Chemical Engineering Commons^™

Optimization Of Pyrochlore Catalysts For The Dry Reforming Of Methane, Felipe Polo Garzon

All Dissertations

The conversion of methane into syngas (a mixture of CO and H2), which can be further converted into a variety of chemicals and particularly liquid fuels, is of growing importance given recent increases in methane production world-wide. Furthermore, since using CO2 as the co-feed offers many environmental advantages, dry reforming of methane (DRM, CH4 + CO2 ⇌ 2CO + 2H2) has received renewed attention. In recent years, experimentalists have shown that the Rh-substituted lanthanum zirconate pyrochlore (LRhZ) material is catalytically active for DRM, exhibits long-term thermal stability and resists deactivation; however, previous to this doctoral work, a detailed understanding of …

Synthesis Of Renewable Aromatic Chemicals And Fuels From Biomass Derived Lignin Model Compounds, Bethany Carter

All Dissertations

Lignocellulosic biomass is the most viable choice for producing high-value chemicals, materials, liquid transportation fuels, and energy from a renewable source. Lignin, in particular, is of interest because it serves as the only significant source of renewable aromatic carbon. Commercially, the Kraft pulping process is the predominant method for separating lignin and hemicellulose (collectively called black liquor) from the cellulose fraction of woody biomass. To enable the production of low molecular weight compounds such phenols and aromatic acids, high-purity, low-ash lignin must first be extracted from the black liquor. This separation is achieved using the Sequential Liquid- Lignin Recovery Process, …

Investigating Polymer Based Scaffolds For Urinary Bladder Tissue Engineering, Srikanth Sivaraman

All Dissertations

Current surgical treatments for urinary bladder disorders rely on the use of autologous intestinal segments and xenografts such as small intestinal submucosa, which suffer from various complications including mechanical mismatch and graft shrinkage. Despite early promises of bladder tissue engineering, a recent report of unsuccessful clinical trials suggests that the technology needs further improvement and evaluation through animal models of bladder dysfunction. Therefore, the objective of this doctoral dissertation was to characterize a viable bladder tissue scaffold (patch) which mimics the mechanical properties of the bladder, maintains the phenotype of the BSMC seeded in it and finally, tested in vivo …

Optimal Design Of Hybrid Renewable Energy Systems, Alphonse Hakizimana, Joseph Scott

Chemical and Biomolecular Graduate Research Symposium

Utilization of renewable energy sources such as wind and solar can overcome environmental threats associated with fossil fuels. But expensive power producing and storage components are required to harness and store renewable energy. In addition renewable sources are intermittent, thus unreliable when used independently.

Alternative Sample Loading Preparation For Thermal Ionization Mass Spectrometry, Scott M. Husson, Brian Powell, Glenn Fugate, David Locklair, Joseph Mannion

Chemical and Biomolecular Graduate Research Symposium

This contribution describes a new sample loading method for Thermal Ionization Mass Spectrometry (TIMS), which is used in nuclear safeguards and non-proliferation efforts worldwide and is known as the “gold standard” in isotopic ratio measurements of plutonium. TIMS analysis is used to determine grades of nuclear material and the extent of enrichment at production sites. The current sample loading method for TIMS analysis is known as “bead-loading”. While it provides the lowest detection limit of any known method for plutonium analysis, bead-loading is a difficult, time consuming, and expensive method that results in up to 20% sample loss. The major …

Micro‐Textured Boron Nitride Nanoplatelet Modified Polyethylene Films, Ozgun Ozdemir, Amod A. Ogale

Chemical and Biomolecular Graduate Research Symposium

Linear low density polyethylene (LLDPE) micro‐textured films filled with boron nitride nanoplatelets (BNN) were produced by continuous melt extrusion. Nanoparticles displayed a significant extent of dispersion inside the matrix. The addition of BNN led to more than 10‐fold increase of the in‐plane thermal conductivity (TC) of the nanocomposite (7.7 W/m.K vs 0.3 W/m.K for pure LLDPE), and 1.3‐fold increase of through thickness TC. To increase the surface area available for convective heat transfer, micro‐textured films (T‐BNN) were produced from a micro‐patterned die. Nanoplatelets were aligned parallel to the film machine direction. Film stiffness and tensile strength are comparable to the …

Cellulose Nanofiber Composite Membranes For Water Purification, Nithinart Chitpong, Scott M. Husson

Chemical and Biomolecular Graduate Research Symposium

Global water demand continues to increase because of population growth, urbanization, and climate change. Since there are limited natural water resources, water purification systems play a critical societal role. Membrane technologies are used widely to improve water quality for beneficial use. Therefore, the development of new membranes is an active area of research in the water purification field.

