Symposium Organizers
Li Shi The University of Texas-Austin
Min Zhou Georgia Institute of Technology
Min-Feng Yu University of Illinois, Urbana-Champaign
Vikas Tomar University of Notre Dame
Symposium Support
Air Force Office of Scientific Research (AFOSR)
R1: Functional Nanomaterials with Coupled Behavior
Session Chairs
Tuesday PM, March 25, 2008
Room 3004 (Moscone West)
9:30 AM - **R1.1
Applications of Carbon Nanotubes Based on Multifunctional Properties.
Pulickel Ajayan 1
1 , Rice University, Houston, Texas, United States
Show Abstract10:00 AM - R1.2
Coupled Piezoelectric and Electrical Properties of Individual ZnO Nanorods.
David Scrymgeour 1 , Julia Hsu 1
1 , Sandia National Laboratories, Albuquerque, New Mexico, United States
Show Abstract10:15 AM - R1.3
Carbon Nanotube Based Coils and Helices: Thermal Effects and Mechanical Properties.
Prabhakar Bandaru 1 , Apparao Rao 2
1 Materials Science Program, Department of Mechanical Engineering, UC, San Diego, La Jolla, California, United States, 2 Department of Physics, Clemson University, Clemson, South Carolina, United States
Show Abstract10:30 AM - R1.4
Integrated Nanoeletromechanical Resonantors Employing Piezoelectric AlN Nanowires.
Jie Xiang 1 , X. Feng 1 , Rassul Karabalin 1 , Yat Li 2 , Yajie Dong 2 , Charles Lieber 2 , M. Roukes 1
1 Kavli Nanoscience Institute, California Institute of Technology, Pasadena, California, United States, 2 Department of Chemistry and Chemical Biology and School of Enginerring and Applied Science, Harvard University, Cambridge, Massachusetts, United States
Show Abstract10:45 AM - R1.5
Mechanical and Electrical Coupling in Nanoscale Piezoelectric Nanowire.
Scott Mao 1
1 , University of Pittsburgh, Pittsburgh, Pennsylvania, United States
Show Abstract11:30 AM - **R1.6
Nanopiezotronics.
Zhong Wang 1
1 School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States
Show AbstractNanopiezotronics is a new field that was introduced based on using the coupled piezoelectric and semiconducting properties of nanowires/nanobelts for fabbricating unique and novel electronic devices and components [1]. For a ZnO nanowire/nanobelt that is piezoelectric n-type semiconductor, it creates an asymmetric strain distribution across its width when being bent laterally by an external force, which results in an asymmetric potential distribution across the nanowire width, with the tensile and compressive sides being positive and negative, respectively. The magnitude of this potential is proportional to the degree to which the nanowire is bent and it can reach a couple of volts depending on the size of the nanowire/nanobelt [2, 3]. As a result, the potential drop across the two sides is effectively a gate voltage that can trap the charge carriers, thus, controlling the current flowing from one end of the nanowire to the other end. This presentation will feature the piezoelectric field effect transistor [3], piezoelectric diode [4] and piezoelectric chemical sensors [5] that were fabricated based on the principle of nanopiezotronics. A prospective will be given about its future applications.[1] Z.L. Wang “Nano-piezotronics”, Adv. Mater., 19, 889 (2007).[2] Z.L. Wang and J.H. Song “Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays”, Science, 312, 242 (2006).[3] Yifan Gao and Z.L. Wang “Electrostatic Potential in a Bent Piezoelectric Nanowire – The Fundamental Theory of Nanogenerator and Nanopiezotronics”, Nano Letters, 7, 2499 (2007).[4] Jr H. He, C. H. Hsin, L.J. Chen, Z.L. Wang* ”Piezoelectric Gated Diode of a Single ZnO Nanowire”, Adv. Mater., 19 (2007) 781-784.[5] C.S. Lao, Q. Kuang, and Z.L. Wang, M.C. Park and Y.L. Deng “Polymer Functionalized Piezoelectric-FET as Humidity/Chemical Nanosensors”, Appl. Phys. Letts., 90 (2007) 262107. [6] for details: http://www.nanoscience.gatech.edu/zlwang/
12:00 PM - **R1.7
Photomechanical Coupling in Polymer-Based Carbon Nanotube Composites.
