Chemical Engineering Commons^™

Plasmonic Nanogel: Structure, Rheology, And Optical Properties, Georo Zhou

Renée Crown University Honors Thesis Projects - All

The invention of plasmonic nanogels (PNG) opens up the field of nanotechnology to a wide variety of applications such as, enhanced light trapping in solar cells, design of smart glasses, chemical detection, and optofluidic devices. In this work, it was determined that, the synthesis of a nanoparticle-micelle network in a fluid state is performed with the ability to suspend metal nanoparticles in a gel-like solution in a stable fashion. Furthermore, the stable suspension of the nanoparticles in the fluidic system allows the user to easily tune the PNG’s optical and rheological properties by controlling the concentration of the nanoparticles and …

Silver Coated Bioactive Glass Particles For Wound Healing Applications, A. W. Wren, A. Coughlan, P. Hassanzadeh, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glass particles (0.42SiO₂-0.15CaO-0.23Na ₂O-0.20ZnO) of varying size (<90 >μm and 425-850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles (PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90 to 9.12 m²/g (90 μm) and 1.09-7.71 m²/g (425-850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little diffusion through the bulk. Antibacterial (Escherichia coli - 13 mm and Staphylococcus epidermidis …

Catalyst Studies With Implications On The Design And Fabrication Of Microreactors, Eric Snider

Honors Theses

Biodiesel, or fatty acid methyl ester (FAME), 'is a potential alternative, renewable fuel source to lessen foreign fuel dependency. Dr. Frank Jones' microreactor research group is investigating the use of microreactors to produce biodiesel. Microreactors can increase reaction rates, heat transfer, and lessen production costs due to their small size. The first generation of microreactors, coated with a nickel oxide (NiO) catalyst, has been developed and needs to be tested to determine their performance. Also, a catalyst study comparing NiO and platinum oxide (PtO2) will be performed to find the better catalyst for FAME production.

Formation Of Molecularly Imprinted Polymer Matrices Using, William Erwin

Chemical Engineering Undergraduate Honors Theses

This study serves as a proof of concept that a poly(acrylonitrile-co-acrylic acid) may be used to form an chiral selective polymer membrane for discrimination of L-tryptophan from racemic tryptophan. Due to the unavailability of necessary equipment, a polymer membrane was not tested, rather, two experiments were run in conjunction; (1) A membrane of L-tryptophan imprinted P(AN-co-AA) was cast and tested on a scanning electron microscope to determine the membrane density, and (2) Imprinted polymer was ground and tested for absorption of L-Tryptophan by finding circular dichroism and concentration for different samples. It was found that it is feasible that P(AN-co-AA) …

Green Ro Pretreatment, Elizabeth Fullerton

Chemical Engineering Undergraduate Honors Theses

The use of sea water desalination to produce potable water for maritime vessels is essential for eliminating storage of potable water. Reverse osmosis (RO) is the technology of choice for desalination purposes; however, raw seawater must undergo pretreatment to avoid rapid fouling and plugging of RO membranes and modules. Current pretreatment technology is effective in the open ocean but in coastal regions involves frequent replacement of filter cartridges and increased maintenance costs. The standard pretreatment process consists of 20 μm cartridge filters and 3 μm cartridge filters in series. Several technologies were considered as options for improving the current pretreatment …

Hollow Fiber Membranes In Increased Algae Growth For Biobutanol Production, Allison Mcatee

Chemical Engineering Undergraduate Honors Theses

Algae are a unique and remarkable species of plant that is capable of thriving on land deemed useless for the cultivation of food crops. They also breathe in the harmful greenhouse gas, carbon dioxide. As the fastest living organism to complete a life cycle, algae is the single most effective user of carbon dioxide in the world thus making it an important ally for diminishing the threat of global warming. Furthermore, algae are comprised of high concentrations of lipids, rendering it an appealing option for use in biodiesel production, specifically butanol. Increasing the algae’s supply of carbon dioxide gas causes …

Using Capillary Electrophoresis To Detect Amyloid Protein Aggregation, Jennifer Kurtz

Chemical Engineering Undergraduate Honors Theses

Alzheimer’s disease (AD) is the leading cause of dementia accounting for ½ to ¾ of all cases. AD is characterized by a progressive loss of cognitive function over a span of 10 years, ultimately ending in death. The main possible cause of AD being researched is the formation of soluble, oligomer amyloids. Amyloids are proteins that misfold and aggregate in the brain causing potent neurotoxic effects on neurons in the brain. Microchip electrophoresis and capillary electrophoresis are two potential methods of determining the level of amyloid aggregation. In order to detect at physiological concentrations, covalent dyes must be used to …

Photocatalytic Reactor Using Tio2 Thin Film On Quartz Tubes, Ram Mahipal Kouda

Graduate Theses and Dissertations

Photocatalysis process, as an environmental application is an advanced oxidation process with tremendous potential in the near future. Previously many researchers, have conducted photocatalysis in different reactor configuration using TiO2 slurry and thin film, using a UV light source, the constraints for these reactors are the need for the removal of TiO2 particles at the outlet stream in a slurry reactor and poor environment for the efficient use of TiO2 film using UV light, as the UV light penetration depth in water is about an inch.

