polymer matrices the optical microscopy and SEM methods were used. For improving mixing quality and exclusion of large aggregates for several batches so-called colloid-deposition method was applied – preparing of mutual suspension of polymer and ND particles in inert liquid medium under action of ultrasound field with further filtration. The average diameter of ND particles visible in optical microscope was around 1-3 mkm. We were wondered to see that shear field increases the tendency of particles to formation of aggregates of different shape in liquid nanocomposite precursors. Presumably, elasticity of matrix and coupling of matrix with particles play important role in aggregation mechanism. Depending on dispersion medium and surfactants we can see in transparent shear cell either radial or ring-like structures formed by NA particles. For clay particles X-ray diffraction method is one of the most informative for estimation of intercalation of polymer molecules to interspaces of clay structure. Since difractograms in two directions are virtually the same (no clay’s reflexes), it is likely that macromolecules not only intercalate clay structure, but can destroy it completely. Measurements of rheological properties of composite melts was performed on rheometer RheoStress RS600 using operating unit plate-plate and capillary viscosimeter of melt-indexer type. The most interesting feature of the viscometrical data consists in non-monotonous location of dependences of viscosity on shear stress, i.e., for non-filled polymer melt the viscosity is not lowest but engages position in the middle of corresponding curves inherent for the filled compositions. The same effect was observed in regime of low-amplitude sinusoidal oscillations: the value of loss modulus for nanocomposite precursors at definite filling degree is less than for neat polymers. The probable explanations of this effect have been considered: formation of absorbed layer by disentangled macromolecules, presence in the system of small gaps where local velocity gradient is much higher than average, specific layered flow mechanism, change of distribution of particles by dimensions in strong shear stream, orientation effects on the level of particles and absorbed layers, preferable absorption of high molecular weight species, etc. Mechanical properties of extruded samples of the circle cross-section were measured on tensile machine Instron 1122. The best performance were realized for formulation containing 0,5 – 1 wt.% of ND. Authors thank for financial support ISTC foundation (project 3238) and Russian Foundation for Basic Research (grants 04-03-32152 and 05-03-08028).
9:00 PM - S4.21
Modification of Nanocomposites/Hybrid Organic-Inorganic Porous Clay Heterostructures for Ethylene Scavenger in Packaging Film
Kasinee Prakobna 1 , Rathanawan Magaraphan 1 , Hathaikarn Manuspiya 1
1 The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok Thailand
Show AbstractRecently, the discovery of a new class of solid porous materials known as porous clay heterostructures (PCH) has been reported. These materials have been prepared by the surfactant-directed assembly of mesostructures silica within the two-dimensional interlayer spacing of clays. The PCH is interesting material to use as entrapping system owing to its structure provides high surface area with uniform and specific pore size. In this work, the PCH is synthesized within the galleries of Na-bentonite clay by the polymerization of tetraethoxysilane (TEOS) in the presence of surfactant micelles (cetyltrimethylammonium bromide and dodecylamine). In addition, a mesoporous clay with hybrid organic-inorganic PCH (HPCH) is modified via co-condensation reaction of TEOS and methyltriethoxysilane (MTS) resulting in the incorporation of methyl group. The effect of pH on the formation of these mesoporous structures was investigated by adjusting pH of Na-bentonite clay to pH 9, 7, 5 and 3 before the modification and then observed the effect of pH by using N2 adsorption-desorption technique. The results shown that the PCHs and HPCHs had surface areas of 501-668 and 467-582 m2/g, pore volume of 0.47-0.58 and 0.33-0.49 cc/g, and average pore sizes in the small mesopore to supermicropore range of 3.01-3.85 and 1.37-3.88 nm, respectively. Furthermore, both PCHs and HPCHs are utilized as ethylene scavenger and blended with polypropylene for producing ethylene scavenging films in food packaging application. In this work, the direct melt intercalation method was applied to prepare the nanocomposites pellets by mixing 1 wt% of porous clay materials, 2 wt% of surlyn ionomer acting as a compatibilizer, and polypropylene under shear and further prepare thin film nanocomposites via blow film extrusion. The eight samples of nanocomposites films including PCH-9, 7, 5, 3 and HPCH-9, 7, 5, 3 (numerals denote the pH-adjusted condition of Na-bentonite clay) will be measured oxygen and ethylene permeabilities; however, the present results obtained from PCH-9 and HPCH-9 nanocomposites films revealed that the PCHs and HPCHs nanocomposites had oxygen permeability rate of 581.48 and 482.04 cm3/m2.d.atm, respectively, which reduced from oxygen permeability rate of polypropylene film (609.42 cm3/m2.d.atm). In addition, ethylene permeability rate of PCHs and HPCHs nanocomposites were 517.41 and 488.90 cm3/m2.d.atm, respectively, which also reduced from ethylene permeability rate of polypropylene film (537.37 cm3/m2.d.atm). It seems that both PCH and HPCH materials affect gas barrier properties of the nanocomposites films and the HPCH could improve gas barrier properties than the PCH because the HPCH has more hydrophobicity in consequence of incorporating with methyl group. So the HPCH material provide more interaction with ethylene gas resulting in improvement in ethylene barrier property and also improve oxygen barrier property because its pore size less than PCH material.
9:00 PM - S4.22
Synthesis and Characterization of MoS2 Intercalated with 1,2,3,4 Tetrahydroquinoline in Search of Cleaner Fuels.
Karina Castillo 1 , Russell Chianelli 1 , Jason Parsons 1 , Felicia Manciu 1
1 , University of Texas at El Paso, El Paso, Texas, United States
Show Abstract9:00 PM - S4.23
Microstructure, Composition and Functional Properties of Organosilicon Plasma Polymers.
Lenka Zajickova 1 , Bursikova Vilma 1 , Zuzana Kucerova 1 , Pavel Stahel 1 , Dan Franta 1 , Vratislav Perina 2 , Anna Mackova 2
1 Deptartment of Physical Electronics, Masaryk University, Brno Czech Republic, 2 , Institute of Nuclear Physics, Rez Czech Republic
Show Abstract9:00 PM - S4.24
Organic-inorganic hybrid materirals using cubic-silsesquioxane as nano-building block.
Ken-ichi Shinotani 1 , Norihiro Takamura 1 , Richard Laine 2
1 , Matsushita Electric Works, Ltd., Kadoma Japan, 2 Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan, United States
Show AbstractFeasibility study for applying cubic-silsesquioxane hybrid to electronic as well as optical material has been conducted. With regards to the electronic material application, cubic-silsesquioxane/epoxy hybrid system was investigated, while for the optical material application, caged-silsesquioxane hydro-silylation system was examined.The octa-amino phenyl cubic silsesquioxane(OA) was utilized as a nano-building block for the epoxy hybrid system. The OA was cross-linked by epoxy resin(@180C) to provide hybrid resin plate and then the cured hybrid properties as electric materials(glass transition temperature, CTE, )are examined.By changing the structure of epoxy resin, the relationship between epoxy structure and cured hybrid properties is investigated. The tetrakis(cyclohexenylethyldimethylsiloxy)octa-silsesquioxane(TCHS) was choose as nano building block for the hydro-silylation hybrid system. The self-cross linked TCHS resin plate(@200C) were subjected to the optical property measurement such as UV-vis along with durability for UV light(@380nm) exposure test. Small angle X-ray scattering measurement was conducted on the TCHS resin plate in order to clarify the network structure of the hybrid in comparison to the epoxy resin plate. Epoxy hybrid resin that cross-linked with OA and DGEBA(eq=170), indicated very high thermal stability and elimination of glass transition was observed, while the hybrid cross-linked by the epoxies that possess longer chain(DGEBA eq=650) as well as Bromine atom substituted showed the glass transition. On the other hands, the dielectric constant of resin plate of OA/DGEBA(eq=170) were much higher than the OA/DGEBA(eq=650) and OA/Br-DGEBA. These results are attributed to the network structure of hybrid materials that was formed by interconnection between cubic silsesquioxane nano block and epoxy resin was discussed. The CCL(Copper clad laminate) was fabricated by the hybrid system and the elimination of Tg as well as good enough flame retardancy of laminate with much lower bromine content % was clarified. Through these study, we clarify the feasibility of the hybrid to apply it for electric material usage. TCHS hybrid resin showed very high transparency even in an exposure of short wave length light.The transmittance of short wave length range light is much better than a transparent epoxy resin system such as aliphatic epoxy rein and is identical with that of inorganic glass material. The TCHS also indicated very high durability for exposure of UV(@380nm) light. Thus the hybrid possesses the advantage of inorganic glass materials while keeping an advantage of organic resin such as low temperature low cost process. This allows us to consider the hybrid system application for the optical devices that is operating using short wavelength light.
9:00 PM - S4.25
A New Fabrication Method of Organic-Inorganic Hybrid Thin Films Using Molecular Layer Depostion
Byoung Hoon Lee 1 , Kyo Keun Im 1 , Myung Mo Sung 1
1 Chemistry, Hanyang University, Seoul Korea (the Republic of)
Show AbstractOrganic-inorganic hybrid films were fabricated by a new growth technique that can control thickness with nanometer level. This method is based on molecular layer deposition of self-assembled monolayers (SAMs) in gas phase. The alkene terminated alkysiloxane self-assembled monolayer was formed by exposing a substrate to C=C terminated alkyltrichlorosilane and water vapor in ALD chamber. The terminal vinyl groups were converted to carboxylic groups with ozone treatment. The highly active titanium hydroxyl linker layer was formed on the carboxylic terminated SAMs by using titanium isoproxide adsorption followed by exchange reaction of water molecule in order to provide highly active adsorption sites for the anchoring of the next monolayer. The hybrid films, which are sequentially deposited in ALD chamber, were investigated by using x-ray photoelectron microscopy (XPS), contact angle analysis (CAA), atomic force microscopy (AFM), transmission electron microscopy (TEM) and digital multi-meter.
9:00 PM - S4.26
Sensitive-dye incorporated PP/Clay Nanocomposites
Sakkarin Tassanawat 1 , Minit Nithitanakul 1 , Rathanawan Magaraphan 1 , Hathaikarn Manuspiya 1
1 Petroleum and Petrochemical College, Chulalongkorn University, Bangkok Thailand
Show AbstractThe color indicator for fresh milk packaging has been newly developed to evaluate the degree of fresh milk deterioration during storage and distribution. The processing of pH-sensitive material used for milk packaging based on organomodified clay nanocomposites incorporated with indicator dye was focused. The nanoclay composites with indicator dye were melt compounding through a twin screw extruder by using Surlyn® as a reactive compatibilizer. The nanoclay composites were fabricated into the sample sheet for Hunter color test. Milk deterioration was assessed for titratable acidity (TA), and color changes of the indicator were measured and expressed as Hunter values as well as total color difference (TCD). TCD values of bromothymol blue (BMB) type indicator (containing BMB as a chemical dye) also changed continuously with the response of the indicator. The color changes of the indicator correlated well with TA value of fresh milk. According to the changes in Hunter color values of the indicator within the packages of fresh milk during storage at room temperature, Hunter L and b values increased gradually with storage time, while Hunter a decreased slowly. The result means that the color of BMB type indicator turned from initially bluish-green to finally yellow. The color changes of the developed indicator represented properly the degree of deterioration of fresh milk. The pH indicator could be employed an effective smart packaging technology for evaluating fresh milk.
9:00 PM - S4.27
Characteristics of SiCN Microstructures Fabricated by Using PDMS Molds
Gwiy Chung 1 , Ki-Bong Han 1
1 School of Electrical Enginnering, University of Ulsan, Ulsan Korea (the Republic of)
Show AbstractThis paper describes a novel fabrication process of high-temperature MEMS based on liquid-polysilazane-derived SiCN ceramic microstructures. First, PDMS (polydimethylsiloxane) molds were fabricated on SU-8 photoresist using standard UV-photolithographic process. Liquid polysilazane (Kion Corp., VL 20) and photoinitiator (2,2-dimethoxy-2- phenyl acetophenone) were injected into the PDMS mold. The liquid-phase polysilazane is converted into solid-phase polysilazane by UV exposure. And then, solid-phase polysilazane structure is cross-linked using HIP (hot isostatic press) at 400°C, 205 bar. Thermal decomposition transformed the polymer to a ceramic capable of withstanding over 1400°C. In addition, Physical and electric properties of SiCN microstructure with different pyrolysis conditions were evaluated. The SiCN microstructures, which is pyrolyzed at HIP, have the greatest insulation resistance and break down voltage characteristics than other SiCN samples or Si substrate. Finally, Optimum pyrolysis process condition was determined for SiCN microstructure fabrication. Consequently, the fabricated SiCN ceramic microstructures may be applied for high-temperature and high-power MEMS applications, such as heat exchanger and combustion chamber.
9:00 PM - S4.28
Synthesis and Properties of Molecular Sub-structures of the Silicon Crystal Lattice.
Andreas Wallner 1 , Jelena Fischer 1 , Judith Baumgartner 1 , Christoph Marschner 1
1 Institut für Anorganische Chemie, TU Graz, Graz Austria
Show Abstract9:00 PM - S4.29
Hybrid Organic-Inorganic Sol-Gels with A Cleavable Tetrasulfide Bridging Group.
Guangqing Guo 1 , Douglas Loy 1 , Dylan Boday 1
1 Materials Science and Engineering, University of Arizona, Tucson, Arizona, United States
Show AbstractThiol-functionalized hybrid materials have attracted much attention in recent years due to their many potential applications for metal ion adsorption, separation, and metallic nanoparticles stabilization. Thiol-functionalized materials were prepared either by grafting mercaptopropyltrialkoxysilane onto pore surface of mesoporous silica, or by co-polymerization of mercaptopropyltrialkoxysilane with tetraethylorthosilicate in the presence of templates. However, both of them have their own limitations, such as bad distribution and low content of thiol group in the materials. Here, we describe a new procedure to prepare thiol-functionalized polysilsesquioxanes using a post-processing modification method. This approach involves a copolymerization of phenylene-bridged monomer and tetrasulfide-bridged monomer followed by reductive cleavage of tetrasulfide to thiols under very mild conditions. Because each tetrasulfide can generate two thiols, the technique allows the introduction of relatively high level of functionality for capturing metal ions. In this study we have prepared materials using standard sol-gel polymerization techniques and with surfactant templating. Results of their characterization and performance as platinum scavengers will be presented.
9:00 PM - S4.3
Phase Separation in Al2O3 Sol-gel System Incorporated With High Molecular Weight Poly(ethylene oxide).
Yasuaki Tokudome 1 , Kazuki Nakanishi 2 , Koji Fujita 1 , Kiyotaka Miura 1 , Kazuyuki Hirao 1
1 , Graduate School of Engineering, Kyoto University, Kyoto Japan, 2 , Graduate School of Science, Kyoto University, kyoto Japan
Show AbstractPolycrystalline alumina (Al2O3) and aluminate ceramics have a broad range of application owing mainly to their high mechanical stability. Porous alumina/aluminates as well as the silicate families have been widely used as catalyst supports. It has been reported that monolithic silica, siloxane-based hybrid and titania materials with well-controlled hierarchical pore systems can be synthesized via sol-gel route accompanied by phase separation. Sol-gel alumina/aluminates, however, have rarely been prepared in monolithic form, because of the difficulty in controlling the reactivity of the precursors. Starting from aluminum salts, Gash et al. reported that monolithic alumina gels, together with supercritically dried aerogels, can be prepared.In our experiments, pure alumina monoliths with well-defined macropores and mesostructured skeleton have been synthesized via a spontaneous route from the aqueous and ethanolic solution of aluminum salts in the presence of propylene oxide and poly(ethylene oxide)(PEO). The addition of propylene oxide to the starting solution controls the gelation, while the addition of PEO induces the phase separation. Adequate choice of the starting composition, by which the phase separation and gelation concur, produces large-dimension (10mm×10mm×10mm), bicontinuous macroporous Al2O3 monoliths. The size of macropores is controlled in the range of 400 nm to 1.8 μm, depending on the starting composition. The dried gel is amorphous, while the heating at temperatures above 800 οC for 5 h leads to the formation of crystalline phases without spoiling the macroporous morphology; nanocrystalline γ-Al2O3 is precipitated at 800 οC, α-Al2O3 starts to form at 1000 οC in addition to γ-Al2O3, and complete transformation of γ-Al2O3 into α-Al2O3, i.e., the formation of a single phase of α-Al2O3, is achieved at 1100 οC. Nitrogen adsorption-desorption measurements revealed that the skeletons of dried gels possess the mesostructure with a median pore size of about 2.6 nm and with the surface area as high as 300~400 m2/g.
9:00 PM - S4.30
Inorganic Organic Composite Polymer Coatings Based on Functionalised Polyhedral Oligomeric Silsesquioxanes.
Duncan Robertson 1 , Russell Morris 1
1 Chemistry, University of St Andrews, St Andrews, Fife, United Kingdom
Show Abstract9:00 PM - S4.31
An Organic-inorganic Hybrid Polymeric Nanocomposites for the Hard Coat Application on Flat Panel Displays.
