Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support National Institute of Standards and Technology
G3: Materials Sustainability in Research Policy
Monday PM, November 26, 2012
Hynes, Level 3, Room 306
2:30 AM - *G3.01
The Sustainable Chemistry, Engineering and Materials Initiative at the National Science Foundation
Ian Robertson 2 1
1University of Illinois Urbana USA2National Science Foundation Arlington USAShow Abstract
Sustainability has become an area of emphasis for the National Science Foundation, NSF, as evidenced by the many programs within the portfolio of the Science, Engineering, and Education for Sustainability (SEES) initiative. A new effort under the SEES initiative, and one outlined in the FY13 Budget Request, is the Sustainable Chemistry, Engineering, and Materials (SusChEM) initiative. The Sustainable Materials effort seeks to support and encourage research projects targeting the discovery of new materials or make materials more sustainable through improved synthesis, enhanced applications, and/or advances in lifecycle management. These efforts as well as those in other participating divisions will be described.
3:00 AM - *G3.02
Sustainability in Materials Research in the EU: From FP7 to Horizon 2020
Renzo Tomellini 1 Johan Veiga Benesch 1
1European Commission Brussels BelgiumShow Abstract
Environmental issues are steadily getting more and more attention at EU policy level. This can for example be seen in the Raw Materials Initiative by DG Enterprise and Resource Efficient Europe by DG Environment which goes back to the theme of a sustainable economy as expressed by the Europe 2020 growth strategy. DG Research and Innovation supports related research activities. The Nanotechnology, Materials & Production (NMP) Theme in the FP7 Cooperation scheme has taken stock of this, by for example by including aspects such as substitution, life cycle assessment, improved resource efficiency and better performance materials in the NMP calls for proposals. This is done with the aim to achieve a more green economy and fostering more sustainable consumption and production patterns. Research on better performing and sustainable materials will more than ever be a pre-condition to meeting such challenges. Progress will come through the development of intelligent materials that embed and transfer knowledge into products and processes or perform certain tasks, when in use or during manufacturing. Already, some 70 percent of all technical innovations hinge directly or indirectly on the properties of the materials employed. We have passed from the perception "materials are in the drawer" to the perception "materials are the bottleneck". The next step can be "materials are the solution". At least 60 % of the total proposed Horizon 2020 budget will be related to sustainable development, the vast majority of this expenditure contributing to mutually reinforcing climate and environmental objectives. In a resource-scarce Europe, new products must have low material / energy resource needs and high knowledge content. As stated in the Europe 2020 strategy endorsed by EU leaders: “Europe must promote technologies and production methods that reduce natural resource use, and increase investment in the EU's existing natural assets”. Materials can have a large environmental impact in many of its stages, from sourcing, extraction, processing, auxiliary materials and processes, use and end of life fate. The choice or design of material solutions can thus have a great impact on the technologies in which they are used. Implying that a material could be an integral part of the solution to a problem created by the use of a specific technology. Such solutions could require entirely new materials either to replace a material or be part of a new technology based on better performing materials and ecodesigned products.
GF2: Sustainability Forum: Successful Interdisciplinary Sustainable Development Research
Monday PM, November 26, 2012
Hynes, Level 3, Room 306
4:15 AM - *GF2.01
Sustainable Materials: With Both Eyes Open
Julian Allwood 1
1University of Cambridge Cambridge United KingdomShow Abstract
One third of the world's carbon emissions are emitted by industry. Most industrial emissions relate to producing materials, and steel and cement are by far the most important contributors. The industries that make materials are energy-intensive, so have always been motivated to be efficient, and have now reached a fantastic level of performance. However the world's demand for materials is growing, and likely to double by 2050. So, by default, industrial emissions will also double, unless we do something differently. This talk sets out an agenda for making a big difference to global emissions, by requiring less new material. Based on a five-year project, with eight researchers and a consortium of 20 large industrial partners, we have gathered evidence on six “material efficiency” options which allow us to provide the same final services (such as housing or transport) with significantly less material. The talk will present a series of case studies to demonstrate how these strategies can be applied in practice, and explore the actions by government, businesses, and consumers that would bring them about.
4:45 AM - *GF2.02
Empowering and Engaging Engineering Students through Immersion and Discourse in Sustainable Development for the 21st Century
Diran Apelian 1
1Worcester Polytechnic Institute Worcester USAShow Abstract
Sustainability is a hot topic nowadays, and seems to be quite the popular issue; and it is about time! Rachel Carson&’s seminal book “Silent Spring” was published in 1962 and ten years later, in 1972, DDT was banned. Sustainable development is and must be part of the engineering curriculum. Societal issues facing the 21st century spanning from energy, food and water, transportation, housing, materials, and health require engineering solutions that are sustainable. But how does one teach this? Where does it fit in our packed curricula? How does one teach the basic concepts that natural systems are closed loop, use few elements, are cyclic, and where the indicator of well-being is equilibrium? At WPI, we have decided to start this journey early on, and in fact the first day the student sets foot on campus. In this presentation, the Great Problem Seminars (GPS) course will be described and discussed, and in particular, the course titled: “Sustainable Development for the 21st Century”, a course developed by D. Apelian and S. Nikitina (from Humanities and Arts). The course is different than any structured engineering course. It is interdisciplinary, it is writing intensive, and requires a Socratic approach to “learning” (not teaching) and an immersion in an eight week long project in teams of five students. In brief, the course implants in the students&’ mind from day one that we can make a difference in the world through engineering, and through elegant solutions that are sustainable.
G4: Poster Session: Materials Sustainability
Laura Espinal Thielen
Monday PM, November 26, 2012
Hynes, Level 2, Hall D
9:00 AM - G4.01
Clay-chitosan Nanobrick Walls: Completely Renewable Gas Barrier and Flame Retardant Nanocoatings
Galina Laufer 1 Jaime C. Grunlan 1 2 3
1Texas Aamp;M University College Station USA2Texas Aamp;M University College Station USA3Texas Aamp;M University College Station USAShow Abstract
Thin films prepared via layer-by-layer (LbL) assembly of renewable materials exhibit exceptional oxygen barrier and flame retardant properties. Positively- charged chitosan (CH), at two different pH levels (3 and 6), was paired with anionic montmorillonite (MMT) clay nanoplatelets. Thin film assemblies prepared with CH at high pH are thicker due to low polymer charge density. A 30 bilayer (CH pH 6-MMT) nanocoating (~100 nm thick) reduces the oxygen permeability of a 0.5 mm thick polylactic acid film by four orders of magnitude. This same coating system completely stops the melting of a flexible polyurethane foam, when exposed to direct flame from a butane torch, with just 10 bilayers (~ 30 nm thick). Cone calorimetry confirms that this coated foam exhibited a reduced peak heat release rate, by as much as 52%, relative to the uncoated control. These sustainable nanocoatings could prove beneficial for new types of food packaging or a replacement for environmentally persistent antiflammable compounds.
9:00 AM - G4.03
Tangible Plasticization Effects of Sodium Salts of Dimer Acids Prepared by Recycling of Waste Cooking Oil on the Mechanical Properties of Styrene Ionomers
Kwang-Hwan Ko 1 Hye Ryeon Park 2 Joon-Seop Kim 1 Young-Wun Kim 3
1Chosun University Gwangju Republic of Korea2Chosun University Gwangju Republic of Korea3KRICT Daejeon Republic of KoreaShow Abstract
These days, the environmental regulations on industrial consumption have been tightened up, leading to an urgent need for the development of new eco-friendly materials. Thus, natural products, non-toxic and environmental-friendly products, have gained much attention in regard to the development of “green chemicals”. During the last five years, we have undertaken research on the preparation and modification of bio-based monomers. In course of our project, a number of “dimer acids” have been prepared by recycling of waste cooking oil, e.g. waste vegetable and animal oils. In general, vegetable oil contains unsaturated fatty acids such as oleic acid and linoleic acid, and, thus, various dimer acids, e.g. monocyclic, bicyclic, acyclic dimer acids can be prepared via the synthesis process using fatty acids as raw materials. In the present work, we investigated the effects of the presence of dimer acid (DA) molecules in the Na-sulfonated polystyrene (PSSNa) and poly(styrene-co Na-methacrylate) (PSMANa) ionomers on the ionomer properties dynamic mechanically. We found that the presence of DA molecules in the PSSNa ionomer decreased the matrix and cluster Tgs of the ionomer strongly without changing the ionic modulus of the ionomer. Thus, we proposed that the DA molecules resided in the matrix and cluster regions of the PSSNa ionomer and acted mainly as effective plasticizer. In the case of the PSMANa ionomers, the presence of the DA molecules decreased the cluster Tg of the ionomer, without chaining the matrix Tg, and increased the ionic modulus of the ionomer. Thus, we suggested that the monocyclic and bicyclic DA molecules in the PSMANa ionomer also acted as plasticizer, but the acyclic DA molecules were phase-separated to form filler particles that increased the ionic modulus of the PSMANa ionomer. We also observed that the positions of X-ray peak of PSSNa ionomers containing DA did not change with DA amounts, but those of PSMANa ionomers shifted to higher angles. This X-ray result was also supportive for the proposed roles of Na molecules in PSSNa and PSMANa ionomers. In conclusion, we found that the NA can be used as very effective “green” plasticizer [This study was supported by the R&D Center for Valuable Recycling (Global-Top Environmental Technology Development Program) funded by the Ministry of Environment, Korea (Project No.:11-D27-OD)].
