Chemical Engineering Commons^™

Behavior Of Selective Oxygen Functional Groups Upon Hydrothermal Carbonization And Pyrolysis Of Biomass And Their Roles On Selective Applications, Nepu Saha

Theses and Dissertations

Hydrothermal carbonization (HTC) is a thermochemical process where biomass is treated in water under high temperature and corresponding vapor pressure. During HTC, biomass undergoes a series of reactions including hydrolysis, decarboxylation, dehydration, aromatization, and polymerization. As a result, a solid product is produced from biomass after HTC process, which is widely known as hydrochar. Depending on the HTC process conditions, a wide-variety of oxygen-containing groups formed on hydrochar surfaces. Many of these groups could play critical roles in applications such as adsorption, and energy and gas storage, etc. However, not all functional groups are exposed on the surface due to …

Degradative Processes Of Commercial And Next-Generation Lithium-Ion Battery Materials, Benjamin Ng

Theses and Dissertations

The work embodied in this thesis bridges the gap between modern and next-generation Li-ion batteries (LIBs). First, a detailed study of the complex interfacial interactions (e.g. electrode/electrolyte, particle/particle, particle/solid-electrolyte interphase) in existing LIBs (graphite anode, Li(Ni_0.5Mn_0.3Co_0.2)O_2 cathode) are investigated and then used to develop strategies for safer, more energy-dense, and more durable electrode materials (i.e. tailored hybrid materials). The first portion of this thesis focuses heavily on decoupling the complex thermodynamics, reaction kinetics, and mass transport properties in commercially available LIBs. This thesis includes a detailed investigation into the operating parameter space for LIBs, including temperature (-30^oC to +52^oC), state-of-charge …

Polymer Microparticles For Encapsulation And Presentation Of Anti-Inflammatory Agents For Inflammatory Diseases, Christopher Isely

Theses and Dissertations

Inflammatory diseases have a huge economic impact on the healthcare system. Incidence of obesity and muscle atrophy, two high profile inflammatory diseases, continues to increase. Anti-inflammatory agents are potential therapeutics for these diseases. Resveratrol is a polyphenol that has anti-inflammatory effects; however, resveratrol suffers from low bioavailability and hasn’t had impressive clinical results when delivered orally. Mannose is a monosaccharide that also has anti-inflammatory effects, however, effects are highest when mannose is presented on the surface of a support the size of a bacteria. Incorporation of resveratrol and mannose into biodegradable polymer microparticles could be a feasible approach to overcome …

Discovery And Investigation Of Ammonia Decomposition Catalysts, Katherine Mccullough

Theses and Dissertations

Liquid ammonia can be used as a hydrogen transportation and generation source for use in PEM fuel cells. Current Ru catalysts for ammonia decomposition contain high loadings of Ru and require reaction temperatures at or above 550°C to attain equilibrium conversion. For on-site hydrogen generation, it is of interest to combine hydrogen generation from ammonia decomposition directly with PEM fuel cells. For this occur, operating temperatures need to be considerably lowered and effluent concentrations of ammonia need to be minimized to avoid poisoning of the membrane. Therefore, it is of interest to develop a low-cost catalyst that exhibits high activity …

Mitigating Corrosion And Enhancing Energy Density Of Zinc-Based Anodes In Primary And Secondary Aqueous Batteries, Ehsan Faegh

Theses and Dissertations

Today Lithium-ion (Li-ion) batteries are the most-emphasized battery technology among the many different battery systems in the market. However, due to their high cost (especially for electric vehicle applications), flammability and toxicity, the development of inexpensive and safer alternative battery chemistries has been the focus of a significant amount of recent research. Among various battery chemistries, Aluminum-based (Al-based) and Zinc-based (Zn-based) batteries have been touted as promising options to compete with Li-ion batteries. However, the practical realization of Al battery chemistries has been difficult over a long period of time (170 years) due to a number of fundamental and intrinsic …

Experimental And Computational Investigations Of Type Iii Deep Eutectic Solvents For Btx Removal From Light Naphtha, Kyle Mcgaughy

Theses and Dissertations

Light naphtha is a crucial chemical feedstock that is used to make value-added products from plastic to fuels. Whether it is derived from fossil fuels or renewable resources, naphtha typically contains small fraction of aromatic contaminants such as benzene, toluene, and xylene (BTX). Polar solvents such as sulfolane, ethylene glycol, and glycerol are industrially used to separate BTX from naphtha. Each of these solvents has some processing difficulties though, whether it be sulfolane degrading and corroding equipment or ethylene glycol and glycerol not being particularly selective for BTX over light naphtha. Some of the traditional solvents used for naphtha purification …