Raymond Tsiang 1 , Hau-Chun Chiang 1
1 Chemical Engineering, National Chung Cheng University, Ming-Hsiung, Chiayi Taiwan
Show Abstract9:00 PM - S4.32
Templating of Hybrid Cationic Inorganic 2D Materials using Interlamellar Organic Anion Arrays
David Rogow 1 , Claudia Swanson 1 , Xiaojuan Fan 1 , Scott Oliver 1
1 Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California, United States
Show AbstractWe are investigating the solvothermal synthesis of new inorganic materials using organic small molecule templates. We have discovered a series of 2D cationic inorganic layered structure types using different carbon chain length alkyldisulfonate molecules. The organic molecules form a surfactant assembly, directing the structure and charge of the inorganic framework. Unlike existing 2D hybrid inorganic-organic materials, our examples are the only synthetic examples where the inorganic portion is cationic and the anionic portion is organic. The only known cationic layered structures that can exchange their anions are the layered double hydroxides (LDHs). All of the LDHs are isostructural, whereas our structures do not exhibit the same coordination and geometry around the metals as well as having different bridging atoms. These types of materials may be useful for intercalation of anions in a number of applications including base catalysis and anion exchange.
9:00 PM - S4.33
Tuning of Glass Transition in Nanoparticle-embedded Polymers through Contolled Variation of Interfacial Morphology
Jaydeep Basu 1 , Sunita Srivastava 1
1 Physics, Indian Institute of Science, Bangalore, Karnataka, India
Show Abstract9:00 PM - S4.34
Chemical Raction of Hydrogenated Diamond Surface with Amino Acid in Solvent Containing Radical Initiator.
Toshiki Tsubota 1 , Yuta Hagiwara 1 , Teruhisa Ohno 1
1 Department of Chemistry, Faculty of Engineering, Kyushu Institute ofTechnology, Kitakyushu, Fukuoka, Japan
Show Abstract9:00 PM - S4.35
Nanostructured Ceramic or Hybrid Thin Film and Coating Process thereof for Silica and Zirconia Based-materials.
Valle Karine 1 , Guenadou David 1 , Belleville Philippe 1 , Bianchi Luc 1 , Wittmann-Teneze Karine 1 , Boscher Christophe 1
1 , CEA, Monts France
Show Abstract9:00 PM - S4.36
Studies on Photoluminescence from Porous Silicon by Post Anodization Treatment in MEH-PPV.
Pallab Banerji 1 , Susanta Banerjee 1 , Jayanta Mishra 1
1 Materials Science Centre, Indian Institute of Technology, Kharagpur India
Show Abstract9:00 PM - S4.38
New Organo-inorganic Materials for Water Contaminants Remediation.
Aracely Ortiz 1 , Rosa Richards 1 , Elena Otazo 1 , Otilio Acevedo 1 , Francisco Prieto 1 , Juan Hernandez 1 , Alberto Gordillo 1
1 Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Pachuca, Hidalgo, Mexico
Show Abstract9:00 PM - S4.4
Comparison of Different Reversed-Phase Packing Materials Based on Higher Organic Hybrid Particles.
Nicole Lawrence 1 , Kevin Wyndham 1 , Ken Glose 1 , Jim Cook 1 , Darryl Brousmiche 1 , Pamela Iraneta 1 , Bonnie Alden 1 , Cheryl Boissel 1 , Thomas Walter 1
1 , Waters Corporation, Milford, Massachusetts, United States
Show Abstract9:00 PM - S4.41
Low Temperature Deposition of Metal Oxide Thin Films in Supercritical Carbon Dioxide using Metal-organic Precursors.
Theodosia Gougousi 1 , Zhiying Chen 1
1 Physics, UMBC, Baltimore , Maryland, United States
Show Abstract9:00 PM - S4.42
Effect of Particle Morphology and Interfacial Behavior on Properties of Hydroxyapatite Nanocomposites.
Jasmeet Kaur 1 , Meisha Shofner 1
1 School of Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show Abstract9:00 PM - S4.43
Constitutive Response of Collagen Hydrogels Around a Sharp Notch Under Tension
Joshua Lee 1 , Michael Shaw 1
1 Bioengineering, California Lutheran University, Thousand Oaks, California, United States
Show AbstractWounds that penetrate multiple dermal layers in human skin trigger cellular signaling cascades that initiate healing and reconstructive processes. Specifically, in addition to biochemical cues, cells both induce and respond to mechanical signals through a variety of mechanotransduction processes. These mechanical cues may originate directly from the extracellular matrix (ECM) or from neighboring cells within the ECM. Prior studies have correlated tensile stress and strain with a variety of cell responses, including development of scar tissue. However, although the redistribution of strain and stress around sharp notches are known for linear elastic and strain-hardening materials, this information has yet to be established for hyperelastic materials. Such materials include those envisaged as skin replacement scaffolds, specifically collagen and fibrin hydrogels. Hybrid scaffolds created through the inclusion of stiff, second phase particulates, such as calcium phosphate and hydroxyapatite particles are also candidates for treating bone defects. This knowledge is critical for the design of skin replacement materials for controlled, scarless healing, especially in the vicinity of incisions, sutures and other structural discontinuities.Here, we utilize a novel, in situ notched-tensile specimen to determine the magnitude and distribution of in-plane strain in the region of the notch-tip in a Type-I collagen specimen. Experiments were performed with model specimens in-situ using a fixture mounted on the stage of an optical microscope. A scalpel was used to give a full-thickness notch through the center of each specimen and inert, image-contrasting markers were applied to the surface of the specimen in the notch tip region. A remote, tensile strain was applied in a step-wise linear fashion and multiple high-resolution images collected at different levels of far-field strain. Image analysis was then performed using a coordinate system to track movements of individual markers from a series of sequential images. The resultant displacement fields were then analyzed to yield the in-plane strain fields, including in-plane strain components along trajectories parallel and perpendicular to the crack plane.Significant local strain concentrations were observed near the notch tip of well over 180% within a region extending to nearly 1 mm from the notch tip. Regions of over 20% strain elevation were also observed at distances of up to 2.5 mm from the notch tip. The magnitudes and spatial dependence of these strain concentrations are then analyzed using known constitutive models for crack-tip strain fields in linear elastic and strain-hardening materials. Furthermore, the results are interpreted with respect to previous studies correlating magnitudes of strain and cell function. Finally, implications for the design of skin replacement scaffolds and bone replacement hybrid scaffolds are presented.
9:00 PM - S4.44
Preparation and Properties of Amino-Terminated Anionic Waterborne Polyurethane-Silica Hybrid Materials through Sol-Gel Process in the Absence of External Catalyst
Jui-Ming Yeh 1
1 Chemistry, Chung Yuan Christian University, Chung Li Taiwan
Show Abstract In this paper, a series of polymer-silica hybrid materials consisted of amino-terminated anionic waterborne polyurethane (WPU) and inorganic silica particles have been successfully prepared through the sol-gel process in the absence of external catalyst. Typically, amino-terminated anionic WPU was first synthesized from specific feeding molar ratio of polycaprolactone (PCL), dimethyllo propionic acid (DMPA) and 4,4'-methylenebis(cyclohexylisocyanate) (H12MDI), followed by further reacting with TEA and TETA to give as-prepared WPU. The obtained WPU was characterized by FTIR spectroscopy and gel permeation chromatography (GPC). Subsequently, a series of hybrid materials with different silica content were prepared by performing the sol-gel reactions of tetraethyl orthosilicate (TEOS) in the amino-terminated WPU matrix without the addition of external catalyst and followed by examined by transmission electron microscopy (TEM), powder XRD, solid-state NMR and FTIR. It should be noted that the terminated primary amine groups attached on the as-prepared WPU chains could be functioned as internal base catalyst for the sol-gel process of TEOS. Effect of material composition on the thermal stability, mechanical strength, surface wettability and optical clarity of hybrid materials was also evaluated by the TGA, DMA, contact-angle measurement and UV-vis transmission spectroscopy, respectively.
9:00 PM - S4.45
Study on the Adsorption Behavior of Fluorescence Protein in the Pure and Modified clays
Tsung-Yen Tsai 1 , Yun-Zhen Tseng 1
1 Chemistry, Chung Yuan Christian University, Chung-Li Taiwan
Show AbstractIn order to purify the fluorescence protein for further application in the biosensors, we apply nanolayer materials as an adsorption subtract. In this study, when clays were intercalated by cocamidopropylhydroxysultaine, the adsorption of DsRed protein (Red fluorescence protein) could be improved for modified clays. The enhancement of the adsorption of DsRed protein was influenced by the kind of diluted water, pH condition of modified clay, and the concentration of the protein. The optimized process conditions of the protein adsorption has shown when the protein was intercalated/adsorbed by the modified clay, pretreated with cocamidopropylhydroxysultaine (C-50) in RO water with pH=7~8. The intercalation/adsorption amount of the protein was highly increased from 0.1083 mg/ml to 0.3448 mg/ml when the purified clay was treated by C-50, compared with the purified clay. This result shows that the protein, DsRed, was successfully intercalated/ adsorbed in the gallery of clay. There were evidences made by XRD, TGA and FTIR analysis.
9:00 PM - S4.46
Nanoscale Toughness of Ductile Materials Using Nanoindentation
Jiahau Yan 1 , Burak Taskonak 1
1 Restorative Dentistry, Indiana University , Indianapolis, Indiana, United States
Show AbstractOne of the main reasons for constructing nanosized organic/inorganic hybrid materials is to achieve high toughness. However, to date, there is no established method for measuring the toughness of ductile materials at nanoscale. While the toughness of brittle materials at nanoscale can be characterized using crack length and a fracture mechanics method similar to that of microindentation, it cannot be applied to estimate the toughness of ductile materials since generally no cracks are formed during the indentation process. We propose using a nanoindentation technique to measure the toughness of ductile materials based on the energy consumed in the plastic deformation regime and the volume created by the indents. We performed nanoindentation on soda-lime glass, gold, and poly-methyl methacrylate (PMMA) using a maximum load of 36 mN. The plastic energy was calculated from the plastic part of load-displacement curves. The volumes of the indents were estimated from scanning images and depth profiles. The toughness was then calculated using the plastic energy divided by the indent volume. The toughness values of glass, gold, and PMMA were 3.3x10^7, 1.3x10^9, and 3.1x10^9 J/m^3, respectively. It was found that the toughness of gold is 94 times that of glass and 2.4 times that of PMMA. The load-displacement curves of glass, gold, and PMMA shows different plasticity for the three materials. The plastic regime and toughness of gold and PMMA are much great than that of glass. We suggest that this method can be applied to study the toughness of biological composites or organic/inorganic hybrid materials at nanoscale.
9:00 PM - S4.49
3D Composites Based on Hydroxyapatite-Chitosan-Polysiloxane as a Biomimetic Scaffold Materials.
Andronico Carrillo 1 , Jose Arias 1 , Soledad Fernandez 1 , Claudia Quilodran 1 , Jose Arias 1
1 CIMAT, Biological and Animal science, University of Chile, Santiago Chile
Show Abstract9:00 PM - S4.5
Mesostructured Materials Containing [Re6Q8(CN)6]4- Cluster Anion
MinJung Suh 1 , Sung Huh 1 , Vien Vo 1 , Youngmee Kim 1 , Sung-Jin Kim 1
1 NanoScience, Ewha Womans University, Seoul Korea (the Republic of)
Show AbstractWe synthesized the new mesostructured materials by a surfactant-templated assembly of [Re6Q8(CN)6]4-(Q= Te, Se), an octahedral cluster precursor. The mesostructured lamellar phases with the general formula [CnH2n+1N(CH3)3]4[Re6Q8(CN)6] (n=14,16,18) (Q= Te, Se) were prepared by ion exchange/precipitation reaction of alkyltrimethylammonium surfactants and the cluster K4[Re6Q8(CN)6] in H2O/acetone medium at room temperature. The rhenium clusters in the lamellar material were charge balanced by surfactants. The other mesostructured cubic phases materials were synthesized by the assembly of hexanuclear rhenium chalcocyanide cluster, TMA4[Re6Se8(CN)6], and transition metal cations(Co2+, Mn2+) in formamide at 60 degrees. The transition metal ions linked rhenium cluster to rhenium cluster. The two phases were characterized using powder X-ray diffraction, single-crystal X-ray diffraction ([C14H29N(CH3)3]4[Re6Te8(CN)6], [C16H33N(CH3)3]4[Re6Se8(CN)6]), IR spectroscopy, Raman spectroscopy, TEM, thermogravimetric and differential scanning calorimetry means. The crystal data of [C14H29N(CH3)3]4[Re6Te8(CN)6] are a=11.4818(50) Å, b=11.6253(48) Å, c=22.2004(97) Å, α= 78.24(1) °, β= 82.31(1) °, γ= 61.28(1) °, triclinic, space group = P-1, and Z=1. The crystal data of [C16H33N(CH3)3]4[Re6Se8(CN)6] are a=11.7167(50) Å, b=11.8438(37) Å, c=21.3933(97) Å, α= 87.996(21) °, β= 87.5891(18) °, γ= 60.972(23) °, monoclinic.
9:00 PM - S4.50
Conducting Adhesives for Advanced Manufacturing
Douglas Schulz 1 , Kristen Keller 1 , Samali Datta 1 2 , Dean Webster 1 2
1 Center for Nanoscale Science and Engineering, North Dakota State University, Fargo, North Dakota, United States, 2 Department of Coatings and Polymeric Materials, North Dakota State University, Fargo, North Dakota, United States
Show AbstractConventional silver paste inks contain considerable solvent, which contributes to air pollution. UV curable technology can eliminate or minimize the solvent content; however, current commercial UV curable inks have poor conductivity and cannot be thermally bonded to another material (i.e. an antenna). UV "curable" inks having improved conductivity and maintain thermoplasticity were prepared and optimized for screen printing and other key properties. Screen printed deposits on FR-4 boards showed dc sheet resistance 0.074 Ω/sq/mil and ac impedance (6.0 GHz) of 466 µdB/mil as compared to 0.017 and 299 for a Cu control, respectively. The applicability of these materials (and similar variants) in the manufacture of large-area electronics (e.g., rfid tags) will be discussed.
9:00 PM - S4.6
New Generation of Hybrid Organic-Inorganic macrocellular Foams: Integrative Chemistry toward Reaching Enhanced Heterogeneous Catalysis and Scavenging Properties
Ungureanu Simona 1 3 4 , Herve Deleuze 4 , Clement Sanchez 2 , Marcel Popa 3 , Renal Backov 1
1 , CNRS-Universite Bordeaux-I, Pessac France, 3 , Facultea Chimie Industriala, Iasi Romania, 4 , Université Bordeaux-I, Iasi France, 2 , CNRS-Université Pierre et Marie Curie, Paris France
Show Abstract9:00 PM - S4.7
The Solvent Effects on the Formations of Lanthanide-Organic Porous Frameworks
Kuei-Fang Hsu 1
1 Chemistry, National Cheng Kung University, Tainan Taiwan
Show AbstractThe utilization of various solvents in the similar hydrothermal reactions has obtained two new lanthanide-based organic hybrid materials. Crystal Data: 1, Orthorhombic Fddd, a = 9.7277(4) Å, b = 15.4399(6) Å, c = 28.0108(12) Å, Z = 8, V = 4218.5(5) Å3; 2, Monoclinic P21/c, a = 6.3295(3) Å, b = 9.4446(5) Å, c = 16.1768(8) Å, b = 93.283(1)o, Z = 2, V = 965.5(2) Å3. Both structures are composed of neodymium ions, oxalates ligands and succinates ligands to form the porous frameworks with multi-dimensional tunnels. In 1, the Nd3+ ions are coordinated with four succinates and one oxalate- in the geometry of distorted square-pyramidal; while in 2, the Nd3+ ions are coordinated with four oxalates and one succinate in the geometry of distorted trigonal-bipyramidal. Both frameworks can be viewed as two-dimensional nets pillared by the oxalate ligands. The thermal stability and antiferromagnetic behaviors of the two compounds will be presented.
9:00 PM - S4.8
Preparation of Polyaniline Nanowires in Porous Alumina Templates.
Jinsub Choi 1 , Kyungja Kim 2 1 , Sung Joong Kim 1 , Jeong Ho Chang 1
1 Nanomaterials Application Division , Korea Institute of Ceramic Engineering and Technology (KICET), Seoul Korea (the Republic of), 2 Department of Electrical and Computer Engineering , University of Illinois at Urbana-Champaign, Urbana, Illinois, United States
Show Abstract9:00 PM - S4.9
synthesis of Various Ordered Mesoporous Carbons with Controlled Properties and its Application as Catalyst Support of Dirct Methanol Fuel Cell.
Hyung Ik Lee 1 , Jin Hoe Kim 1 , Chanho Pak 2 , Sang Hoon Joo 2 , Hyuk Chang 2 , Doyoung Seung 2 , Ji Man Kim 1
1 chemistry, Sungkyunkwan University, Suwon Korea (the Republic of), 2 , Samsung Advanced Institute of Technology, SAIT, Suwon Korea (the Republic of)
Show Abstract
Symposium Organizers
Richard M. Laine University of Michigan
Clement Sanchez Universite Pierre et Marie Curie
Christophe Barbe Ceramisphere, ANSTO
Ulrich Schubert Vienna University of Technology
S8: Controlled Release
Session Chairs
Thursday AM, April 12, 2007
Room 2004 (Moscone West)
9:30 AM - **S8.1
Silica-based Nanostructured Materials as Drug Delivery Systems.
