GLRPPR Projects Database

Development of Nanocrystalline Zeolite Materials as Environmental Catalysts: From Environmentally Benign Synthesis to Emission Abatement

Wed, 16 Jan 2008 22:06:54 GMT

This proposal describes the development of nanometer-sized zeolites and zeolite nanostructures as environmental catalysts. Zeolites, which are widely used in applications in separations and catalysis, are aluminosilicate molecular sieves with pores of molecular dimensions. The crystal size of zeolites formed during conventional synthesis range in size from 1000 to 10,000 nm. However, for some applications it would be advantageous to employ much smaller nanometer-sized zeolite crystals in the range, 10-100 nm. Specific advantages to be gained by using zeolite nanostructures include facile adsorption and desorption, the ability to form dense films to facilitate separations applications and optical transparency. The first hypothesis of the proposed project is that the properties of zeolites with respect to reactant and product diffusion and light scattering can be significantly improved by using nanometer-sized zeolites and nanostructures (fibers or thin films). The second hypothesis of the proposed project is that these zeolite nanostructures will be superior materials for applications in heterogeneous environmental catalysis.

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Green Engineering of Dispersed Nanoparticles: Measuring and Modeling Nanoparticle Forces

Wed, 16 Jan 2008 22:00:58 GMT

Nanotechnology will be critical to advances in electronics, materials, medicine, and the environment. This is in large part due to their remarkable electronic, optical, magnetic, and mechanical properties. However, a significant limitation of nanotechnology is the ability to produce bulk quantities of dispersed particles. One possibility for dispersing nanoparticles (which have a high area/mass ratio) is to use adsorbed polymer, oligomer, or surfactant molecules; however, disposal of the enormous quantity of additives would involve huge environmental and financial stresses. The expected engineering breakthrough of the proposed research is to identify whether solvation or depletion forces can be manipulated to produce dispersed suspensions of "bare" nanoparticles (i.e., without adsorbed additives). The central scientific questions to be answered are these: What are the magnitudes of the van der Waals, solvation, and depletion forces for nanoparticle systems, and what variables can we control to alter these forces? The research will involve two primary components: 1) development and use of "particle force light scattering" (PFLS), an experimental method for measuring sub-piconewton nanoparticle forces, 2) use of molecular dynamics (MD) simulations to predict the individual forces. Synergy is essential to this research: PFLS is the first technique capable of measuring the nanoparticle forces, and MD enables the interpretation of exactly how the forces are acting. Measured forces will be compared with bulk stability and rheology measurements.

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Plasmon Sensitized TiO2 Nanoparticles as a Novel Photocatalyst for Solar Applications

Wed, 16 Jan 2008 21:57:29 GMT

Efficient conversion of sunlight into electrical and/or chemical energy is of great technological importance for modern society and future generations. One attractive possibility for utilization of solar energy is based on the ability of small semiconductor particles to function as photocatalysts promoting various oxidation and reduction reactions under sunlight. Titanium dioxide (TiO2) is the most promising material for such applications because it is an efficient, environmentally friendly, and relatively inexpensive photocatalyst. However, wide technological usage of this photocatalyst is largely hindered by the fact that ultraviolet light that does not constitute a significant fraction of the solar spectrum that is required for its activation. Any improvement of photocatalytic efficiency of TiO2 by shifting its optical response from UV to the visible spectral range will have a profoundly positive effect. The main objective of the proposed research is to synthesize and test a novel photocatalyst that consists of small silver or gold nanoparticles covered with a thin TiO2 shell. Silver and gold nanoparticles are very efficient systems for the interaction with visible light due to the excitation of plasmon resonances. It is expected that, due to the coupling of plasmon resonances in the core with the electron-hole pair generation in the shell, these hybrid Ag/Au TiO2 nanoparticles will exhibit photocatalytic activity in the visible spectral range thereby more efficiently utilizing solar energy.

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Ecocomposites Reinforced with Cellulose Nanoparticles: An Alternative to Existing Petroleum Based Polymer Composites

Wed, 16 Jan 2008 21:53:43 GMT

This project will make wholly biobased and biodegradable nanocompostites. These will be compared in terms of thermal and mechanical properties to existing glass filled composites made from petrochemicals. Because the reinforcing particles are microfibrils of cellulose or crystals derived from such microfibrils, it is correct to classify these materials as Nanocomposites. The primary objective is to show that such composites can compete in performance areas with current materials.

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Nanostructured Microemulsions as Alternative Solvents to VOCs in Cleaning Technologies and Vegetable Oil Extraction

Wed, 16 Jan 2008 21:47:01 GMT

The objective of this project is to develop and evaluate non-toxic, non-volatile, and biodegradable oil extraction. Specifically, we plan to formulate water continuous microemulsions to dissolve the oil in the hydrophobic core of swollen micelles (1-50 nm droplets). We will study the impact of novel microemulsion additives, called "linkers", on the interfacial properties (interfacial tension, rigidity and curvature) and dynamic aspects of oil solubilization and displacement from porous and smooth surfaces under different shear conditions. Linkers are surfactant-like molecules that are wither too lipophilic or hydrophilic to self-assemble at the O/W interface, but in the presence of surfactant they self-assemble to produce microemulsions with improved performance for a variety of oils. We hypothesize that by introducing linkers we can formulate aqueous surfactant solutions that, upon contact with the oil to be removed, and under optimum flow conditions, will spontaneously from microemulsions that keep the oil in micelles. These surfactant solutions can therefore be used as alternatives to VOC solvents, such as hexane, in cleaning hard surfaces, textiles and vegetable oil extraction.