Enhancement Of Electrospun Nanofiber Properties Via Automated Track Post-Draw Processing, David Anthony Brennan

Theses and Dissertations

Electrospinning is an alternative manufacturing method, capable of producing fibers with nanoscale diameters from a wide range of different polymers in a process which is relatively simple and inexpensive in comparison to other forms of nanofiber production. This has made electrospinning the subject a great deal of research as a method of producing nanofibers for various high-performance applications. However, electrospun nanofiber tensile strength is weak in comparison to conventional fibers of the same material, preventing widespread use and marketization. This disparity in mechanical strength is attributed to poor polymer chain alignment in individual fibers, caused by the absence of a …

Dewetting Induced Lipid Bilayer Multicomponent Scaffold For Synthetic Cell Vesicle And Their Stability, Anjana Khanal

Theses and Dissertations

This thesis introduces a microfluidic method to generate monodisperse water-in-oil-in water double emulsions. The microfluidic method is able to produce double emulsions with high degree of controllability and flexibility on size and number of droplets. We demonstrate this by producing double emulsions containing 1-8 inner water droplets and studied their dewetting phenomena to lipid bilayer scaffold. Our study shows that for the dewetting phenomenon to occur the oil must be volatile, polar and should make low contact angle with the involved interfaces. The chloroform shows self-emulsification behavior in presence of surfactant F127. The topological droplets formation with multiple compartments is …

Investigating The Performance Of Hydroponic Nutrient Solutions As Potential Draw Solutions For Fertilizer Drawn Forward Osmosis, Mohamed Bassiouny Abu Qersh

Theses and Dissertations

This research project aims at investigating the performance of hydroponic nutrient solutions as draw solutions for desalination using the fertilizer drawn forward osmosis (FDFO) process. Six different lettuce and leafy greens hydroponic nutrient stock solutions were prepared according to the literature and used in this study and tested on a bench-scale forward osmosis unit as draw solutions for the process. The feed solutions for the process was de-ionized water mixed with Sodium Chloride in different concentrations to represent different salinities of brackish groundwater. The draw efficiency of each solution was measured based on water flux, reverse solute flux, water recovery, …

Biomass-Derived Electrode Materials And Sustainable Processes For Supercapacitors, Katelyn M. Shell

Theses and Dissertations

Biomass is one of the most abundant natural resources and has been used as a source of energy for thousands of years. Biomass as a precursor for energy storage materials is still relatively novel and faces several obstacles before becoming commonly used in today’s electrical devices. Currently, energy storage devices, such as batteries, capacitors, and supercapacitors, utilize petroleum-derived graphitic carbons for anodes, generating a need for more sustainable materials. Biomass, as a carbon-rich source for electrode materials, presents a viable and economically feasible alternative due to the prevalent lignocellulosic compounds: lignin, cellulose, and hemicellulose. Preliminary studies on the solid residues …

Information Architecture For A Chemical Modeling Knowledge Graph, Adam R. Luxon

Theses and Dissertations

Machine learning models for chemical property predictions are high dimension design challenges spanning multiple disciplines. Free and open-source software libraries have streamlined the model implementation process, but the design complexity remains. In order better navigate and understand the machine learning design space, model information needs to be organized and contextualized. In this work, instances of chemical property models and their associated parameters were stored in a Neo4j property graph database. Machine learning model instances were created with permutations of dataset, learning algorithm, molecular featurization, data scaling, data splitting, hyperparameters, and hyperparameter optimization techniques. The resulting graph contains over 83,000 nodes …

Nature-Inspired Material Strategies Towards Functional Devices, Sayantan Pradhan

Theses and Dissertations

Naturally sourced, renewable biomaterials possess outstanding advantages for a multitude of biomedical applications owing to their biodegradability, biocompatibility, and excellent mechanical properties. Of interest in this dissertation are silk (protein) and chitin (polysaccharide) biopolymers for the fabrication of functional biodevices. One of the major challenges restricting these materials beyond their traditional usage as passive substrate materials is the ability to combine them with high-resolution fabrication techniques. Initial research work is directed towards the fabrication of micropatterned, flexible 2D substrates of silk fibroin and chitin using bench-top photolithographic techniques. Research is focused on imparting electrochemical properties to silk proteins using conducting …

Continuous Preparation And Application Of Novel Heterogeneous Catalysis, Michael B. Burkholder

Theses and Dissertations

Transition metal heterogeneous catalysts are widely used across many chemical industries to reduce waste and emissions and reduce production time while increasing rate. The prevalence of these materials results from the complex relationship between metal nanoparticles and supports affecting final catalytic performance. Rational catalyst synthesis describes the ability to precisely engineer structures through controlled preparation. Novel materials and continuous processing represent a promising approach for rational catalyst synthesis.