9:00 AM - G4.05
Investigation of Castor Oil-based Polyurethane Reinforced by Nanocellulose
Seong Hun Kim 1 Sang Ho Park 1 Kyung Wha Oh 2
1Hanyang University Seoul Republic of Korea2Chung-Ang University Seoul Republic of KoreaShow Abstract
Polyurethane (PU) is one of the most frequently used for various applications such as insulation, automotive parts and seating materials. However, these materials were strongly depended on petroleum as feedstock and this fact became problematic because of steadily going up of petroleum oil price and environmental aspect as well as sustainability. Therefore the development of bio-renewable feedstocks for PU such as plant oil-based materials became highly desirable in industrial field. In this research, the bio-based PU was synthesized by reaction between isocyanate and castor oil. The castor oil was used as polyol among various plant oils because it was excellent polyol candidate because of its low toxicity, availability, and low cost. In addition, the castor oil could be used for polyol directly to react with isocyanate groups without chemical modification because it had already hydroxyl groups. The nanocellulose of eco friendly nanofillers was prepared in order to reinforce the castor oil-based polyurethane. Nano size cellulose fiber and whisker have a great interest as new excellent reinforcements because it was biodegradable and had remarkable mechanical properties and lightness than those of natural fiber or glass fiber. The nanocellulose whiskers were prepared by chemical and mechanical treatments. The castor oil-based PU (CPU) was reinforced by nanocellulose with two different methods, which the CPU was physically bonded with nanocellulose (CPU/nanocellulose) by solution casting and chemically bonded with nanocellulose (CPU-nanocellulose) to improve interfacial adhesion. The covalent bonding formation between hydroxyl group of nanocellulose and isocyanate was confirmed by FTIR. The nanocellulose covalently bonded with CPU increased storage modulus and complex viscosity of CPU as measured by rheological analysis. This was due to improvement of cross-link density of the elastomer network because of nanocellulose-PU molecular interaction. The mechanical properties of CPU reinforced by nanocellulose composites were investigated. Tensile test revealed that CPU-nanocellulose composites had highest tensile strength and modulus because of improvement of interfacial adhesion and nanoreinforcing effect of nanocellulose with high aspect ratio. The effect of nanocellulose on thermal stability of CPU was also investigated. This research was supported by National Research Foundation of Korea. (Project No. 2011-0028966)
9:00 AM - G4.06
Distributed Recycling of Post-consumer Plastic Waste in Rural Areas
M. Kreiger 1 G. C. Anzalone 2 M. L. Mulder 1 A. Glover 1 J. M. Pearce 1 3
1Michigan Technological University Houghton USA2Michigan Technological University Houghton USA3Michigan Technological University Houghton USAShow Abstract
Although the environmental benefits of recycling plastics are well established and most geographic locations within the U.S. offer some plastic recycling, recycling rates are often low. Low recycling rates are often observed in conventional centralized recycling plants due to the challenge of collection and transportation for high-volume low-weight polymers. The recycling rates decline further when low population density, rural and relatively isolated communities are investigated because of the distance to recycling centers makes recycling difficult and both economically and energetically inefficient. The recent development of a class of open source hardware tools (e.g. RecycleBots) able to convert post-consumer plastic waste to polymer filament for 3-D printing offer a means to increase recycling rates by enabling distributed recycling. In addition, to reducing the amount of plastic disposed of in landfills, distributed recycling may also provide low-income families a means to supplement their income with domestic production of small plastic goods. This study investigates the environmental impacts of polymer recycling. A life-cycle analysis (LCA) for centralized plastic recycling is compared to the implementation of distributed recycling in rural areas. Environmental impact of both recycling scenarios is quantified in terms of both emissions and energy use per unit mass of recycled plastic. A sensitivity analysis is used to determine the environmental impacts of both systems as a function of distance to recycling centers. The results of this LCA are discussed and conclusions are drawn about the viability of distributed recycling from an ecological perspective and trajectories of future research in open source hardware for recycling plastics are established.
9:00 AM - G4.08
Microwave Assisted In situ Synthesis of Proton Conducting Titanate Nanotubes into Nafion
Bruno R Matos 1 Elisabete I Santiago 1 Andre S Ferlauto 2 Fabio C Fonseca 1
1IPEN Sao Paulo Brazil2UFMG Belo Horizonte BrazilShow Abstract
The in situ synthesis of inorganic nanoparticles such as titania and silica by using the sol-gel method has been successfully reported previously in organic-inorganic hybrids. Such a technique takes advantage of the hydrophobic-hydrophilic phase-separated structure of ionomers as a template for in situ grow of finely dispersed inorganic particles. However, one disadvantage of the sol-gel method is the restriction for producing nanoparticles with new architectures such as nanotubes . In the present study, spherical titania nanoparticles incorporated in a ionomer-matrix composite were converted in situ to titanate nanotubes aiming at enhanced properties at high temperature (~130°C). Nafion-titania (anatase) hybrids produced by in situ sol-gel, with high inorganic phase content (~25 wt.%) and titania average particle size of ~5 nm, were used as a precursor. Hybrid membranes were immersed in a concentrated basic solution and a microwave-assisted hydrothermal treatment was carried out in a microwave oven at 150 °C for 180 min. Both the precursor and the modified composite membranes were characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), small angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). The experimental results revealed that the anatase precursor phase was successfully converted into the proton conducting titanate phase, as confirmed from XRD, RS , and TEM results. The composite membranes based on Nafion containing proton conducting fillers are envisioned as good candidates for the application as electrolytes in proton exchange membrane fuel cells operating at high temperature.
9:00 AM - G4.10
SnP2O7 Dispersed Proton/electron Mixed Conducting Glass-ceramics
Satoshi Yamanishi 1 Yusuke Daiko 1 Atsushi Mineshige 1 Tetsuo Yazawa 1
1University of Hyogo Himeji JapanShow Abstract
Introduction Inorganic electrolytes with high proton conductivity in temperatures ranging from approximately 300 to 500°C have attracted much attention owing to their various applications such as fuel cells, sensors, electrolyzers, and solid catalysts. An anhydrous proton conductor, M3+-doped SnP2O7 (M = In or Al ), shows high proton conductivities ( > 10-1 S cm-1) and good fuel cell performance between 150 and 350°C under dry conditions [1,2]. However, pure SnP2O7 has some serious problems including chemical durability and sinterability for practical applications. We have studied a new type of proton conducting glass-electrolyte prepared utilizing a conventional melting method. Recently, we successfully prepared a glass electrolyte with 100 % proton transport (proton transport number, tH=1) at 400-500 °C . In this study, crystallization behavior of tin-phosphosilicate glasses and those electrical conductivity under the intermediate temperature (300 - 700 °C) were investigated. Experiments Regent grade of SnO2, Al2O3 (or In2O3), P2O5, SiO2 and B2O3 were melted in an alumina crucible at 1600°C, and the obtained glasses were heat-treated at 900°C for the crystallization. X-ray diffraction (XRD), differential scanning calorimeter (DSC), alternate current (AC) and direct current (DC) conductivities, open-circuit voltage (OCV) under H2/O2 fuel cell conditions and proton transport number (tH) measurements were performed under the intermediate temperature region. Results Glasses with different Sn/P ratio (Sn/P = 0.15~1.53) were prepared, and all the as-deposited glasses obtained were x-ray amorphous. It was found that only SnP2O7 crystal was precipitated in the glass with Sn/P = 0.52 after the crystallization at 900°C. Proton/electron conductivities and the results of proton transport number measurement revealed that the glass with Sn/P = 0.52 shows pure proton conduction (tH=1 meaning no electron conductivity). On the other hand, in the samples with Sn/P > 0.90, both the SnP2O7 and Sn2.5P3O12 crystalline phases were precipitated. Interestingly, these samples show not only proton conductivity but also electron conductivity. Effect of the trivalent cation dopant into the tin-phosphosilicate is also discussed in relation to the proton/electron conductivity. Reference  M. Nagao et al., J. Electrochem. Soc., 153, A1604(2006).  A. Tomita et al., J. Electrochem. Soc., 154, B1265 (2007).  Y. Daiko et al., J. Electrochem. Solid State Lett., 14, B63 (2011).
9:00 AM - G4.13
Up-cycling of Solid Polymer Wastes and Biomass Residues to Carbon Nanomaterials
Chuanwei Zhuo 1 Joner Alves 1 2 4 Jorge Tenorio 2 Henning Richter 3 Yiannis Levendis 1
1Northeastern University Boston USA2University of Sao Paulo Sao Paulo Brazil3Nano-C, Inc. Westwood USA4Aperam South America Timamp;#243;teo BrazilShow Abstract
This work addresses the up-cycling of common solid wastes by utilizing them as carbon sources for the synthesis of carbon nanomaterials (CNMs). Agricultural sugar cane bagasse and corn residues, scrap tire chips, and postconsumer polyethylene terephthalate (PET) and polyethylene (PE) bottle shreddings were either thermally treated by sole pyrolysis, or by sequential pyrolysis and partial oxidation. The resulting gaseous carbon-bearing effluents were then channeled into a heated reactor. CNMs, including carbon nanotubes, were catalytically synthesized therein on stainless steel meshes. These feedstocks could supersede the use of costly and often toxic or highly flammable chemicals, such as hydrocarbon gases, carbon monoxide, and hydrogen, which are commonly used as feedstocks in current nanomanufacturing processes for CNMs. This work revealed that the structure of the resulting CNMs is determined by the feedstock type, through the disparate mixtures of carbon-bearing gases generated when different feedstocks are pyrolyzed. CNM characterization was conducted by scanning and transmission electron microscopy, as well as by Raman spectroscopy and by thermogravimetric analysis. Gas chromatography was used to characterize the gases in the synthesis chamber. This work demonstrated an alternative method for efficient manufacturing of CNMs using both biodegradable and nonbiodegradable agricultural and municipal carbonaceous wastes.
9:00 AM - G4.14
Chemically Synthesized ZnSb Alloy Nanoparticles towards Thermoelectric Applications
Mai Thanh Nguyen 1 Derrick Michael Mott 1 Higashimine Koichi 1 Maenosono Shinya 1
1Japan Advanced Institute of Science and Technology Nomi JapanShow Abstract
Recently thermoelectric (TE) materials are becoming a very attractive field of research toward applications in micro cooling devices, energy conversion and waste heat recovery. For this purpose, these materials should have high thermoelectric figure of merit arising from high Seebeck coefficient, high electrical conductivity and low thermal conductivity. From bulk materials, it is challenging to achieve a high value for TE efficiency because of the close inverse relation between electrical and thermal conductivity. On the other hand, low dimensional materials offer a host of advantages to address this challenge based on electron transmission and phonon blocking at the particle grain boundary which helps maintain the electrical conductivity while reducing the thermal conductivity or the increase of the Seebeck coefficient due to the quantum confinement effect or energy filtering. Therefore, TE research now focuses on nano-structured materials. Among many TE materials, ZnSb systems consist of relatively abundant elements and exhibit excellent TE performance (especially β-Zn4Sb3 phase) because of the remarkably low thermal conductivity (κ) arising from their disordered local structure. Nanostructured Zn-Sb, therefore, is expected to have extremely low κ due to the multiplier effect of intrinsic disordered structure and nanograin boundaries which makes it a promising material for energy harvesting purposes. To achieve this, we have developed a synthetic method towards Zn-Sb alloy nanoparticles (NPs) via a sequential reduction of metal precursors and subsequent alloying. Sb cores were first synthesized followed by the growth of Zn shell onto the cores and subsequent alloying. Resulting NPs collected after the synthesis were characterized by various methods including TEM, Scanning TEM, XRD, TEM-EDS, XPS and EDS mapping. It is found that the NPs are nearly spherical in shape with a mean size of 21.1±3.4 nm and are composed of both Zn and Sb. The XRD and XPS analysis of ZnSb containing NPs indicate alloy phases with higher oxidation stability compared to monoelemental Zn or Sb NPs. EDS mapping furthermore illustrates the alloy structure with a composition gradient along the NP radius in which the core is Sb rich and the shell is Zn rich. Primary results in processing and characterizing the thermoelectric properties of thin film made from these NPs show the ability to use these chemically-synthesized ZnSb NPs as building blocks for efficient nanostructured thermoelectric materials.
