Chemical Engineering Commons^™

Investigating Nanoparticle Capture By Condensed Phase Coacervates And Their Mixtures, Sanjna A. Bhakta

Chemical and Biological Engineering ETDs

The thermoresponsive polymers elastin-like polypeptides (ELPs) and poly(N-isopropylacrylamide) (PNIPAM) have served as a programmable bioseparation tool for applications in nanoparticle capture due to biocompatibility and tunable properties. This work investigates how the polymer composition of ELP and PNIPAM coacervates influences their phase behavior, structural morphology, and nanoparticle recruitment. In addition, the influence of interfacial interactions in nanoparticle recruitment using Tween 80 as a mechanistic probe was also investigated. Different mixtures of ELPs E1.40, E1.80, and E3 with PNIPAM14 and PNIPAM20 were used to characterize their phase behavior and analyze structural morphology using turbidity measurements and microscopy, respectively. Nanobead recruitment using …

Impact Of Gas Interactions With Nano Porous Geological Material In The Presence Of Water Vapor, Matthew D. Powell

Chemical and Biological Engineering ETDs

Predicting gas transport in nanoporous geological material requires understanding competitive adsorption and transport under humid conditions. However, most adsorption studies rely on single-component equilibrium measurements that do not capture these effects. This dissertation develops an experimental methodology to directly quantify multicomponent gas adsorption and breakthrough behavior under controlled relative humidity. The method was first applied to the Kr/Xe–N2–H2O system, where it resolved competitive adsorption behavior in humid porous media and produced a bivariate model relating noble gas adsorption to noble gas partial pressure and water saturation. The methodology was then extended to the CO2–N2 H2O system. Results showed that water …

Multiscale Network Modeling Of Native And Modified Photosynthetic Light-Harvesting Complexes, Zane E. Armijo

Chemical and Biological Engineering ETDs

Photosynthetic light-harvesting complexes harvest solar energy and direct electronic excitations toward reaction centers with exceptional efficiency. This dissertation models the Fenna--Matthews--Olson complex of green sulfur bacteria, coupled to the PscA1 reaction center, as a chromophoric network. Forster resonance energy transfer theory, validated against numerically exact hierarchical equations of motion, was implemented in kinetic Monte Carlo simulations to resolve fine-grained excitation-transport pathways. The predicted charge-transfer efficiency of 77\% agrees with experiment, with the FMO2 monomer and its gateway pigment governing interfacial transfer. Systematic single, multi, and symmetry-preserving site removals, interpreted through Mobius inversion, identify critical pigments and show that cooperative effects …

Technical Advancements In Single-Molecule Spectroscopy For High-Throughput Measurement Of Long-Time Dynamics, Quyen B. Le

Chemical and Biological Engineering ETDs

Single-molecule fluorescence spectroscopy is a powerful technique for resolving transient biomolecular dynamics and quantifying free energy landscapes, kinetics, and binding interactions. However, two fundamental limitations restrict its broader application: slow, labor-intensive data acquisition and the limited observation time imposed by fluorophore photobleaching. These limitations hinder its use in drug discovery and biomedical engineering applications that require both high-throughput and access to long-time dynamics. In this work, both challenges are addressed through technical advancements. First, a simple, generalizable approach is introduced to automate data acquisition, eliminating manual intervention during experiments. This increases the acquisition rate by more than an order of …

Nuclear Deterrence: Enhancing The Mission Through Smart Factory Predictive Solutions, Jarrod Matthew Ronquillo

Chemical and Biological Engineering ETDs

To meet the stewardship and modernization initiatives set by the Department of Energy new technologies must enter the manufacturing facilities within the nuclear deterrent complex. Predictive solutions begin with collecting data. An equipment health monitoring device was created to streamline data collection and organization for equipment and processes. A predictive and process performance dashboard was developed for a deionized water system. The dashboard used Western Electric statistical process rules and a machine learning regression algorithm to predict when the resistivity would fall out of specification. Lastly, a remaining useful life calculation was developed for all equipment related to nuclear deterrent …

Application Of Bimetallic Transition Metal Oxides Electrocatalysts For Li-Co2 Batteries And Li-O2 Batteries, Jianda Wang