Jean-Marie Devoisselle 1
1 UMR CNRS/ENSCM/UM1 5618, Institut Charles Gerhardt, Montpellier France
Show Abstract10:00 AM - S8.2
Effect of the Sol-Gel Synthesis Parameters on the Incorporation of an Anti-inflammatory Drug in a Ceramic Material.
Aracely Hernandez 1 , Jorge Esquivel 1 , Patricia Esquivel-Ferrino 1 , Idalia Gomez 1
1 , Universidad Autónoma de Nuevo León, Monterrey N.L. Mexico
Show Abstract10:15 AM - **S8.3
Design and Properties of HYbrid MAgnetic Carriers (HYMAC).
Thibaud Coradin 1 , Joachim Allouche 1 , Boissiere Michel 1 , Corinne Chaneac 1 , Roberta Brayner 2 , Jacques Livage 1
1 Chimie de la Matiere Condensee, CNRS-UMR7574, Université Paris VI, Paris France, 2 ITODYS, CNRS-UMR7086, Université Paris VII, Paris France
Show Abstract10:45 AM - S8.4
Nearly Perfect Silsesquioxane as Polyfunctional Nanobuilding blocks
Richard Laine 1 2 , Mark Roll 2 , Michael Asuncion 2 , Chad Brick 1 , Santy Sulaiman 2
1 Dept of Materials Science & Engineering, University of Michigan, Ann Arbor, Michigan, United States, 2 Molecular Science and Engineering, University of Michigan, Ann Arbor, Michigan, United States
Show AbstractOctafunctional, dodecafunctional phenylsilsesquioxanes [RxPhSiO1.5]8/12 and octavinyl silsesquioxanes [RvinylSiO1.5]8, are unique molecules wherein the silica core offers the heat capacity of silica and each Si vertex contains a diversity of functional group. These materials are easily accessible in high yields from simple starting materials including rice hull ash. Fur-thermore, an extensive variety of functional groups can be introduced. Consequently, these materials offer unique opportunities to engineer new nanobuilding blocks and polyfunctional materials. The nanobuilding blocks provide the tools for creating novel nanocomposites nanometer by nanometer in 1-, 2- or 3- dimensions. The polyfunctional materials have unique properties in their own right. We describe here methods of making highly imperfect, slightly imperfect and perfect nanostructures from Q8 [RSiMe2SiO4]8, [RPhSiO1.5]8 (ROPS) and [RPhSiO1.5]12 , (RDPS) and polymerizable ROVS systems and their properties.
11:00 AM - S8:Release
BREAK
S9: Surface and interface modification and characterization
Session Chairs
Thursday PM, April 12, 2007
Room 2004 (Moscone West)
11:15 AM - **S9.1
Characterisation of Organic-inorganic Interfaces in Hybrid Materials.
Niki Baccile 1 , Geoffrey Hartmeyer 1 , Thierry Azais 1 , Christian Bonhomme 1 , Florence Babonneau 1
1 LCMCP, Université Pierre et Marie Curie/CNRS, Paris France
Show Abstract11:45 AM - **S9.2
Surface Modification of Metal and Metal Oxide Substrates with Phosphonate Coupling Molecules (invited presentation)
Hubert Mutin 1 2 , Gilles Guerrero 2
1 Chemistry, CNRS, Montpellier France, 2 , University Montpellier 2, Montpellier France
Show AbstractDue to their affinity for a wide range of substrates, organophosphorus acids and their esters derivatives are finding increasing applications as coupling molecules to anchor organic groups to inorganic surfaces.[1-6] Here, we wish to present recent results on the kinetics of octadecylphosphonic acid SAM formation followed by in situ ATR-FTIR and on the bonding mode of phosphonate units in titania/phosphonate hybrids and SAMs studied by high-field (17 Tesla) 17O MAS-NMR. In addition, we illustrate the possibilities offered by organophosphorus coupling molecules to prepare hybrid materials by several examples, including: phase transfer of titania nanoparticles, selective surface modification of patterned SiO2 – TiO2 supports and mixed oxides, alkylphosphonic acid self-assembled monolayers (SAMs) on TiO2 as boundary lubricant coatings, phosphonate monolayers on titanium and stainless steel for biomaterials. References:(1) Gao, W.; Dickinson, L.; Grozinger, C.; Morin, F. G.; Reven, L. Langmuir 1996, 12, 6429-6435.(2) Schwartz, J.; Gawalt, E. S.; Lu, G.; Milliron, D. J.; Purvis, K. L.; Woodson, S. J.; Bernasek, S. L.; Bocarsly, A. B.; VanderKam, S. K. Polyhedron 2000, 19, 505-507.(3) Helmy, R.; Fadeev, A. Y. Langmuir 2002, 18, 8924-8928.(4) Raman, A.; Dubey, M.; Gouzman, I.; Gawalt, E. S. Langmuir 2006, 22, 6469-6472. (5) (a) Guerrero, G.; Mutin, P. H.; Vioux, A. Chem. Mater. 2000, 12, 1268. idem, Chem. Mater. 2001, 13, 4367.(6) Lafond, V.; Gervais, C.; Maquet, J.; Prochnow, D.; Babonneau, F.; Mutin, P. H. Chem. Mater. 2003, 15, 4098.
12:15 PM - S9.3
DOSY NMR : an Efficient Tool to Study Ligands at the Surface of Nanoparticles.
Francois Ribot 1 , Luk Van Lokeren 2 , Geraldine Maheut 2 , Virginie Escax 2 , Ingrid Verbruggen 2 , Claire Roiland 1 , Clement Sanchez 1 , Jose Martins 3 , Monique Biesemans 2 , Rudolph Willem 2
1 CMCP - UMR7574, CNRS / UPMC, Paris France, 2 High Resolution NMR Centre (HNMR), Vrije Universiteit Brussel, Brussel Belgium, 3 NMR and Structural Analysis Unit, Universiteit Gent, Gent Belgium
Show AbstractNanoparticles represent an important research subject from both an academic and a technologic point of view. Indeed, they can exhibit physical phenomena related to their size (ex. quantum confinement, surface plasmon resonance), and their very high surface-to-volume ratio is of great interest in the areas of catalysis, reinforcement of polymers, and membranes. A good understanding of their surface chemistry is required because the adjustment of their size can rely on the controlled poisoning of their growing surface by complexing ligands, and also because their use often needs the functionalization of their surface in order to avoid aggregation or to introduce new characteristics such as hydrophobicity, specific recognition of certain chemical functions or an easy dispersion in organic solvents or polymers. However, the in situ measurement of the affinity of an organic ligand for an inorganic nanoparticle is not an easy task, but is needed for a good control over the properties of hybrid organic-inorganic nanoparticles.In consequence, a practical technique, fast and selective for probing the ligands at the surface and for quantifying them against the free ligands is highly desirable. Pulsed field gradient and DOSY (Diffusion Ordered Spectroscopy) NMR can be that technique since it offers, on top of the classical NMR parameters in solution (chemical shifts and scalar coupling constants), an elegant method for measuring diffusion coefficients, which in turn permit to sort the species as a function of their size/interaction. In this way the free ligands can be discriminated from bound ones, even when they have the same chemical shift, since they will display different diffusion coefficients.Two examples will be presented to illustrate this technique : cerium dioxide nanoparticles functionalized with long chain carboxylic acids and titanium dioxide nanoparticles prepared by hydrolysis-condensation of titanium butoxide in the presence of acetylacetone and p-toluene sulfonic acid.
12:30 PM - S9.4
Covalent Grafting of Organoalkoxysilanes on Silica Surfaces in Water-Rich Medium as evidenced by 29Si NMR
Sophie De Monredon - Senani 1 , Francois Ribot 1 , Florence Babonneau 1 , Christian Bonhomme 1
1 LCMCP, Universite P et M Curie, Paris France
Show AbstractDespite the huge amount of experimental investigations dedicated to the functionalization of silica particles with organoalkoxysilanes, there are only a few accurate description of the resulting anchoring. In most cases, the formation of a covalent link is taken for granted and not discussed. In this study, we have investigated the reaction between methylated alkoxysilanes and a precipitated silica in water-rich medium. Such medium is of prime importance for a large range of applications, but these unusual grafting conditions could promote extensive self-condensation reactions of the alkoxysilanes, with the resulting polysiloxanes hydrogen-bonded to the surface. Solution and solid-state 29Si NMR, coupled with a rigorous synthetic protocol, have been used to demonstrate unambiguously the formation of covalent bonds. Alkoxysilanes of increasing complexity were used. Our demonstration was obvious with monofunctional ethoxysilane (Me3Si(OEt), and was succesfully transposed to di- (Me2Si(OEt)2) and trifunctional (MeSi(OEt)3) ethoxysilanes.
12:45 PM - S9.5
Polymer-silica Nnanocomposite Aerogels with Enhanced Mechanical Properties using Chemical Vapor Deposition (CVD) of Ethylcyanoacrylate.
Dylan Boday 1 , Kimberly DeFriend 2 , Kennard Wilson 2 , David Coder 1 , Douglas Loy 1
1 Materials Science and Engineering, The Univeristy of Arizona, Tucson, Arizona, United States, 2 Material Science and Technology, Los Alamos National Labratories, Los Alamos, New Mexico, United States
Show AbstractS10: New Concepts
Session Chairs
Thursday PM, April 12, 2007
Room 2004 (Moscone West)
2:30 PM - **S10.1
High Resolution 1H NMR Of Inorganic-Organic Hybrid Materials.
Joao Rocha 1
1 Department of Chemistry, University of Aveiro, CICECO, Aveiro Portugal
Show AbstractMetal-organic frameworks, coordination polymers and other inorganic–organic hybrid materials have been much studied in the last few years mainly because they offer the opportunity of mining the better of two chemical worlds. Most reports use relatively routine NMR techniques to characterise the structures of such solids, which contain protons in the organic and inorganic components and, thus, the attribution of the 1H NMR resonances is not trivial, requiring high-resolution spectra. We have been preparing new inorganic–organic hybrids, solving their structure by X-ray diffraction, and assessing the use of multinuclear MAS NMR techniques based on the frequency switched Lee–Goldburg (FS-LG) sequence to study these materials. Here, I shall present an overview of this work (as examples, see [1-3]).Because of the strong 1H–1H dipolar interactions, which broaden the resonances, conventional solid-state NMR techniques (MAS, CP MAS) usualy afford poorly-resolved spectra. Since the pioneering work of Lee and Goldburg and Waugh and co-workers, multipulse homonuclear decoupling has been applied to improve the decoupling performance [4-6]. In the last fifteen years, new homonuclear decoupling pulse sequences have been proposed, particularly the FS-LG sequence [7]. In general, multipulse sequences fail at high MAS rates due to the interference between the sample spinning and rf cycles. However, with the recent windowless 1H–1H CRAMPS-MAS techniques (such as FS-LG-2, [4] PM-LG [6], DUMBO-1 [5]) based on off-resonance rf fields, it is possible to simultaneously manipulate the spin and spatial parts of the dipolar Hamiltonian, without decreasing the decoupling efficiency. Sequences like FS-LG-2 have short cycle times and may be combined successfully with moderately fast MAS (up to 12–15 kHz) [8].[1] L. Mafra, L., J. Rocha, C. Fernandez and F. A. A. Paz (2006) J. Magn. Reson. 180, 235.[2] L. Mafra, F. A. A. Paz, J. Rocha, A. Espina, S. A. Khainakov and J. R.Garcia (2005) Chem. Mater. 17, 6287.[3] M. Mafra, F. A. A. Almeida Paz, F. N. Shi, J. Rocha, T. Trindade, C. Fernandez, A. Makal, K. Wozniak and J. Klinowski (2006) Chem. Eur. J. 12, 363.[4] A. Bielecki, A. C. Kolbert and M. H. Levitt (1989) Chem. Phys. Lett. 155, 341.[5] D. Sakellariou, A. Lesage, P. Hodgkinson and L. Emsley (2000) Chem. Phys. Lett. 319, 253.[6] E. Vinogradov, P. K. Madhu and S. Vega (1999) Chem. Phys. Lett. 314, 443.[7] M. H. Levitt, A. C. Kolbert, A. Bielecki and D. J. Rubben (1993) Solid State Nucl. Magn. Reson. 2, 151.[8] B. J. van Rossum, H. Forster and H. J. M. de Groot (1997) J. Magn. Reson. 124, 516.
3:00 PM - S10.2
Polymerization Kinetics of Methacrylic Groups in Organic-Inorganic Hybrid Polymeric Thin Films
Congji Zha 1 , Xinshi Luo 2 1 , Barry Luther-Davies 1
1 Laser Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australian Capital Territory, Australia, 2 , CSIRO, Clayton, Melbourne, VIC3169, Victoria, Australia
Show AbstractFabrication of integrated optical components and devices using photosensitive organic-inorganic hybrid polymers has attracted considerable attention in recent years. Hybrid polymeric thin films can be fabricated by spin-coating process, and waveguide structure can be easily defined on these polymeric films by direct laser-writing or UV-printing process, enabling low cost fabrication of photonic chips and devices. Since waveguide fabrication using photolithographic process usually requires the unsaturated C=C bonds in the hybrid thin films to be sufficiently cross-linked upon UV irradiation, understanding the polymerization kinetics of these bonds is of interest. Furthermore, the determination of parameters, such as photo-initiator type and concentration, UV power density and dose, thermal curing temperature and time for waveguide patterning also requires us to understand the process of polymerization. Recently we developed an anhydrous sol-gel process for synthesis of TiO2- and ZrO2-doped hybrid polymers and demonstrated the material’s promising optical properties, such as linear thermo-optic coefficients, low birefringence and low optical absorption losses. In this paper, the polymerization kinetics of unsaturated double bonds (C=C) in TiO2- and ZrO2-doped hybrid polymeric thin films during UV irradiation and thermal curing is studied by monitoring the variation of C=C absorption band at 1630 cm-1 using FT-IR spectroscopic technique. Experimental results showed that polymerization of the unsaturated C=C groups in the TiO2- and ZrO2-doped hybrid polymers can be realized by either photo-irradiation or thermal treatment. The UV-induced polymerization process is much faster than thermal curing, but a full conversion of C=C groups into polyacrylate chains cannot be achieved without thermal treatment. The catalytic effect of TiO2 and ZrO2 on promoting the polymerization of C=C groups was observed, and the time of UV exposure and thermal curing for cross-linking C=C bonds was found to decrease with the increase of the concentration of TiO2 and ZrO2. The activation energy of the hybrid material containing varied concentration of TiO2 and ZrO2 was calculated, and the results indicated that TiO2 is more active than ZrO2 in promoting the polymerization of the unsaturated C=C bonds. The refractive index changes in the hybrid thin films during UV polymerization and thermal curing process were measured, and the results are in good agreement with those from the polymerization kinetics study. Finally, the mechanisms for TiO2 and ZrO2 enhancing the material’s photosensitivity (i.e. promoting polymerization of C=C bonds) have been proposed and discussed based on spectroscopic evidence.
3:15 PM - S10.3
Poly(dialkylstannane)s: Synthesis and Orientation of Semiconducting, Liquid-Crystalline Materials
Fabien Choffat 1 , Walter Caseri 1 , Paul Smith 1 , Sara Fornera 1 , Matthijs de Haas 2 , John Warman 2 , Dag Breiby 3 , Nielsen Martin 3
1 Department of Materials, ETH Zurich, Zurich Switzerland, 2 Optoelectronic Materials Section, TU Delft, Delft Netherlands, 3 Danish Polymer Centre, Riso National Laboratory, Roskilde Denmark
Show AbstractPolystannanes are little-explored polymeric hybrid materials consisting of a backbone of covalently bound tin atoms which are connected to organic moieties. The synthesis of such materials, which are specified by the chemical formula (SnR2)n, yielded typically polymers which contained large amounts of impurities (mainly cyclic oligomers). Recently, however, we developed a new, facile synthetic route providing pure linear poly(dialkylstannane)s through dehydropolymerization of the dialkylstannanes, H2SnR2, with the catalyst [RhCl(PPh3)3] (Wilkinson’s catalyst) [1]. Poly(dibutylstannane), poly(dioctylstannane) and poly(didodecylstannane) were prepared with this method. These polymers appear to be liquid-crystalline, and remarkably poly(dibutylstannane) is present in this state already at room temperature. This polymer was also subjected to charge mobility measurements, resulting in high charge mobilities which is indicative for semiconductivity [2]. The charge mobilities changed significantly at the transition temperature from the solid to the liquid-crystalline state. Moreover, the polymers could be oriented by different methods. Orientation of the polystannane backbone was clearly evident by polarized UV-vis spectroscopy, X-ray diffraction and polarized light microscopy. Most interestingly, the orientation direction depended not only on the preparation method but also the length of the side groups of the poly(dialkylstannane). Depending on the length of the alkyl groups, the orientation of the backbone was parallel or perpendicular to an ambient orientation axis. [1] Choffat F., Smith P., Caseri W., J. Mater. Chem. 2005, 15, 1789[2] de Haas M. P., Choffat F., Caseri W., Smith P., Warman J. M., Adv. Mater. 2006, 18, 44
3:30 PM - S10.4
Synthesis and Characterization of Self-assembled Block Copolymer Templated Calcium Phosphate Nanocomposite Gels
Drew Enlow 1 2 , Aditya Rawal 3 2 , Mathumai Kanapathipillai 4 2 , Klaus Schmidt-Rohr 3 2 , Surya Mallapragada 4 2 , Mufit Akinc 1 2
1 Materials Sci. & Eng., Iowa State University, Ames, Iowa, United States, 2 Ames Laboratory, Iowa State University, Ames, Iowa, United States, 3 Chemistry , Iowa State University, Ames, Iowa, United States, 4 Chemical & Biological Engineering, Iowa State University, Ames, Iowa, United States
Show AbstractThursday, April 12thNew Presentation Time and Paper NumberS11.4 @ 4:30 pm to S10.4 @ 2:30 pmSynthesis and Characterization of Self-assembled Block Copolymer Templated Calcium Phosphate Nanocomposite Gels.Mufit Akinc
3:45 PM - S10:Concepts
BREAK
S11: Nanoparticle Synthesis and Assembly I
Session Chairs
Thursday PM, April 12, 2007
Room 2004 (Moscone West)
4:15 PM - **S11.1
Latex Controlled Surface Nucleation As A New Tool For Polystyrene-Decorated Silica Nanoparticles Of Controlled Morphology.
