Engineering Commons^™

Homochiral Metal-Organic Materials: Design, Synthetic And Enantioseletive Separation, Shi-Yuan Zhang

USF Tampa Graduate Theses and Dissertations

Owing to the growing demand for enantiopurity in biological and chemical processes, tremendous efforts have been devoted to the synthesis of homochiral metal-organic materials (MOMs) because of their potential applications in chiral separation and asymmetric catalysis. In this dissertation, the synthetic strategies for homochiral MOMs are discussed keeping the focus on their applications. Two distinct approaches have been taken to synthesize chiral structures with different topologies and accessible cavities. The chiral MOMs have been utilized in enantioselective separation of racemates.

Chiral variants of the prototypal metal-organic framework MOF-5, δ-CMOF-5 and [lambda]-CMOF-5, have been synthesized by preparing MOF-5 in the presence …

Electro-Catalytic Oxidation Of Hydrogen Peroxide On Au/ L-Methionine /Gc Electrode, Jian-Feng Fan, Xue-Mei Luo, Jing Li, Lou-Zhen Fan

Journal of Electrochemistry

The modified electrodes have been fabricated by generation of Au nanoparticle chains, which was produced by reaction between HAuCl4 and sodium citrate without any additional capping agents or surfactants. The self-assembled Au nanoparticles were attached to the surface of glassy carbon electrode (GCE) layer by layer, using L-methionine (L-Met), thiourea (TU), allyl thiourea (ATU) and polyvinylpyrrolidone (PVP) as a crosslinking agent, respectively. The experimental results showed that the electrochemical performance of the different modified electrodes varied in [Fe(CN)₆]^3-/4- solution. The Au/L-Met/GCE exhibited an excellent electrochemical property, which is superior to other modified electrodes. In addition, the catalysis …

Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao

Journal of Electrochemistry

Platinum nanocrystallites were synthesized by the colloidal method using oxamide as the stabilizer. The morphologies and electrocatalytic performances for methanol of platinum nanocrystallites prepared at different pH values and with different reactant ratios of precursor and stabilizer were investigated. It was found that the platinum nanocrystallites synthesized at pH=5 and with the reactant ratio of 1:20 showed the best electrocatalytic activity for methanol. The peak current density reached up to 1709 μA·cm^-2. Furthermore, the electrocatalytic activity of platinum nanocrystallites for methanol reduced significantly although the cyclic voltammograms in the blank solution were not obviously changed after exposing in …

Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun

Journal of Electrochemistry

White TiO₂ nanorods were synthesized by hydrothermal method with TiCl₄ as a precursor. As-synthesized TiO₂ nanorods were further subjected to high-temperature (550 ^oC) heat treatment for 2 h under H₂ atmosphere to prepare gray black hydrogen-treated TiO₂ (H-TiO₂) nanorods with oxygen vacancies and Ti³⁺ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO₂ nanorods to form Pt/TiO₂ and Pt/H-TiO₂ catalysts. XRD data indicates that the crystal structure of TiO₂ was still reserved as rutile after hydrogen treatment, but the surface …

Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang

Journal of Electrochemistry

A platinum electrode decorated with the ordered Nd-Fe-MoO₄^2- cyano-bridged mixed coordination polymer was successfully prepared by electrodeposition in virtue of the lyotropic liquid crystal soft template methods, and electrocatalytic oxidation behavior of glycerol was investigated on the chemically modified electrode by cyclic voltammetry. The influences of experimental factors such as the concentrations of H⁺ and SO₄^2- in electrolytes, glycerol concentration and scan rate on the electrocatalytic activity of glycerol at the modified electrode were also studied. It indicated that the proper amount of SO₄^2- in weakly acidic electrolyte could help to improve the …

Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie

Journal of Electrochemistry

Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.