Taking all this into consideration, we propose a design for reactor with efficient contact …

Innovative Desalination Systems Using Low-Grade Heat, Chennan Li

USF Tampa Graduate Theses and Dissertations

Water and energy crises have forced researchers to seek alternative water and energy sources. Seawater desalination can contribute towards meeting the increasing demand for fresh water using alternative energy sources like low-grade heat. Industrial waste heat, geothermal, solar thermal, could help to ease the energy crisis.

Unfortunately, the efficiency of the conventional power cycle becomes

uneconomically low with low-grade heat sources, while, at the same time, seawater desalination requires more energy than a conventional water treatment process. However, heat discarded from low-grade heat power cycles could be used as part of desalination energy sources with seawater being used as coolant …

Mesh Adaption For Efficient Multiscale Implementation Of One-Dimensional Turbulence, D. O. Lignell, A. R. Kerstein, G. Sun, E. I. Monson

Faculty Publications

One-Dimensional Turbulence (ODT) is a stochastic model for turbulent flow simulation. In an atmospheric context, it is analogous to single-column modeling (SCM) in that it lives on a 1D spatial domain, but different in that it time advances individual flow realizations rather than ensemble-averaged quantities. The lack of averaging enables a physically sound multiscale treatment, which is useful for resolving sporadic localized phenomena, as seen in stably stratified regimes, and sharp interfaces, as observed where a convective layer encounters a stable overlying zone. In such flows, the relevant scale range is so large that it is beneficial to enhance model …

Synthesis Of Lini0.5Co0.2Mn0.3O2 For Lithium Ion Batteries And The Mechanism Of Capacity Fading At High Temperature, Wen Liu, Miao Wang, Ji-Tao Chen, Xin-Xiang Zhang, Heng-Hui Zhou

Journal of Electrochemistry

The Ni-rich cathode materials, LiNi_0.5Co_0.2Mn_0.3O₂, have been synthesized by Co-precipitation and high-temperature solid-phase sintering method. Constant current charge-discharge tests showed high discharge capacity of 179.2 mAh·g^-1 in the 3.0~4.4 V at 0.2C. However, at 55 °C the LiNi_0.5Co_0.2Mn_0.3O₂ experienced the dramatic capacity fading after 100 charge-discharge cycles. Electrochemical Impedance Spectroscopy, X-Ray Photoelectron Spectroscopy, Atomic Emission Spectroscopy have been employed to study the capacity fading mechanism of LiNi_0.5Co_0.2Mn_0.3O₂ cycled at high temperature in range of high-voltage charge and …

Synthesis And Electrochemical Properties Of Lifeso4F/Graphene Composite As Cathode Material For Lithium-Ion Batteries, Wei Guo, Ya-Xia Yin, Li-Jun Wan, Yu-Guo Guo

Journal of Electrochemistry

The LiFeSO₄F was successfully synthesized from the reactions of FeSO₄∙xH₂O (x=1, 4, 7) with LiF in tetraethylene glycol media through a facile low temperature method. The structures and microscopic features of the products were characterized by XRD, SEM and TEM. TGA result shows the good thermal stability of the as-prepared LiFeSO₄F. No diffraction peaks of the FeSO₄ are observed in the as-prepared products with the starting material of either FeSO₄∙4H₂O or FeSO₄∙7H₂O, which should be ascribed to delaying the release of H_{2 …}

Ethanol Electrooxidation On Pt/Mo2/Cnts Catalysts, Yu-Long Cheng, Jie Sun, Ji-Gang Li, Li-Gong Zhang, Tian Zhou, Geng Chang, Zhong-Chao Dong

Journal of Electrochemistry

The ethanol electrooxidation behaviors on Pt/MO₂/CNTs（M=Sn, Ti, Ce）and Pt/CNTs catalysts in H₂SO₄ solutions were researched by cyclic voltammetry. It has revealed that the catalysts with the addition of metal oxides presented higher electrooxidation activity for ethanol, in particular, the Pt/CeO₂/CNTs catalyst showed the best activity for ethanol electrooxidation intermediate. The Pt/SnO₂/CNTs catalyst demonstrated the best ethanol electrooxidation activity when considering the synthetic effects of such parameters as the onset oxidation potential, peak current densities and total oxidation area.

Catalytic Activities Of Electrochemically Dealloyed Pt(Pd)-Cu Catalysts For Oxygen Reduction Reaction, Rui-Zhi Yang, Strasser Peter, Toney Michael

Journal of Electrochemistry

The electrochemically dealloyed Pt(Pd)-Cu catalysts were prepared by electrochemical dealloying of Cu₃Pt(Pd) and their catalytic activities toward oxygen reduction reaction (ORR) were studied in 0.1 mol·L^-1 HClO₄ . solutions. The structural features of the dealloyed Pt(Pd)-Cu were revealed by synchrotron-based anomalous X-ray diffraction (AXRD) and surface X-ray scattering (SXS) at an atomic scale. We established a relationship between the structure and the catalytic activity by comparing the ORR activity and the structure of dealloyed Cu₃Pt nanoparticles with similarly dealloyed Cu₃Pt thin films and Cu₃Pt(111). The enhancement in the activity of …

