Chemical Engineering Commons^™

Electrospun Chitosan Nanofibers For Virus Removal, Bingyu Bai

Dissertations, Master's Theses and Master's Reports - Open

Electrospinning uses electrostatic forces to create nanofibers that are far smaller than conventional fiber spinning process. Nanofibers made with chitosan were created and techniques to control fibers diameter and were well developed. However, the adsorption of porcine parvovirus (PPV) was low. PPV is a small, nonenveloped virus that is difficult to remove due to its size, 18-26 nm in diameter, and its chemical stability. To improve virus adsorption, we functionalized the nanofibers with a quaternized amine, forming N-[(2-hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC). This was blended with additives to increase the ability to form HTCC nanofibers. The additives changed the viscosity …

Life Cycle Assessment Of Biofuels Produced By The New Integrated Hydropyrolysis-Hydroconversion (Ih2) Process, Edwin Maleche

Dissertations, Master's Theses and Master's Reports - Open

Biofuels are alternative fuels that have the promise of reducing reliance on imported fossil fuels and decreasing emission of greenhouse gases from energy consumption. This thesis analyses the environmental impacts focusing on the greenhouse gas (GHG) emissions associated with the production and delivery of biofuel using the new Integrated Hydropyrolysis and Hydroconversion (IH²) process. The IH² process is an innovative process for the conversion of woody biomass into hydrocarbon liquid transportation fuels in the range of gasoline and diesel.

A cradle-to-grave life cycle assessment (LCA) was used to calculate the greenhouse gas emissions associated with diverse feedstocks …

Synthesis Of Pdms-Metal Oxide Hybrid Nanocomposites Using An In Situ Sol-Gel Route, Qiaoyu Lu

Dissertations, Master's Theses and Master's Reports - Open

Organic-inorganic hybrid nanocomposites are widely studied and applied in broad areas because of their ability to combine the flexibility, low density of the organic materials with the hardness, strength, thermal stability, good optical and electronic properties of the inorganic materials. Polydimethylsiloxane (PDMS) due to its excellent elasticity, transparency, and biocompatibility has been extensively employed as the organic host matrix for nanocomposites. For the inorganic component, titanium dioxide and barium titanate are broadly explored as they possess outstanding physical, optical and electronic properties.

In our experiment, PDMS-TiO₂ and PDMS-BaTiO₃ hybrid nanocomposites were fabricated based on in-situ sol-gel technique. By …

Investigation Into The Enhancement Of Polycarbonate With Conductive Nanomaterials, Michael D. Via Jr.

Dissertations, Master's Theses and Master's Reports - Open

Polymers are typically electrically and thermally insulating materials. The electrical and thermal conductivities of polymers can be increased by the addition conductive fillers such as carbons. Once the polymer composites have been made electrically and thermally conductive, they can be used in applications where these conductivities are desired such as electromagnetic shielding and static dissipation.

In this project, three carbon nanomaterials are added to polycarbonate to enhance the electrical and thermal conductivity of the resulting composite. Hyperion Catalysis FIBRILs carbon nanotubes were added to a maximum loading of 8 wt%. Ketjenblack EC-600 JD carbon black was added to a maximum …

Biochemical Conversions Of Lignocellulosic Biomass For Sustainable Fuel-Ethanol Production In The Upper Midwest, Michael James Brodeur-Campbell

Dissertations, Master's Theses and Master's Reports - Open

Biofuels are an increasingly important component of worldwide energy supply. This research aims to understand the pathways and impacts of biofuels production, and to improve these processes to make them more efficient. In Chapter 2, a life cycle assessment (LCA) is presented for cellulosic ethanol production from five potential feedstocks of regional importance to the upper Midwest - hybrid poplar, hybrid willow, switchgrass, diverse prairie grasses, and logging residues - according to the requirements of Renewable Fuel Standard (RFS). Direct land use change emissions are included for the conversion of abandoned agricultural land to feedstock production, and computer models of …