Chemical and Biological Engineering ETDs

Li-ion batteries are the dominant commercial rechargeable batteries nowadays, which are used in electronic devices and electrified transportation widely. However, undesirable energy density of Li-ion batteries prohibits them from meeting requirements of new generation electronic devices. Therefore, it is important to find more alternative electronic energy storage systems with higher capacity. Fortunately, Li-CO2 batteries, featured high capacity and ability to convert CO2, have become a promising candidate to replace Li-ion batteries. In addition, Li-O2 batteries also attract people’s attention due to their high energy density and low cost. However, Li-CO2 batteries and Li-O2 batteries both face challenges of terrible cycle …

Thermally Stable And Regenerable Catalysts For Alkane Dehydrogenation, Ryan Alcala

Chemical and Biological Engineering ETDs

Shale gas upgrading reactions have gained much interest since production dramatically increased around 2010. These reactions occur at high temperatures (600°C +) where undesired processes like sintering and/or coking often occur. It is of interest to use materials like ceria as a catalyst support in these alkane conversion reactions, but ceria is prone to losing active surface area through sintering. It is also of interest to understand the behavior of PtMn and PtZn intermetallics for propane dehydrogenation as they have been identified as some of the best catalysts by theory-based prediction in literature. This manuscript explores ways of utilizing ceria’s …

Techno-Economic Analysis (Tea) And Life-Cycle Assessment (Lca) Of Sustainable Aviation Fuel (Saf) Production Through Circular Economy (Ce) Practices: A Focus On Supply Chain Optimization And Policy Implications, Edmund Gyandoh

Chemical and Biological Engineering ETDs

This study provides a comprehensive systems-level evaluation of an integrated circular biorefinery for sustainable aviation fuel (SAF) production. Employing supply chain optimization, technoeconomic analysis, lifecycle analysis, policy modeling, and multicriteria decision analysis, the research assesses technical feasibility, economic viability, and environmental performance. The circular economy model demonstrates exceptional resource efficiency, achieving a 92.3% overall circularity score with strong material recycling, water reuse, waste minimization, and near-complete energy recovery, resulting in net-negative carbon emissions and net energy export. Scaling the facility to commercial capacity (500 million liters per year) enables significant economic improvements. The minimum fuel selling price (MFSP) decreases from …

Theoretical And Experimental Investigation Of Liquid-Liquid Phase Separation: Characterizing Elastin-Like-Polypeptides, Adam D. Quintana

Chemical and Biological Engineering ETDs

This dissertation develops and validates a semi-empirical Flory–Huggins-based interaction model, combined with Cahn–Hilliard simulations, for predicting multi-component liquid–liquid phase separation (LLPS) in elastin-like polypeptide (ELP) systems. Equilibrium droplet compositions, measured using a PDMS-based microfluidic device, enabled direct parameterization of interaction coefficients. The model was applied to generate phase diagrams and assess composition dependence in ternary mixtures. Cahn–Hilliard simulations were conducted to explore potential phase morphologies under different interfacial conditions. Multi-component Lattice Boltzmann simulations were implemented to model droplet morphology evolution under varying interfacial and diffusive parameters, reproducing experimentally relevant morphologies. A three-phase wetting study revealed conditions for selective wetting and …

Pd-Based Hydrogen Separation Membranes Synthesized Via A Liquid-Phase Route, Chase W. Thompson

Chemical and Biological Engineering ETDs

Palladium (Pd) membranes have gained significant attention for their ability to selectively separate hydrogen, a critical process for clean energy applications such as fuel cells and hydrogen storage. However, challenges such as grain growth, sintering, hydrogen embrittlement, and film uniformity limit their scalability and long-term stability. This thesis focuses on the controlled synthesis, deposition, and stability of Pd nanoparticles to optimize membrane performance for hydrogen separation. This work investigates solution-phase synthesis of Pd nanoparticles, focusing on temperature, precursor concentration, and solvent composition as key variables influencing particle growth and dispersion. Pd membranes were fabricated using nanoparticle deposition onto porous supports, …

Instability-Driven Phase Separation For Quantum Structure Formation In Iii-V Semiconductors, Leonid Miroshnik