Enhancement Of Mass Transfer And Electron Usage For Syngas Fermentation, James J. Orgill

Theses and Dissertations

Biofuel production via fermentation is produced primarily by fermentation of simple sugars. Besides the sugar fermentation route, there exists a promising alternative process that uses syngas (CO, H2, CO2) produced from biomass as building blocks for biofuels. Although syngas fermentation has many benefits, there are several challenges that still need to be addressed in order for syngas fermentation to become a viable process for producing biofuels on a large scale. One challenge is mass transfer limitations due to low solubilities of syngas species. The hollow fiber reactor (HFR) is one type of reactor that has the potential for achieving high …

A Sequential Grid, Relaxation Method For Use In Oil Reservoir Simulation, Brian Stimpson, Dr. Hugh Hales

Journal of Undergraduate Research

The demand for petroleum products has never been higher, despite the opposition and environmental skepticism that has been present against the petroleum industry in recent years. This requires the production of petroleum products to increase. However, as politics and nature will have it, the waning supply of petroleum is becoming ever more difficult to access and tap into. To make sure we are using our reserves in the best possible ways, this industry must adapt, create better technology, and have careful planning and predictions.

Advanced Measuring Techniques Of Ionic And Electronic Conductivities In Battery Electrodes, Joshua Flygare, Dr. Dean Wheeler

Journal of Undergraduate Research

Introduction: There are many significant barriers still to be overcome before chemical storage becomes satisfactory. One of the most significant issues is how much the electrodes vary in their electronic and ionic conductivities. Both of these issues are highly complex. My funding was used to help me learn the basic mathematics and physics that occur inside of batteries. I used this understanding to make two models, one using COMSOL multiphysics, and another cruder model using Excel. The most significant change made in my execution from my original proposal was I used all of my time in understanding and making models, …

Spin Cycle: Hand Powered Washing For Peru, Jared Bruton, Dr. Randy Lewis

Journal of Undergraduate Research

Washing clothes is time consuming and physically difficult for women on the islands of Lake Titicaca. Women fill buckets with water and soap, allow the clothes to soak, rub them together to get the dirt out, and then wring them out. Doing this is physically demanding, especially during the harsh cold of winter. This project develops a human-powered, affordable, and easy to build clothes-washing device that allows women to save time and energy washing clothes. It builds on a similar washing machine project from one year ago, but seeks to reduce the cost of the hand-powered machine from 300 Peruvian …

Kinetic Modeling Of Self-Hydrolysis Of Aqueous Nabh4 Solutions By Model-Based Isoconversional Method, Rajasree Retnamma, A. Q. Novais, C. M. Rangel, Lin Yu, Michael A. Matthews

Faculty Publications

The present work reports the kinetic modeling of self-hydrolysis of non-buffered, non-stabilized NaBH4 solutions by model-based isoconversional method. The overall kinetics is described by a „reaction-order‟ model in a practical operating window of 10-20 wt% NaBH4 solutions at 25-80 C and 0-50% conversions. The apparent activation energy and pre-exponential factor are interrelated through a kinetic compensation effect (KCE). The apparent reaction order remains constant at a given temperature irrespective of extent of conversion and decreases with increase in temperature. It decreases from firstorder to 0.26 with increase in temperature from 25 to 80 C. The apparent activation energy is found …

Evaluation Of Thin Film Nanotube-Antibody Matrix Materials For Potential Integration Into Immunodiagnostic Biosensors, Brian Young

Faculty Research and Creative Activities Award (FRACAA)

Most quantitative immunodiagnostic assay products require large laboratory equipment, controlled lab environments, and highly skilled technicians, making them expensive and impractical for use in other environments such as physician offices, the home and field clinics of developing countries. The long-range goal of this work is to attempt to develop an inexpensive quantitative hand-held immunobiosensor-based technology that can easily be applied to any antibody:antigen combination and used in any setting. A new approach to measure antibody:antigen binding in the presence of nanotubes has been described in several recent studies. Using conductive polymer/nanotube/antibody solution-impregnated filter paper, these researchers showed a change in …