9:00 AM - G4.15
Stable, Single-layer MX2 Transition-metal Oxides and Dichalcogenides in a Honeycomb-like Structure
Can Ataca 1 2 4 Hasan Sahin 3 4 5 Salim Ciraci 2 3 4
1Massachusetts Institute of Technology Cambridge USA2Bilkent University Ankara Turkey3Bilkent University Ankara Turkey4Bilkent University Ankara Turkey5University of Antwerp Antwerpen BelgiumShow Abstract
Recent studies have revealed that single-layer transition-metal oxides and dichalcogenides (MX2) might offer properties superior to those of graphene. So far, only very few MX2 compounds have been synthesized as suspended single layers, and some of them have been exfoliated as thin sheets. Using first-principles structure optimization and phonon calculations based on density functional theory, we predict that, out of 88 different combinations of MX2 compounds, several of them can be stable in free-standing, single-layer honeycomb-like structures. These materials have two-dimensional hexagonal lattices and have top-view appearances as if they consisted of either honeycombs or centered honeycombs. However, their bonding is different from that of graphene; they can be viewed as a positively charged plane of transition-metal atoms sandwiched between two planes of negatively charged oxygen or chalcogen atoms. Electron correlation in transition-metal oxides was treated by including Coulomb repulsion through LDA + U calculations. Our analysis of stability was extended to include in-plane stiffness, as well as ab initio, finite-temperature molecular dynamics calculations. Some of these single-layer structures are direct- or indirect-band-gap semiconductors, only one compound is half-metal, and the rest are either ferromagnetic or nonmagnetic metals. Because of their surface polarity, band gap, high in-plane stiffness, and suitability for functionalization by adatoms or vacancies, these single-layer structures can be utilized in a wide range of technological applications, especially as nanoscale coatings for surfaces contributing crucial functionalities. In particular, the manifold WX2 heralds exceptional properties promising future nanoscale applications. This work is published at J. Phys. Chem. C 116, 8983 (2012).
9:00 AM - G4.16
Towards a Factory for Infinity
Raymond Oliver 1 Alexander Louis Bone 1 Oliver Poyntz 1
1Northumbria University London United KingdomShow Abstract
To be competitive in the 21st Century on a global basis, manufacturing technologies have to demonstrate low cost, low inventory, high functionality, high added value product flexibility and be amendable and agile enough to work in both societal (concerns driven) and commercial (opportunities driven) environments. This paper focuses on the rate at which we consume and waste material and how therefore we can use lean manufacturing to create the lowest possible energy-materials cycles. We examine additive technologies, rapid prototyping and 3D printing/extrusion, self assembly materials (SAMs) and directed assembly materials (DAMs) as well as ambient processing on a local scale, going against the 20th Century view of ‘heat, beat and treat&’ where we overwhelm materials with energy until the materials succumb to our designs. The Factory for Infinity is the foundation for future factories, supporting an ideal system for consumption of products. Using only 100% recyclable (no ‘downcycling&’) or truly biodegradable materials, we have designed a system of low energy, small scale manufacturing processes that require old products to make new ones, allowing materials to be recycled infinitely in a local, closed loop cycle. This project led to the coining of the term ‘Disassembly is Manufacture&’ , a phrase which epitomises the ethos and ideals of this vision. The pursuit of this ideal vision lead the research team to the repurposing of techniques used within the extractive sector to enable new recycling systems and technologies. In practical terms experiments were conducted in two major sectors - zero waste, low energy metals remanufacture; by taking waste metals, dissolving them into an acid solution then precisely printing specific metals out of solution directly into new product; and rapid growth bio-materials; where microbials assist in new bio composites. The outcomes of this research were 3 sample products which exemplify current consumption. The Copper Bottle Filling discarded, one-use plastic bottles with frozen water; we melted forms that people would keep for much longer. We used electroforming from copper e-waste and lined the inside of the bottle with an antibacterial film of silver. The Glass keyboard The keyboard was selected as it is considered to be a device with a limited life expectancy, soon to be made obsolete by a variety of new types of input device. Having a short life expectancy it seemed an excellent product to display the qualities of the factory for infinities methodology. The Lamp Mycelium bond together local crop waste to form a light, fire-retardant, fully compostable material. The material is grown around the electronic components. A hazel neck and recycled glass printed with copper from e-waste complete the circuit.
9:00 AM - G4.18
Energy Efficient and Multi-functional Liquid Infused Nanostructured Coatings on Aluminum Surfaces
Philseok Kim 1 2 Michael J Kreder 1 Jack Alvarenga 1 Joanna Aizenberg 1 2 3
1Harvard University Cambridge USA2Harvard University Cambridge USA3Harvard University Cambridge USAShow Abstract
Liquid interfaces typically provide ultrasmooth, defect-free, and chemically homogeneous characteristics. If a layer of liquid film is locked in place on a porous solid surface, the surface can also present similar properties. Our group has recently developed this novel concept of surface, SLIPS (Slippery Liquid Infused Porous Substrates, Nature 477 443, 2011) that exhibits extremely low friction and adhesion to a wide range of materials with extreme temperature and pressure stability. SLIPS-coated surfaces thus present extreme repellent properties to almost any type of materials and have been proven to prevent ice and frost formation and to show about an order of magnitude lower adhesion to ice than other known materials (ACS Nano ASAP 2012). We will discuss recent advances in materials and methods to allow SLIPS coatings on aluminum to improve the energy efficiency and sustainability of many infrastructures, for example, as energy-efficient frost-free refrigeration coils and as drag reducing coatings in fluid transport pipeline systems. Preliminary results show that our new approach combining microtexturing and nanotexturing methods exhibits a wide range of applicability of SLIPS coating as well as improved long term performance of maintaining low friction and adhesion than previously reported approaches based on electrodeposited nanostructured polypyrrole coating. Characterizations of surface micro/nanostructures, contact angles and hysteresis, adhesion properties, and the robustness of SLIPS performance under high shear conditions will be presented. These studies will provide basic understanding for the mechanisms associated with the topography of textured substrates and their SLIPS performances. We envision that further development of materials and methods based on these design principles will lead to universal and general coating methods to create SLIPS on a wide range of substrates including metals, glass, plastics, ceramics, fabrics, etc.
G1: Materials for Sustainable Development and Technologies
Laura Espinal Thielen
Monday AM, November 26, 2012
Hynes, Level 3, Room 306
9:30 AM - *G1.01
Materials for Sustainable Development
Martin L Green 1
1NIST Gaithersburg USAShow Abstract
Every human endeavor should be informed by sustainable development, because none of our material resources are infinite and only a few sources of energy are sustainable. The most common definition of sustainable development comes from the 1987 Brundtland report, “Our Common Future”, and states that “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” However, this is not a scientific definition, and essentially refers to economic development. Further, it requires that we know, or at least accurately estimate, what the needs of future generations will be. In this talk I will address the meaning and definition of sustainable development, and explore the space at its intersection with materials science. Materials have always served the role of technology enablers, and will continue to do so for sustainable development. The immediate and direct connections between sustainable development and materials science include efficient use of materials (conservation, substitution, reuse, repurposing, recycling), materials life cycle assessment, replacement materials (scarcity, resource availability, materials flow analysis and economics), energy (materials to support alternative energy technologies, to mitigate problems with fossil-fuel technologies, and to increase energy efficiency), mitigation of undesirable impacts on environment and human health from technology and economic growth (corrosion, pollution, toxic waste), and water purification. In this talk I will further highlight a few examples of materials for sustainable development in research programs at NIST, such as materials for carbon capture, thermoelectric devices, and standards for bio-derived products.
10:00 AM - G1.02
Environmental Impacts of Distributed Manufacturing from 3-D Printing of Polymer Components and Products
M. Kreiger 1 J. M. Pearce 1 2
1Michigan Technological University Houghton USA2Michigan Technological University Houghton USAShow Abstract
Although additive layer manufacturing is well established for rapid prototyping the low throughput and historic costs have prevented mass-scale adoption. The recent development of the RepRap, an open source self-replicating rapid prototyper, has made low-cost 3-D printers readily available to the public at reasonable prices (<$1,000). The RepRap (Prusa Mendell variant) currently prints 3-D objects in a 200x200x200 square millimeters build envelope from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). ABS, a rigid thermoplastic, can be injection molded to manufacture polymer objects that need strength and durability. PLA, which can also be injection molded is a plant-based thermoplastic that can be recycled and composted. The melting temperature of ABS and PLA enable use in low-cost 3-D printers, as these temperature are low enough to use in melt extrusion in the home, while high enough for prints to retain their shape at average use temperatures. Using 3-D printers to manufacture provides the ability to both change the fill composition by printing voids and fabricate shapes that are impossible to make using tradition methods like injection molding. This allows more complicated shapes to be created while using less material, which could reduce environmental impact. As the open source 3-D printers continue to evolve and improve in both cost and performance, the potential for economically-viable distributed manufacturing of products increases. Thus, products and components could be customized and printed on-site by individual consumers as needed, reversing the historical trend towards centrally mass-manufactured and shipped products. Distributed manufacturing reduces embodied transportation energy from the distribution of conventional centralized manufacturing, but questions remain concerning the potential for increases in the overall embodied energy of the manufacturing due to reduction in scale. In order to quantify the environmental impact of distributed manufacturing using 3-D printers, a life cycle analysis was performed on three plastic products. The energy consumed and emissions produced from conventional large-scale production overseas are compared to experimental measurements on a RepRap producing identical products with ABS and PLA. The results of this LCA are discussed in relation to the environmental impact of distributed manufacturing with 3-D printers and polymer selection for 3-D printing to reduce this impact. Conclusions are drawn about the viability of distributed manufacturing from an ecological perspective and trajectories of future research in open source 3-D manufacturing are established.