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Graft Polymerization as a Route to Control Nanofiltration Membrane Surface Properties to Manage Risk of EPA Candidate Contaminants and Reduce NOM Fouling

Wed, 16 Jan 2008 21:40:07 GMT

We propose to develop new nanofiltration membranes by modifying the surface structure of commercial membranes at the molecular level via UV-assisted graft polymerization of hydrophilic monomers using our patented method. Our objective is to transfer major successful developments from biotechnology applications to environmental protection. New materials will be developed that offer high flux compared to commercial membranes (by improving membrane porosity), enhanced rejection of inorganic anions and ionizable organic compounds (by controlling membrane pore size distribution and surface charge), and enhanced ability to resist fouling by natural organic matter (NOM) by reducing adhesion. We seek to understand the characteristics of natural organic matter accumulated on membrane surfaces both in terms of resistance to flow (which can influence the cost of membrane processes) and its affects on the transport and rejection of charged solutes.

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Sustainable Biodegradable Green Nanocomposites From Bacterial Bioplastic For Automotive Applications

Wed, 16 Jan 2008 21:30:29 GMT

Renewable resource-based "green" nanocomposites are the next generation of materials which provide a combination of performance and environmental compatibility. This proposal seeks to replace/substitute existing petroleum derived polypropylene (PP)/TPO (thermoplastic olefin) based nanocomposites with environmentally-friendly nanocomposites produced from bacterial-based bioplastic (polyhydroxyalkanoate, PHA) reinforced with compatibilized nanoclay for automotive applications.

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Use of Ozonation in Combination with Nanocrystalline Ceramic Membranes for Controlling Disinfection By-products

Wed, 16 Jan 2008 21:15:15 GMT

The objective of this study is to determine the feasibility of using a combined ozonation and membrane filtration system to control disinfection by-products (DBPs) precursors in drinking water treatment process. Conventional ceramic membranes and ceramic membranes coated with a nano-crystalline catalyst that decomposes ozone will be used in this study. The particular objectives are: 1. To develop methods for the preparation of a nano-crystalline ceramic membranes which catalyze the decomposition of ozone and foulants and to characterize these membranes. 2. To determine the effect of ozonation on membrane fouling in filtration systems using both conventional and catalytic membranes. 3. For the source waters studied, determine the effect of ozonation on the properties of natural organic matter and relate this information to the overall performance of the system. 4. To investigate the effect of control parameters on the fouling rate and product water quality using selected conventional and catalytic membranes. The initial goal of this project is the development of a nano-crystalline ceramic membrane that catalyzes the decomposition of ozone and has the desired porosity, permeability and MWCO. Once a suitable membrane (or membranes) is (are) formed, we will evaluate the membrane(s) in combination with ozone for its ability to resist fouling, alter the NOM and control DBPs. The optimized membrane will be investigated to determine the effect of control parameters on the fouling rate and product water quality. We expect to develop and demonstrate that treatment using catalytic nanocrystalline ceramic membranes in combination with ozonation is more effective than conventional methods, including ozonation, and other membrane processes in terms of operational performance and removal of DBPs.

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Nanotechnology: A Novel Approach to Prevent Biocide Leaching

Wed, 16 Jan 2008 21:06:46 GMT

The primary objective of this proposal is to develop a practical and effective approach to prepare biocide-loaded nanoparticles (organic and copper-based biocides) that can be efficiently introduced into wood to reduce or eliminate biocide leach into sensitive environments. Preventing biocide loss to leach is also expected to increase the useful lifetime of wood products while using less biocide. To accomplish this objective the nanoparticle must be constructed to serve as a protective reservoir for the biocide that prevents its loss by leach or by degradation, but that also releases biocide into the wood in a controlled manner at a rate that maintains the minimal amount of biocide required within the wood for wood preservation.

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A Bioengineering Approach to Nanoparticle based Environmental Remediation

Wed, 16 Jan 2008 20:58:10 GMT

The management of anthropogenic chemical toxins is a major environmental challenge. Various strategies have been employed to facilitate the degradation of this class of pollutant. Processes involving nano-sized materials have garnered interest because it is well known that nano-sized particles exhibit unusual thermal and photo-chemistry in a variety of chemical applications when compared to particles of larger dimensions. Our objective is to develop a bioengineering approach that can be used to develop nano-size catalytic materials as the basis for new remediation strategies. Here we propose a research program to assess the potential use of ferritin, and ferritin-derived compounds, as catalysts in environmental degradation processes. The ferritin system has the advantage of being environmentally benign and biodegradable. Ferritin is an iron-storage protein that consists of a native nano-size iron oxide core (ferrihydrite) encapsulated within a spherical protein cage (120 D diameter). Ferritin is commercially available, but it has also been cloned in our laboratory and can be produced in gram quantities. We have shown that the size of the iron oxide particles can be controlled to form homogeneous nanoparticles from 20 to 75 D. Also, the native iron oxide core of ferritin can be replaced by other metal oxides such as Mn and Co oxides. Such inorganic materials at more traditional size ranges (> micron) exhibit photocatalytic and catalytic activity in a variety of systems. Our hypothesis is that by assembling these materials as nanoparticles within the ferritin (i.e., the protein shell) we can "tune" their surface chemistry toward beneficial environmental chemistry through our control of their size and electronic structure. Furthermore, by the chemical functionalization of the ferritin cage, we can further alter the chemical reactivity of the nanoparticle. Our research focuses on: (1) the development of a bioengineered synthesis of a variety of homogeneous nano-sized metal and metal oxide particles; (2) the determination of the electronic properties of the nanoparticles and their reduced forms (i.e., the base metal) as a function of size; (3) a determination of the reactivity of the particles toward beneficial environmental chemistry, as a function of size and electronic structure.

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