Model Predictive Control With A Rigorous Model Of A Solid Oxide Fuel Cell, Lee T. Jacobsen, Dr. John D. Hedengren

Journal of Undergraduate Research

Degradation of Solid Oxide Fuel Cells (SOFCs) can be minimized by maintaining reliability parameters during load changes. These reliability parameters are critical to maintain power generation efficiency over an extended life of the SOFC. For SOFCs to be commercially viable, the life must exceed 20,000 hours for load following applications. This is not yet achieved because transient stresses damage the fuel cell and degrade the performance over time. This study relates the development of a dynamic model for SOFC systems in order to predict optimal manipulated variable moves along a prediction horizon. The model consists of hundreds of states and …

Development Of Multimodal Membrane Adsorbers For Antibody Purification Using Atom Transfer Radical Polymerization, Juan Wang, Scott M. Husson

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Carbon Fibers Derived From Sustainable Precursors, Meng Zhang, Jing Jin, Amod A. Ogale

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Producing A Liquid-Lignin Phase From Kraft Black Liquor: Phase Behavior And Structural Characterization, Julian Velez, Mark C. Thies

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Density Functional Theory-Based Modeling Of Catalyzed Water Purification, Lizzie Bollman

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Effect Of Co Adsorption And Coverage On Ethanol Production From Syngas, Anuradha Gundamaraju, Ming He, David A. Bruce

Graduate Research and Discovery Symposium (GRADS)

In the future, the availability of reliable alternative fuels will be crucial for any country to become energy independent. One such alternative is ethanol as it can be used both as a fuel and as a fuel additive. Most of the ethanol produced in the world today is derived from biomass. The biomass feedstocks and fermentation broths used in ethanol production both contain high amounts of water and therefore, the energy efficiency of the process is lessened by product separation processes (azeotropic separation of water and ethanol) that are non-trivial and highly inefficient (due to the evaporation of water). An …

Template Free-Synthesis Of Polypyrrole Microtubes For Supercapacitor Electrodes, Kryssia P. Diaz, Mark E. Roberts

Graduate Research and Discovery Symposium (GRADS)

The purpose of this work is to develop a simple, scalable and template-free method to synthesize conducting polymer nano/micro-structures for supercapacitor electrodes. The microstructure and electrochemical properties of structure polypyrrole on various mesh substrates is investigated.

Recovering A Liquid-Lignin Phase From Paper Mill Black Liquors, Julian Velez, Adam Klett, Mark C. Thies

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Analysis Of Solvation Model, Adsorption Site, And Adsorbate Coverage Effects On Adsorption Energies At The Anode In Direct Methanol Fuel Cells, Cameron J. Bodenschatz, Rachel B. Getman

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Synthesis And Characterization Of Extractive Scintillating Resin For Ultra-Trace-Level Quantification Of Uranium In Aqueous Media, C Duval, V Bliznyuk, A Seliman, T Devol, S Husson

Graduate Research and Discovery Symposium (GRADS)

The detection and quantification of radionuclides in aqueous media is of interest to both the Environmental Protection Agency, for matters of public health, and international organizations like the Comprehensive Test Ban Treaty Organization, that use environmental samples to investigate claims of illicit nuclear activities. The current method of quantification involves batch style analytical techniques which utilize bulky instruments. Portable, flow cell detectors utilizing extractive scintillating resin with physically sorbed extractants and fluorophores have been developed; however, this resin shows poor long term stability as the active components leach from the resin over time. There is a need to develop chemically …

Roll-To-Roll Synthesis Of Vertically Aligned Carbon Nanotubes For Electrical Double Layer Capacitors, Margarita R. Arcila-Velez, Jingyi Zhu, Anthony Childress, Mehmet Karakaya, Ramakrishna Podila, Apparao M. Rao, Mark E. Roberts

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Effect Of Surface Parameters On Interfacial Water Film Behavior, Brittany Glatz, Luke Rhym, Sapna Sarupria

Graduate Research and Discovery Symposium (GRADS)