10:15 AM - G1.03
Sustainable Semiconducting Copper Zinc Sulfide Nanoparticles
Derrick Mott 1 Shinya Maenosono 1
1Japan Advanced Institute of Science and Technology Nomi JapanShow Abstract
One of the primary drawbacks of nanotechnology today is the limited abundance of the elements used to create the most enhanced materials. Nanoparticles composed of precious and rare metals such as gold, platinum, palladium, antimony, tellurium, etc. have been demonstrated in fundamental studies to possess novel properties that can be used in advanced applications such as sensors, catalysis, thermoelectrics, solar cells, as well as many others. The advances in these areas are exciting, but there are few cases of these fundamental studies moving on to widespread development and overall adoption of the new technology by society. The advancement of these materials has been restricted by the non-sustainability of the technology, namely the limited availability and resulting cost of the raw materials needed to create the nanoparticles is too high. In response, studies are needed that focus on the synthesis and characterization of new nanoparticle systems that utilize abundant and non-toxic elements. In this study, we have developed a synthetic technique towards copper zinc sulfide nanoparticles, which are highly attractive because of the high abundance and low toxicity of these elements. These chalcogenide type nanoparticles are semiconducting in nature which is advantageous for use in a wide variety of applications including thermoelectrics, solar cells and solar catalysis. The particles are also highly intriguing from a fundamental perspective because the relative composition of copper and zinc in the particles can be tuned, resulting in the ability to manipulate the electronic or band gap properties for the desired application. The synthetic technique and compositional/structural nanoparticle characterization are discussed using techniques such as XRD, XPS, HAADF-STEM, elemental mapping and others. An assessment of the thermoelectric and electronic properties for these materials will also be presented.
10:30 AM - *G1.04
Engineering Atoms in Silicon: Building Qubits for the Quantum Internet of the Mid-21st C
David Jamieson 1
1University of Melbourne Parkville AustraliaShow Abstract
New technologies based on the applications of fundamental quantum mechanical principles promise revolutionary applications for information gathering, storage, processing and transmission. The emerging field of quantum technologies has been identified as a research priority area by the 2001 report from the Board on Physics and Astronomy, National Research Council, USA. Deployment of these technologies could lead to the quantum internet of the mid-21st C which could be part of the smart grid to securely manage the complex distributed power systems characteristic of intermittent sustainable power generators based on wind or solar that could help mitigate our present high carbon emissions. The development of next-generation materials for quantum technologies presents a significant challenge. We address this challenge and aim to exploit quantum superposition and entanglement in nanoscale quantum devices engineered with just a single atom that could sustain the extraordinary progress in the ever expanding capabilities of silicon nano-scale Complementary Metal-Oxide-Semiconductor (CMOS) field effect transistors. Present generation devices are now so small that the channel length in the transistors (~20 nm) is comparable in size to the Bohr orbit of the donor electrons (~1.22 nm for Si:P). The devices are sensitive to the variation in the position of the donor atoms and, when cooled, also to the quantum state of single donors. The position variability issue is flagged in the International semiconductor roadmap for 2011. We have exploited these issues to engineer silicon CMOS devices with a single phosphorous atom implanted with a deterministic doping method that is cited by the 2011 roadmap. Our devices, fabricated in natural silicon, have now proved the ability to perform single shot readout of a single donor electron spin. We use electron spin resonance to drive Rabi oscillations to show a coherence time (T2) exceeding 200 µs suggesting a single electron spin can be used as a long-lived quantum bit. Further, the same device has allowed us to perform nuclear magnetic resonance on the single 31P nuclear spin by coupling the electron and nuclear spins and hence providing access to an even longer-lived nuclear qubit. Future devices, built from enriched 28Si, described as a “semiconductor vacuum” because of the absence of nuclear spin, offer longer coherence times. This presentation reviews the remaining challenges of building a large scale silicon quantum device for computation and communication especially if we are to securely control dispersed, low emission technologies that may be adopted by the mid-21st C.
G2: Materials for Transportation
Laura Espinal Thielen
Monday AM, November 26, 2012
Hynes, Level 3, Room 306
11:30 AM - *G2.01
Materials for Energy and Environmental Sustainability: Aviation Materials Advancements
Linda Cadwell Stancin 1 Robin Bennett 1 William Carberry 1 Peter Thompson 1 Jeannie Yu 1
1Boeing Seattle USAShow Abstract
To ensure a balance between the social and economic benefits of commercial aviation and it's energy and environmental impacts, the industry is working on improvements across the entire life cycle of its products and services. Opportunities for environmental improvement reside in advanced materials and manufacturing technologies, improved aerodynamics systems and engine efficiency, alternative fuels, increased fleet operational efficiency, and aircraft recycling. The design of aircraft is highly dependent on materials and technologies that can meet the stringent performance requirements established by manufacturers and aviation authorities to ensure safe flight. Additionally, aircraft manufacturers focus on materials technologies that can improve fuel efficiency, thereby lessening the impact on the environment. Some technologies modify the airplane itself and other technologies improve operational systems, helping aircraft fly the most efficient routes. In addition to fuel conservation, technologies are also focused on the fuel itself and sustainable alternatives. Sustainable fuels based on renewable resources provide long term viability and can reduce environmental impact. At the end of service, the aircraft-recycling industry is capturing high value materials found in aircraft for processing reuse by other industries. Ideally the goal is a closed loop material cycle that optimizes material resource utilization, minimizes both the energy required for processing and the environmental impacts over the entire life cycle of an aircraft. This presentation describes the research and development work being conducted on materials and processes to advance aviation industry sustainability.
12:00 PM - G2.02
Thermal and Rheological Investigation of Surface Interactions in Poly(butylene succinate) Nanocomposites
Margaret Sobkowicz 1 JeongIn Gug 1 Xun Chen 1
1University of Massachusetts Lowell Lowell USAShow Abstract
Fossil resources are becoming increasingly expensive and difficult to extract, which puts pressure on the market for conventional polymers. Polymers from renewable resources have the potential to perform as well or better than materials in use today. The same lightweight, high-strength properties of petroleum-based polymers and composites are required for renewable materials, and a better understanding of processing properties will improve their ability to compete with existing materials. In this work, a promising polyester made from renewable starting materials, poly(butylene succinate), is melt-mixed with silica to create nanocomposites. The surface of the silica nanofiller is modified to explore the effects of surface chemistry on filler dispersion and mixing energy. Rheological and thermal measurements are used to probe the interactions between filler and polymer, and to provide guidance for improved nanocomposite preparation. The demonstrated mechanical property improvements over neat polymer enable a broader range of applications.
12:15 PM - G2.03
Novel Protection Solutions against Environmental Attack for Light Weight High Temperature Materials
Alexander Donchev 1 Michael Schuetze 1
1DFI Frankfurt/Main GermanyShow Abstract
The use of light weight structural materials such as titanium in transport systems such as aero planes leads to significant reduction in fuel consumption. However, titanium and its alloys cannot be used at elevated temperature above 500°C for several reasons. Today aero engine compressors are made of a mixture of light Ti- and heavy Ni-alloys. The improvement of Ti-alloys to withstand the conditions in the high pressure compressor i.e. temperatures above 500°C would enable the manufacturing of a compressor from titanium as a whole with all its associated benefits. Intermetallic TiAl-alloys are another class of light weight materials for several high temperature applications. The use of TiAl as low pressure turbine (LPT) blades in the last sections of a large jet engine could save up to 150 kg which would be beneficial for fuel consumption. In the last sections of the LPTS the temperature is quite moderate (max. 650°C). The improvement of the high temperature capability of TiAl would allow the use in hotter sections of the engine with higher weight reduction. Similarly, the response performance of TiAl-turbocharger rotors in an automotive engine would be 120% compared to the heavy Ni-based alloys used today. Furthermore higher rotation speeds are possible. Due to the novel so called fluorine effect the oxidation mechanism of TiAl is changed. Fluorine treated TiAl-components are protected by an alumina layer formed during high temperature exposure in oxidizing environments. This effect can be transferred to Ti-base materials if they are enriched with aluminum in a thin surface zone. The concepts and the results of high temperature exposure experiments of treated Ti- and TiAl-specimens are presented in this paper. They are discussed in the view of a use for real components.
12:30 PM - *G2.04
Materials in Use in Mobile Emissions after Treatment Systems
Chris Heckle 1
1Corning Incorporated Corning USAShow Abstract
As global concern for air quality intensifies, emissions control technologies play an increasing role in designing materials for transportation. Innovative diesel and gasoline emissions control technologies that help prevent harmful pollutants from entering the air rely on sophisticated materials understanding and product design. Substrates are extruded honeycomb monoliths containing thousands of parallel channels. The channel walls are coated with precious metal catalysts that convert noxious emissions into less harmful gases and water vapor. Filters are used in diesel-powered passenger cars, tractor trailers, buses, agriculture and construction equipment. Diesel particulate filters remove particulate matter (soot) and reduce harmful gases from diesel emissions. Both product families rely on high surface area, excellent thermomechanical performance and low pressure drop. The materials aspects of these products will be reviewed, especially as they pertain to tightening air quality regulations around the world.