The application of these catalysts in continuous, multiphase processes, such as cross-coupling reactions, oxidation chemistry, and nitroreduction processes, are paramount to developing new commercial routes for high-value products. Pd/G catalysts synthesized by …

Applied Machine Learning In Extrusion-Based Bioprinting, Shuyu Tian

Theses and Dissertations

Optimization of extrusion-based bioprinting (EBB) parameters have been systematically conducted through experimentation. However, the process is time and resource-intensive and not easily translatable across different laboratories. A machine learning (ML) approach to EBB parameter optimization can accelerate this process for laboratories across the field through training using data collected from published literature. In this work, regression-based and classification-based ML models were investigated for their abilities to predict printing outcomes of cell viability and filament diameter for cell-containing alginate and gelatin composite hydrogels. Regression-based models were investigated for their ability to predict suitable extrusion pressure given desired cell viability when keeping …

Perovskite Thin Films Annealed In Supercritical Fluids For Efficient Solar Cells, Gilbert Annohene

Theses and Dissertations

In the field of photovoltaics, scientists and researchers are working fervently to produce a combination of efficient, stable, low cost and scalable devices. Methylammonium lead trihalide perovskite has attracted intense interest due to its high photovoltaic performance, low cost, and ease of manufacture. Their high absorption coefficient, tunable bandgap, low-temperature processing, and abundant elemental constituent provide innumerable advantages over other thin film absorber materials. Since the perovskite film is the most important in the device, morphology, crystallization, compositional and interface engineering have been explored to boost its performance and stability. High temperatures necessary for crystallization of organic-inorganic hybrid perovskite films …

Mathematical Modeling Of Lithium-Sulfur Batteries, Niloofar Kamyab

Theses and Dissertations

Energy storage market transformed by utilization of lithium-ion batteries, will demand high and affordable deliverable energy in the near future which it would be impossible for the current employed technologies to meet those needs Among new generation of lithium batteries, high theoretical energy density, good low-temperature performance, and abundance of inexpensive nontoxic raw material, make the lithium-sulfur batteries (LiS) a promising candidate to outperform the current lithium-ion batteries and transform the technology of the future. However, the problems and challenges that LiS batteries are currently facing with, which stem from the inherent complex mechanism of these cells, are hindering their …

Volume Frequency Response Method For Determining Mass Transfer Mechanisms Of O2 In Carbon Molecular Sieve 3k172, Olivia Smithson

Theses and Dissertations

Carbon molecular sieves (CMS) have grown more desirable over the years as an adsorbent for industrial separation processes as CMS technology has advanced. CMS is commonly used in nitrogen inerting (i.e, oxygen removal from air), carbon dioxide removal from methane and oxygen purification. However, knowledge of the dynamic behavior of these gases on CMS is needed to design and operate efficient and effective separation processes. For this reason, the mass transfer resistances within the micropore at both low and high frequencies were characterized using frequency response, COMSOL Multiphysics modeling, and MATLAB optimization , because frequency response methods have demonstrated the …

Hydrogenation Of Dimethyl Oxalate To Ethylene Glycol Over Silica Supported Copper Catalysts, Xinbin Yu

Theses and Dissertations

Ethylene glycol is a bulk chemical and hydrogenation of dimethyl oxalate (DMO) on Cu/SiO2 catalysts is the final reaction step in a growing industrial syngas to ethylene glycol (StEG) process. Efforts to improve the performance of the catalysts are still ongoing and the detailed catalytic mechanism remains controversial.