Adeline Perro 1 2 , David Nguyen 1 2 , Stephane Reculusa 2 , Serge Ravaine 2 , Elodie Bourgeat-Lami 3 , Olivier Lambert 4 , Jean-Christophe Taveau 4 , Etienne Duguet 1
1 , ICMCB/CNRS, Pessac France, 2 , CRPP/CNRS, Pessac France, 3 , LCPP/CNRS, Villeurbanne France, 4 , UBS/CNRS, Talence France
Show AbstractHybrid organic-inorganic nanoparticles with well-controlled morphology are currently of great interest for numerous applications. Synthetic routes leading to robust aggregates made of nanoparticles of different chemical natures which are associated in a controlled manner (i.e. number of nanoparticles and geometrical arrangement) are especially investigated. They are essentially derived from techniques allowing a directed assembling of preformed nanoparticles.Our strategy is based on a seeded emulsion polymerization process leading to hybrid colloidal particles, which are composed of spherical silica spheres surrounded by a varying number of polystyrene (PS) nodules. The hydrophilic character of silica seed particles (from 50 to 400 nm in diameter) needs to be previously altered by a surface functionalization step. Emulsion polymerization of styrene is carried out in presence of these particles, the formation of polystyrene nodules being highly favored at the silica surface in such conditions. While varying different experimental parameters, it may be demonstrated that both the ratio between the number of silica seeds and the number of growing polystyrene nodules and the silane grafting density were key parameters to control the morphology of the final hybrid particles.
4:45 PM - **S11.2
Optical and Sensing Thin Film Properties of Nanosized Silica Particles.
Philippe Belleville 1 , Xavier Le Guevel 1 , Philippe Prene 1 , Pierre Montmeat 1 , Lionel Hairault 1 , Monique Gervais 2
1 , C.E.A., Monts France, 2 LEMA, University François Rabelais, Tours France
Show AbstractColloidal silica is an endless source of applications. Due to a specific area great value, nanosized silica particle reactivity is sharpened and we propose here two convincing examples of colloidal silica thin film use for optical coatings and for gas sensing.Today, sol-gel thin films used for optical coating are mainly prepared from alcoholic solutions. Use of large-size coating tank containing alcoholic media involve tricky constraints due to safety and environmental reasons. We have developed a coating solution suitable for optical thin film preparation which is non or slightly-flammable, time-stable and environmentally friendly. Ethanolic-based colloidal silica sol was first prepared using the Stöber process and water was chosen as a co-solvent in order to develop water-based coating solution so-called BLUESIL. Aqueous synthesis route was find to be an important factor determining both mechanical and optical film properties. Water layer physically adsorbed around the silica nanoparticles was highlighted and definitely impact onto silica particle surface reactivity. BLUESIL films were then exposed to catalytic curing (ammonia-hardening). We show that this procedure dramatically improve film scratch-resistance maintaining good optical properties such as high-transparency (99.8% transmission) and low refractive index. We demonstrate that coating macroscopic features are related to inter-particle bond formation involving solid-state siloxane bridging and hydrogen bonding.For 10 years, many studies have been performed on the detection of nitroaromatics compounds using chemical gas sensors as highly sensitive and selective detectors of various explosives. Silica-based materials have ever been used as chemical sensor for humidity or NO detection. We report here a new promising material based on nanostructured highly-porous silica films specifically developed and tested as chemical sensors for nitroaromatics detection. Since chemical gas detection is based on sensor surface interaction, such mesoporous silica material offers a very high specific area (>400m2/g) and allows to promote chemical sensor sensibility. Moreover, the silica particle surface properties can be easily controlled by tailoring the surface hydroxyl groups density with the peptization solvent (water or ethanol) or by using surface functionalization such as specific species grafting. The evaluation of detection performances of functionalized nanostructured silica-based films using quartz crystal microbalance or fluorescence devices exhibits very interesting results. Those systems show a good sensibility (@ 0.1ppm), excellent reversibility for nitroaromatic compounds detection whatever the operating relative humidity conditions (from 0% to 80% at 20°C) and good selectivity in comparison with standard interfering volatile organic compounds. Life-time duration of such functionalized nanostructured film sensors is exceeding six months under operational air atmosphere conditions.
5:15 PM - S11.3
A New Precursor Route to Bulk and Thin Films of Bismuth Vanadates (BiVO4, γ-Bi4V2O11) based on Hybrid Materials Made From a Zwitterionic Organic Polymer and Inorganic Salts.
Francois Rullens 1 , Andre Laschewsky 2 , Michel Devillers 1
1 Chemistry, Université Catholique de Louvain, Louvain-la-Neuve Belgium, 2 , Fraunhofer Institute for Applied Polymer Research, Potsdam-Golm Germany
Show Abstract5:30 PM - S11:Nanosynthe 1
S11.4 TRANSFERRED TO S10.4
Show AbstractS12: Poster Session: Organic/Inorganic Materials II
Session Chairs
Chris Barbe
Richard Laine
Friday AM, April 13, 2007
Salon Level (Marriott)
9:00 PM - S12.1
Synthesis and Properties of Barium Titanate Nanoparticle/Polymer Hybrid Materials.
Kosuke Hiramatsu 1 , Wataru Sakamoto 1 , Toshinobu Yogo 1 , Satoshi Kawado 2 , Yoshiaki Uesu 2
1 EcoTopia Science Institute, Nagoya University, Nagoya University, Nagoya, Aichi, Japan, 2 Dept. of Physics, Waseda University, Tokyo, Tokyo, Japan
Show Abstract9:00 PM - S12.10
Hydrothermal Synthesis of Organic-Hybridized Cerium Oxide Nanoparticles and the Effect of Functional Group of Organic Modifiers on the Growth Kinetics, Shape, and Surface Properties of Synthesized Nanoparticles.
Seiichi Takami 1 , Tadafumi Adschiri 2 , Yutaka Wakayama 1 , Toyohiro Chikyow 1
1 Advanced Electronic Materials Center, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, 2 Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, Japan
Show AbstractWe report growth kinetics, shape, and surface properties of cerium oxide nanoparticles that were hydrothermally synthesized in the presence of C5H11COOH, HOCO-(CH2)4-NH2, and HOCO-(CH2)4-COOH. The amount of reacted cerium ion was evaluated using inductively coupled plasma (ICP) method to evaluate the first-order reaction rate. The results showed that the presence of organic molecules slowed the consumption of cerium ion, which was plausibly caused by the capping of the growing surface of the cerium oxide nanoparticles. Transmission electron microscope (TEM) images of the products indicated that the size of synthesized nanoparticles in the presence of the surface modifiers was much smaller than that of the products without surface modifiers. The addition of the surface modifiers also affected the shape of the nanoparticles. These results showed that the used surface modifiers reacted with the surface of cerium oxide nanoparticles during their hydrothermal synthesis. As a result, we can successfully control the surface properties of cerium oxide nanoparticles. For example, the aggregation were observed between the nanoparticles that were synthesized with HOCO-(CH2)4-COOH. On the other hand, no aggregation occurred between the nanoparticles that were synthesized with HOCO-(CH2)4-NH2.
9:00 PM - S12.11
Structure of Metal Nanoparticles in Microcrystalline Cellulose Matrix.
Kari Pirkkalainen 1 , Ulla Vainio 1 , Nina Kotelnikova 2 , Ritva Serimaa 1
1 Division of X-ray Physics, University of Helsinki, Helsinki Finland, 2 Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg Russian Federation
Show AbstractNanosized transition metal particles were manufactured by chemical reduction within a microcrystalline cellulose matrix. The porous cellulose matrix was introduced to act as a nanoreactor for nanoparticle formation, as a deterrent for spontaneous oxidation and irreversible agglomeration of particles. Different chemical reduction agents were used, and so-formed nanoparticles were characterized with x-ray diffraction, anomalous small angle x-ray scattering, x-ray absorption spectroscopy, scanning electron microscopy and magnetization measurements. These experimental techniques were used to gain insight into the effect of different synthesis routes on nanoparticle size distribution, shape, oxidation state and magnetic behavior. As an example, a study on Ni nanoparticles in microcrystalline matrix is presented. Nickel nanoparticles were manufactured by adding aqueous Ni salt into microcrystalline cellulose matrix, in which the Ni-ions were chemically reduced with sodium borohydride, NaBH4, or potassium hypophosphite, KH2PO2. The so-manufactured nanoparticles were mostly in nanocrystalline or amorphous metallic phase and were paramagnetic or ferromagnetic depending on the used synthesis route. The synthesis route had no distinct effect on the structure of the cellulose matrix.
9:00 PM - S12.12
Vertically Aligned CdS Nanorods for Organic Solar Cells
Dongjuan Xi 1 , Qibing Pei 1
1 material science, UCLA, los angeles, California, United States
Show Abstract Organic solar cells have been developed as a low-cost alternative to conventional silicon solar cells. However, due to the low mobility and short exciton diffusion length in existing organic materials, hybrid structure from organic and inorganic nanocrystals becomes more attractive. The ideal vision for a high-efficiency polymer solar cell calls for well-ordered p- or n- nanorods and a second complementary layer to form an interdigitated structure. In such a hybrid, every exciton formed on the conjugated polymer will be within a short diffusion length to the p-n interface and dissociate efficiently into holes and electrons. The charge carriers will then travel along respective straight pathways to the charge-collecting electrodes. The fabrication of this ideal structure has been attempted in several studies. In 2005, a high efficiency organic solar cell was achieved by the high temperature organic vapor-phase deposition of CuPc nanoforrest and PTCBI. Low temperature processes have also been used via anodized alumina template, porous titanium oxide or vertically aligned zinc oxide (ZnO) nanorods. However, the anodized alumina template approach has limitations in geometry control and resulting nanorod quality. Both titanium oxide and zinc oxide are large bandgap semiconductors which absorb only at the ultraviolet range, limiting the generation of excitons. Researches have shown that by placing a thin layer of absorbing material such as low bandgap cadmium sulfide or cadmium selenide, which have better energy level match with conjugated polymers, on top of the ZnO nanorod template, the efficiency of the electrochemically deposited solar cell can be increased to 2.3% with another layer of CuSCN. Instead of using titanium oxide and zinc oxide nanostructures as templates, in this paper, we directly grow vertically aligned low bandgap cadmium sulfide (CdS) nanorods electrochemically at low temperature. The nanorods are single crystals as indicated by XRD and SEM. CdS nanorod arrays with 20 nm rod-to-rod spacing are used to fabricate polymer solar cells. P3HT is deposited by spin coating, followed by annealing to facilitate the infiltration of the polymer into the opening space between the nanorods. The absorption spectrum and photovoltaic property of the resulting CdS/P3HT interdigitated nanostructures will also be presented and analyzed.
9:00 PM - S12.13
Templated route to Multiferroics
Deepa Khushalani 1
1 Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai India
Show Abstract9:00 PM - S12.14
Physical Properties of Electrospun PVAc/MWNT Composite Nanofibers and Their Gas Sensing Applications
Guan Wang 1 , Vladimir Samuilov 1 , Zhongkui Tan 2 , Xueqing Liu 2 , Michael Dudley 1
1 Materials Science Dept., Stony Brook University, Stony Brook, New York, United States, 2 2Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York, United States
Show AbstractUtilizing polymer as a carrier media to assemble the carbon nanotubes (CNTs) into continuous filament allows well-controlled alignment and tailored distribution of the CNTs within an external structure. Successful incorporation of CNTs with appropriate polymer matrix systems in filament or fine fiber forms can work as an effective bridge to translate the superior properties of carbon nanotubes to meso- and macro-scale structures. In this work, we demonstrate electrospinning as a relatively simple and versatile method to realize this incorporation. Multiple outstanding properties of CNTs are retained within the matrix of polymer nanofibers, which is produced by electrospinning. Alignment of the composite nanofibers has been achieved by using a rotating drum as the collector. An AFM-based three-point-bending method was employed to study the mechanical properties of individual composite nanofibers. Electrical properties of a single composite fiber have been investigated at room temperature as well as cryogenic states. By integrating these composite nanofibers with interdigitated electrode structure, both quantitative and qualitative measurements of sensitivity of the materials have been carried out. Evaluation of the composite nanofibers for potential sensing applications is also carried out.
9:00 PM - S12.15
Biomimetic Mineralization of Natural Fibrillar Collagenous Films from a Supersaturated Hydroxyapatite Solution.
Chuanbin Mao 1 , Haiqin Lu 1 , Penghe Qiu 1 , Dong Li 1
1 Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, United States
Show Abstract9:00 PM - S12.16
Electrodeposited Platinum in The Copolymer of 2,5-dimethoxyaniline and 2,5-diaminobenzensulfonic acid for Methanol Oxidation
T. Chang 1
1 , Nation Cheng Kung University, Tainan Taiwan
Show Abstract9:00 PM - S12.17
Electrospinning Polymer Nanocomposites: A Route to Multiferroic Materials
Jennifer Andrew 1 , David Clarke 1
1 Materials Department, University of California- Santa Barbara, Santa Barbara, California, United States
Show AbstractMultiferroic materials exhibit both ferromagnetic and ferroelectric properties, which tend to be mutually exclusive in most materials. However, materials exhibiting these properties can be achieved through electrospinning nanocomposite fibers with a ferroelectric polymer, polyvinylidene difluoride (PVDF), matrix phase and a ferrite (MFe2O4, M=Ni0.5Zn0.5, Co) nanoparticle filler phase.
Homogenous ferrite-PVDF continuous composite nanofibers were successfully electrospun from a dimethyl formamide (DMF) solution. The ferrite nanoparticles were synthesized using aqueous coprecipitation routes and were subsequently surface functionalized with silica, forming a stable ferrofluid in DMF. The effects of various electrospinning processing conditions were examined, as these conditions contain many variables affecting the morphology and diameter of the fibers. Solution properties (viscosity, solids loading) and processing parameters (flow rate and voltage) were varied, and their effects on fiber morphology were studied. The ferrite-PVDF composite fibers were characterized structurally and electrically. Structural characterization was performed via x-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. Dielectric measurements and SQUID magnetometer measurements were performed to determine the material’s properties.
By varying the outlined processing parameters we have successfully prepared ferrite-PVDF nanocomposite fibers. These nanocomposite fibers have diameters that can be tuned from 150nm up to 2 microns by adjusting the processing parameters. The average size of the ferrite nanoparticles used as the filler phase, determined from x-ray diffraction, is 8-10nm.
9:00 PM - S12.18
Design of Functionalized Fe3O4 Nanoparticles for Elaboration of Nanostructured Films with Magnetic Properties.
Toufic Jean Daou 1 , Benoit Pichon 1 , Fayna Mammeri 1 , Diane Ung 1 , Saiwan Buathong 1 , Yves Le Bras 1 , Corinne Ulhaq 1 , Jean Louis Gallani 1 , Bertrand Donnio 1 , Daniel Guillon 1 , Genevieve Pourroy 1 , Sylvie Begin-Colin 1
1 UMR CNRS-ULP 7504, IPCMS, Strasbourg, alsace, France
Show Abstract9:00 PM - S12.19
Integrative Chemistry toward Designing Vanadium Oxide Macroscopic Fibers: High Sensitive Alcohol Sensors.
Celine M. Leroy 1 , Helene Serier 1 , Marie-France Achard 2 , Nathalie Steunou 2 , Jacques Livage 2 , Renal Backov 1
1 , CNRS-Universite Bordeaux-I, Pessac France, 2 , Université Pierre et Marie Curie, Paris France
Show Abstract9:00 PM - S12.2
Hybrid Nanoparticles Prepared by In-situ and Post-synthetic Surface Modification of Neodymium-based Nanoparticles with Phosphonic Acid Derivatives.