Chemical and Biological Engineering ETDs

High temperature phase instability limits the performance of III-V zinc blende semiconductor devices. A technique using an encapsulant and sacrificial layer is developed to reduce thermal degradation by group V sublimation during thermal processing of InGaAs/GaAs structures. This technique is successful in preventing As sublimation and preserving an atomically smooth surface required for surface-sensitive characterization. The degradation of the GaAsSb/InP interface by phase separation is studied. Significant interdiffusion and intermixing occurs due to the formation of a molten InSb at the interface. The intermixing is driven by phase separation and melting of the InSb interfacial layer that enhances atomic mobility. …

Reconfiguration-Driven Assembly Of Inorganic Nanomembranes, Divya Jyoti Prakash

Chemical and Biological Engineering ETDs

This thesis focuses on the guided self-assembly of metastable nanomembranes (NMs) that are either amorphous or polycrystalline. Guided self-assembly of NMs is a robust and scalable method to obtain a variety of three-dimensional structures such as helices, rolled-up tubes, and networks of interconnected channels. These 3D structures have important applications as on-chip actuators, sensors, inductors, transformers, waveguides, and antennas. Furthermore, a large amount of strain and strain gradient can be imparted in NMs by bending them to a nanoscale and microscale radius of curvature, making guided self-assembly on NMs a viable route to extreme strain engineering of amorphous and polycrystalline …

Nanostructured Transition Metal Oxides For Electrochemical Co2 And Methane Conversion, Olumide O. Oladoyin

Chemical and Biological Engineering ETDs

Rising atmospheric CO₂ and CH₄ drive climate change, prompting research into their electrochemical conversion to valuable products. This study investigates electrodeposited nanostructured transition metal oxides (TMOs), unary (CuO, Co₃O₄) and dual (Cu-Co oxide) as catalysts for CO₂ reduction and CH₄ oxidation under ambient conditions. Fabricated on various substrates (Cu foil, SS316, carbon paper) and characterized by SEM, their electrochemical performance was evaluated via cyclic voltammetry.

Cu-Co oxide showed superior CO₂ reduction, leveraging the strengths of individual oxides. Co₃O₄ exhibited higher current densities for CH₄ oxidation, with SS316 proving the best substrate. Catalyst composition, morphology, and substrate significantly influenced efficiency. While …

Mg And Fe Co-Doped Perovskites For The Electrochemical Oxidative Coupling Of Methane In Solid Oxide Electrolyzers, Luke H. Denoyer

Chemical and Biological Engineering ETDs

More efficient usage of shale gas reserves and natural gas resources will allow for higher olefin yields and lower greenhouse gas emissions. The oxidative coupling of methane (OCM) is a direct pathway for converting methane to ethylene at temperatures >700 °C. The OCM process is typically regulated via the choice of catalyst, reactor conditions, temperature range and gas mixing. The electrochemical oxidative coupling of methane (E-OCM) is a modification to the OCM reaction by controlling the oxygen content via externally applied potentials to an SOEC. Perovskite oxide catalysts are useful for E-OCM due to their flexible bond networks and desired …

Rational Design Of Nanoparticles For Overcoming Barriers Of Nucleic Acid Delivery: Applications In Cancer Therapeutics, Angelea M. Maestas-Olguin

Chemical and Biological Engineering ETDs

The use of exogenous nucleic acid technologies to modulate aberrant protein expression resulting from genetic mutations is a promising therapeutic approach for the treatment of diseases such as cancer. The promise of nucleic-based therapeutics is dependent on the development of platforms that effectively protect nucleic acids from nuclease degradation and deliver the nucleic acids to specific intracellular locations (nucleus or cytosol) of target cells. The application of nanotechnology for development of nucleic acid-based nanomedicines is poised to revolutionize the clinical landscape of cancer. In this dissertation, I demonstrated the rational design, synthesis and evaluation of a lipid coated mesoporous silica …

Antimicrobial Activity And Photostability Of Cationic Conjugated Polyelectrolytes, Mohammed Ismael Khalil

Chemical and Biological Engineering ETDs

Antimicrobial resistance is a growing global health concern, driving the need for novel

therapeutic strategies. This study explores the antimicrobial efficacy of conjugated

polyelectrolytes (CPEs) and oligo-phenylene ethynylenes (OPEs) in bacterial and viral

inactivation. Quantitative analysis revealed that light-activated CPEs and OPEs

effectively reduced bacterial viability within minutes, with significant log reductions

observed under both light and dark conditions. Additionally, the antiviral potential of a

cationic conjugated oligomer was investigated, demonstrating rapid and near-complete

inactivation of SARS-CoV-2 under visible light, both in solution and on filter materials.