Laura Espinal, National Institute of Standards and Technology
Enrico Traversa, University of Rome Tor Vergata
Samuel S. Mao, Lawrence Berkeley National Laboratory
Marie-Isabelle Baraton, Centre Europeen de la Ceramique
Symposium Support National Institute of Standards and Technology
G6/D5: Joint Session: Materials Availability
Tuesday PM, November 27, 2012
Hynes, Level 3, Room 306
2:30 AM - *G6.01/D5.01
Energy Limitations on Materials Availability
Igor Lubomirsky 1 David Cahen 1
1Weizmann Institute of Science Rehovot IsraelShow Abstract
Rapidly occurring changes in energy availability lead to the question if energy and materials sustainability are equivalent. The answer is not straightforward because of two reasons: a) the amount of energy or of major materials types that can be diverted from one to the other to allow changes to new energy sources, without disrupting our daily life, is restricted to at most a few percent of the total energy production; b) if the transition to new energy sources requires large quantities of materials that are byproducts of large scale production cycles, this may pose a problem that has no obvious solution at present. The reason is that any increase in the production of a byproduct requires an almost proportional increase in the production of the primary product. Increased production of the primary product may require materials and energy expenditures, which are too large to be practical. Both theses lead to a number of issues that are critical in considering materials-energy interdependence: a) there is very little flexibility in the ability to divert energy resources to new technologies; b) production of those materials that are by-products cannot be increased rapidly, something that imposes severe restrictions on the rate of technology change and c) recycling can provide only a partial relief of the demand for energy to produce materials, because many items with high energy consumption cannot be recycled. d) although production becomes less and less materials- and energy-intensive, because of the introduction of more and more efficient processes, energy expenditure for production of materials may strongly deviate from this trend for a number of reasons, the most obvious of which is depletion of rich ores and increased hauling distances.
3:00 AM - G6.02/D5.02
Cellulose Nanomaterials: Imaging, Characterization and Applications
Jeffrey William Gilman 1
1NIST Gaithersburg USAShow Abstract
Cellulose is the most abundant organic polymer on Earth, found in plants (cotton, hemp, wood), marine animals (Tunicate), algae (Valonia) bacteria (Acetobacter xylium) and even amoeba (Dictyostelium discoideum). Critical features of the structural performance of cellulose in these diverse settings are the large aspect ratio and high strength properties of the cellulose nanocrystals (CNC) and cellulose nanofibers (CNF), which provides nano-scale reinforcement. Acid hydrolysis of the native cellulose is the predominant method used to prepare pure CNC and CNF. Depending on the source of the cellulose and the chemical treatment the resulting material can vary in crystalline type, surface chemistry, dimensions, and aspect ratio. This new class of materials is gaining increased importance due to their novel properties (high strength, low thermal expansion, rich surface chemistry and optical transparency). Primary drivers for their use include their renewability and proven low toxicity. Consequently, several pilot plants and a number of commercial scale CNC manufacturing facilities have recently gone online worldwide utilizing wood as raw material. The applications envisioned range from transportation to biomedical. The use of CNC/CNF to enhance the properties of polymers originated with Marchessault&’s research in1959.1 Recently, this approach has become the focus of international research efforts.2 The development of measurement method which can characterize the structure and morphology of cellulose nanocomposites over many length scales are needed to enable successful manufacturing and product development of cellulose nanomaterials. Our application of laser scanning confocal microscope (LSCM) imaging combined with Forster resonance energy transfer (FRET)3 has enabled multi-scale characterization of the dispersion of nanofibrillated cellulose fibers in a polymer matrix. The LCSM-FRET method has supplied detailed nano-scale interface information, which has been used to inform more detailed structure property force-indentation studies of CNF nanocomposites. The results of these efforts will be presented, along with our recent efforts to characterize the different surface chemistry and morphologies of the CNC/CNF from various sources. 1. R. H. Marchessault, F.F. Morehead, N. M. Walter, Nature 1959, 184, 632. 2. Y. Habibi, L.A. Lucian, O. Rojas, Cellulose nanocrystals: chemistry, self-assembly and applications. Chem. Rev. 2011, 110, 3479-3500. 3. M. Zammarano, P. Maupin, L.P. Sung, J. W. Gilman, D. M. Fox, "Revealing the Interphase in Polymer Nanocomposites" ACS Nano, 2011, 3391-3399.
3:15 AM - G6.03/D5.03
Glass: An Old Material for the Future of Manufacturing
Susanne Klein 1 Steven J Simske 2
1HP Labs Bristol United Kingdom2HP Labs Ft. Collins USAShow Abstract
Traditional assembly line manufacturing is speculative, costly and environmentally unsustainable. It is speculative because it commits substantial resources—energy, materials, shipping, handling, stocking and displaying—without a guaranteed sale. It is costly because each of these resources—material, process, people and place—involves expense not encountered when a product is manufactured at the time of sale. It is environmentally unsustainable because, no matter how much recycling is done, not using the resources unless actually needed is always a better path. As part of the Ragnarok (Research on Advancing Glass & Nonorganic Applications to Recreate Objects & Kinetics) project in HP Labs, we identified glass as a promising candidate for additive manufacturing based on 3-D printing methods. Glass is a silica-based material. With 90% of the earth&’s crust composed of silicate minerals, there will be no shortage of silica resources. Glass is easy to recycle and is environmentally friendly. Only when glass dust is inhaled can ill health effects be associated with glass. Glass is inexpensive but looks precious, is pleasant to the touch and is so familiar that customers will not be disappointed by its fragility—under certain conditions. Glass is versatile. Glass is ubiquitous in time and space—the ancient Egyptians valued glass as precious jewellery, and energy saving light bulbs are still made of glass. Look around in your environment and you will suddenly realize how widely glass is used. But it can also be used in other high tech applications like: Printed electronics Electronic codes (readable by smartphones, tablets or touchscreens) Security printing (color effects, coatings) Functional surfaces for part assembly Tactile surfaces for touchscreen applications Tactile surfaces on objects replacing classic methods; e.g. veneer. Industrial surfaces—sandpaper, polishing surfaces, abrasive surfaces, friction surfaces, etc. Protective films and coatings The basis of all applications is ‘glass ink&’ for 3D printing. To achieve a sustainable, environmental friendly and ‘carefree&’ technology we concentrate on water-based inks. Glass will suspend in water when the particles are small enough but a glass and water mixture alone is not printable. Under pressure the water is expelled from the mixture and jamming occurs. A binder is needed to trap the water between the glass particles. Traditionally polysaccharides are used for glass, see for example http://www.washington.edu/news/archive/id/52160. In small amounts, the sugar will simply burn off during firing: when it is trapped inside the glass object, it will lead to discolouration. We will present alternative approaches leading to transparent glass objects.
3:30 AM - *G6.04/D5.04
Will Metal Scarcity Impede Routine Industrial Use?
Thomas Graedel 1
1Yale University New Haven USAShow Abstract
Materials scientists today employ essentially the entire periodic table in creating modern technology. In an age of sharply increasing usage, it is reasonable to wonder about the supplies of these elemental building blocks. This talk will present a recent history of resource use trends, emphasizing the rapid recent growth in the use of scarce “specialty metals”. A methodology for assessing relative metal criticality is discussed, and illustrated with a sampling of results for a variety of metals. The implications of criticality and its evolution provide food for thought with respect to the widespread use of metals based solely on their physical and chemical properties, with little or no consideration given to long term availability.
4:30 AM - *G6.05/D5.05
Project Phoenix: Making More Clean Energy-critical Materials Available
John L. Burba 1 Andy Davis 1
1Molycorp, Inc. Greenwood Village USAShow Abstract
One way to reduce the criticality of materials is to increase their production and recycling on a local basis. This talk will focus on Molycorp&’s Project Phoenix at Mountain Pass, CA, a major expansion, renovation, and restarting of rare earth production in the U.S. after a decade-long hiatus. Molycorp is expected achieve a Phase 1 rate of production of 19,050 tonnes/year in the fourth quarter of 2012, and is expected to expand its production capacity in mid-2013 to as much as 40,000 tonnes/year. Coupled with its additional processing facilities around the world, the Company will produce a wide variety of high-purity, custom engineered, light and heavy rare earths. Molycorp's production will go a long way to reducing the criticality of such key elements as neodymium, europium, dysprosium, terbium and others.
5:00 AM - *G6.06/D5.06
Critical Elements and New Energy Technologies
Robert L Jaffe 1
1MIT Cambridge USAShow Abstract
The twin pressures of growing demand for energy and increasing concern about anthropogenic climate change have stimulated research into new sources of energy and novel ways to harvest, transmit, store, transform or conserve it. At the same time, advances in physics, chemistry, and material science have enabled researchers to identify chemical elements with properties that can be finely tuned to their specific needs and to employ them in new energy-related technologies. Elements that were once laboratory curiosities, like neodymium, tellurium, and terbium, now figure centrally when novel energy systems are discussed. Many of these elements are not at present mined, refined, or traded in large quantities. New technologies can only impact our energy needs, however, if they can be scaled from laboratory, to demonstration, to massive implementation. As a result, some previously unfamiliar elements will be needed in great quantities. Although every element has its unique story, these Energy Critical Elements have many features in common. I will describe the shared characteristics of these elements, their roles in emerging technologies, potential constraints on their availability, and government actions that can help avoid disruptive shortages. As an example, I will focus especially on elements that are required for photovoltaic technologies.
5:30 AM - G6.07/D5.07
Microbial Approaches to the Extraction and Recovery of Scarce Metals
William Bonificio 1 David Clarke 1
1Harvard University Cambridge USAShow Abstract
Biologically mediated extractive metallurgy promises to be a sustainable and environmentally low impact approach to the production of critical energy materials. Our work focuses on the role microbes may have in the recovery of tellurium and rare earth elements (REEs). The microbes used in our studies are three strains of extremophilic microbes from the East Pacific Rise hydrothermal vent fields: pseudoalteromonas sp., alcanivorax sp., and acinetobacter sp., two copper mine drainage microbes: acidithiobacillus thiooxidans and leptospirillum ferrodiazotrophum, and the dissimilatory metal reducer shewanella oneidensis. These microbes, specifically pseudoalteromonas sp., have shown an unusually high resistance to both tellurium and the REEs with a minimum inhibitory concentration (MIC) of ~0.1mM for both. Pseudoalteromonas sp. has the ability to reduce tellurite (TeO32-) to metallic tellurium (Te0) and methylate it forming dimethyl telluride (Te(CH3)2). Our investigations into these exact mechanism has demonstrated the direct conversion of various other tellurium compounds, such as tellurium dioxide (TeO2), and telluric acid (Te(OH)6) to Te0, paralleling that already occurs during standard, chemical tellurium production. Furthermore we have demonstrated the recovery of Te0 from cadmium telluride, which lends itself to CdTe solar cell recycling, and recovery from autoclave leach slime, the effluent from copper production. We are currently exploring the role of reactive oxygen species (ROS) in these tellurium transformations and will describe our findings. These microbes also appear to biosorp REEs from solution. When incubated with 100 ppb of the rare earth chlorides they have demonstrated enhanced uptake, extracting >95% of REEs from their medium. During this extraction the microbes fractionate individual REEs resulting in separation factors for neighboring REEs of ~1.2, comparable to current industrial solvent-extraction methods. Finally, we will discuss our research on the interaction between these strains and bastnasite concentrate and how it applies to microbially-aided rare earth production.