Christoph Rill 1 , Sorin Ivanovici 1 , Guido Kickelbick 1
1 Institute of Materials Chemistry, Vienna University of Technology, Vienna Austria
Show AbstractOrganically surface-functionalized nanoparticles play an important role in the synthesis of nanocomposites. In this work the use of various phosphonic acids – some of which contain polymerizable groups – and their alkyl and silyl esters as surface modifying agents was studied both in-situ during the particle synthesis as well as in a separate step after particle preparation. The in-situ method is a single-pot reaction where the nanoparticles are precipitated from methanolic solutions of a neodymium salt and sodium hydroxide in the presence of the respective phosphonic acid derivative. The free phosphonic acids were unsuitable for this purpose because of the premature formation of the scarcely soluble phosphonate salts. The phosphonic acid esters, however, were able to coordinate the ions in solution as evidenced by UV/Vis spectroscopic measurements, thus acting as good surface blocking agents during the particle precipitation. The size of the nanoparticles was determined by dynamic light scattering to be as small as a few nanometers in diameter. The presence of the phosphonates on the surface of the particles was confirmed by FT-IR measurements.The second method consists of a more conventional, hydrothermal particle synthesis where bulk-precipitated neodymium hydroxide is hydrothermally treated to form crystalline neodymium hydroxide nanorods with high aspect-ratio. In a separate step the particles were reacted with phosphonic acids and their esters. Powder diffraction, thermogravimetric, and FT-IR measurements of the nanorods before and after the modification showed that the free acids attached to the surface to the highest degree, while the alkyl esters showed no evidence for a reaction. The particle morphology was investigated by transmission electron microscopy. Furthermore, some of the particles which were modified with polymerizable groups were incorporated into organic polymer matrices to form inorganic-organic hybrid materials. These materials were characterized by spectroscopic methods, thermal analysis, and electron microscopy.
9:00 PM - S12.20
Novel Methods for ``in bulk" Fabrication of Anisotropic Colloid Particles.
Olivier Cayre 1 2 , Anne-Claude Courbaron 1 , Hartmut Wege 1 2 , Orlin Velev 2 , Vesselin Paunov 1
1 Department of Chemistry, University of Hull, Hull, North Humberside, United Kingdom, 2 Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, United States
Show Abstract9:00 PM - S12.21
Study of the Architecture of Inorganic-Organic Matrix in the Ventral Segmental Concretion of Porcellio scaber (Crustacea, Isopoda)
Ranjith Pai 1 , Andrónico Neira-Carrillo 1 , Maria Fernandez 1 , José Arias 1
1 Center for Advanced Interdisciplinary Research in Materials (CIMAT), Faculty of Veterinary and Animal Science, Department of Biological Science, University of Chile, Santiago, Santiago, Chile
Show AbstractBefore the molt terrestrial isopods resorb calcium from the posterior cuticle and store it in concretion within the cranial (head) and caudal (tail) ventral segments. The caudal ventral segmental (CVS) concretion of the woodlice Porcellio scaber was analyzed with respect to their content of inorganic material. It was found that the concretion consists of amorphous calcium carbonate (ACC), and amorphous calcium phosphate (ACP), besides small amounts of water and an organic matrix. The presence of ACC and ACP within the CVS concretion of Porcellio scaber has considerable functional implications. It seems likely that most of the amorphous fraction of CaCO3 within the cuticle is resorbed and recycled during every moulting cycle, while most of the less soluble crystalline part is shed with the old cuticle. We therefore propose that the need for frequent recycling of cuticular calcium is the reason for the presence of ACC in the ventral segmental concretion. Phosphorus in CVS concretion can occur in an organic form like phospholipid. Phospolipids are a major component of the cell walls, and the crustacean cuticle contains numerous cellular constituents that may account for part of the phosphorus content. The present paper indicates that most phosphorus within CVS concretion of terrestrial isopods occurs as amorphous calcium phosphate. ACP is more soluble than its crystalline phases. The use of calcium phosphate in its amorphous form, therefore, suggests that it is subject to resorption and recycling during the frequent moulting cycles of terrestrial isopods, like ACC. It is thought that the organic matrix plays a role in the structural organization of concretion and in the stabilization of ACC and ACP, which is unstable in vitro. In this paper we present a thorough analysis of the ultrastructure of the organic matrix in the CVS concretion using scanning electron microscopy. The concretion of structurally distinct layers contains an elaborate organic matrix with similar structural organization consisting of plates with interconnected filaments. The decalcification experiments reveal an inhomogeneous solubility of ACC and ACP within the CVS concretion probably caused by variations in the stabilizing properties of matrix components. The work was financially supported by the Project FONDAP 11980002 granted by the Chilean Council for Science and Technology (FONDECYT)
9:00 PM - S12.22
One-step Method for the Self-assembly of Metal Nanoparticles onto Oxide Surfaces.
Deepa Khushalani 1
1 Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai India
Show Abstract9:00 PM - S12.23
Biomimetic Silk-Zinc Oxide Composite Material
Melanie Tomczak 1 , Maneesh Gupta 1 , Lawrence Drummy 1 , Joseph Van Nostrand 1 , Rajesh Naik 1
1 Materials and Manufacturing Directorate, Air Force Research Laboratory, WPAFB, Ohio, United States
Show AbstractBiomolecules are used throughout nature to template inorganic materials, such as silica in diatoms and magnetite in bacteria. Using nature as an inspiration, peptide phage display has been used by our group and others to identify peptides sequences that bind to and precipitate inorganics of interest. Here, we have used that approach to direct the growth of zinc oxide nanocrystals. We find that one of the peptides identified, termed ZnO1, selectively inhibits growth of the c-axis of zinc oxide, resulting in single crystal hexagonal platelets with excellent photoluminescent properties. We have investigated a series of experimental conditions to determine the factors affecting the resulting structure and fluorescence character of the zinc oxide templated by ZnO1 peptide. These experiments then were extended to form composite materials of ZnO and Bombyx mori silk films. We found that the ZnO1 peptide adheres to the silk film and templates ZnO hexagonal platelets directly on the film. The optical properties of the composite material and the expanded use of silk as a template for other inorganics will be discussed.
9:00 PM - S12.24
Organic/Inorganic Hybrid Mixed Sn(II)/Sn(IV) Copper Thiostannates: Uncommon Structural Coexistence.
Jason Cody 1 , Catherine Guillot-Deudon 2 , Alain Lafond 2 , Klaus-Dieter Becker 4 , M. Behrens 3 , M. Ordolff 3 , Christian Nather 3 , Wolfgang Bensch 3
1 Chemistry, Lake Forest College, Lake Forest, Illinois, United States, 2 Laboratoire de Chimie d'Etat Solide, Institut des Matériaux Jean Rouxel, Nantes France, 4 , Technische Universität zu Braunschweig, Brunswick Germany, 3 Institut für Anorganische Chemie, Christian Albrechts Univ Kiel, Kiel Germany
Show Abstract9:00 PM - S12.25
Effective Nanofiller Dispersion and Property Modification in Polymer Nanocomposites Made by Solid-State Shear Pulverization.
Katsuyuki Wakabayashi 1 , John Torkelson 1 2
1 Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, United States, 2 Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois, United States
Show AbstractPolymer nanocomposites have recently proven to be successful hybrid materials, in which enhanced mechanical, thermal, barrier, and/or electrical properties are achieved at low filler loadings. The type of nanofillers often dictates the property improvements imposed on a polymeric material, and varies from one-dimensional nanoparticles, two-dimensional nanotubes, and three-dimensional layered nanosheets. Though polymer nanocomposites often employ inorganic fillers such as silica, alumina, and layered silicates, there are also successful nanocomposites made with organic fillers such as carbon nanotubes and graphite nanosheets. A common challenge associated with polymer nanocomposites is effective dispersion of the nanofiller in the polymer matrix, due to the tendency of the filler to self-aggregate, the lack of interaction between the filler and the polymer, or low thermal stability of the polymer at conditions used during melt mixing. Processes such as in situ polymerization in the presence of nanofiller and solution mixing of pre-functionalized nanofiller have been successful in the past, but only on a small, laboratory-scale. On the other hand, commercially applicable melt mixing methods like co-extrusion have had limited success in producing well-dispersed polymer-based hybrids. We herein report on solid-state shear pulverization (SSSP) as an innovative processing technique that is capable of producing well-dispersed polymer nanocomposites with inorganic or organic nanofillers. Unlike the conventional nanofiller dispersion techniques in the literature, SSSP is a direct, continuous process that allows for industrial scale-up and facile tuning of the nanocomposite properties. SSSP relies on the mechanical mechanism of repeated fragmentation and fusion in the solid state to disperse nanofillers without pre-functionalization of materials, use of solvents, or heat. A static annealing study of the hybrids has shown that the dispersed state is kinetically stable during post-melt processing. For a series of polypropylene-based nanocomposites, the morphology and the resulting physical properties are examined and compared with the counterparts made via conventional melt-mixing. We employ electron microscopy and X-ray diffraction to confirm the level of dispersion of the nanofillers, while conducting uniaxial tensile testing for mechanical behavior analysis, differential scanning calorimetry and thermogravimetry for thermal characterization, and oxygen permeation for barrier property measurements.
9:00 PM - S12.27
Fabrication of Bonelike Composites Based on Biomineralization of PEG-Based Hydrogel Scaffolds.
Kyung Ja Kim 1 2 , Chan Woo Kim 1 , Sang Cheon Lee 1 , Hyungsoo Choi 2 , Kyekyoon Kim 2
1 Nanomaterials Application Division, Korea Institute of Ceramic Engineering and Technology, Seoul Korea (the Republic of), 2 Department of Electrical & Computer Engineering, University of Illinois, Urbana-Champaign, Illinois, United States
Show AbstractA biomineralization process is a sophisticated, elegant process for formation of natural bones in vertebrates. To date, many approaches have been designed to induce nucleation and growth of crystalline carbonated apatites on polymer substrates. The natural bone is a composite of a collagen-based hydrogel and inorganic apatite crystals. Thus, the use of the hydrogels with biocompatibility and biodegradability as a 3-dimensional template is an ideal approach for developing artificial bonelike composites. In this study, we describe the new fabrication approach of artificial bonelike composites based on biomineralization of PEG-based hydrogel templates. To provide the apatite-nucleating function of phosphorylated proteins in the collagen-associated extracellular matrix (ECM), the phosphorylated anionic functionality was introduced in the PEG-based hydrogels during the crossliking polymerziation. We employed the urea-mediated solution precipitation technique for biomineralization of the hydrogel template. Thermally induced urea decomposition led to the gradual, homogeneous rise of the pH throughout the whole solution. SEM images confirmed that the hydrogels containing anionic ligands can template the nucleation and growth of calcium phosphate minerals. The morphology of minerals on hydrogel surfaces was the rosette structure, which was nucleated and grown outward in a perpendicular direction (c-axis) of hydrogel surfaces. The micro-level crystallites consisted of anisotropic nano-crystals of which size was around 40 nm, which is comparable to the size of mineral crystallites of natural bones. XRD experiments indicated that the calcium phosphate crystalline platelets were preferentially aligned along the crystallographic c-axis direction. Besides, the strong (210) peak exhibited the formation carbonated crystalline hydroxyapatite, which is the main structure of natural apatite minerals. The Ca/P molar ratio of the mineral in the natural bone is known to be 1.6. Interestingly, inductively coupled plasma mass spectroscopy (ICP-MS) analysis showed that the Ca/P molar ratio of apatites grown on PEG-based hydrogel templates was found to be 1.6±0.09. These results strongly support that the mineral formed on hydrogels has a similarity in crystalline structure and composition to biological apatites. Biomineralization of PEG-based hydrogels containing phosphate anionic groups could mimic the mineral formation on collagen in natural bones. The approach described in this work may serve as a useful guide to rationally designed bonelike materials.Acknowledgement. This research was supported by a grant (code #: 06K1501-01510) from ‘Center for Nanostructured Materials Technology’ under ‘21st Century Frontier R&D Programs’ of the Ministry of Science and Technology, Korea.
9:00 PM - S12.28
Nanoconfined Ionic Liquids : New Route For New Monolithic Electrolytes.
Jean Le Bideau 2 1 , Andre Vioux 1
2 , Institut des Matériaux de Nantes, Nantes France, 1 , Institut Charles Gerhardt, Montpellier France
Show Abstract9:00 PM - S12.29
Nanocomposite Films of Zinc Oxide with Polymers
Insun Park 1 , Xin-Ran Zhang 1 , Mustafa Demir 2 , G. Wegner 2 , Do Yeung Yoon 1
1 Chemistry, Seoul National University, Seoul Korea (the Republic of), 2 , Max-Planck-Institute for Polymer Research, Mainz Germany
Show AbstractNanocomposite films of zinc oxide (ZnO) with various polymers have been prepared. ZnO is a II-VI type of semiconductor with a wide band gap and is a UV-absorber. ZnO nanocomposite films were prepared with various polymers, including poly(methyl methacrylate) (PMMA), poly(4-vinyltriphenylamine) (PVTPA), and poly(3-hexylthiophene) (P3HT). PVTPA and P3HT are good hole transporting materials and have a bandgap which matches well with zinc oxide. The nanocomposite films of these compounds are of interest due to potential applications such as transparent flexible display substrates, UV protection materials, flame retardant materials, and especially hybrid photovoltaic devices. Moreover, the drawbacks of polymers such as high thermal expansion coefficient and high permeability of H2O and O2 can be reduced by adding inorganic materials. In this paper, the procedure of preparing ZnO and polymer nanocomposite films and their structure-property relationships will be presented.
9:00 PM - S12.3
Gold-Coated Magnetic Nanoparticles For EnhancingReusability of Hexa-Arginine Tagged Esterase
Jinyoung Jeong 1 2 , Tae Hwan Ha 1 , Bong Hyun Chung 1 2
1 Bionanotechnology Research Center, KRIBB, Daejeon Korea (the Republic of), 2 Nanobiotechnology, University of Science and technology, Daejeon Korea (the Republic of)
Show AbstractMagnetic nano-materials have been explored for practical uses in biomedical fields, such as a contrast enhancing agent for magnetic resonance imaging (MRI), separation methods for various biomolecules and targeted drug delivery systems followed by magnetic heating. [1,2] Among the manufactures of magnetic nanoparticles for providing biocompatibility and targeting, we investigated to form gold-coated magnetic nanoparticles (GMPs) as a carrier for the immobilization of hexa-arginine-tagged esterase (Arg6-esterase). The GMPs were prepared by an iterative reduction of gold ion in the presence of magnetic nanoparticle (Fe2O3) using hydroxylamine [3]. The synthesized GMPs with an average diameter of 70 nm were found to have typical superparamagnetic property by measuring the hysteresis loop using SQUID. The GMPs were further modified by 16-mercapto-hexadecanoic acid (MHA) to tether the positively charged Arg6-esterase via electrostatic attraction [4]. The enzyme immobilized on carboxylated GMPs exhibited sufficient enzymatic activity, which corresponded to 60 % of free enzyme by monitoring the dissociation of enzymatic substrate, p-nitrophenyl butylate (pNPB). Moreover, it was revealed that the remaining activity was retained even after seven repetitive uses by magnetic decantation. This manufacture of gold-coated magnetic nanoparticles is expected to useful for both separation and reuse of biomolecules as multifunctional materials. [1] M. Lewin, N. Carlesso, C.H. Tung, X.W. Tang, D. Cory, D.T. Scadden, R. Weissleder, Nat. Biotechnol. 18 (2000) 410.[2] A.K. Gupta, M. Gupta, Biomaterials 26 (2005) 3995.[3] J.L. Lyon, D.A. Fleming, M.B. Stone, P. Schiffer, M.E. Williams, Nano letters, 4 (2004) 719 [4] T.H. Ha, J.Y. Jeong, B.H. Chung, Chem. Comm., 31 (2005) 3959
9:00 PM - S12.32
Nanocomposite Hybrid Photopolymers for Stereolithography.
Eric Crawford 1 , Meisha Shofner 1
1 School of Polymer Textile & Fiber Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show Abstract In order to use current rapid prototyping technologies for rapidmanufacturing, improved materials and a full understanding of theirproperties are needed. In this research, inorganic-organic hybrid materialscomprised of surface modified silica nanoparticles and a photopolymer resinare processed using stereolithography and characterized to determine theirability to produce parts with improved properties as compared to the neatresin. It is anticipated that low filler loadings of well dispersednanoparticles will produce measurable changes due to their large surfacearea. Chemical functionalization of silica with surface grafted acrylic isused to improve the dispersion of silica nanoparticles in the photopolymermatrix due to the added hydrophobic nature of the organic group. Also, theunsaturated bond in the surface moiety can participate in the polymerizationof the acrylate group creating a covalent linkage between the nanoparticleand the polymer. Adequate dispersion in conjunction with covalent bondsbetween the particles and the polymer will modify the network structure ofthe matrix and produce improved properties. In the presented work, chemicalfunctionalization of the silica particles is achieved via condensationreaction with acryloyl chloride. The functionalized silica particles arecharacterized using thermogravimetric analysis and infrared spectroscopy toconfirm the presence of grafted groups and their relative weight percentage.The particles are incorporated into a photopolymer resin using solutionprocessing methods and processed into test specimens usingstereolithography. Neat resin samples are produced in a similar manner forcomparison. Dispersion is assessed in the hybrid samples using electronmicroscopy, and thermal analysis by differential scanning calorimetry andthermomechanical testing by dynamic mechanical analysis are used to evaluatechanges to the network structure resulting from the nanoparticles. Initialresults demonstrating the shelf life of the processed hybrid resins are alsopresented.