Template-Free Synthesis Of Porous Nio Hierarchical Structure For High Performance Supercapacitors, Yun Huang, Zhong Wu, Xin-Bo Zhang

Journal of Electrochemistry

A facile and template-free hydrothermal method is proposed to successfully synthesize porous NiO hierarchical structure, which is found to be assembled from ultrathin NiO nanosheets. As for electrochemical pseudocapacitor application, the obtained material exhibits not only high specific capacitances of 435 F·g^-1 at 20 mV·s^-1 and 367 F·g^-1 at 10 A·g^-1, but also holds a good electrochemical stability over 1000 cycles at a current rate of 20 mV·s^-1. These results suggest that the hierarchical structured porous NiO is a promising supercapacitor electrode material.

Electrochemical Reduction Of Co2 On Sn/Cu Electrodes, Chen-Chen Zhao, Jian-Wei Guo, Li Wang, Xiang-Ming He, Cheng Wang, Zhi-Xiang Liu

Journal of Electrochemistry

The Sn/Cu electrodes were prepared by electroplating method and their morphologies under different galvanization current densities were determined by SEM. In alkali, the effects of Sn/Cu electrodes on the activities towards hydrogen evolution and electrochemical reduction of CO₂ were investigated in alkaline solutions using a three-electrode system. These results indicated that the Sn/Cu electrodes prepared at 10 mA/cm² and 15 mA/cm² showed good activities, while that prepared at 15 mA/cm² was even better in activities. The synergetic structure of the Sn/Cu electrode to be beneficial to electrochemical reduction of CO₂ has been pointed out.

Electrochemical Properties Of The Keggin-Type Lacunary Heteropolysilicate Anion And Its Eectrocatalysis For H2O2 Reduction, Xi-Long Liu, Chun-Yan Wu, Fang Zhou, Hong-Sheng Liu, Ying-Jie Hua, Chong-Tai Wang, Xiao-Yang Liu

Journal of Electrochemistry

Electrochemical properties of the Keggin-type lacunary heteropolysilicate anion SiW₁₁O₃₉^8- (SiW₁₁) and its indirect electrocatalysis for H₂O₂ reduction in the supporting electrolyte containing 0.1 mol·L^-1 NaHSO₄ and Na₂SO₄ solutions were investigated using cyclic voltammetry, square wave voltammetry and alternating current impedance spectroscopy. Experimental results indicated that SiW₁₁ showed two pairs of reversible redox waves on the glassy carbon (GC) electrode in an acidic solution. The electron transfer number corresponding to the two pairs of waves was one, and the proton transfer number involved was two during …

Electrocatalytic Oxidation Of Ethanol On Ni-P-Tio2 Composite Coating Electrodes, Guang-Hui Hu, Hai-Xia Zeng, Zhi-Gang Wei, Zhan-Chang Pan, Shu-Guang Xie, Yan-Di Zou

Journal of Electrochemistry

The Ni-P-TiO₂ composite coating electrodes with different contents of TiO₂ particulates were prepared by electroless plating technique from Ni-P plating bath containing TiO₂ powders on brass. Cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) were used to test the electrochemical performance of Ni-P-TiO₂/Cu electrodes. It was indicated that the Ni-P-TiO₂/Cu electrodes exhibited very strong electrocatalytic activity toward the oxidation of ethanol in alkaline medium at ambient temperature. The electrocatalytic activity of ethanol oxidation on the Ni-P-TiO₂ electrodes depended on the amounts of TiO₂ in the coatings. The …

Replacement Options For The Ap1-Lew System, Tiffany M. Sherburn

Honors Theses

This report details the upgrade of Pfizer’s Active Pharmaceutical Ingredient-Low Endotoxin Water (API-LEW) distribution system. The current system is suffering from chloride induced stress corrosion which has caused pitting and cracking throughout the exterior portions of the loop. The system will eventually fail catastrophically if an update is not undertaken. Many variables and system constraints are considered to maintain the API-LEW grade water.

The system operates at 65 ^○C and maintains turbulence to prevent any microbial growth. The distribution loop spans 8,500 feet of 4 inch diameter stainless steel pipe which is carried on trestles that are exterior to …

Synthesis And Electrochemical Properties Of Yttrium-Doped Lini0.49Mn1.49Y0.02O4, Xian-Wen Zhang, Zheng-Xi Zhang, Li Yang, Shao-Hua Fang, Long Qu

Journal of Electrochemistry

The LiNi_0.49Mn_1.49Y_0.02O₄ cathode material was synthesized using the citric acid-assisted sol-gel method by partial substitutions of Ni and Mn with Y in the LiNi_0.5Mn_1.5O₄ material. The influences of Y doping on the structure and electrochemical properties were investigated by means of X-ray diffraction, cyclic voltammetry, galvanostatic charge/discharge tests and AC impedance spectroscopy. The results showed that the introduction of Y into the LiNi_0.5Mn_1.5O₄ greatly improved the cycle performance and rate capability. When the charge and discharge current was 1 C in the potential …