5:45 AM - G6.08/D5.08
Thermochemistry of Indium Recovery in the Pyrometallurgical Recyling Technology
Joo Hyun Park 1 Kyu-yeol Ko 1
1University of Ulsan Ulsan Republic of KoreaShow Abstract
Indium (In) is usually produced as a minor by-product of lead and zinc smelting and refining processes, and is used in flat panel display (ITO) and thin film solar cell (CuInSe2, CuInGaSe2), etc. Recently, the pyrometallurgical recycling of In-containing materials has been issued in view of 'Urban Mining' due to very high cost and scarceness of indium. However, the solubility of indium into the molten flux has not been fully understood yet. Therefore, in the present study, the solubility of indium at 1773 K in molten CaO-SiO2-Al2O3 flux was measured under reducing atmosphere. The pure indium (99.99%) contained in a graphite crucible was equilibrated with a purified CO(+Ar) gas mixture in the mullite reaction tube which was heated by MoSi2 heating element. The oxygen potential was controlled by C/(CO+Ar) equilibrium. After equilibrating, the samples were quenched by dipping the crucible into brine and crushed for chemical analysis. The content of indium was analyzed by ICP-AES and that of slag components was analyzed by XRF spectroscopy. In high silica region, the solubility of indium increases with increasing oxygen potential and decreases with increasing content CaO, which is in proportion to the basicity. Also, the effect of flux composition and temperature on the solubility of indium is discussed. The solubility of indium was measured in the low silica melts to ensure the applicability of the established reaction mechanism. The solubility of indium follows different mechanism at low silica region. The solubility of indium at low silica region decreases with increasing oxygen potential and increases with increasing CaO content. Consequently, the optimized flux composition was designed to increase the recovery of indium in the pyrometallurgical treatment of In-containing materials.
G7: Poster Session: Materials for Sustainable Technologies
Laura Espinal Thielen
Tuesday PM, November 27, 2012
Hynes, Level 2, Hall D
9:00 AM - G7.01
Nano Lift-off Method for Fabricating GaN Thin Films
Yuefeng Wang 1 5 Liang Tang 2 5 Gary J Cheng 3 5 Michael J Manfra 1 2 5 Timothy D Sands 1 4 5
1Purdue University West Lafayette USA2Purdue University West Lafayette USA3Purdue University West Lafayette USA4Purdue University West Lafayette USA5Purdue University West Lafayette USAShow Abstract
GaN is one of the most widely used semiconductor materials in optoelectronic devices, high speed transistors, high power electronics, spintronics and biocompatible devices. Compared to GaN on sapphire or SiC substrate, free-standing GaN films have multiple exclusive benefits such as strain relieve, light extraction, defect reduction and potential flexibility. While the traditional Laser lift-off (LLO) was developed to separate GaN from sapphire substrates, the technique has limitations of only being able to lift off GaN film with a thickness of several um and leaving degraded surfaces. In this work, we present a novel method able to fabricate thin film GaN suitable for electronics device application with a thickness greater than tens of nm. Starting from GaN on sapphire substrate, MBE or MOCVD can be used to fabricate an epitaxial superlattice sacrificial layer and the GaN epilayer to be lifted off. The average In composition in the sacrificial layer is critical for effective laser absorption, which is examined by XRD and EDS. By manipulating growth parameters, the In composition can be control from 0% to over 50%. The sacrificial layer is lattice matched to the GaN substrate, enabling high quality GaN epilayer growth to an arbitrary thickness. After growth, photoluminescence and ellipsometer were used to determine the effective bandgap of the sacrificial layer. Pulsed laser with photon energy of ~2.3eV and fluencies ranging from 50mJ/cm2 to 300mJ/cm2 was irradiated onto the sample which leads to the controlled decomposition of sacrificial midlayer and easy separation of the top GaN film from the substructure by adhesive transfer. This technique can be used to fabricate GaN films with low defects and a wide range of thickness, especially sub-um level. TEM, AFM and FESEM were used to characterize the crystallinity and surface morphology of the freestanding film. A numerical laser-solid interaction model was developed to optimize the lift-off process. Lamellar structures were demonstrated for the possibility of multiple-film nano lift-offs on single substrate, which substantially reduced the cost and improved the crystal quality of freestanding GaN film. LED devices were integrated on a GaN epilayer to confirm the preservation and enhancement of device performance. Overall, the recently developed nano lift-off process is a promising pathway to nanoscale GaN freestanding devices and high quality GaN substrates.
9:00 AM - G7.02
Flame-made Nanostructured Ca/Fe Oxides for Nutritional Supplements
Jesper T.N. Knijnenburg 1 Florentine M. Hilty 2 Michael B. Zimmermann 2 Sotiris E. Pratsinis 1
1ETH Zurich Zurich Switzerland2ETH Zurich Zurich SwitzerlandShow Abstract
Calcium and iron are essential for humans, but inadequate intakes are common and adversely affect health. Dietary intakes of these minerals can be improved by supplementation, typically with element-specific but also with multivitamin/multimineral supplements. Since recently, nanostructured iron compounds emerged as promising materials against iron deficiency [1,2] The large surface area of these iron oxides and phosphates enhances their dissolution in the stomach. Very recently we have shown that the incorporation of calcium into nanostructured iron oxide increases iron solubility even further  and potentially also bioavailability  compared to pure iron oxide. For high dopant contents the solubility was comparable to the “gold standard” FeSO4. The increase in iron solubility is a result of the formation of a solid solution, decreasing the average bond energy of the crystal. Calcium-containing supplements are the most commonly consumed mineral supplements worldwide. Their high solubility and bioavailability makes them attractive as carrier matrix for trace minerals such as iron. Here, nanostructured calcium oxide-based supplements are developed as carriers for iron supplementation. Calcium oxide doped with nutritionally relevant amounts of iron was produced in one step by flame spray pyrolysis. Inexpensive precursors (nitrates) and solvents (ethanol-based) were used to minimize synthesis costs. Large amounts of calcium resulted in matrix encapsulation of iron, preventing the formation of low-solubility oxides, but forming Ca/Fe oxide solid solutions instead. Solubility measurements i.d.a. demonstrated rapid and complete dissolution of all elements, suggesting they would have high in vivo bioavailability. This rapid, simple one-step synthesis process allows tunable composition of multimineral supplements with high mineral solubility, making them promising for nutritional applications.  Miller DD. New leverage against iron deficiency, Nature Nanotechnology (2010), 5, 318-319.  Hilty FM, Arnold M, Hilbe M, Teleki A, Knijnenburg JTN, Ehrensperger F, Hurrell RF, Pratsinis SE, Langhans W & Zimmermann MB. Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation, Nature Nanotechnology (2010), 5, 374-380.  Hilty FM, Knijnenburg JTN, Teleki A, Krumeich F, Hurrell RF, Pratsinis SE & Zimmermann MB. Incorporation of Mg and Ca into Nanostructured Fe2O3 Improves Fe Solubility in Dilute Acid and Sensory Characteristics in Foods, Journal of Food Science (2010), 76, N2-N10.
9:00 AM - G7.03
Solvent-mediated H2-release from Ammonia Borane
Chang Won Yoon 1 Yong Min Kim 1 Suk Woo Nam 1
1Korea Institute of Science and Technology Seoul Republic of KoreaShow Abstract
Ammonia borane (AB) and its related amine boranes have widely been studied as promising hydrogen storage materials. We found that the rate and extent of H2-release from AB were increased at 85 oC in the presence of various types of polyetheral solvents. These enhanced effects were pronounced particularly with tetraetraethylene glycol (T4EG) and tetraethylene glycol dimethyl ether (T4EGDE). Spent-fuels produced by the thermolyses of AB with either T4EG or T4EGDE at 85 oC were found to be polyaminoborane (PAB) and diammoniate of diborane (DADB), as evidenced by 11B NMR spectroscopy. In situ infrared spectroscopy indicated the formation of B-(cyclodiborazanyl)amino-borohydride (BCBD) and borazine as gaseous byproducts. Density functional theory (DFT) methods were employed to understand the influence of the solvents on the enhancement of rate and extent of H2-release from AB.
9:00 AM - G7.04
Forward Voltage Reduction and Light Extraction Enhancement of InGaN/GaN MQW LEDs Using ALD-grown Ga-doped Transparent Conductive Layers
Kuo-Yi Yen 1 Chien-Hua Chiu 1 Chien-Hua Chou 1 Tzu-Pei Chen 1 Tai-Yuan Lin 2 Jyh-Rong Gong 1
1National Chung Hsing University Taichung Taiwan2National Taiwan Ocean University Keelung TaiwanShow Abstract
Ga-doped zinc oxide (GZO) transparent conducting layers (TCLs) were deposited at 300oC by atomic layer deposition (ALD) on the InGaN/GaN multiple quantum well (MQW) light emitting diode (LED) structures. The GZO-coated InGaN/GaN MQW LED structures were then annealed at 400, 500, 600, 700, 800oC for 5 min under N2 ambient prior to LED chip fabrication. It was found that reduced forward voltage and enhanced light extraction were achieved in certain annealed GZO-coated InGaN/GaN MQW LED structures. A forward voltage of 3.1 V at 20mA was found for an LED with annealed GZO TCL at 400oC with the GZO on p-GaN contact showing a specific contact resistance of 4.1×10-3Omega;-cm2. The ohmic nature between GZO and p-GaN is attributed to the very high electron background of 1.5×1021cm-3 in the 400oC-annealed GZO, which supports electron tunneling through the GZO/p-GaN heterointerface. An increment of light output power by 15% at 20mA for an InGaN/GaN MQW LED having 400oC-annealed GZO TCL compared with the same InGaN/GaN LED structure having an ITO TCL was observed. It is believed that the enhanced light extraction of the GZO TCL-coated InGaN/GaN MQW LED is mainly the consequence of higher refractive index of GZO than that of ITO.
