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Green Energy Technology Projects - 2013

Long-range alignment of gold nanorods in conjugated polymer thin film

Faculty: Deidre O'Carroll

Mentors: B. Yu, R. Thomas

Project Description: Gold nanorods exhibit a variety of unique anisotropic, and size-dependent electrical and optical properties such as polarized light scattering and directional electrical transport. Therefore, long-range alignment of gold nanorods is of interest in order to take advantage of these properties on a large scale for their use in various optoelectronic devices such as organic photovoltaic solar cells and light emitting diodes. To help address the need for long-range nanorod alignment, the work presented here attemptss to combine the well-known techniques for aligning polymer chains in thin films with the idea of polymer-directed alignment of embedded gold nanorods. We have demonstrated a procedure in our lab for rubbed alignment of polyimide thin films and have optimized the process to create surfaces that exhibit densely-spaced grooves on the polyimide surface. The next step will be to create a colloidal solution of gold nanorods and a compatible conjugated polymer and to subsequently coat the solution onto the rubbed polyimide surface. This will form a thin composite conjugated polymer/nanorod film. Through subsequent annealing, the conjugated polymer molecular chains are expected to align along the direction of the rubbed polyimide grooves. We will investigate if alignment of the conjugated polymer chains causes alignement of the embedded gold nanorods using optical dark field microscopy and transmission electron microscopy. If controlled alignment of the gold nanorods is successful, the mechanisms behind their anistropic and their interactions with polymer semiconductors can be systematically studied and characterized with the ultimate goal of optimizing current and future optoelectronic devices.

Vapor-phase carbonylation of propylene over H-zeolites to produce butanol

Faculty : Fuat E. Celik

Mentors : Longfei Chao

Project Description: The synthesis of Butanol by introducing carbon monoxide to propylene under low pressure in the vaporphase over solid acid H-zeolites is a modification of the Koch Reaction—using strong acids and high pressure. H-zeolites are equally acidic compared to aqueous acids, but are safer to handle. Methods used in this project can be adapted in order to produce several other petrochemicals using sustainable biomass as the source of their carbon; eventually eliminating dependency on oil, coal and natural gas. Butanol, a derivative of butyric acid, is being investigated as a liquid fuel to directly replace gasoline due to its similar combustion energy and blending percentage with gasoline. It can go directly into current combustion engines without any modifications. The process of synthesizing butanol begins with the production of butyric acid in a heated, closed system of tubing where the gases will be introduced using various valves and flow regulators; a secondary step will be taken to reduce butyric acid to butanol. The products, as well as the catalysts surface, will be analyzed in situ using Infrared Spectroscopy, Gas Chromatography, and Mass Spectroscopy to determine the active sites of the catalysts, intermediates formed, as well as rate, selectivity, and yield. By investigating different catalytic pathways, this will allow for advancements in catalyst design and improve carbon efficiency.

Synthesis and characterization of lithium-nickel-cobalt oxides for water oxidation catalysis

Faculty : Gerald Charles Dismukes

Mentors : Graeme P. Gardner

Project Description: Cubic phase lithium-cobalt oxide has become an attractive catalyst for water oxidation. These structures can serve as inorganic analogues of the Mn₄CaO₅ cluster present in PSII, which is responsible for catalyzing light-induced water oxidation. We aim to possibly increase the catalytic activity by doping the cubic phase with nickel, which can be a challenge because there are sparse reports of successful doping and formation of unwanted phases and impurities that could be active catalysts themselves. In this project we synthesized a series of modified-spinel LiNiₓCo₁₋ₓO₂ using different synthetic routes, and found that stoichiometry, and calcination temperature and time all affect the purity of the final phase. We characterized the catalysts' structure by using PXRD and their catalytic activity by measuring the evolution of dissolved O₂ in water using a Clark electrode.

Soft, inflatable actuators for kite-based energy harvesting

Faculty : Aaron Mazzeo

Mentors : H. Sinan Bank, Jingjin Xie

Project Description: Kite-based energy harvesting systems have become a recent area of interest due to their ability to produce power within the range of 1kW to 5MW (with minimal detrimental environmental effects) depending on the size/mass of the system and available wind energy. Many of these kite-energy harvesting systems use electrically powered rotors to control kite trajectory for optimal power production. These rotor systems are relatively expensive, and are comprised of dense materials. The goal of this study is to investigate an alternative approach for kite trajectory control that incorporates soft, inflatable actuators that will be used to change the aerodynamic performance of a kite. The advantages of soft based actuators are that they can be custom designed; and the materials are more lightweight than conventional rotors and are morphable. Hence, in this paper we will describe the design of a proof-of-concept device, wherein soft, inflatable actuators are attached to a kite and used to control the trajectory of motion through actuation induced with compressed air. Two methods being pursued are the redistribution of mass and the use of flaps to affect aerodynamic performance. The project will conclude by demonstrating that the soft, inflatable actuators can control the movement of the kite during flight.