Protein Based Biomimetic Approachs To Surface Hemocompatibility And Biocompatibility Enhancement, Matthew Thomas Dickerson

Theses and Dissertations--Chemical and Materials Engineering

T. pallidum can survive a primary immune response and continue growing in the host for an extended period of time. T. pallidum is thought to bind serum fibronectin (FN) through Tp0483 on the surface to obscure antigens. A Tp0483 fragment (rTp0483) was adsorbed onto functionalized self-assembled monolayers (SAMs) with FN. FN capture by adsorbed rTp0483 depended greatly on surface chemistry with COO- groups being best for FN binding. Hemocompatibility was determined by analysis of plasma protein adsorption, intrinsic pathway activation, and platelet activation. rTp0483+FN bound an equal or lesser amount of fibrinogen (Fg), human serum albumin (HSA), and factor XII …

Effect Of Ionic Surfactants On Electrostatic Charging Of Spray Droplets, Mark T. Warren

Theses and Dissertations--Chemical and Materials Engineering

Dust capture for small coal particles (<2.5µm) can be improved if one takes advantage of electrostatic charges that resides on the surface of coal dust particles and on the surface of water spray droplets used to capture coal dust. Traditional dust capture methods that use water sprays are ineffective in capturing small dust particles since the motion of small dust particles is governed by electrostatic forces. If additives such as ionic surfactants could be added to water that would enhance the surface charge on water spray droplets, dust capture with water sprays could be improved.

The results presented show that n-sodium octyl sulfate causes the greatest charge enhancement versus the longer chained n-sodium dodecyl sulfate and n-sodium octadecyl sulfate. This can be explained by considering the factors that lead to droplet charge enhancement. Those factors are the mass of surfactant ions at the droplet surface, and the diffusion rate of the surfactant ions from the bulk droplet to the surface of the droplet. Sodium octyl sulfate will have a faster diffusion rate to the droplet surface because of its relatively short length, and will also maximize the mass …

Nanoparticle Additives For Multiphase Systems: Synthesis, Formulation And Characterization, Vinod Kanniah

Theses and Dissertations--Chemical and Materials Engineering

Study on nanoparticle additives in multiphase systems (liquid, polymer) are of immense interest in developing new product applications. Critical challenges for nanoparticle additives include their synthesis, formulation and characterization. These challenges are addressed in three application areas: nanofluids for engine lubrication, ultrathin nanocomposites for optical devices, and nanoparticle size distribution characterization.

Nanoparticle additives in oligomer mixtures can be used to develop extended temperature range motor oils. A model system includes poly(α-olefin) based oligomers with a modest fraction of poly(dimethylsiloxane) oligomers along with graphite as nanoparticle additive. Partition coefficients of each oligomer are determined since the oligomer mixture phase separated at …

Fabrication Of An Epithelial Cell-Based Ion-Selective Electrode And Its Application For Use As Alternative Tumor Angiogenesis Assay, Christina Nicole Simmons

Theses and Dissertations--Chemical and Materials Engineering

Previous studies have provided evidence that endothelial cell-based potassium ion selective electrodes possess the ability to quantify substances that have permeability-altering effects on those endothelial cells. The capability of these so-called biosensors to detect elevated concentrations of certain chemical agents found following tumor formation make them useful in the application as an alternative tumor angiogenesis assay. In this study an epithelial cell line, human colon adenocarcinoma epithelial cells (Caco-2), was used to fabricate membranes that were used to test concentrations of these chemical agents, known as cytokines, mimicking the concentrations that have been observed in the serum of healthy individuals …

Biodegradable Hydrogels And Nanocomposite Polymers: Synthesis And Characterization For Biomedical Applications, Ashley Marie Hawkins