9:00 AM - G7.05
Carbon Dioxide Separation of Ultrathin Multilayers Prepared Using Layer-by-layer Self-assembly Technique
Tatsuya Funaoka 1 Yusuke Daiko 1 Atsushi Mineshige 1 Tetsuo Yazawa 1
1University of Hyogo Himeji JapanShow Abstract
Introduction Greenhouse effect is becoming an urgent environmental problem, and removal or separation of carbon dioxide from flue gases are considered to be a promising technology for greenhouse-gas emission control. One technology for carbon dioxide separation is based on an adsorption process using liquid amines. Compared with adsorption method, membrane separation method has advantages such as low cost and rapid recovery. For practical application, membranes with both a high gas permiability and high carbon dioxide selectivity are required. However, there is a trade-off relationship between them. The thinner membrane shows better gas permeability whereas shows lower carbon dioxide selectivity. We have focused on the preparation of ultrathin coatings with a good carbon dioxide affinity utilizing layer-by-layer (LbL) self-assembly. We anticipate that a separation membrane with both a good gas permeability and selectivity would be obtained by controlling the thickness and polarity (affinity) for carbon dioxide. In this study, various cationic polymers with amino groups were deposited, and carbon dioxide separation and its relation to the LbL structure were investigated. Experimental A porous alumina tube with the pore diameter of 0.1 mu;m was used as a support. At first, a commercial silica colloid and then silica/PEG hybrid membrane were coated on the alumina support by dip coating. Finally, cationic primary ammonium salt of poly(allylamine hydrochloride) (PAH) or quaternary ammonium of poly(diallyl dimethylammonium)choloride (PDDA) were deposited on the silica coating via LbL technique. Result and discussion Pore structure was measured by using nitrogen gas absorption/desorption method. The pore diameter of alumina substrate with silica coatings was estimated to be 2 nm. After the deposition of polycation thin film, carbon dioxide adsorption on the film was measured utilizing quartz crystal microbalance (QCM). The QCM results revealed that the amount of carbon dioxide adsorption increased clearly after the deposition of PAH or PDDA. Interestingly, carbon dioxide separation factor was also increased after the LbL deposition.
9:00 AM - G7.06
Self-separating Catalyst Using Magnetic Nanoparticles Combined with Thermoresponsive Polymers
Martin Zeltner 1 Alexander Schaetz 1 Max Leo Hefti 1 Wendelin Jan Stark 1
1ETH Zurich Zurich SwitzerlandShow Abstract
Catalysis is among the most important applications within the field of nanoscience . The large surface area of nanoparticles qualifies them naturally to act either as heterogeneous promoters for catalytic reactions or as a support for homogeneous catalysts. Especially magnetic nanoparticles are meant to overcome the most tantalizing drawback in homogeneous catalysis, i.e. reliable separation and recycling of often toxic and expensive transition metal complexes for more sustainability in catalysis. Thus, they simultaneously comply with economical and ecological requirements. We have synthesized highly ferromagnetic, thermoresponsive nanomagnets with a graphene coated cobalt metal core to which amphiphilic N-isopropylacrylamide polymer branches were covalently attached.  This novel hybrid material could be further modified with a Pd-phosphine complex to catalyze Suzuki-Miyaura cross-coupling reactions. The heterogenized metal-complex acted as a ‘self-separating&’ catalyst. Thermally triggered switching of poly-NIPAM coated C/Co-nanoparticles in typical biphasic water/toluene reaction systems allowed for a temperature- controlled shift of the catalyst from the organic to water phase and vice versa. This enabled the catalyst to switch in the organic layer at reaction temperature and to return into the aqueous layer once the reaction mixture was cooled (ambient temperature; magnetic removal and reuse of the catalyst). Thus, the product phase was isolated via simple extraction/decantation. Moreover, the supported catalyst was recycled from the aqueous phase by taking advantage of the magnetic cores and reused over ten times.  A. Schaetz, O. Reiser, W.J. Stark, Chem. Eur. J., 2010, 16, 8950.  R. N. Grass, E. K. Athanassiou, W. J. Stark, Angew. Chem., 2007, 119, 4996.  M. Zeltner, A. Schaetz, M.L. Hefti, W.J. Stark, J. Mater. Chem., 2011, 21, 2991.
9:00 AM - G7.07
Photocatalytic Properties of TiO2/WO3/FTO Multi-layer Structures Prepared by Spray Pyrolysis Deposition
Masahiko Maeda 1 Takahiro Horikawa 1
1Kanazawa Institute of Technology Ishikawa JapanShow Abstract
In recent years, titanium dioxide (TiO2) with super-hydrophilic and photocatalytic characteristics has received a great deal of attention. In environmental fields, particularly, such materials are important because of their ability to detoxify environmental pollutants. When the TiO2 is irradiated with ultraviolet-light (UV-light), organic compounds are decomposed on their surface and water spreads evenly to their super-hydrophilic surface, as a result, surface self-cleaning can be easily realized. Because the bandgap energy of TiO2 is 3.2 eV, UV-light of wavelength of 380 nm or less is necessary to fulfill their photocatalytic properties. Even in outdoors during daytime, the intensity of UV-light is only about 1 mW/cm2. Under these circumstances, the demand for the photocatalytic materials that can respond to visible-light has strengthened day by day. Visible-light photocatalytic materials have been intensively investigated. For development of visible-light response of TiO2 photocatalytic materials, novel metal oxides with narrow bandgap and doping of transition metals or non-metallic elements into the TiO2 have been intensively investigated until now. The other approach for improvement of TiO2 photocatalytic activity, it has been reported that bilayer structures of TiO2 and other metal oxide films with appropriate conduction band and valence band edges are effective. In these structures, charge separation of photogenerated electron/hole pairs takes place effectively. In this study, we investigated on the visible-light response of photocatalysis for TiO2/WO3/FTO multi-layer structures prepared by spray pyrolysis deposition. The effect of fluorine concentration in SnO2 under layer on photocatalytic activity was investigated. The precursor solutions used for preparation of the TiO2/WO3/FTO multi-layer structures were ethanol solution dissolved titanyl(IV) acetylacetonate, ammonia solution dissolved WO3, and ethanol solution dissolved tin(IV) chloride and ammonium fluoride, respectively. Each film was continuously deposited on the substrate by spraying the precursor solution through the spray nozzle. The visible-light response of photocatalysis was successively observed in these structures and its activity increases with increasing fluorine concentration in the SnO2 films. Because the bandgap energies of TiO2, WO3, and SnO2 films were 3.2, 2.5, and 3.6 eV, respectively, the visible-light absorption takes place in WO3 layer. The generated electrons and holes diffuse to SnO2 conduction band and TiO2 covalent band, respectively, due to difference of band edges. The conductivity of FTO films increases with increasing the fluorine concentration, therefore, the electron diffusion takes place effectively from WO3 to FTO. As a result, higher photocatalytic activity is observed in order to enhancement of hole diffusion from WO3 to TiO2.
9:00 AM - G7.10
Iron Phosphate Nanoparticles for Food Fortification by Combustion of Sprays
Thomas Rudin 1 Sotiris E. Pratsinis 1
1ETH Zurich Zurich SwitzerlandShow Abstract
Iron deficiency is still a major global public health issue that can be addressed by food fortification, an effective way to improve iron intake. Low-cost synthesis of iron phosphate nanostructured powders is attractive for large scale fortification of basic foods (rice, bread etc.). This is achieved here by flame-assisted and flame spray pyrolysis of inexpensive precursors (iron nitrate, phosphate), solvents (ethanol) and support gases (acetylene and methane). The iron phosphate powders produced here were mostly amorphous and exhibited excellent solubility in dilute acid, an indicator of relative iron bioavailability. The amorphous and crystalline fractions of such powders were determined by X-ray diffraction (XRD) and their cumulative size distribution by X-ray disc centrifuge. Fine and coarse size fractions were obtained also by sedimentation and characterized by microscopy and XRD. The coarse size fraction contained maghemite Fe2O3 while the fine was amorphous iron phosphate. Furthermore, the effect of increased production rate (up to 11 g/h) on product morphology and solubility was explored. Using increased acetylene/methane flow rates for the flames and inexpensive powder precursors resulted in homogeneous iron phosphate nanoparticles with excellent iron solubility in dilute acid, independent on the production rates investigated here.
9:00 AM - G7.11
Carbonyl-based Organics as Novel Cathodes for Lithium Ion Batteries
Kenneth Hernandez-Burgos 1 Stephen Edwards Burkhardt 1 Hector Abruna 1
1Cornell University Ithaca USAShow Abstract
An important challenge for enabling the wide-spread utilization of renewable energy sources, such as solar and wind, consists in developing high efficiency, low cost, high energy density, safe and environmentally benign batteries. Lithium ion batteries (LIBs) represent an attractive alternative as energy storage devices because they exhibit a higher voltage, and higher energy density compared to traditional batteries. Organic compounds are an attractive alternative for use as cathodes in LIBs. The building blocks of Carbonyl based organic molecules (C-bOMs) (i.e. carbon, hydrogen, nitrogen, oxygen and sulfur) are abundant and inexpensive and shows rapid and chemically reversible electrochemical behavior and their reduced forms (enolates) display a strong ionic interaction with lithium cations. Furthermore, a wide range of chemical variations/modifications can be performed on C-bOM structures to predictably modify their electrochemical behavior, e.g. to maximize the interaction of the material with lithium, maximize the number of electrons transferred while minimizing the molecular weight of the compound, thus maximizing energy density. Is our plan to present the developing of high performance electrical energy storage devices for application in LIBs by identifying/designing new low molecular weight and high voltage C-bOMs, which will overcome the high cost, low gravimetric capacities and energy densities, slow charge discharge rates, typical of the currently employed inorganic (especially oxides) materials. The studies consist of three steps: computational screening and designing of new molecules, electrochemical characterization, and practical testing using “coin cells”. Computational chemistry was used to predict the formal potentials of the new materials (E= 2.5-3.0 V) and identify the most promising candidates. Also was studied the influence in the formal potential of the addition of electro-withdrawing groups. Finally, for the electrochemical characterization cyclic voltammetry (CV) was employed to characterize the molecules that were identified from the computational screening. In the electrochemical characterization we were able to study the influence of alkali metals base electrolytes in aprotic organic solvents, which shows how from a two one electrons waves were found a conjoining of the two waves into one two electrons wave. After all the studies we were able to design and characterize new C-bOMs molecules, which represent new alternatives as cathodes materials for LIBs.