Development of barium titanate Strontium Ferrite thick films

Faculty : Kimberly Cook-Chennault

Mentors : Wanlin Du, Sankha Banerjee, Udhay Sundar

Project Description: In recent years there has been a large growth in interest in developing piezoelectric materials that exhibit high electromechanical characteristics for energy harvesting and material applications in electronic devices, sensors, actuators and memories. Lead based piezoelectric thin films exhibit high performance ferroelectric, dielectric and piezoelectric characteristics, however since there are environmental, social, and health concerns with the production and use of lead, there is a need for a shift to a new safer material. One of the major challenges with finding an alternative to lead based materials is that due to a large coercive field and high conductivity there are difficulties poling the lead free materials composite piezoelectric materials, such as two and three phase barium titanate (BT) - based composites. Previous studies suggest that composite BTbased materials that are combined with other materials such as sodium bismuth titanate ordoped with electrically conductive additives such as strontium have larger ferroelectric and dielectric properties than their homogenous counterparts. Hence there is an interest in exploring these materials further. Our aim is to produce BT- strontium ferrite thick films using sol-gel spin coat techniques and to then analyze the properties using XRD (X-ray diffraction), test the dielectric constant and piezoelectric coefficients using a piezometer. We will also use SEM (scanning electron microscope) to get the thickness and morphology of the films.

Determining methionine content in 5 genera of duckweed through ethionine assay and biosensor using cystathionine-gamma-synthase deficient E. coli.

Faculty : Eric Lam

Mentors : Kenny Acosta

Project Description: Duckweed research has recently focused on developing it as a valuable crop, with uses focusing on wastewater remediation, fermentation to fuel ethanol, and production of animal feed. A good feedstock for animal feed will have not only high protein content, but an appropriate balance of amino acids that matches as closely as possible the nutritional needs of the target animal. However, plant-based proteins and feeds are traditionally low in essential amino acids such as methionine (met), requiring the addition of exogenous amino acids. Here, we find and report the optimal strains of duckweed for animal feed by quantifying those strains which produce the most protein and the most methionine. In the first part of the process, an ethionine resistance assay shows the genus Wolffia to contain the highest levels of soluble methionine, confirming preliminary data. The second part is a biosensor assay consisting of an E.coli bacterial biosensor which cannot synthesize methionine due to the silencing of the gene for the met-precursor cystathionine-gammasynthase, resulting in a dependence on environmental methionine for growth. The biosesor’s growth in each sample of duckweed is limited by the amount of methionine which is produced by the sample, so total growth is directly translatable to met-content through optical density measurements.

Breeding for improved ethanol yield in switchgrass

Faculty : Stacy A. Bonos

Mentors : Laura Cortese, Hilary Mayton, Ph.D.

Project Description: Switchgrass (Panicum virgatum) was first considered as a potential bioenergy feedstock only a few decades ago. This low maintenance, North America native, perennial, fast-growing grass can be harvested and converted to ethanol or burned to generate heat and/or electricity. Ethanol is an alcohol that could substitute fossil fuels. The most commonly used source for ethanol production is corn. Cellulose and other complex sugars are the primary ingredients in to the process of producing ethanol using switchgrass. The production of ethanol would mitigate the fossil fuel and energy crisis. For this reason, looking for sustainable crop to produce ethanol is of vital importance. Very little research has been done regarding the effects of the environment on switchgrass bioenergy traits in the northeastern US. The objectives of this investigation are to determine to what degree variations in cellulose, hemicellulose and lignin in the plant are due to genetics and to what degree to environmental factors, and to identify cultivars best suited for use as a bioenergy feedstock in the northeastern US. Thirty switchgrass genotypes were planted at three locations in New Jersey, (one on prime quality soil and two marginal soils) in a randomized complete block design with 5 replications. Leaf and stem tissue was collected from each replicate of each genotype in both 2009 and 2010. Tissue samples were dried and then ground using a Wiley Mill with a 1ml screen. Fiber analysis was conducted using two different methods: wet chemistry and NIR (Near Infrared Spectroscopy). Percent lignin, cellulose and hemicellulose were calculated and data was analyzed using SAS (Statistical Analysis Software). This analysis will be used to determine what factors influence the percentages of lignin, celllose and hemicellulose in switchgrass genotypes. My goal is to gather data that will be useful for switchgrass breeding efforts to improve ethanol yield from switchgrass and further the knowledge base of the use of switchgrass for bioenergy.