Further analysis of their photophysical properties revealed that, even after

photobleaching, the compounds …

Mixed Potential Sensor For Natural Gas Leak Detection Design, Manufacturing, And Simulation, Sleight Halley

Chemical and Biological Engineering ETDs

There is a need for a low-cost robust sensor accurately detecting leaks from oil and gas infrastructure. This work presents the development of an electrochemical sensor based on an yttria stabilized zirconia (YSZ) electrolyte with La_0.87Sr_0.13CrO₃, Indium Tin Oxide (In₂O₃ 90 wt%, SnO₂ 10 wt%), Au, Pt electrodes. Selectivity to target gasses of the three sensing electrodes in conjunction with machine learning allows for the accurate discrimination between possible methane sources as well as the quantification of methane concentration. Sensor sensitivity is improved through a low-ionic conductivity substrate of magnesia …

Electrodeposition Of Gadolinium Metal Thin Films For Neutron Phase Contrast Imaging, Mary Louise Gucik

Chemical and Biological Engineering ETDs

A rare earth metal, gadolinium has unique magnetic properties and the largest neutron absorption cross section making it highly sought after in emerging technology. However, unlike most metals, it is difficult to work with and lacks a damascene process. When incorporated into alloys, gadolinium’s properties are muted and the film thickness must increase to account for the low concentration. Gadolinium metal films have been deposited successfully through sputter coating, but these films have density deficiencies and are limited to line-of-sight substrates. In this work, the deposition of gadolinium metal thin films was investigated for use on complex geometries via electrophoretic …

Formation And Interrogation Of A Modeling Excel Database For Sorbent Preconcentrate With Gc/Ms, Lisa Caravello

Chemical and Biological Engineering ETDs

Volatile organic compounds (VOCs) are of great interest and the subject of much research, as they can be used in various applications. Preconcentrating this class of analytes is necessary as they can be elusive with simple sampling techniques. VOCs are often captured using sorbents in thermal desorption tubes as preconcentrates prior to analysis, commonly gas chromatography mass spectroscopy (GCMS). There are gaps in knowledge in behavior of materials used as sorbents i.e., if they will retain an analyte of interest appropriately. In this research I seek to eliminate speculation and unknown variables of analyte and sorbent combinations by creating a …

Modeling And Performance Analysis Of Deb Based Hydrogen Getters, John A. Matteson

Chemical and Biological Engineering ETDs

Hydrogen getter materials are used to irreversibly absorb hydrogen gas in sealed environments. The DEB based getter system, despite finding widespread use in this application, still posses challenges with respect to experimental performance analysis and fundamental understanding of reaction mechanism. The second chapter of this report addresses the experimental challenges of this getter system by demonstrating the utility and experimental strengths of a custom magnetic suspension balance (MSB) based gravimetric sorption system. This apparatus enables performance evaluation in process relevant conditions including dilute mixed gas environments which our results indicate is necessary for accurate performance evaluation of getter systems. Chapter …

Prediction Of Self-Diffusion Constants In Model And Real Systems Using Machine Learning, Joshua P. Allers

Chemical and Biological Engineering ETDs

Understanding diffusion of chemical compounds is important for the design and optimization of many chemical engineering and energy processes. Recent modifications to the Darken equation allow for accurate prediction of Maxwell-Stefan (MS) diffusion in mixtures. Still, there are few practical applications due to the requirement of individual self-diffusion constants. A reliable predictive model for self-diffusion constants would be highly valuable when used in conjunction with the modified Darken equation. Here, we show that Machine Learning (ML) can be used to develop generalized models for self-diffusion in Lennard Jones (LJ) systems and real systems of pure solutions. The use of Artificial …

Copper Electrodeposition In Full Wafer Thickness Through-Silicon Vias, Rebecca P. Schmitt