Jeffrey Kysar 1 , Benjamin Fragneaud 2
1 Mechanical Engineering, Columbia University, New York, New York, United States, 2 Mechanical Engineering, Columbia University, New York, New York, United States
Show AbstractRecent work has demonstrated that polymer / Multiwalled Carbon Nanotubes (MWNT) composites have a photo-mechanical coupling when the material is exposed to visible light. In this study we synthesized poly(dymethyl siloxane) (PDMS) based composites with two types of carbon nanotubes: pure carbon MWNTs and nitrogen doped MWNTs. The composites were prepared by dispersing MCNTs in a solvent with sonication after which the polymer matrix was added to the mixture. The composites were dried in a vacuum oven in order to completely remove residual solvent. Various composites with different CNTs concentration were prepared (0 vol. % to 2.5 vol. %). When the composites were exposed to a visible white light, they tended to contract or expand depending on the prestrain applied to the specimen. This phenomenon reaches an optimum for about 1% concentration, which may indicate the concentration of total light absorption. The composites that contain pure carbon MWNTs and the composites that contain nitrogen-doped MWNTs exhibit a similar behavior, but the magnitude of the effect is larger for the nitrogen-doped MWNTs. The composites were characterized by various experimental methods such as stress evolution as a function of the light wave length, coupled opto-resistive mechanical analyses, Raleigh spectroscopy, among others. The goal of the research is to correlate the MWNTs electronic structure to the photo-mechanical coupling properties.
12:30 PM - R1.8
Charge Generation and Ferroelectric Characterization of Individual Piezoelectric/ferroelectric Nanowires.
Min-Feng Yu 1 , Zhaoyu Wang 1 , Jie Hu 1 , Abhijit Suryavanshi 1
1 Department of Mechanical Science and Engineeing, Univ. of Illinois at Urbana-Champaign , Urbana, Illinois, United States
Show Abstract12:45 PM - R1.9
Strain-dependent Twist–stretch Elasticity in Chiral Nanofilaments.
Moneesh Upmanyu 1 2 , Hailong Wang 1
1 Engineering Division, Materials Science Program, Colorado School of Mines, Golden, Colorado, United States, 2 Bioengineering and Life Sciences Program, Colorado School of Mines, Golden, Colorado, United States
Show Abstract
Symposium Organizers
Li Shi The University of Texas-Austin
Min Zhou Georgia Institute of Technology
Min-Feng Yu University of Illinois, Urbana-Champaign
Vikas Tomar University of Notre Dame
R6: Nanomaterials with Coupled Behavior in Biology and Chemistry
Session Chairs
Thursday AM, March 27, 2008
Room 3004 (Moscone West)
9:30 AM - **R6.1
Magnetic Nanoparticle Heating for Hyperthermia Treatment.
Ian Baker 1 , Q. Zeng 1 , J. Loudis 1 , P. Hoopes 2 , J. Weaver 2 , R. Strawbridge 2 , Z. Pierce 2 , J. Tate 2 , J. Ogden 2
1 Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire, United States, 2 Dartmouth Medical School, Dartmouth College, Hanover, New Hampshire, United States
Show AbstractNanoparticles for cancer treatment via magnetic hyperthermia ideally develop sufficient heating at the lowest possible frequency and the smallest external magnetic field strength. In this presentation, we will compare both the structure, and the magnetic and heating behavior of coated Fe/Fe oxide core/shell composite nanoparticles to that of several different sizes of dextran-coated iron oxide nanoparticles. The Fe/Fe oxide nanoparticles were synthesized to utilize the fact that the high saturation magnetization of an iron core (120-190 emu/g, which is twice that of iron oxide) could give a greater heating effect than iron oxide nanoparticles, while the iron oxide coating will allow the nanoparticles to be observed using magnetic resonance imaging (MRI) so that therapy can be effectively monitored. Preliminary in vivo studies on tumors in mouse models directly injected with iron oxide nanoparticles will also be presented. These show that under an alternating magnetic field of 700 Oe at 166 kHz flank tumors could be lethally heated and that 60% of treated mice had no observable tumor regrowth after 35 days (seven times the time required for a three-fold increase in tumor volume for untreated animals).