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

Chemical and Biomolecular Graduate Research Symposium

Concern over ever decreasing oil supplies, increasing levels of pollution and energy independence have been the primary driving forces behind significant efforts focused on the development of new technologies capable of increasing the production of alternative fuels. To-date, ethanol and to a lesser extent biodiesel have been the only alternative fuels or fuel additives to gain widespread use and be synthesized on a commercial scale. Currently, most of the World’s ethanol is produced from renewable biomass. The biomass feedstocks and fermentation broths used in ethanol production contain high amounts of water, and therefore, the energy efficiency of the process is …

Density Functional Theory Simulations Of Mofs Encapsulated-Catalyzed Systems, Jiazhou Zhu, Rachel B. Getman

Chemical and Biomolecular Graduate Research Symposium

The research is mainly on Computational Design of Highly Selective Transition Metal Catalysts Encapsulated by Metal-­‐Organic Frameworks for Butane Oxidation to 1-­‐Butanol. Metal Organic Framework (MOF) grown over a heterogeneous catalyst. Pores of framework allow only certain molecules of correct size, orientation, or chemical properties to access catalyst. The framework will force molecule into desired orientation where only the terminal atoms will “see” the catalyst. In our simulation we would like to use the helium ring to simulate the MOFs pores, since He is inert and exhibits the no chemical reactivity. The reaction we are looking into is butane oxidation …

Modification Of Liposome Release Characteristics With Metal Nanoparticles, Saptarshi Chakraborty, Christopher L. Kitchens

Chemical and Biomolecular Graduate Research Symposium

Gold nanoparticles have been getting increasing amount of attention due to their stability, optical properties and low toxicity in the field of consumer products and biomedicines. Gold nanoparticles with various surface chemistries have been synthesized in order to take advantage of the size, shape and morphology dependent properties of the nanoparticles which vary greatly from the bulk properties. These properties of gold nanoparticles have made them attractive in optical sensing, targeted drug delivery, bio imaging, chemical, catalytic and photo thermal applications. These surface functionalized nanoparticles were used to study nanoparticle-lipid bilayer interactions using lipid bilayer permeability studies, where permeability of …

Polymer Sensors For The Quantification Of Waterborne Uranium, C E. Duval, A F. Seliman, T A. Devol, S M. Husson

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Development Of Anti-Fouling, Anti-Microbial Membranes By Chemical Patterning, Steven Weinman, Na Li, Viatcheslav Freger, Moshe Herzberg, Scott Husson

Chemical and Biomolecular Graduate Research Symposium

Over 1 billion people lack access to clean drinking water. Membranes are a tool that can help provide clean water to these people. However, treatment of impaired waters for beneficial use exposes the membranes to feed waters containing biological and abiotic species, which leads to fouling and loss of membrane productivity over time. Since reduction in flux due to fouling is one of the largest costs associated with membrane processes in water treatment, new coatings that limit fouling would have significant economic and societal impacts. Developing these advanced coatings is the focus of our work.

Carbon Fibers Derived From Bi-Component Precursors, Jing Jin, Amod A. Ogale

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Conducting Polymer Microstructures And Composites For Supercapacitors, Kryssia P. Diaz-Orellana, Mark E. Roberts

Chemical and Biomolecular Graduate Research Symposium

To increase the performance of conducting polymer electrodes for supercapacitors by controlling polymer assembly, ion transport, electron transfer, and redox processes. The electrode morphology and electrochemical performance are studied.

Dendrimer-Guest Interactions: Challenging Conventional Wisdom, Ryan S. Defever, Sapna Sarupria

Chemical and Biomolecular Graduate Research Symposium

Solutions to many future challenges - including water purification, drug delivery, and energy storage - will require innovative new materials. Dendrimers are a class of materials with wide-ranging applications whose behavior is not fully understood. In many potential applications, dendrimers interact with small molecules. Our work focuses on describing the fundamental mechanisms governing the interactions between dendrimers and hydrocarbons using molecular modeling and computer simulations. A common view of dendrimer host-guest interactions is that the guest molecules are encapsulated in protected interior voids within the dendrimer structure. Our results present an alternative picture and show that the association of a …

Effect Of Process Variables On Mechanical And Transport Properties Of Carbon Fibers From Mesophase Pitch, Victor Bermudez, Amod Ogale

Chemical and Biomolecular Graduate Research Symposium

To obtain mesophase pitch-based carbon fibers with improved mechanical strength while retaining superior electrical and thermal properties by

i) Systematic investigation of the relationship between DDR versus longitudinal and transverse microstructure of mesophase MP fibers; and

ii) Developing a novel type of microstructure

Heterogeneous Catalysis Of Aqueous Phase Reforming Of Glycerol With First Principle Calculations And Molecular Dynamics Simulations, Tianjun Xie, Rachel B. Getman

Chemical and Biomolecular Graduate Research Symposium

No abstract provided.