9:00 PM - S12.33
Influence of Polyborosiloxane on the Flame Retardancy of Polyethylene Terephthalete-Clay Nanocomposite
Prabir Patra 1 , Yue Huo 1
1 Materials and Textiles, UMass Dartmouth, North Dartmouth, Massachusetts, United States
Show AbstractA highly crosslinked polyborosiloxane (Pobosil), with narrow molecular weight distribution as evident from gel permeation chromatography (GPC), was synthesized as a flame retardant component for polyethylene terephthalate(PET)-clay compositions. In addition to its inherent flame retardancy, Pobosil has high thermal stability at the processing temperature (270-285 degree C) of PET and acts as a compatiblizer between PET and clay that are otherwise incompatible. During burning, the Pobosil-containing flame retardant PET forms a protective borosilicate intumescent char on the surface. Montmorillonite (MMT) clay, owing to its high aspect ratio and specific surface area, is coated with Pobosil to introduce synergism in flame retardation to the PET along with enhanced thermal and mechanical properties of PET film. As MMT clay is not compatible to PET, Pobosil is selected for coating the clay via solution intercalation. Cone calorimeter tests were performed to evaluate key fire properties of the PET/Pobosil/MMT nanocomposites. The peak heat release rate (PHRR) of PET containing 5 wt% Pobosil and 2.5 wt% MMT is reduced by 60% with similar reduction in mass loss rate (MLR) . In comparison to the control PET, PET/Pobosil5/MMT2.5 shows a dramatic decrease in the average smoke production rate by 78% and a decrease in average specific extinction area (SEA) by 52%. This indicates the prominent smoke suppression effect and overall flame retardancy of the borosilicate intumescent char during nanocomposite burning
9:00 PM - S12.34
Characterization of Polystyrene-based Hybrid Particles Containing Highly Dispersed Mg(OH)2 Powder Fabricated by Bulk and Suspension Polymerization Method.
Shuichi Kimura 1 2 , Takeo Hyodo 3 , Yasuhiro Shimizu 3 , Makoto Egashira 3
1 Graduate School of Science and Technology, Nagasaki University, Nagasaki Japan, 2 Advanced Material R&D Centeer, Yazaki Parts Co., Ltd., Susono, Shizuoka, Japan, 3 Faculty of Engineering, Nagasaki University, Nagasaki Japan
Show AbstractThe present paper reports preparation procedure and characterization of polystyrene (PS)-based flame retardant hybrid particles containing highly dispersed Mg(OH)2 powder. In preparing the hybrid particles, the surface of Mg(OH)2 powder was treated with methylhydrogen polysiloxane (MHS) and then was subjected to heat treatment at 423 K for 7.2 x 103 s. This MHS-treated Mg(OH)2 powder will be referred to as ST-3 powder. Hybrid particles were fabricated from the mixture of styrene monomer (St), maleic anhydride (5 parts per hundred parts of St) and ST-3 powder (0, 10, 30 or 50 parts per hundred parts of St) by a two-stage, which is bulk and subsequent suspension, free-radical polymerization method. The surface modification of Mg(OH)2 was done to enhance the affinity to PS matrix, and maleic anhydride was added to ensure the increase in the affinity. The resultant hybrid particles are expressed as PM, PMS-10, -30, -50, depending on the amount of ST-3 powder added, e.g., PM for no ST-3 powder, PMS-10 for 10 parts of ST-3 powder per hundred parts of St. The effect of the additive amount of ST-3 powder on the microstructure and mechanical properties of the hybrid particles has been investigated.All the hybrid particles fabricated showed spherical shape and their particle sizes were about 500 μm, irrespective of the different additive amounts of ST-3 powder. The content of ST-3 powder in each kind of hybrid particle was almost the same as that in the raw mixture, and no agglomeration of ST-3 powder was observed inside the hybrid particles. These results indicate that ST-3 powder could be kept tightly inside a droplet of St during the bulk polymerization, due to the enhanced affinity to St and a decrease in flexibility of ST-3 powder with increasing the viscosity of the PS matrix induced by a progress of polymerization.Compressive strength of PM hybrid particles was ca. 28.5 MPa, but the addition of ST-3 powder led to a decrease in compressive strength, i.e., 16.6, 15.5, and 18.6 MPa for PMS-10, -30 and -50, respectively. The decrease in compressive strength may arise from the increase in the frequency of crack generation due to the formation of the interface between PS matrix and ST-3 powder. However, the compressive strength remained almost unchanged irrespective of the increase in the ST-3 powder content, though the reason for such phenomenon is still unclear. This feature is very attractive as a flame retardant material, since we can expect the enhancement of flame retardancy without any degradation of mechanical properties, and therefore a wide variety of application fields of these hybrid particles.
9:00 PM - S12.38
Biomimetic Peptide Amphiphile Modified Nanofiber Mesh as Scaffold for Tissue Engineering.
Bindhu VasanthaKumari 1 , Asha Rani Nair 1 , Gina Chew 1 , Fathima Jahir Hussain 1 , Suresh Valiyaveettil 1
1 Chemistry, National University of Singapore, Singapore Singapore
Show Abstract9:00 PM - S12.39
Site-specific Assembly of Gold Nanoparticles on Single-walled Carbon Nanotubes.
Lifeng Dong 1 , Shifeng Hou 2 , Charles Hendrix 3 , Sunny Qiu 4
1 Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, Missouri, United States, 2 Department of Chemistry, Missouri State University, Springfield, Missouri, United States, 3 Department of Biology, Missouri State University, Springfield, Missouri, United States, 4 Greenwood Laboratory School, Missouri State University, Springfield, Missouri, United States
Show Abstract9:00 PM - S12.4
Preparation and Characterization of Polyurethane-Nanogold Hybrid Materials
Chao-Ching Chang 1 , Wei-Li Cheng 1 , Chih-Ming Chang 1
1 Chemical and Materials Engineering, Tamkang University, Tamsui, Taipei County Taiwan
Show AbstractPolyurethane hybrids containing gold nanoparticles (GNPs)were prepared and characterized in this study. MUD coated gold nanoparticles were synthesized by the chemical reduced method and used as the chain extender in the polyurethane structure. The prepared materials were characterized using various spectroscopic, microscopic, thermal, and mechanical analyses. The results showed the gold contain can be as high as 1.45 wt%, and GNPs can be dispersed uniformly without aggregation in the hybrid materials. The prepared polyurethane hybrids showed better thermal and mechanical properties than their relative polyurethanes with 1,4-BD as the chain extender. A significant increase in the tensile strength and elongation was demonstrated in the prepared polyurethane hybrids. The increase of crystallization of the soft-segment and the decrease of the hydrogen bond of the hard-segment in the polyurethane hybrids were also observed.
9:00 PM - S12.40
Organobentonite / Polypropylene Nanocomposite for Packaging Application
Yukhanthorn Varothai 1 , Atinuch Pandee 1 , Manit Nithitanakul 1 , Rathanawan Magaraphan 1 , Hathaikarn Manuspiya 1
1 Petroleum and Petrochemical, Chulalongkorn university, Bangkok Thailand
Show Abstract9:00 PM - S12.42
Size Tuning of CdS Quantum Dots with Polymeric Surfactant System in Aqueous Solutions.
Havva Yagci Acar 1 , Serdar Celebi 1 , Alphan Sennaroglu 2 , Koray Erdamar 2 , Nazli Serttunali 1
1 Chemistry, KOC UNIVERSITY, Istanbul Turkey, 2 Physics, KOC UNIVERSITY, ISTANBUL Turkey
Show AbstractQuantum confinement in nanosized semiconductors created new opportunities in areas such as optoelectronics, catalysis, lasers, fluorescent tagging and imaging. Among the various II-VI semiconductor materials, CdS nanoparticles are the most widely studied because of their tunable emission wavelengths in the visible range. In order to suspend CdS inorganic particles in an aqueous medium, various surfactants are studied by using long or short hydrocarbon chains. Coating materials which have mercapto (thiol) groups are very effective surfactants for stabilization of II-IV inorganic nanocrystals through surface bonding. Carboxylic acids can adsorb on particle surface to aid colloid formation as well. Our ongoing efforts are to understand the behavior of surfactant systems on the formation of the nanoparticles which are highly dependent on temperature changes and composition. In controlling particle size and properties considerable research has been devoted to the initial concentration, pH, length of the hydrocarbon chains and reaction time. However, much less attention has been paid to the temperature dependence. Therefore, a systematic study is constructed in order to explain the influence of surfactant composition and temperature on CdS nanocrystal formation and properties. We will discuss the preparation of Poly(acrylic acid) coated CdS quantum dots and the influence of the mentioned variables on the size and photoluminesence. Also, we will mention the first time preparation of CdS in binary surfactant mixture which provides an effective method for size tuning in aqueous solutions.
9:00 PM - S12.43
Fabrication of Mesoporous Hollow Spheres Embedded with Magnetic Nanoparticles
Ru Qiao 1 , Xiao Li Zhang 1 , Young Soo Kang 1
1 Chemistry, Pukyong National Univ., Pusan Korea (the Republic of)
Show Abstract9:00 PM - S12.44
Biomimetic Silica Formation Mediated by Poly(ethylene imine).
Pritesh Patel 1 , Jessica Eckart 2 , Maria Advincula 3 , A. Jon Goldberg 3 , Patrick Mather 1
1 Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, Ohio, United States, 2 Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, 3 Department of Oral Rehabilitation, Biomaterials and Skeletal Development, University of Connecticut Health Center, Farmington, Connecticut, United States
Show Abstract9:00 PM - S12.45
Identification of Gold-Nanoshell Binding Peptides using Phage Display
Sharon Jones 1 , Joshua DeWeese 2 , Emily Stucke 1 , Joseph Slocik 1 , Felicia Tam 3 , Naomi Halas 3 , Madhavi Kadakia 2 , Rajesh Naik 1
1 Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio, United States, 2 Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, United States, 3 Department of Electrical and Computer Engineering, Rice University, Houston, Texas, United States
Show AbstractGold nanoshells are composed of a dielectric silica core and surrounded by a thin gold metal and have unique and tunable optical properties. As a result, nanoshells represent an excellent platform for the potential creation of a sensor that uses peptides capable of detecting specific agents of interest. Examples include: the potential detection of viruses, small molecule targets, vapors, and explosive residue. By bringing the target species in close proximity with the localized surface plasmons of the nanoshells results in large signal enhancements. Towards this end, we have identified peptides that bind specifically to gold nanoshells using phage display. These nanoshell-binding peptide(s) will used in the design of specific ligands for binding to specific targets. We will present results on the identification of nanoshell-specific peptides and characterization of the peptide-nanoshell complexes.
9:00 PM - S12.46
Stamping Quantum Dot LEDs Using Inkjet Assisted Patterning Method
Jennifer Yu 1 , Jianglong Chen 1 , Hao Huang 2 , Moungi Bawendi 2 , Vladimir Bulovic 1
1 Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractColloidal quantum dots (QDs) with tunable emission wavelength, narrow emission band and efficient luminescence have been incorporated into OLEDs and used as lumophores in the QD-LED structure. In the past, the favored method of QD deposition has included a spin-coating process: either spin-coat QD/organic solution to phase segregate QDs from the organic layer or spin-coat QD solution onto a flat or relief stamp to transfer QDs to an organic layer. Both techniques do not utilize most of the QD material during the spin-coating process.Here we propose an alternative method that can directly pattern the QD layers onto a transfer stamp by inkjet printing QD solution. This technique not only allows patterning of the QD material but also maximizes QD material usage. In contrast to the low material usage efficiency in the spin-coating process, inkjet printing of QDs can utilize almost 100% of the QD solution, making it possible to drastically improve material usage in fabrication of QD-LEDs and other optoelectronic devices that utilize QD thin films.With a thermal inkjet printer, we have successfully patterned QDs of various emission wavelengths onto a stamp with a feature size of 50um, and transferred printed QDs patterns into organic layers to fabricate QD-LEDs. Interaction between the QD solution and the stamp surface plays an important role in the formation of the inkjet printed QD patterns. We will discuss how the stamp surface chemistry and the ink properties affect the QD pattern morphology.
9:00 PM - S12.48
Polyacrylate Ionomer-templated Magnetic Nanocomposites.
Alia Weaver 1 , Joseph Silverman 1 , Lourdes Salamanca-Riba 1 , Mohamad Al-Sheikhly 1
1 Materials Science & Engineering, University of Maryland, College Park, Maryland, United States
Show AbstractCurrently there is a significant amount of research interest in magnetic nanoparticle-organic polymer hybrid materials in many technological applications, including magnetic data storage, medical diagnostic imaging, and drug delivery. Most of the challenges to the development of these materials concern prevention of the agglomeration of nano-sized particles. One of the most popular approaches for the stabilization of these nanoparticles involves their formation within a polymer matrix that is composed of two immiscible components (amphiphilic) in which the hydrophilic and hydrophobic portions segregate into well-defined regions. This process may generate distinct regions of hydrophilic nature into which an inorganic component may be incorporated.In order to achieve our ultimate objective (nanocomposite), we synthesized 2-ethylhexyl acrylate/acrylic acid (EHA/AA) copolymers using ionizing radiation and then incorporated a metal salt. We developed the following 3-step method: (i) EHA/AA copolymer synthesis, (ii) EHA/AA/Fe3+ ionomer synthesis, (iii) EHA/AA/iron oxide nanocomposite synthesis. The synthesis of the copolymer was performed using cobalt-60 gamma irradiation and electron beam irradiation. The structure and composition of this copolymer has been studied by NMR as a function of dose, dose rate, and concentration of acrylic acid. Incorporation of the inorganic component of the material was achieved through contact of the copolymer with a metal salt (FeCl3) solution, and was characterized by FTIR and XPS. An ionomer was then produced through ion exchange between the hydroxyl protons of the acrylic acid groups and the metal cation of the salt, which was identified by the emergence of a carboxylate salt peak at 1612 cm-1 of the FTIR spectra. Efforts to determine the optimal irradiation conditions for the product properties are currently under investigation. This work was supported by the DOE/Industry Matching Grants Program under contract number DEFG0702ID14356.
9:00 PM - S12.5
Characterisation of Poly(ethyl methacrylate)/Silica Nanocomposites
Kalliopi Vartzeli-Nikaki 1 , Anna Spanoudaki 1 , Apostolos Kyritsis 1 , Manuel Monleon Pradas 2 , Polycarpos Pissis 1
1 Department of Physics, National Technical University of Athens, Athens Greece, 2 Center for Biomaterials, Polytechnic University of Valencia, Valencia Spain
Show AbstractPoly(ethyl methacrylate) (PEMA) prepared with the sol-gel method and nanocomposites containing porous silica (SiO2) inclusions at concentrations 0.5, 1, 3 and 5% were investigated regarding their structural and dynamical properties. The nanoparticles were prepared in a separate process and added to the monomer solution prior to the in situ polymerization. The characteristic dimensions of the nanoparticles was 12-17 nm. The main aim of this work was to study the influence of the presence of the nanoinclusions on the dynamic properties of the PEMA matrix.The techniques employed for the structural characterisation were density measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The properties of the matrix were studied using a number of techniques probing different manifestations of the polymer chain dynamics. These included differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), water sorption and diffusion monitoring, thermally stimulated depolarisation currents (TSDC) and mainly dielectric relaxation spectroscopy (DRS) in broad temperature and frequency range.
9:00 PM - S12.50
Biomimetic Synthesis of Organic-Inorganic Composites Mimicking the Nanostructured Architecture of Bone
SangSoo Jee 1 , Laurie Gower 1
1 Materials Science & Engineering, University of Florida, Gainesville, Florida, United States
Show AbstractBiologically formed hard tissues, often referred to as biominerals, are hierarchical composite structures formed of mineral and organic matrix. A classic example is the nanostructured architecture of bone, which consists of aligned platelets of hydroxyapatite nanocrystals embedded within the gaps and grooves of self-assembled collagen fibrils. The organic matrix of biominerals, being composed of proteins and/or polysaccharides, often consists of an insoluble phase (such as collagen in bone, or chitin in mollusk shells), as well small quantities of water soluble acidic (i.e., polyanionic) proteins. The acidic macromolecules associated with biominerals have long been thought to regulate the formation of the biomineral crystals, as well as influence the final properties of the bioceramic composite if they become occluded within the mineral phase. Our in vitro studies have led us to propose that these acidic proteins may serve as process-directing agents, in which we have shown that mimetic polypeptides (e.g. polyaspartate) can induce liquid-liquid phase separation in the crystallizing medium, which transforms the conventional solution crystallization process into an amorphous precursor process. Using this polymer-induced liquid-precursor (PILP) process, our laboratory has been able to duplicate many features found in biominerals, both for the calcium carbonate biominerals of invertebrates and the calcium phosphate biominerals of vertebrates. In the latter case, we have been able to duplicate the nanostructure of bone by stimulating intrafibrillar mineralization of collagen. We propose that the fluidic mineral precursor is drawn into the collagen fibrils by capillary action, which upon solidification, leads to an interpenetrating composite structure. Etching studies using SEM, along with darkfield and brightfield TEM and SAED analysis, demonstrate that [001] oriented crystals of hydroxyapatite are aligned and embedded within the collagen fibrils. This in vitro model system provides a new perspective on the potential role of the proteins involved in bone formation, and demonstrates a novel method for forming interpenetrating organic-inorganic composites.
9:00 PM - S12.51
Like-charge Interactions in Membrane-derivatized Colloidal Monolayers.
Esther Winter 2 , Nathan Clack 3 , Jay Groves 1
2 Chemical Engineering, University of California, Berkeley, California, United States, 3 Biophysics Graduate Group, University of California, Berkeley, California, United States, 1 Chemistry, University of California, Berkeley, California, United States
Show Abstract9:00 PM - S12.52
Templated Self-assembly of Quantum Dots from Aqueous Solution using Protein Scaffolds.