10:00 AM - **R6.2
Functional Inorganic Nanofillers in Transparent Polymers.
Stefan Kaskel 1
1 , Technical Unicersity Dresden, Dresden Germany
Show AbstractThe integration of inorganic nanoparticles into transparent polymers allows for the functionalization of plastics. Due to the small particle size, a high transmittance may be achieved even for high filler contents. However, a crucial point is to achieve integration of the particles inside the matrix without aggregation of the inorganic nanoparticles. The generation of particles in w/o-microemulsions is a general technique for the control of particle size. Using the two-emulsion technique, crystalline particles of BiOI can be obtained with a diameter of 5-12 nm showing a quantum size effect. The integration into polymers is achieved with the in situ generation-polymerization approach. In this technique, the oil phase of the microemulsion is composed of a monomer. Thus after particle generation, the surrounding phase is polymerized. The resulting transparent nanocomposites show a new photochromic effect. The integration of ZnO nanoparticles into transparent polymers results in nanocomposites with high UV-absorption but high transparency in the visible range. Luminescent nancomposites are obtained from ZnS:Mn and YVO4:Eu nanoparticles using the phase transfer technique, or the surface functionalization. YVO4:Eu/polymer nancomposites show an interesting UV-bleaching effect, that can be used to create volatile patterns in bulk transparent polymers.In all cases, the integration has to result in a strong interaction of the polymer matrix and the particle surface. The latter is crucial to avoid aggregation and achieve transparency, but is also important for the mechanical properties.
10:30 AM - R6.3
Virus Templated Functional Nanomaterials for Nanoelectronics.
Cengiz Ozkan 1
1 Mechanical Engineering, University of California at Riverside, Riverside, California, United States
Show Abstract11:15 AM - R6.4
Controlled Clustering of Polymer-Functionalized Nanoparticles: Core-Shell and Janus Nanoparticles by pH and Temperature.
Tatsushi Isojima 1 , Alan Hatton 1
1 Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show Abstract Functionalized nanoparticles, prominent among which are gold(Au) and magnetic (Fe3O4) nanoparticles, are applied in a wide range of fields, including drug delivery systems, diagnostics, gene analysis, proteomics, quantum dots, separation, purification, hyperthermia therapy, in vivo imaging and the like. There are undoubtedly still many gains to be made in the synthesis, functionalization, characterization and applications of these systems.In this report, we present polymer functionalized gold and magnetite nanoparticles. Two forms of functionalization have been employed which resulted in the core shell type and the Janus type nanoparticles. Poly acrylic acid (PAA)-coated core-shell gold and magnetic nanoparticles were prepared by surface initiated atomic transfer radical polymerization (ATRP) (namely "grafting from method") as has been the recent trend in synthesizing core-shell type nanoparticles. ATRP is a well-known technique for creating a narrow polymer distribution which allows us to make core-shell nanoparticles with a precisely designed and high density polymer shell. The methods of attaching polymer on the surface of nanoparticles (namely "grafting onto method") tend to lead to a relatively low graft density because of the steric repulsions. In addition, PAA is a well-known and a very useful polymer because of its numerous carboxyl groups. We can control the aggregation and dispersion by changing pH because of the isoelectric point for PAA(pKa=4.5). Also these carboxylic groups on the surface help in the easy functionalization of the nanoparticles. We examined the PAA coated core shell structure of nanoparticles by TEM, TGA, FT-IR, GPC, DLS, UV/Visible spectroscopy (for gold particles) and Zeta potential measurement and their pH dependent behaviors by DLS, Zeta potential and UV/Visible spectroscopy (for gold particles) at pH values from 10 to 2. Also, we have recently developed methods for the synthesis of a new set of functional nanoparticles with asymmetric surface properties; Janus Particles. Specifically, our Janus nanoparticles consist of magnetite nanoparticles coated on one side with a pH-dependent and temperature-independent polymer (PAA), and on the other side functionalized by a second polymer that is either pH-independent polymer (PSSNa) or temperature-dependent polymer (PNIPAM). Therefore, these Janus particles can be dispersed individually at high pH values or low temperature, but can self assemble at low pH value or at high temperature. This was confirmed by DLS and Zeta potential measurements. A stable dispersion of clusters of approximately 80-100 nm in diameter can be formed at pH 2 and high temperature.