In the present work, a series of 10 wt% Cu/SiO₂ is prepared.by urea hydrolysis method and indium species is introduced by incipient wetness impregnation. Reaction studies show that 0.25 wt%-0.5 wt% of indium species can dramatically enhance the performance of 10 wt% Cu/SiO₂ catalyst. Various characterizations reveal that indium species …

Epoxy-Functional Thermoplastic Copolymers And Their Incorporation Into Thermosetting Resins, Kayla Rose Sweet

Theses and Dissertations

While polymers have secured a place in the consumer, industrial, and military markets over the last seventy years, the next generation of polymers must become more renewable, more adaptive, and higher performing to bridge industrial needs and environmental gaps. To this end, unique network configurations of copolymers and interpenetrating polymer networks (IPNs) have been employed to combine features of two or more polymers into a single material that surpasses the sum of its parts. The customization of polymer networks can be made possible via dual-functional monomers, molecules characterized by two different reactive substituents that allow for versatile methods of polymerization. …

Synthesis And Characterization Of Thermosetting Epoxy Resins From Lignin-Inspired Phenolics, Kelli Marie Hambleton

Theses and Dissertations

The need for renewable polymers able to replace their petrochemical counterparts continues to grow as sustainability concerns constantly rise. Bisguaiacol, a bio-based alternative to bisphenol-A, has been synthesized using vanillyl alcohol and guaiacol via an electrophilic aromatic condensation. Purification provides both bisguaiacol and an oligomeric coproduct with a consistent number average molecular weight and dispersity of about 650 Da and 1.00, respectively, across multiple reaction volume scales. This coproduct has been well characterized as a low molecular weight novolac averaging 5 hydroxyls per molecule and was transformed into an epoxy resin suitable for use in thermosetting resin development. By utilizing …

Solid Materials Discovery For Thin Films, Oxide Catalysts, And Polymer Sealants, Benjamin Ruiz-Yi

Theses and Dissertations

Solid materials are made up of multiple classes, including metals, ceramics, and polymers. While each class can be developed for general purpose applications or highly specialized, discovery of new materials in order to improve upon desired properties is a non-trivial task for any type of material. A wide variety of materials encompass expansive design spaces, consisting of parameters such as chemical compositions, synthesis conditions, and post-processing. Due to this, narrowing down the design space to fit within a given figure-of-merit and economic viability becomes time consuming at best and infeasible at worst. High-throughput experimentation

High-throughput experimentation (HTE) is a methodology …

Fundamental Studies Of Oxygen Electrocatalysis In Alkaline Electrochemical Cells, Victoria F. Mattick

Theses and Dissertations

Until recently the world’s main source of energy has been fossil fuels, such as coal and petroleum. However, these energy sources are polluting our planet, becoming scarce and increasingly inaccessible, and are costly to extract. Therefore, much attention has been directed to harvesting clean, abundant, and renewable energy, such as solar rays and wind. However, the intermittency of solar and wind power generation requires an effective energy buffering solution (aka energy storage) to become efficient and reliable. With high efficiency and energy density, rechargeable batteries and reversible fuel cells are two of the best methods for this purpose. Unfortunately, a …

Investigation Of Oxidized Carbon Supported Au Catalysts Synthesized Via Strong Electrostatic Adsorption Of Au(En)2Cl3 For The Hydrochlorination Of Acetylene To Vinyl Chloride Monomer, Sean Reginald Noble

Theses and Dissertations

Over 20 million tons of vinyl chloride monomer (VCM) is produced every year using acetylene hydrochlorination using a supported mercuric chloride catalyst. During this process mercury is reduced and sublimes into the environment harming all living animals and humans, so carbon-supported Au catalysts have been developed in attempts to replace it. Various techniques have been used to make these catalysts including several variations of dry impregnation. In this study we investigate the ability of Strong Electrostatic Adsorption (SEA) of Au(en)₂Cl₃ onto various supports to demonstrate the ability to rationally and consistently synthesize gold catalysts with ultra-small particle …

Theoretical Investigation Of The Biomass Conversion On Transition Metal Surfaces Based On Density Functional Theory Calculations And Machine Learning, Wenqiang Yang

Theses and Dissertations

During the past decades, heterogenous catalyzed conversion of biomass to hydrocarbons with similar or identical properties to conventional fossil fuels has gained significantly academic and industrial interest. However, the conventional heterogeneous catalysts such as sulfided NiMo/Al₂O₃ and CoMo/Al₂O₃ used have various drawbacks, such as short catalyst lifetime and high sulfur content of product. To overcome the limitations of the conventional sulfided catalysts, new catalysts must be developed, which requires a better understanding of the reaction mechanism of the biomass conversion. Based on density functional theory, in this thesis, we reported a computational calculation study …

Bijels Made By Solvent Transfer Induced Phase Separation: Formation Principles And Transport, Stephen Boakye-Ansah

Theses and Dissertations

Bijels are made of non-equilibrium particle-stabilized emulsions with a bicontinuous arrangement of the constituent fluid phases. They spontaneously form through arrested spinodal decomposition in mixtures of partially miscible liquids and neutrally wetting colloidal particles. Soon after their discovery over 10 years ago, Prof. Mike Cates, Lucasian Professor of Mathematics, predicted their future use as continuously operated cross-flow reactors for chemical reactions between immiscible reactants.