Amy Blum 1 , Carissa Soto 1 , Charmaine Wilson 3 , Jessica Whitley 3 , Kim Sapsford 2 , Anju Chatterji 4 , John Johnson 4
1 Code 6930, Naval Research Lab, Washington, District of Columbia, United States, 3 , Geo-Centers, Inc., Newton, Massachusetts, United States, 2 , George Mason University, Manassas, Virginia, United States, 4 Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, United States
Show Abstract9:00 PM - S12.53
Highly Dense Dispersion of TiO2 Nanoparticles into Polymer Materials by the Combination of Mechanical Treatment and Multiple Surface Modifications.
Murino Kobayakawa 1 , Motoyuki Iijima 1 , Mayumi Tsukada 1 , Hidehiro Kamiya 1
1 Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
Show Abstract9:00 PM - S12.54
Templated Functional Biomaterials for Nanoelectronics and Nanosystems
Cengiz Ozkan 1
1 Mechanical Engineering, University of California at Riverside, Riverside, California, United States
Show Abstract9:00 PM - S12.55
Hybrid Nanocomposites Based on Metal Oxides and Polysiloxanes with Controlled Morphology.
Guido Kickelbick 1 , Sorin Ivanovici 1
1 Institute of Materials Chemistry, Vienna University of Technology, Vienna Austria
Show Abstract9:00 PM - S12.57
Selective Growth of Organic 1D-structures on Au Nanoparticles Arrays
Esther Barrena 1 2 , Beri Mbenkum 1 3 , Xue Na Zhang 1 , Marion Kelsch 1 , Joachim Spatz 1 3 , Helmut Dosch 1 2
1 , Max-Planck-Institut fuer Metallforschung, Stuttgart Germany, 2 Institut für Theoretische und Angewandte Physik, Universität Stuttgart, Stuttgart Germany, 3 , Heidelberg University , Heidelberg Germany
Show AbstractAlthough organic semiconductors based on small aromatic molecules have been successfully implemented in electronic devices (such as OFETs or OLEDs), very few studies have addressed the fabrication of 1-D organic structures. Thus, controlled growth of low-dimensional organic architectures remains an experimental challenge.Here we show that the growth of organic 1-D nanostructures can be directed by templates of gold nanoparticles [1]. The growth occurs via vapour-phase transport, whereby the gold nanoparticles act as nucleation sites for the molecules and promote their anisotropic growth. This is demonstrated for F16CuPc, one of the few oligomers which exhibits air-stable electron transport. The F16CuPc 1-D nanostructures are crystalline and adopt a diameter of 15-30 nm independently of the nanoparticle size. This approach enables a technologically simple and inexpensive fabrication of very uniform organic 1-D structures (aspect ratio of ~30) with precise control of their location and packing density. The extension of this strategy to other organic molecules is discussed.[1] B.N. Benkum, E. Barrena, X. Zhang, M. Kelsch, H. Dosch, Nano Letters (in print, November 2006)
9:00 PM - S12.58
Tunable Electronic Interfaces between Bulk Inorganic Semiconductors and Organic-Crosslinked Inorganic Nanoparticle Films
Shannon Boettcher 1 , Nina Lock 3 , Mark Lonergan 2 , Galen Stucky 1
1 Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California, United States, 3 Department of Chemistry, University of Aarhus, Aarhus Denmark, 2 Department of Chemistry, University of Oregon, Eugene, Oregon, United States
Show AbstractSolution-synthesized ligand-stabilized inorganic nanoparticles (NPs) are of interest for electronic, electro-optic, and photovoltaic applications because they have tunable properties based on size, shape and composition and can also be easily processed into thin-films from solution using inexpensive, low-temperature techniques. Such thin films are typically composed of close-packed arrays of inorganic nanoparticles separated by stabilizing organic ligands. Although there has been extensive research to uncover the electronic properties of NPs, both at the ensemble and single particle level, there has been little work describing electronic properties of interfaces between NPs and other materials. We describe the fabrication, characterization, and electrochemical tuning of Schottky diodes fabricated from cross-linked, ligand-stabilized gold nanoparticles (AuNPs, d ~ 2 nm) and the inorganic semiconductor Indium Phosphide. The work function of the AuNP film is controlled in a non-aqueous electrolyte by the quantized electrochemical charging (QEC) of the AuNP cores. Charged ions, or dopants, permeate the organic phase of the film to compensate the injected charge. As deduced from current-voltage and impedance analyses, QEC allows for the continuous and reversible tuning of the AuNP|InP Schottky barrier height by more than 0.5 eV. A single AuNP|InP interface allows for a wider degree of barrier height control than a series of conventional metal|InP interfaces. This work highlights a distinguishing feature of ligand-stabilized nanoparticle assemblies relative to traditional (bulk) electronic materials—dopants can permeate the hybrid NP assembly, thereby enabling electrochemical manipulation. Such methods to control charge transfer processes at interfaces between bulk semiconductors and nanoparticle assemblies may be important for the rational design of hybrid microelectronic devices, sensors, and photovoltaics.
9:00 PM - S12.59
Ideal Schottky Junctions Using Methyl Terminated Si(111) Interfaces
Stephen Maldonado 1 , Nathan Lewis 1
1 , California Institute of Technology, Pasadena, California, United States
Show Abstract9:00 PM - S12.6
Quantum Dot/Polymer Films for Optoelectronic Applications - Characterization of Quantum Dot Spatial Distribution
Anita Ghia 1 , Jacek Jasinski 1 , Michael Dunlap 1 , Valerie Leppert 1 , Xia Sheng 2 , Si-Ty Lam 2 , Gary Gibson 2 , Krzysztof Nauka 2 , C. Yang 2
1 School of Engineering, University of Califronia, Merced, Merced, California, United States, 2 , Hewlett-Packard Laboratories, Palo Alto, California, United States
Show AbstractIn recent years, there has been considerable effort to fabricate inorganic/organic hybrid materials utilizing quantum-dot (QD)/polymer thin films. The main driving force is to combine high-performance optical and electronic properties of inorganic QDs with the flexibility and ease of processing of polymers. QD/polymer-based optoelectronic devices, such as solar cells or light emitting diodes have already been reported and more technological advances in this area should result in further reduction in processing costs, improved scalability, and opportunity for lightweight, flexible devices. Recently, we have initiated research into methods of producing thin QD/polymer films for high-performance, easily-fabricated optoelectronic devices. Due to the complexity of such inorganic/organic nanocomposites, many parameters affect their performance in the actual device structure, including polymer and QD type or layer thickness. A key issue is also the QD distribution, characterized by such parameters as uniformity or the QD-QD distance. Due to the small size of QDs, there are few techniques capable of monitoring their distribution within the polymer film. In this study, we use transmission electron microscopy (TEM), in both plane-view and cross-section sample configurations, to explore the quantum dot distribution in a series of thin polymer films.QD/polymer thin films of a thickness in the range of 50-100 nm are fabricated by spin-casting of the QD/polymer solution mixture onto substrates. For plan-view study, rock salt crystals are used as substrates and TEM specimens are obtained by dissolving the substrate in water and recovering the film onto a supporting copper grid. While this is an easy and quick method, it also has its down-sides since it provides limited information: (1) plane-view TEM images only give insight at the projected, in-plane, QD distribution, whereas the normal component remains unknown, and (2) there is a question as to whether the QD distribution of the film spin-cast on rock salt crystal represents the actual device structure, where a plastic or glass substrate is typically used. Both problems can be addressed by the cross-section approach. In this case, we prepare samples similar to the ones used in real devices: an Al/PEDOT layer structure is deposited on polycarbone substrate, and the QD/polymer film is spin-cast on the top. Two such samples are bonded together using epoxy and an ultramicrotome is used to obtain electron transparent sections. Due to a number of characteristics of the samples, such as the hardness mismatch, poor adhesion and thin layer thickness, several challenges are encountered during ultramicrotomy. We will discuss these problems and methods of dealing with them. We will also present TEM data from a series of QD/polymer films fabricated for various technological parameters and illustrate that the ultramicrotomy-based technique can be routinely used for cross-section study of such films.
9:00 PM - S12.8
Versatile Hybrid Polymers as Matrices for Nanoparticle Preparation.
Claudia Feldgitscher 1 , Guido Kickelbick 1
1 Institute of Materials Chemistry, Technical University of Vienna, Vienna Austria
Show Abstract9:00 PM - S12.9
Synthesis and Characterization of High Dispersive Silica-coated Magnetic Nanoparticles
Jeong Ho Chang 1 , Joong Hee Nam 1 , Kyung Ja Kim 1
1 , Korea Institute of Ceramic Engineering & Technology, Seoul Korea (the Republic of)
Show AbstractThis work presented the manipulation of sol-gel coating process on the preparation of the silica coated magnetic nanoparticles. The magnetic nanoparticles were synthesized with average particle size of 9 nm and silica-coated magnetic nanoparticles were obtained by controlling the coating thicknesses on magnetic nanoparticles. The silica coating thickness could be uniform-sized in the diameter of 10-40 nm by a sol-gel approach. The thickness of the silica layer could be controlled by TEOS amount. The ratio between the concentration of magnetic nanoparticles and TEOS had been optimized to avoid the homogeneous nucleation of silica and thus the formation of core-free silica spheres. The silica layer served as a biocompatible and versatile group for further molecular functionalization. The spectroscopic measurements such as a FT-IR(ATR-method) and Vibrational Sample Magnetometer(VSM) were used to characterize the chemical structures and magnetic strengths. To elucidate the relationship among the surface area, pore size distribution and reactivity of the materials, XRD, TEM, BET and Zeta potential were used.
Symposium Organizers
Richard M. Laine University of Michigan
Clement Sanchez Universite Pierre et Marie Curie
Christophe Barbe Ceramisphere, ANSTO
Ulrich Schubert Vienna University of Technology
S13: Nanoparticle Synthesis and Assembly II
Session Chairs
Friday AM, April 13, 2007
Room 2004 (Moscone West)
9:15 AM - **S13.1
Chemically Designed Nanoparticles and Nanowires: Controlled Growth, Applications and Devices
Sanjay Mathur 1 2
1 Division of Nanocrystalline Materials and Thin Film Systems, Leibniz-Institute of New Materials, Saarbruecken Germany, 2 Institute of Inorganic Chemistry, University of Wuerzburg, Wuerzburg Germany
Show Abstract9:45 AM - **S13.2
Metal Oxide Nanocrystals: Building Blocks for Mesostructures and Precursors for Metal Nitrides
Markus Niederberger 1 2 , Markus Antonietti 1 , Jelena Buha 1 , Igor Djerdj 1 2
1 Colloid Chemistry, Max Planck Institute of Colloids and Interfaces, Potsdam Germany, 2 Department of Materials, ETH Zürich, Zürich Switzerland
Show AbstractSol-gel routes to metal oxide nanoparticles in organic solvents under exclusion of water have become a versatile alternative to aqueous methods. In comparison to the complex aqueous chemistry, nonaqueous processes offer the possibility to better understand and to control the reaction pathways on a molecular level, enabling the synthesis of nanomaterials with high crystallinity and well-defined and uniform particle morphologies. The manifold role of the organic species in providing the oxygen for the oxide formation and in controlling the crystal growth and the assembly properties makes it possible to tailor the morphological and also the compositional characteristics of the final inorganic products to a striking extent [1].The nanocrystalline metal oxides, generally in the size range of 1-10 nm, can be used as building blocks for the preparation of various nano- and mesostructures such as mesoporous materials [2], nanowire bundles [3], lamellar organic-inorganic nanohybrids [4], or anisotropically arranged columns of nanoplatelets [5].In this presentation, an overview of the various nonaqueous, surfactant-free reaction routes to metal oxide nanoparticles will be given, together with some selected reaction and crystallization mechanisms. Furthermore, the use of metal oxide nanoparticles as nanobuilding blocks for the preparation of nano- and mesostructures as well as first results regarding their transformation into metal nitride nanocrystals will be discussed.[1] M. Niederberger, G. Garnweitner, Chem. Eur. J. 2006, 12, 7282[2] J. Ba, J. Polleux, M. Antonietti, M. Niederberger, Adv. Mater. 2005, 17, 2509[3] J. Polleux, A. Gurlo, N. Barzan, U. Weimar, M. Antonietti, M. Niederberger, Angew. Chem. Int. Ed. 2006, 45, 261[4] N. Pinna, G. Garnweitner, P. Beato, M. Niederberger, M. Antonietti, Small 2005, 1, 112[5] J. Polleux, M. Antonietti, M. Niederberger, J. Mater. Chem. 2006, 16, 3969
10:15 AM - S13.3
Virus-Based Nanowires and Nanocrystals for Electrochromic Displays
Dong Soo Yun 1 , Angela Belcher 1 2
1 Materials Science, MIT, Cambridge, Massachusetts, United States, 2 Biological Engineering Division, MIT, Cambridge, Massachusetts, United States
Show AbstractNew synthesis routes using nanocrystals and nanowires formed through solution-based, room temperature processes offer potential advantages in electrochromic displays. These improvements include better contrast ratio, longer term cyclic stability, better coloration efficiency, better switching speed, substantial cost reductions, lower power consumption, and process simplicity. However, current nanomaterial synthetic routes have not yet enabled electrochromic devices with performance characteristics comparable to that of conventional processing routes. Here, we use biological mechanisms to synthesize and assemble nanocrystalline iridium oxide nanoparticles and nanowires as the basis for our electrochromic device anode. These materials were grown using molecular recognition and assembled at room temperature. The structural and electrochromic properties of biotemplated iridium oxide nanowires will be discussed.
10:30 AM - S13.4
Hybrid Virus-Nanoparticles Memory Device.
Ricky Tseng 1 , Chunglin Tsai 2 , Cengiz Ozkan 3 , Yang Yang 1
1 Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California, United States, 2 Electrical Engineering, University of California, Riverside, Riverside, California, United States, 3 Mechanical Engineering, University of California, Riverside, Riverside, California, United States
Show AbstractBiomolecules are ideal templates to organize nanocrystals for building blocks toward next generation information processing system.(1) Most of the applications of these hybrid systems have been focused on biosensing; on the other hand, there are few examples of electronic devices due to the lack of charge transport through the biomolecular junctions. By incorporating platinum nanoparticles on tobacco mosaic virus (TMV), a unique function of memory effect is developed in this conjugate system.(2) The device consisting of virus-nanoparticle nanowires in a polymer matrix is sandwiched between two electrodes. Such system shows electrical bistability depending on the voltage-controlled conductance states. The operation of the virus memory is done by applying electrical potential between two electrodes, a sudden current increase to the high conductance state is observed after the voltage is larger than 3 volts, and later the state can return to low conductance state after the application of a negative voltage such as -2.4 volts. This process is repeatable and the high conductivity can remain in a prolonged period of time. Additionally the data access time of this device is in microsecond regime, which has advantages over other nonvolatile memories. Therefore, an electrically bistable bio-inorganic system can thus be a digital memory chip towards applications in future nanoelectronics. On the basis of this research and from future experiments, we might finally make commercial electronic devices with biological components.Reference1.Mao, C.; Solis, D. J.; Reiss, B. D.; Kottmann, S. T.; Sweeney, R. Y.; Hayhurst, A.; Georgiou, G.; Iverson, B.; Belcher, A. M. Science, 2004, 303, 214-217.2. Tseng, R. J.; Tsai, C.; Ma, L. P.; Ouyang, J.; Ozkan, C. S.; Yang, Y. Nature Nanotechnology 2006, 1, 72-77.
10:45 AM - S13.5
Co-assembly of Genetically-modified Viruses and Metal Nanoparticles into 3D Arrays via a Novel Deposition Technique.
Carlee Ashley 1 , Eric Carnes 1 , Zhen Yuan 1 , Ying Bing Jiang 3 , Darren Dunphy 3 , Jerri Calderia 2 , Dimiter Petsev 1 , Plamen Atanassov 1 , David Peabody 2 , C. Brinker 1 2 4
1 Chemical and Nuclear Engineering , University of New Mexico, Albuquerque, New Mexico, United States, 3 Ceramic Processing and Inorganic Materials , Sandia National Laboratories, Albuquerque, New Mexico, United States, 2 Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico, United States, 4 Self-Assembled Materials , Sandia National Laboratories, Albuquerque, New Mexico, United States
Show AbstractViral particles possess several characteristics that make them ideally suited for use as templates in the facile assembly of spatially-defined arrays of metal nanoparticles. Viruses have highly regular, symmetrical geometries and surface properties and have dimensions from tens to hundreds of nanometers, enabling their self-assembly into ordered arrays via evaporation-driven processes. Additionally, viruses possess relatively simple genomes, and their protein capsids can be easily engineered to express non-native functional groups or ligands at specific surface locations that react with various metal nanoparticles. Co-assembly of genetically-modified viruses and metal nanoparticles can, therefore, be used to produce highly ordered 3D devices in which the geometry, size, and reactivity of the viral template can be controlled to create new nanoparticles architectures with unique properties. We have engineered a virus-like particle (VLP) with identical surface characteristics to the 25-nm, icosahedral male-specific 2 (MS2) bacteriophage, but with cysteine residues at 180 evenly-spaced locations on its surface. We have used a novel deposition technique, convective assembly, to assemble these VLPs on assorted substrates and have reacted the VLPs with gold nanoparticles both before and after the assembly process. Convective assembly enables rapid deposition of colloidal particles without employing non-biocompatible solvents by trapping microliter-sized droplets between two fixed-angle plates and dragging the ensuing meniscus with constant velocity. Deposition speed, relative humidity, and particle volume fraction can be varied to control film structure and thickness. We assessed the influence of substrate surface chemistry on long-range order by measuring the affinity of VLPs assembled on anionic, cationic, and non-ionic, polar surfaces. We determined the degree to which viral particles deform or denature during the assembly process using un-modified MS2 phage and Pseudomonas phage 7 (PP7), which is similar in size and geometry to MS2 phage but offers increased structural stability due to extensive disulfide cross-linking in its capsid. We also used sol-gel processing techniques to create superhydrophobic surfaces that can be patterned by UV-ozone exposure to generate alternating hydrophobic and hydrophilic regions; viruses have a net negative charge at biologically-relevant pH values and, therefore, selectively wet hydrophilic regions, enabling us to construct patternable nanoparticle-based devices.