11:30 AM - R6.5
Coupling Ohmic Heating, Chemical Mixing and Thermal Transport in the Ignition and Self-propagation of Exothermic Reactions in Nanolayered Materials.
Stephen Spey 1 , Jonathan Trenkle 1 , Gregory Fritz 1 , Etienne Besnoin 6 , Todd Hufnagel 1 , Omar Knio 2 , Betsy Rice 3 , Lucas Koerner 4 , Mark Tate 4 , Sol Gruner 4 5 , Timothy Weihs 1
1 Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States, 6 , Reactive NanoTechnologies, Hunt Valley, Maryland, United States, 2 Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland, United States, 3 Weapons & Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland, United States, 4 Department of Physics, Cornell University, Ithaca, New York, United States, 5 Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York, United States
Show AbstractExothermic reactions can be ignited and can self-propagate in foils containing nanoscale layers that alternate between materials with negative heats of mixing. Reaching maximum temperatures as high as 3000oC, these reactions can travel at velocities greater than 30 m/s. One common example includes alternating layers of Ni and Al that range in thickness from 5 to 100nm. With a pulse of electrical current at one end of a Ni/Al multilayer foil, ohmic heating provides sufficient thermal energy to initiate atomic diffusion between the layers and compound formation, which then leads to energy release and propagation of the reaction along the foil, away from the point of ignition. Using a combination of ohmic heating ignition experiments, velocity and temperature measurements, in situ X-ray diffraction experiments, continuum modeling, and molecular dynamic simulations we have identified many of the physical parameters that control the current density required for ignition and the velocity and temperature of reaction propagation. These include layer thickness, initial intermixing between layers, heat of reaction, atomic diffusivity, heat capacity, density, and thermal conductivity. We have also begun to identify the phases that form during reaction propagation. Here we present a combination of experimental and modeling results to explain the coupled electrical, thermal and chemical behavior of exothermic reactions in nanoscale materials.
11:45 AM - R6.6
Understanding Degradation of Doped Electroluminescent ZnS Phosphors.
Yu Jiang 1 , Jacob Stanley 1 , Frank Bridges 1
1 Physics, UC Santa Cruz, Santa Cruz, California, United States
Show Abstract12:15 PM - R6.8
Lithographically Patterned Nanowire Electrodeposition:Coupled Electrochemical and Electrical Behavior.
Chengxiang Xiang 1 2 , Erik Menke 1 , Aleix Guell 3 , Reginald Penner 1
1 Chemistry, University of California,Irvine, Irvine, California, United States, 2 Physics and Astronomy, University of California,Irvine, Irvine, California, United States, 3 Physical Chemistry, University of Barcelona, Barcelona Spain
Show Abstract12:30 PM - R6.9
Cellular Uptake Behavior of Different Charged Nanoparticles Studied by Surface Zeta Potential.
Yu Zhang 1 , Mo Yang 3 , Jennifer Singelyn 2 , Jo Ho Park 2 , Michael Sailor 2 , Mihrimah Ozkan 1 , Cengiz Ozkan 1
1 , UC, Riverside, Riverside, California, United States, 3 , Hong Kong Polytechnic University, Hongkong China, 2 , University of California, San Diego, San Diego, California, United States
Show Abstract