Microanalysis Of Polymer Chain Diffusion In Heat Seals, Russell Cooper

All Theses

Heat sealing is an integral method for the closure and protection of packaging. Previous work has shown that seal strength is developed by the interdiffusion of polymer chains within heat seals. Heat seals were made between two dissimilar materials. Poly(ethylene-co-acrylic acid) (EAA) was heat sealed to ionomer. Diffusion within the EAA-ionomer heat seals was estimated. The diffusion estimates were then related to resulting seal strength in the EAA-ionomer sealant system. Heated tooling sealing was utilized to make heat seals at 40 psi (275.79 kPa), 0.5 seconds, and a range of temperatures between 180˚F (82.22˚C) and 300˚F (148.89˚C). Scanning electron microscopy …

Synthesis And Characterization Of Chemically Functionalized Shape Memory Nanofoams For Unattended Sensing Applications, Anna Paola Soliani

All Dissertations

The work in this dissertation is devoted to the synthesis and characterization of novel materials for off-line unattended sensing: shape-memory grafted nanofoams. The fabrication process and characterization of highly efficient, polymeric nanosensor element with the ability to selectively detect analytes and retain memory of specific exposure events is reported. These shape memory nanofoams could potentially act as efficient and highly sensitive coatings for evanescent waveguide-based optical monitoring systems. On exposure to specific analytes, the polymeric coatings locally change their internal structure irreversibly at the nanolevel, affecting the local optical properties such as refractive index. Currently, enrichment polymer layers (EPLs) are …

Thermally Responsive Polymer Electrolytes For Inherently Safe Electrochemical Energy Storage, Jesse Kelly

All Dissertations

Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in …

High-Productivity Membrane Adsorbers: Polymer Surface-Modification Studies For Ion-Exchange And Affinity Bioseparations, Heather Chenette

All Dissertations

This Dissertation centers on the surface-modification of macroporous membranes to make them selective adsorbers for different proteins, and the analysis of the performance of these membranes relative to existing technology. Traditional chromatographic separations for the isolation and purification of proteins implement a column packed with resin beads or gel media that contain specific binding ligands on their exposed surface area. The productivity of this process is balanced by the effective use of the binding sites within the column and the speed at which the separation can take place, in addition to the need to maintain sufficient protein purity and bioactivity. …

Improved Oxidative Stability In Biodiesel Via Commercially-Viable Processing Strategies, Gregory Lepak

All Theses

Biodiesel made from waste cooking oil (WCO) frequently requires antioxidants to meet oxidation stability specifications set forth in ASTM D6751 or EN 14214. In contrast, unrefined cottonseed oil (CSO), containing tocopherols and high concentrations of gossypol, a toxic polyphenolic antioxidant, is unique for biodiesel processing because it produces biodiesel resulting in higher oxidation stability. During biodiesel production, however, only a portion of these endogenous natural antioxidants are suspected to be retained. Because the economics of biodiesel manufacturing rely upon inexpensive sources of triglycerides, emphasis was placed upon developing improved alternative commercially-viable processing strategies where WCO is the main source of …

Drug Delivery With Feedback Control In Bioresponsive Hydrogels, Andrew Wilson

All Dissertations

Bioresponsive hydrogels are emerging with technological significance in targeted drug delivery, biosensors and regenerative medicine. The design challenge is to effectively link the conferred biospecificity with an engineered response tailored to the needs of a particular application. Moreover, the fundamental phenomena governing the response must support an appropriate dynamic range, limit of detection and the potential for feedback control. The design of these systems is inherently complicated due to the high interdependency of the governing phenomena that guide sensing, transduction and actuation of the hydrogel. The objective of the dissertation is to review the current state of bioresponsive hydrogel technology …

Density Functional Theory Study Of The Thermodynamics Of Catalytic Remediation Of Nitrate In Water, Lizzie Bollmann

All Theses

Over 1 billion people worldwide lack access to safe drinking water and 5,000 people die each day due to drinking contaminated water. With the development of new industries, new substances and chemicals are entering the waters every day, and the current water treatment processes are unable to remove them entirely. For example, agriculture is the world's heaviest consumer of water, and nitrates and nitrites from fertilizers are washed away with the water to rivers and streams. These chemicals can cause problems to humans and to the environment. To humans, they can cause methemoglobinemia, also known as 'blue baby syndrome'. To …

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.