Theses and Dissertations--Chemical and Materials Engineering

Hydrogels are popular materials for biological applications since they exhibit properties like that of natural soft tissue and have tunable properties. Biodegradable hydrogels provide an added advantage in that they degrade in an aqueous environment thereby avoiding the need for removal after the useful lifetime. In this work, we investigated poly(β-amino ester) (PBAE) biodegradable hydrogel systems. To begin, the factors affecting the macromer synthesis procedure were studied to optimize the reproducibility of the resulting hydrogels made and create new methods of tuning the properties. Hydrogel behavior was then tuned by altering the hydrophilic/hydrophobic balance of the chemicals used in the …

Application Of Thin Film Analysis Techniques And Controlled Reaction Environments To Model And Enhance Biomass Utilization By Cellulolytic Bacteria, Hsin-Fen Li

Theses and Dissertations--Chemical and Materials Engineering

Cellulose from energy crops or agriculture residues can be utilized as a sustainable energy resource to produce biofuels such as ethanol. The process of converting cellulose into solvents and biofuels requires the saccharification of cellulose into soluble, fermentable sugars. However, challenges to cellulosic biofuel production include increasing the activity of cellulose-degrading enzymes (cellulases) and increasing solvent (ethanol) yield while minimizing the co-production of organic acids. This work applies novel surface analysis techniques and fermentation reactor perturbations to quantify, manipulate, and model enzymatic and metabolic processes critical to the efficient production of cellulosic biofuels.

Surface analysis techniques utilizing cellulose thin film …

Membrane Immobilized Reactive Fe/Pd Nanoparticles: Modeling And Tce Degradation Results, Ruo He

Theses and Dissertations--Chemical and Materials Engineering

Detoxification of chlorinated organic compound is an important and urgent issue in water remediation nowadays. Trichloroethylene (TCE), as a model compound in this study, has been proved to be degraded effectively by bimetallic nanoparticles (NPs) in solution phase. In this study, Fe/Pd bimetallic NPs were synthesized in poly (acrylic acid) (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes. TCE dechlorination with these bimetallic NPs was conducted under different pH values and different metal loadings to study the role of corrosion on reaction rates.

One-dimensional mathematical model with pseudo first-order reaction kinetic was introduced to discuss the TCE dechlorination profile in membrane …

Study Of Characterization Of Submicron Coal Particles Dispersed In Air And Capture Of Coal Particles By Water Drops In A Scrubbing Column, Utshab Chakravorty

Theses and Dissertations--Chemical and Materials Engineering

Present day water spray based dust removal technologies do not effectively remove respirable submicron coal and silica dust particles in the underground coal mines causing Coal worker’s pneumoconiosis (CWP). The objective of this research was to study the electrostatic charges present in the airborne coal dust in order to develop efficient water spraying based dust removal technology where water drops charged using ionic compounds and surfactants would be used to capture the oppositely charged coal particles. In an experimental scrubbing column, coal particles dispersed in an air stream by a Fluidized Bed Aerosol Generator were captured by water drops sprayed …

The Effect Of Supercritical Water On Crude Glycerin Solution, Jared Bouquet

Doctoral Dissertations

"Crude glycerin solution, a principal byproduct of the conventional biodiesel process, was reacted in supercritical water using a specially designed Haynesʼ Alloy 282 reactor system for the production of hydrogen rich syngas. The effects of temperature, pressure, water-to-carbon molar ratio, reactor residence time, and glycerin-to-methanol weight ratio on the extent of carbon gasification and gas composition were explored. Based on the results, the extent and selectivity of reactions that concurrently occur when methanol and glycerin are in the presence of supercritical water were analyzed. A decomposition reaction pathway for glycerin conversion to syngas was hypothesized, and then utilizing the results …

Numerical Simulations Of Fracture Propagation And Sealing: Implications For Wellbore Strengthening, Saeed Salehi

Doctoral Dissertations

"To mitigate the small tolerance between pore pressure and fracture gradients an engineering practice referred to as "wellbore strengthening" is conducted to increase the fracture gradient. The method relies on propping and/or sealing the fractures with specially designed materials. Different competing theories exist for physical wellbore strengthening mechanisms which can be categorized into two groups. The first group explains that strengthening happens as a result of increasing wellbore hoop stress when fractures are sealed while the second group emphasis is on fracture tip isolation with suitable materials and enhancing fracture propagation pressure. The numerical models and lab experiments …