11:00 AM - S13:Nanosynthe 2
BREAK
S14: Nanoparticle Composites I
Session Chairs
Friday PM, April 13, 2007
Room 2004 (Moscone West)
11:30 AM - S14.1
Surface Modification of Flame-made, Radiopaque Ta2O5-containing SiO2 Nanocomposites.
Heiko Schulz 1 , Sotiris Pratsinis 1 , Heinz Ruegger 2 , Joerg Zimmermann 3 , Simone Klapdohr 3 , Ulrich Salz 3
1 Department for Mechanical and Process Engineering, ETH Zurich, Zurich Switzerland, 2 Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich Switzerland, 3 , Ivoclar Vivadent AG, Schaan Liechtenstein
Show Abstract11:45 AM - S14.2
Metal and Metal Oxide Nanoparticles in a Sol-gel Matrix.
Miroslava Malenovska 1 , Marie-Alexandra Neouze 1 , Ulrich Schubert 1
1 Institut for Material Chemistry, University of Technology of Vienna, Vienna Austria
Show Abstract12:00 PM - S14.3
Photocatalytic Synthesis of Uniform Silica-Porphyrin-Platinum Composite Coreshell Structure and Its Application in Photocatalytic Hydrogen Generation
Haorong Wang 2 1 , Yujiang Song 1 , Craig Medforth 1 , John Shelnutt 1
2 Center for Micro-Engineered Materials, University of New Mexico, Albuquerque, New Mexico, United States, 1 Advanced Material Labs, Sandia National Labs, Albuquerque, New Mexico, United States
Show AbstractNanoscale metal coreshells have many potential uses and in some applications offer significant advantages over nanoparticles. Platinum nanostructures have been well known for various catalytic applications. In our synthesis, we firstly assembled porphyrin on the surface of uniform silica spheres through electrostatic interactions. Platinum(II) complex was added and reduced at the silica surface through porphyrin assisted photocatalytic-autocatalytic reduction under light illumination forming a silica-porphyrin-platinum coreshell composite. The porphyrin acts both as photocatalyst and anchoring reagent during the synthesis, which are equally important in making a uniform platinum shell. Hollow platinum shells were formed after silica cores were removed. The platinum-porphyrin-silica composite is capable of reducing water to hydrogen at ambient temperature with the helps of sacrificial electron donors and photons. The research is supported by Sandia National Labs. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DEAC04-94AL85000.
12:15 PM - **S14.4
Multifunctional Hybrid Materials: from Hybrid Solar Cells to Hybrid Solar Sensors
Monica Lira-Cantu 1 , Frederik Krebs 2
1 , Institut de Ciencia de Materials de Barcelona, Barcelona Spain, 2 , RISO National Laboratory, Roskilde Denmark
Show AbstractThe multifunctionality of hybrid organic-inorganic materials has been clearly demonstrated in recent years. Nevertheless, their application in solar-related devices is a relative new research area and our interest is focused on the interplay between the light-harvesting properties of conjugated polymers and the wide band gap values observed from different inorganic semiconductor oxides. The materials applied in this work are semiconductor oxides like TiO2, ZnO, Nb2O5, CeO2 and TiO2-CeO2, and the light-harvesting polymer MEH-PPV. We will show the possibility to fabricate a single hybrid organic-inorganic device suitable to work in two different applications: hybrid solar cells and hybrid solar sensors. We characterized our devices in terms of Voc, Jsc, IV-curves, effect of different atmospheres and device lifetime under simulated sunlight irradiation. We will demonstrate that the delicate interplay between oxygen from the atmosphere and the constituents of the device define final device characteristics, device performance and lifetime. Tuning the different device parameters such as type of oxide applied, active layer thickness, starting materials concentration, effect of different atmospheres, effect of UV irradiation, etc., permit the fabrication of devices with well-defined properties.1. M. Lira-Cantu and F. C. Krebs. Sol. En. Mater. Sol. Cells. 2006, 90, 2076-20862. M. Lira-Cantu, F. C. Krebs. UK Patent Application GB0509767.0. May 15, 2005 and UK Patent Application GB0607669.9 April 21, 2006.3. M. Lira-Cantu, K. Norrman, J.W. Andreasen, F. C. Krebs. Chem. Mater. Web Release Date: 25-Oct-2006; (Article) DOI: 10.1021/cm061429d4. M. Lira-Cantu, P. Gomez-Romero. In “Hybrid Nanocomposites for Nanotechnology: Electronic, Optical, Magnetic and Bio/Medical Applications” Springer Verlag (L. Merhari Ed). In Press.
S15: Nanoparticle Composites II
Session Chairs
Yoshiki Chujo
Monica Lira-Cantu
Friday PM, April 13, 2007
Room 2004 (Moscone West)
2:30 PM - **S15.1
Organic-Inorganic Polymer Nano-Hybrids Based on Sol-Gel Reaction.
Yoshiki Chujo 1
1 Polymer Chemistry, Kyoto University, Kyoto Japan
Show AbstractNano-ordered composite materials consisting of organic polymers and inorganic materials have been attracting attention for the purpose of the creation of high-performance or high-functional polymeric materials. Especially, the word of "polymer hybrid" claims the blends of organic and inorganic components at nano-level dispersion. By using this idea, an enhancement of mechanical strength of organic polymers with silica particles is possible. High transparency of this material is another important property and indispensable for development of optical waveguides, optical biosensors, non-linear optical materials, and contact lenses. Hybrid materials are also potential candidates for catalysts and gas separation membranes. The sol-gel reaction makes possible to incorporate the organic polymer segments in the network matrix of inorganic materials. The high homogeneity of the hybrid strongly suggests that the organic polymer segments and inorganic one are blended at the nano-meter level. The organic polymer nano-hybrids can be considered not only as the combination of organic polymer and inorganic materials, but as quite new materials.Recently, we have explored new methods for the preparation of organic-inorganic polymer hybrids [1][2][3]. (1) In-situ polymerization method: The radical polymerization of N,N-dimethylacrylamide or styrene was carried out simultaneously together with the sol-gel reaction (hydrolysis and condensation of alkoxysilanes) to produce homogeneous and transparent polymer hybrids. IPN (interpenetrating polymer network) hybrids were prepared by this method using bifunctional vinyl monomers (methylenebisacrylamide or divinylbenzene). The IPN polymer hybrids obtained showed excellent solvent-resistant properties. (2) In-situ hydrolysis method: The sol-gel reaction of tetraethoxysilane in the presence of poly(vinyl alcohol) produced only phase-separated materials due to the aggregation of alcohol groups within organic polymer segments. Thus, the acid-catalyzed sol-gel reaction of tetraethoxysilane was carried out in the presence of poly(vinyl acetate). During the formation of silica matrix, the acid-catalyzed hydrolysis of poly(vinyl acetate) took place. As a result, the homogeneous polymer hybrids consisting of silica gel and poly(vinyl alcohol) were successfully obtained. (3) π−π interaction between organic and inorganic matrix: The combination of polystyrene and tetramethoxysilane produced only turbid materials. On the other hand, in the presence of polystyrene, the sol-gel reaction of phenyltrimethoxysilane gave homogeneous polymer hybrids. In this reaction, the interaction of phenyl groups of polystyrene and phenyl groups of silica gel matrix was found to play an important role for the preparation of homogeneous polymer hybrids.
3:00 PM - **S15.2
Design of Nanohybrids From Well Defined Nanobuiding Blocks.
Laurence Rozes 1 , Giulia Fornasieri 2 , Theo Frot 1 , Capucine Sassoye 1 , Clement Sanchez 1
1 Chimie de la Matière Condensée de Paris, Université Pierre et marie Curie , Paris France, 2 Laboratoire de chimie inorganique, Université Paris 11, Orsay France
Show Abstract3:30 PM - S15.3
Nano-Ordered Ceramics Via Self-assembly of a Novel Hybrid Organic-Inorganic Block Copolymer
Patrick Malenfant 1 , Julin Wan 2 , Seth Taylor 3
1 Polymer & Chemical Technologies, GE Global Research, Niskayuna, New York, United States, 2 Ceramic and Metallurgy Technologies, GE Global Research, Niskayuna, New York, United States, 3 Material Analysis and Chemical Sciences, GE Global Research, Niskayuna, New York, United States
Show AbstractSelf-assembly is a promising method to achieve controlled nanoscale architectures in hybrid materials and ceramics. To date, surfactants and block copolymers have been used as templates to synthesize nanoporous oxides and nanostructured non-oxide ceramics via the controlled addition of ceramic precursors. The manufacture of ordered nanostructured ceramics, whereby the block copolymer intrinsically serves as both template and ceramic precursor, is rare and highly desired. Here we report the facile synthesis and processing of a new class of block copolymers based on polynorbornene-decaborane that form ordered organic/inorganic hybrid materials with controlled morphologies via self-assembly. An interesting solvent dependence on morphology is observed, in which Poly[(norbornene)0.7-b-(norbornenedecaborane)0.3] cast from chloroform solutions led to a lamellar morphology where as polymer cast from tetrahydrofuran provided a cylindrical morphology (polynorbornene-decaborane matrix; polynorbornene cylinders). Moreover, these hybrid materials enable the formation of ordered nanostructured non-oxide ceramics; e.g. pyrolysis of lamellar ordered hybrid block copolymer in nitrogen leads to a layered ceramic nanocomposite of boron carbonitride and carbon. Pyrolysis of ordered hybrid block copolymer with a cylindrical morphology in ammonia yields highly ordered, mesoporous boron nitride having 20 nm diameter pores and surface areas ranging from 700-950 m2/g. These mesoporous ceramics show great promise for a new class of catalyst support materials.
4:00 PM - S15:Composite 2
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4:30 PM - S15.5
In Vitro Osteogenic Gene Expression on Hydroxyapatite/Collagen Self-Organized Nanocomposite Membrane.
Masanori Kikuchi 1
1 Biomaterials Center, National Institute for Materials Science, Tsukuba, Ibaraki Japan
Show AbstractPhysical and biological properties of the novel hydroxyapatite/collagen (HAp/Col) self-organized nanocomposite with bone-like chemical composition and nanostructure had been reported in the previous MRS meetings. Although the HAp/Col nanocomposite demonstrates excellent biological reaction, i.e., the HAp/Col is incorporated into bone remodeling process that is observed on autologous bone transplantation, the effect of the HAp/Col on osteogenic activities is not examined in vitro. In the present paper, the HAp/Col filter paper-like membrane was prepared using its long fibers, and examined alkaline phosphatase (ALkP) gene expression to evaluate effect of the HAp/Col on osteogenic activity.The HAp/Col long fibers with bone-like nanostructure were synthesized by the simultaneous titration method previously reported under fine control of starting material concentrations. The long (5 mm) and short (60 µm) HAp/Col fiber suspension were mixed in the fiber weight ratio of 1:5.7 and flatly filtrated. The filtered membrane was pressed at 10 MPa, vacuum dried, crosslinked and pressed again at 30 MPa to be flat. The membrane has paper-like softness at 250 µm in thickness. The tensile strength at dry and wet conditions of the membrane is 2.9 MPa±0.4 MPa and 0.6±0.1 MPa, respectively. The strength was enough to handle at both cell culture and material/cell hybrid transplantation. The MG-63 cells, derived from human osteosarcoma, were used for cell culture test. The membrane was punched out to 9 mm in diameter to fit 48-well plate. The culture media were the Dulbecco's modified Eagle's essential medium (DMEM) supplemented with 10 % fetal bovine serum and 1% penicillin and streptomycin (growth medium) and the growth medium supplemented with supplemented with 50 µg/ml L-ascorbic acid phosphate magnesium salt and 10 nM β-glycerophosphate (osteogenic medium). Prior to cell culture test, twenty of the HAp/Col membrane were soaked in 25 ml of the growth medium for 5 days with everyday medium change to allow ions (and proteins) adsorption onto the membrane. The cells were seeded onto the membrane and cultured in the growth medium for 7 days followed by 7 days culture in the osteogenic medium. Although, cell attachment and proliferation showed no significant difference between the membrane and the tissue culture polystyrene (TCPS), the AlkP gene expressions at 7, 10 and 14 days on the membrane were significantly higher (1.4, 3.5 and 5.9 times, respectively) than TCPS. The HAp/Col nanocomposite membrane expected to be useful for bone tissue engineering.Acknowledgement: A part of this study was supported by Research Promotion Bureau, Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan under the contract No.17-83.
4:45 PM - S15.6
Tunable Electronic Conduction in Nanoparticle-organic Hybrid Materials.
Jan Herrmann 1 , Karl-Heinz Muller 1 , Gang Wei 1 , David Bray 1 2 , Burkhard Raguse 1 , Lech Wieczorek 1 , Len Lindoy 2
1 Industrial Physics, CSIRO, Lindfield, New South Wales, Australia, 2 School of Chemistry, University of Sydney, Sydney, New South Wales, Australia
Show Abstract5:00 PM - S15.7
Fabrication of Cellular Probes: Hybrid Dendrimer/Gold Nanoclusters
Chang Zhong 1 , Yuping Bao 1 , Dung Vu 2 , Richard Dyer 2 , Jennifer Martinez 1
1 Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico, United States, 2 Physical Chemistry & Applied Spectroscopy, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
Show AbstractNoble metal nanoclusters, which consist of collections of small numbers of metal atoms, are of great interest in photochemistry and photophysics due to their strong size-dependent emission. Historically, their generation was confined to gaseous and solid phases. However, recently a unique organic/inorganic hybrid material approach was developed that utilizes dendrimers as templates to protect the nanoclusters from fluorescence quenching by the solvent. Previous investigators prepared hybrid dendrimer/gold nanoclusters that were water-soluble and highly fluorescent. Yet there are several intrinsic deficiencies in their synthetic method: first, NaBH4, a toxic chemical, was used as reducing agent in the reaction; second, the reaction yield was low due to the concurrent formation of large, non-emissive particle byproducts. Here we report an environment-friendly and particle-free method to produce dendrimer-encapsulated gold nanoclusters. Proof of concept is demonstrated by using OH-terminated poly(amidoamine) dendrimer and Au(PX3)3Cl (X = Ph, Me), but the approach is applicable to the combination of other dendrimers and various organic noble metal salts. Our novel approach yields clusters with homogeneous size distribution. These clusters can be transferred to aqueous solution and used directly for biological applications.This work is funded by Los Alamos Laboratory Directed Research and Development program.
5:15 PM - S15.8
Processing-Structure and Property relationships of Nickel Nanostrand Conductive Nanocomposites for Lightning Strike Protection Applications
Sabyasachi Ganguli 1 , Sirina Putthanarat 2 , Thao Gibson 2 , Jennifer Fielding 1
1 MLBC, AFRL, Dayton, Ohio, United States, 2 MLBC, UDRI, Dayton, Ohio, United States
Show AbstractPolymer matrix composites are increasingly being used for applications needing high specific strength and modulus. However, PMCs are insulative and result in extensive damage when encountering a lightning strike. Composites may be produced with conductive surfaces using various nanofillers. In this study, several conductive nanomaterials such as silver-coated carbon nanofiber, vapor grown carbon nanofiber and nickel Nanostrands have been used to enhance the electrical conductivity of an epoxy resin. Optimization of the dispersion variables was performed to balance the processing parameters and electrical conductivity of the resulting nanocomposites. Percolation threshold plots were constructed for the different nanofiller nanocomposites. Morphological characterization of the nanocomposites was performed using SEM and electrical conductivity was mapped using TUNA AFM. Based on the morphological studies a processing-property relationship was established for the synthesis of the conductive nanocomposites. Nickel Nanostrand nanocomposites showed promising results for lightning strike protection applications.
5:30 PM - S15.9
Functional Hybrid Material Based on Poly(hydroxyethyl methacrylate) (PHEMA) and Iron Oxide Nanoparticles.
Nicolas Chemin 1 2 4 , Etienne Barthel 2 , Eric Le Bourhis 3 , Laurence Rozes 4 , Corinne Chaneac 4 , Sophie Cassaignon 4 , Philippe Espiard 1 , Valerie Goletto 1 , Jean-Pierre Jolivet 4 , Clement Sanchez 4
1 , Saint-Gobain Recherche, Aubervilliers France, 2 Surface du verre et Interface, CNRS/Saint-Gobain RECHERCHE, Aubervilliers France, 4 , Laboratoire Chimie de la matière condensée, Paris France, 3 , Laboratoire de Metallurgie Physique, Poitiers France
Show Abstract