Vapor-to-liquid and liquid-to-solid transitions on mineral surfaces are the primary pathways for phase transitions in atmospheric water. These phase transitions affect the microphysics of clouds and have significant effects on the weather and climate. Our overall goal is to elucidate the mechanisms through which surfaces affect these transitions, and develop predictive abilities to correlate surface properties to the thermodynamics and kinetics of the phase transitions. In this work, we use molecular dynamics simulations to study the structure, and dynamics of water near kaolinite-like surfaces. Kaolinite is the most abundant mineral dust in the atmosphere. We specifically investigate the effect of …

Carbon Fibers Derived From Pan/Bio-Based Bicomponent Precursor, Jing Jin

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Optimization Of Pyrochlore Catalysts For Dry Reforming Of Methane, Felipe Polo-Garzon, Ming He, David A. Bruce

Graduate Research and Discovery Symposium (GRADS)

No abstract provided.

Fabrication And Analysis Of Soy Flour Filled Polyethylene Fibers, Ozgun Ozdemir, Sam Lukubira, Amod Ogale, Paul Dawson

Graduate Research and Discovery Symposium (GRADS)

Fibers composed of soy flour (soy) and linear low density polyethylene (PE) were produced by melt spinning method. The mixing time of soy flour and PE was adjusted to get better dispersion of soy flour inside the matrix. The inclusion of soy decreased tensile modulus by 35% and tensile strength by 30% of the fibers compared with 950 MPa and 43 MPa, respectively, for PE fibers. Strain to failure for soy-PE fibers was 292% where PE fibers have strain to failure at 513%. Tensile properties of soy-PE fibers are comparable to those of pure PE. Even washing did not deteriorated …

Study And Development Of Sulfated Zirconia Based Proton Exchange Fuel Cell Membranes, Brittany Wilson Kemp

Doctoral Dissertations

With the increasing consumption of energy, fuel cells are among the most promising alternatives to fossil fuels, provided some technical challenges are overcome. Proton exchange membrane fuel cells (PEMFCs) have been investigated and improvements have been made, but the problem with Nafion®, the main membrane for PEMFCs, has not been solved. Nafion® restricts the membranes from operating at higher temperatures, thus preventing them from working in small electronics. The problem is to develop a novel fuel cell membrane that performs comparably to Nafion® in PEMFCs.

The membranes were fabricated by applying sulfated zirconia, via template wetting, to porous alumina membranes. …

Development And Utilization Of A Pair Of Sol-Gel Entrapped Lipases For Biodiesel Production From High Free Fatty Acid Oils, Cory M. Schwartz

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Biodiesel, which consists of fatty acid alkyl esters, is one of the most widely adopted and successful renewable fuels. Traditional physiochemical biodiesel production methods require high cost refined feedstocks, and so alternative methods of catalysis and feedstocks have been explored. This research investigated the use of polysiloxane entrapped lipases to catalyze the production of biodiesel from low cost feedstocks.

In this work, lipase from Burkholderia cepacia (lipase PS) and lipase B from Candida antarctica (CalB) were separately entrapped using sol-gel chemistry. Optimal reaction conditions for the esterification of free fatty acids by immobilized CalB with methanol were determined. Immobilized CalB …

Engineering Cell-Free Systems For Vaccine Development, Self-Assembling Nanoparticles And Codon Reassignment Applications, Mark T. Smith

Theses and Dissertations

This dissertation reports on the technology of cell-free protein synthesis (CFPS) including 1) stabilized lyophilized cell-free systems and 2) enhanced heterogeneous cell extracts. This work further considers applications of CFPS systems in 1) rapid vaccine development, 2) functional virus-based nanoparticles, 3) site-specific protein immobilization, and 4) expanding the language of biology using unnatural amino acids. CFPS technology is a versatile protein production platform that has many features unavailable in in vivo expression systems. The primary benefit cell-free systems provide is the direct access to the reaction environment, which is no longer hindered by the presence of a cell-wall. The “openness" …