9:00 AM - G7.12
Testing the Trigger Theory: The Effect of Different Nutrients on the Lipid Content in Tetraselmis suecica
Tanay Lathia 1 Ajay Bhargava 2 Deborah Day 1
1Amity High School Woodbridge USA2NEBA Hamden USAShow Abstract
The world today consumes an enormous amount of unsustainable energy; thus, scientists are trying to identify an alternate, renewable fuel source. One possible fuel source is algal biodiesel, which is made from algal lipids. This study aims to maximize the lipid content in the green microalgae, Tetraselmis suecica, through the deprivation of nutrients. It is hypothesized that as the amount of nutrients, sodium nitrate (NaNO3) and sodium glycerophosphate (C3H7Na2O6P), is decreased in the medium, the lipid content of the Tetraselmis suecica will increase. This hypothesis is based on the trigger theory established in a study completed in 1998 by the National Renewable Energy Laboratory, which stated that as algae are deprived of nutrients they compensate by producing more lipids. To test the trigger theory, different batches of algae were grown with varying concentrations of sodium nitrate. The control group contained 100% of all nutrients as dictated by the UTEX Enriched Seawater Medium. The experimental batches had 75% and 50% of the recommended sodium nitrate content, respectively. These trials were repeated using the same protocol except the sodium nitrate was replaced with sodium glycerophosphate. After two weeks of incubation under 12 hour light/dark cycles and constant shaking, the algae were harvested using a centrifuge. The samples were transported on dry ice to a second laboratory in preparation for the lipid analysis. The total biomass of each sample was measured, followed by a chemical extraction. The chemical extraction consisted of covering the algae in various chemicals, such as methanol and then dichloromethanol. The chemicals caused the algae to split into its various components, such as the carbohydrate portion, the lipid portion, etc. The lipid fraction of each trial was massed and compared to its total biomass. The algae grown in the media with 100% of nutrients consisted of 32% by mass of lipids. Furthermore, when the amount of sodium nitrate in the media was cut in half, the algae were 56% by mass of lipids. A similar result occurred with the media that had 50% of the recommended sodium glycerophosphate; the Tetraselmis suecica was 48% by mass of lipids. These results showed an inverse trend between the amount of a specific nutrient in the medium and the lipid yield of the Tetraselmis suecica, supporting the Trigger Theory. After gathering results, statistical tests were done to analyze the significance of the data. The sodium nitrate results yielded a p-value of 0.0312, while the sodium glycerophosphate results had a p-value of 0.0459. Both of these values are less than 0.05, showing the significance of the data. The results obtained in this study can be utilized to optimize the lipid content and fuel output of algae.
9:00 AM - G7.13
Photocatalytic TiO2 Macroscopic Fiber Obtained through Integrative Chemistry
Natacha Kinadjian 1 2 Mickael Le Bechec 3 Thierry Pigot 3 Fabien Dufour 4 Olivier Durupthy 4 Ahmed Bentaleb 1 Eric Prouzet 2 Sylvie Lacombe 3 Renal Backov 1
1Universitamp;#233; de Bordeaux 1 Bordeaux France2University of Waterloo Waterloo Canada3Universitamp;#233; de Pau et des Pays de lamp;#8217;Adour Pau France4Collamp;#232;ge de France Paris FranceShow Abstract
With the apparition of the “environmentally friendly production” concept, air purification by photocatalysis became one of the major concerns for industries. Photocatalytic properties of titanium oxide (TiO2) depend, not only on its electronic property, but also on the material size and shape, which can favor a higher interaction between reactants and catalyst. In order to make such architectures, we used the concept of integrative Chemistry . In our study, we used a new process to obtain macroscopic TiO2/polyvinylalcohol(PVA) fibers nanocomposite fibers which was developed in the last years for carbon/PVA fibers or again vanadium oxide/PVA fibers.  We studied five different sets of TiO2/PVA nanocomposite, which were synthesized by varying the TiO2 nanoparticles synthesis and the TiO2 nanoparticles concentration in the solution used for the fibers synthesis process (co-axial flux extrusion). All the sets presents a high specific surface area as there are in the range of 100 to 700 m2.g-1 compared to 50 m2.g-1 for the P25 Evonik reference material. Moreover, we demonstrated that the surface roughness and the specific surface area decrease as the particles concentration increases. These parameters combined with the particles shapes gave us specific design for each set. This design have been combined with material 1D processing and orientation, and it has been demonstrated that the photocatalytic properties are f avored, especially mineralization, when the material hierarchical 1D orientation is combined with unidirectional gas flow. These sets of materials have been characterized and tested for the photocatalytic degradation and mineralization (conversion into CO2) of acetone, and compared with commercial catalysts. Our study reveals that a suitable combination of multiscale design and optimized matching between material orientation and gas flow, can favor high mineralization yield.  N. Brun, S. Ungureanu, H. Deleuze and R. Backov. Chem. Soc. Rev., 2011, 40, 771  L. Biette, F. Carn, M. Maugey, M.-F. Achard, J. Maquet, N. Steunou, J. Livage, H. Serier, R. Backov, Adv. Mater. 2005, 17, 2970  N. Kinadjian, M. Le Bechec, T. Pigot, F. Dufour, O. Durupthy, A. Bentaleb, E. Prouzet, S. Lacombe and R. Backov Eur. J. Inorg. Chem. (under submission)
9:00 AM - G7.14
Optimal Design of Ca-modified Ni/Al2O3 Catalyst for Low Temperature Ethanol Steam Reforming
Catherine Kai Shin Choong 1 2 Ziyi Zhong 1 Lin Huang 1 Jianyi Lin 1 Liang Hong 2 Luwei Chen 1
1Institute of Chemical and Engineering Sciences Singapore Singapore2National University of Singapore Singapore SingaporeShow Abstract
Hydrogen is an important energy carrier which can be utilized as a fuel for fuel cell applications. Amid the variety of new technologies available for hydrogen production, catalytic ethanol steam reforming (ESR, C2H5OH + 3H2O -> 2CO2 + 6H2) is a promising reaction and has generated extensive interest in the past decade. The low toxicity and high energy density of ethanol present itself as an attractive precursor. In addition, the production of ethanol from lignocellulosic biomass such as wood chips and grasses is garnering maturity in the technology and hence portrays a positive outlook towards net-zero carbon emission. Nickel catalysts have demonstrated promising results for ESR, mainly because of its excellent C-C bond breaking activity. However, the use of Ni catalyst to perform ESR without coke deposition at low temperature range (T < 400oC) is a challenge in this process. In this study, catalysts comprised of Ni particles were impregnated over Ca-modified Al2O3 (Ca loading = 3-7 wt%). The catalysts were characterized using XRD, XPS, TEM, H2-TPR and TPD of different probe molecules such as NH3, CO2, H2O and C2H5OH. Deactivation study was conducted using a tapered element oscillating microbalance (TEOM). The catalytic properties were studied for ESR using a 5 channels micro-reactor at 400oC. Results showed that catalyst with 3 wt% of Ca remains stable at 400oC for at least 24 hr, while 0 wt% and 7 wt% Ca modified catalysts deactivate easily. The introduction of Ca greatly reduces the acidity of Al2O3, depressing ethanol dehydration and ethylene formation. It brings about positive attributes such as increasing water adsorption, providing Ni catalyst the proximity and abundance of adsorbed OH groups. The involvement of OH groups in the reactions in turn enhances the ethanol adsorption, stabilizes its adsorbate intermediates for further conversions to H2, CH4 and CO2 at relatively low temperatures. In the meantime, the addition of Ca increases the particle size of active Ni which promotes the formation of un-reactive and encapsulating carbons, undermining the stability of highly loaded (7 wt%) Ca-modified Ni catalyst. XPS valence band shows that the presence of Ca increases the density of Ni 3d band valence electrons which helps in dissociation of methane and deactivates the catalysts, as in the case of nickel catalysts supported on 7 wt% of Ca on Al2O3. Excellent catalytic performance of 10Ni/3Ca-Al2O3 is due to the effective coke removal and the amorphous nature of coke deposition. Optimized Ca loading was found to play a critical role in coke removal, through its effect on Ni particle size, valence band of catalyst and steam gasification of coke.
9:00 AM - G7.15
Theoretical Study on Porphyrin Based Covalent Organic Polyhedra as a Hydrogen Storage
Dae jin Kim 1 2 Hyein Guk 1 Dong Hyun Jung 1 Kihang Choi 2 Seung-Hoon Choi 1
1Insilicotech Seongnam-Si, Gyeonggi-Do Republic of Korea2Korea University Seoul Republic of KoreaShow Abstract
As potential candidate materials for hydrogen storage, COFs (covalent-organic frameworks) are appealing because they can take up and release hydrogen reversibly with fast kinetics. And COFs may have an advantage in increasing gravimetric hydrogen storage capacity because their frameworks are light. Porous organic molecules display some striking differences in comparison with porous networks such as COFs, both in terms of processability and physical properties. Much effort has been devoted to discovering new COPs (covalent organic polyhedra) as porous molecules for applications such as gas separation, energy storage and catalysis. Here, we introduce new COP containing porphyrinyl groups. Porphyrin COP can be synthesized by the [6+8] condensation which means that 6 tetraaldehyde molecules with 8 triamine molecules make 24 imine bonds. During the reversible process of imine bond formation and break, the reaction is driven toward the most stable product, and this process is called dynamic covalent bond. Porphyrinyl group is good for metallation which can make coordination with ligands such as bipyridine. This ligand-coordinated metal play an important role in connecting porphyrin COP molecules and creating extrinsic porosity in the crystal in addition to the intrinsic porosity of porphyrin COP molecule. For the modeling of the crystalline structure, polymorphs of molecular crystal are predicted by the simulated annealing Monte Carlo simulation method. Grand canonical Monte Carlo simulations predict the hydrogen uptakes of these polymorphs of porphyrin COP and the values are from 99 to 262 mg g-1 for gravimetric uptake and from 46 to 51 kg m-3 for volumetric uptake at 77 K. Hydrogen uptake of porphyrin COPs is comparable to the best records of MOFs (164.1 mg g-1 for NU-100 and 166.9 mg g-1 for MOF-210 at 77 K). In this work, we suggest new porous organic cage molecules called COPs with large surfac