Updated Eor Screening Criteria And Modeling The Impacts Of Water Salinity Changes On Oil Recovery, Ahmad Aladasani

Doctoral Dissertations

"Developing technologies for enhanced oil recovery (EOR) from existing oil fields would supply the world's energy needs for several decades. The application of EOR in many major oil-producing countries remains in its conceptual stage. Thermal and gas EOR methods achieve high incremental rates; however, their application range has not broadened significantly as they have matured, while the rate at which new, promising EOR methods such as Low-salinity water flooding (LSWF) are being implemented is alarming. Despite, the potential of LSWF its development and application has been hindered by the lack of consensus concerning its recovery mechanism(s). Every oil reservoir has …

Volume-Phase Transitions In Responsive Photo-Cross-Linked Polymer Network Films, Leena Patra

USF Tampa Graduate Theses and Dissertations

The overall thrust of this project is to gain an insight into a class of surface-tethered cross-linked thin films of poly(N-alkylacrylamides) that display a lower critical solution temperature (LCST).The structure of the alkyl group and the modification of the amide groups determine the LCST and resultant volume-phase transition behavior. The aim of this study involves synthesis and characterization of thin films and to correlate the volume-transition behavior to the structure of the alkyl group. For better understanding the volume-transition behavior, the polymer films are perturbed by the Hofmeister salt series to examine trends between different alkyl groups. While most of …

Novel Blends Of Sulfur-Tolerant Water-Gas Shift Catalysts For Biofuel Applications, Timothy Michael Roberge

USF Tampa Graduate Theses and Dissertations

As traditional sources of energy become depleted, significant research interest has gone into conversion of biomass into renewable fuels. Biomass-derived synthesis gas typically contains concentrations of approximately 30 to 600 ppm H2S in stream. H2S is a catalyst poison which adversely affects downstream processing of hydrogen for gas to liquid plants. The water-gas shift reaction is an integral part of converting CO and steam to H2 and CO2. Currently, all known water-gas shift catalysts deactivate in sulfur concentrations typical of biomass-derived synthesis gas. Novel catalysts are needed to remain active in the presence of sulfur concentrations in order to boost …

Catalytic Tri-Reforming Of Biomass-Derived Syngas To Produce Desired H2:Co Ratios For Fuel Applications, Devin Mason Walker

USF Tampa Graduate Theses and Dissertations

This study focuses on upgrading biomass derived syngas for the synthesis of liquid fuels using Fischer-Tropsch synthesis (FTS). The process includes novel gasification of biomass via a tri-reforming process which involves a synergetic combination of CO2 reforming, steam reforming, and partial oxidation of methane. Typical biomass-derived syngas H2:CO is 1:1 and contains tars that deactivate FT catalyst. This innovation allows for cost-effective one-step production of syngas in the required H2:CO of 2:1 with reduction of tars for use in the FTS. To maximize the performance of the tri-reforming catalyst, an attempt to control oxygen mobility, thermal stability, dispersion of metal, …

Smart Packaging: A Novel Technique For Localized Drug Delivery For Ovarian Cancer, Eva Christabel Williams

USF Tampa Graduate Theses and Dissertations

Localized drug delivery is emerging as an effective technique due to its ability to administer therapeutic concentrations and controlled release of drugs to cancer sites in the body. It also prevents the contact of harsh chemotherapy drugs to healthy regions in the body that otherwise would become exposed to current treatments.

This study reports on a model chemotherapy drug delivery system comprising non-ionic surfactant vesicles (niosomes) packaged within a temperature-sensitive chitosan network. This smart packaging, or package-within-a package system, provides two distinct advantages. First, the gel prevents circulation of the niosomes and maintains delivery in the vicinity of a tumor. …