Project : Few-layer graphene synthesis using pulsed laser deposition

Faculty : Stephen Tse

Mentors : William Mozet

Project Description: Graphene research has surged in recent years due to its incredible properties, such as ballistic electron transport and high tensile strength to weight ratio, suggesting staggering potential applications. Efforts to produce graphene have naturally followed. Using an Nd:YAG laser of 266 nm to ablate highly ordered pyrolytic graphite (HOPG), graphene is fabricated on polished copper substrates for varying times (T = 900ºC, P = 10-5 Torr, E = 50 mJ/pulse). The graphene is examined using Raman spectroscopy with a focus on studying the number of layers grown as a function of the time of deposition using peak intensity ratios. It has been determined that the number of graphene layers decreases with decreasing deposition time while the disorderedness of the graphene crystals remain unaffected. This study advances the current state of knowledge on graphene synthesis, aiding in further efforts to not only create graphene, but also study its properties and seemingly countless potential applications.

Development of zinc oxide nano-generators

Faculty: Kimberly Cook-Chennault

Mentors: Wanlin Du, Udhay Sundar, Sankha Banerjee

Project Description: Piezoelectric materials are important for charge production and storage with capacitor devices. Zinc Oxide (ZnO) nanowire is piezoelectric and can be grown using a seed layer deposition technique and a hydrothermal process. The current work is looking at the growth, population density, and related electromechanical properties of the ZnO nanowire in relation to substrate roughness and stress reaction/viscosity of sol-gel, which is used as a seed layer. A working hypothesis is that the thicker more viscous gels and rougher substrates will grow a denser population of thicker nanowires thereby decreasing the piezoelectric constant and increasing the dielectric constant. It is thought that the relationship between the electrical properties and the thicker, denser geometries is found in the description of the stress and strain of the structure. The bulkier structure will disperse the mechanical and electrical loads decreasing the amount of compression applicable to the wires. The microstructure and wire dispersion will have been measured with Scanning Electron Microscopy (SEM). The electromechanical properties will be analyzed with a Piezometer and Impedance-meter.

Algae and photosynthetic bacteria

Faculty: Donna Fennell

Project Description: Algae and photosynthetic bacteria are widely studied for bioenergy applications. The organisms produce intracellular compounds that can be chemically converted to liquid fuels. Algae and microalgae are typically grown in liquid culture in various types of bioreactors. Use of photosynthetic organisms requires sufficient light. Since light penetrates only the first few centimeters of high density cultures, large scale culture requires large surface areas to maximize growth. Culture of photosynthetic microorganisms in an aerosolized state could overcome some of the limitations resulting from light limitation. In conjunction with ongoing NSF project IOS-1022254 entitled “Air as an Active Bacterial Ecosystem” with D.E. Fennell PI, Lee J. Kerkhof and Gediminas Mainelis, co-PIs, an undergraduate fellow will investigate the growth and activity of photosynthetic microbes in the aerosolized state.

Life-cycle assessment and material flow analysis of selected green building practices

Faculty: Uta Krogmann

Project Description: Responding to the fact that natural resources are limited and that certain human activities are impacting the planet in unsound ways, there is a call for implementation of sound policies and practices to improve environmental quality and sustainability. To address this, life cycle thinking is necessary to design products, choose materials and processes, and decide what to do at the end of a product’s life in ways that produce fewer environmental discharges and use less material and energy from a systems perspective. The undergraduate student will learn how to assess various environmental impacts with material flow analysis and life-cycle assessment. The focus will be on green building practices.

Catalytic functionalization of C-H bonds

Faculty: Alan Goldman

Project Description: The catalytic functionalization of alkanes and other molecules with normally inert C-H bonds is a scientifically challenging problem that presents great opportunities in terms of economics, environmental benefits, and energy self-sufficiency. Catalysts for the dehydrogenation of alkanes have been extensively developed in our group; these are among the most efficient organometallic alkane functionalization catalysts. Olefins are ubiquitous as intermediates in the petrochemical, commodity chemical, and pharmaceutical industries. Tandem systems that could effect dehydrogenation of alkanes or alkyl groups, followed by a useful secondary reaction of the resulting olefin, offer potentially powerful routes to various products, while avoiding undesirable secondary reactions that can occur in simple alkane dehydrogenation systems.