Towards this goal, work in this thesis focuses on designing bijels via Solvent Transfer Induced Phase Separation (STrIPS) for microfluidic transport applications. Structure-function relationships of STrIPS bijels stabilized by silane functionalized nanoparticles are developed. In-situ surfactant …

Study And Characterization Of Conductive Elastomers For Biomedical Applications, Hadis Gharacheh

Theses and Dissertations

Health issues have always been one of humankind's biggest challenges. Over the last century, there has been significant and monumental progress in health and biomedical science, with the end goal of alleviating and eliminating illnesses and ailments. For developing biomedical devices, polymers and elastomers group among other types of biomaterials have been highlighted to be used due to high flexibility, stability, biocompatibility, and mechanical and rheological characteristics. In this work, the characterization of acrylated poly glycerol_sebacate (PGSA) polymer conjugated with bio ionic liquid (BIL) was investigated. Results showed high biocompatibility, high printability with tunable mechanical, adhesive, and conductivity properties. For …

Synthesis And Evaluation Of Catalytic Application Of Porous Resin, Mahboubeh Nabavinia

Theses and Dissertations

The abilities to tailor catalytic functional groups and chemical characteristics onto a robust polymer structure make mesoporous phenolic resins great candidates for catalytic support applications. The use of a template synthesis method for configuring a catalytic structure is neither commercially nor environmentally friendly. In this Ph.D. thesis, new one-pot template-free methods for synthesizing mesoporous metal-doped phenol-formaldehyderesin were developed. The methods facilitate scaling for industrial catalytic applications in pharmaceutical, environmental, and medical applications. Heterogeneous palladium centered catalytic mesoporous structures were synthesized by a single-stage template-free method. BET adsorption measurements, SEM, EDX, XPS, and TEM were used to study the surface area, …

Influence Of Coordination Environment On Catalyst Structure And Function For Co2 Hydrogenation And Ethane Partial Oxidation, Juan D. Jimenez

Theses and Dissertations

In this work, we set out to establish strong structure/activity relationships for various catalytic compositions and reactions. Through in situ spectroscopic approaches, specifically DRIFTS, Raman XPS, and XAFS, we were able to discern the reactive species in CO₂ hydrogenation over highly active cobalt nanostructures, the relevant ensemble size and composition of single site catalysts for CO₂ hydrogenation, and active vibrational modes of mixed oxide catalysts for ethane partial oxidation (EPO).

First, we illustrate how tailoring surface orientations of Co₃O₄ catalysts on the nanoscale results in control over catalytic performance via the preferential formation of active …

Multi-Scale Modeling For Transport Study Inside Porous Layers Of Polymer Electrolyte Membrane Fuel Cell Using Direct Numerical Simulation, Pongsarun Satjaritanun

Theses and Dissertations

The direct modeling-based Lattice Boltzmann Agglomeration Method (LBAM) is used to explore the electrochemical kinetics and multi-scalar/multi-physics transport inside the detailed structure of the porous and catalyst layers inside polymer electrolyte membrane fuel cells (PEMFCs). The complete structure of the samples is obtained by both micro- and nano- X-ray computed tomography (CT). LBAM is able to predict the electrochemical kinetics in the nanoscale catalyst layer and investigate the electrochemical variables during cell operation. This work shows success in integrating the lattice elements into an agglomerate structure in the catalyst layer (CL). The predictions using LBAM were compared and validated with …

The Development Of Polymer Constructs For Adipose Tissue Engineering Applications, Kendall Murphy

Theses and Dissertations

The adipose tissue functions as the body’s main energy reservoir and plays a central role in maintaining whole body energy homeostasis. The ability to modulate this tissue’s inherent endocrine and metabolic functions has promising implications in treating disease associated with adipose tissue dysfunction. This work revolves around two diseases where adipose tissue inflammation and metabolic dysfunction drive the disease, obesity and cachexia. Both diseases impact a significant population of U.S. adults and substantially reduce patient quality of life.

In this study, we first demonstrate the use of novel therapeutic platforms engineered to specifically target adipose tissue inflammation and lipid catabolism …