Chemical and Biological Engineering ETDs

Through-silicon vias (TSVs) are a key interconnect technology for advanced packaging of microelectronic devices, and full wafer thickness TSVs are required for certain microelectromechanical systems (MEMS) applications. In this work, electrolytes containing copper sulfate, an acid, chloride, and Tetronic 701 suppressor were implemented for Cu filling of high aspect ratio (10:1), full wafer thickness TSVs. For each electrolyte system, rotating disk electrode voltammetry was used to identify a voltage range for bottom-up Cu filling in the TSVs. Die level feature filling was performed using voltage ramping, which moved active deposition through the vias to yield void-free Cu features. During voltage-controlled …

Investigating The Effects Of Accelerated Lithium Deposition On The Abuse Response Of Lithium-Ion Batteries, Eric J. Deichmann

Chemical and Biological Engineering ETDs

Li deposition at the graphitic anode is widely reported in literature as one of the leading causes of capacity fade in lithium-ion batteries (LIBs). Previous literature has also linked Li deposition resulting from low-temperature and high-rate ageing to diminished safety characteristics, however no current research has probed the effects of Li deposition on the abuse response of well- characterized cells. Additionally, no previous studies have investigated the use of an accelerated Li deposition technique for probing the effects of Li deposition. Using overtemperature testing, a relationship between increased concentrations of Li deposition and exacerbated abuse response in 1Ah pouch cells …

Coulombic And Non-Coulombic Effects Of Single And Overlapping Electric Double Layers With Surface Charge Regulation, Raviteja Vangara

Chemical and Biological Engineering ETDs

The physical origin of charged interfaces involving electrolyte solutions is in the thermodynamic equilibrium between the surface reactive groups and certain dissolved ionic species in the bulk. This equilibrium is very strongly dependent on the precise local density of these species, also known as potential determining ions in the solution. The latter, however, is determined by the overall solution structure, which is dominated by the large number of solvent molecules relative to all solutes. Hence, the solvent contribution to the molecular structure is a crucial factor that determines the properties of electric double layers. Models that explicitly account for the …

An Investigation Of The Chemistry, Thermodynamics And Catalytic Activity Of Molybdenum Carbides, Shanti Kiran Nayak

Chemical and Biological Engineering ETDs

These studies investigate the chemistry and stability of molybdenum carbides as an electrocatalyst. Due to their unique electronic properties, molybdenum carbides are purposed as electrocatalysts for reaction systems such as hydrogen evolution reaction, bifunctional water splitting and CO oxidation.

In this study, various synthesis processes were utilized to produce different types of molybdenum carbide with varying properties of particle size, surface area and excess carbon. The samples characterized by XRD accompanied by Whole Profile Fitting, Electron Microscopy, Gas Adsorption (surface area) and XPS.

These synthesis processes were refined using fundamental thermodynamic analyses. These analyses highlight regions of stability of different …

Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han

Chemical and Biological Engineering ETDs

In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal …

Fluid Transport In Porous Media For Engineering Applications, Eric M. Benner

Chemical and Biological Engineering ETDs

This doctoral dissertation presents three topics in modeling fluid transport through porous media used in engineering applications. The results provide insights into the design of fuel cell components, catalyst and drug delivery particles, and aluminum- based materials. Analytical and computational methods are utilized for the modeling of the systems of interest. Theoretical analysis of capillary-driven transport in porous media show that both geometric and evaporation effects significantly change the time dependent behavior of liquid imbibition and give a steady state flux into the medium. The evaporation–capillary number is significant in determining the time-dependent behavior of capillary flows in porous media. …

Cellular Modification And Artificial Cell Construction, Jimin Guo

Chemical and Biological Engineering ETDs

With all its complexities and different biofunctionalities, a cell is the basic structural and functional unit of all living organisms with the exception of viruses. In this dissertation, I demonstrated gain of function strategies of modifying mammalian cells using silicification and modular nanoparticle (NP) exoskeletons. In addition, I used a modular design concept to build a multifunctional artificial RBC system which can mimic the unique characteristics (e.g. shape, flexibility, the ability to carry oxygen, and long circulation times) of the native RBCs. Together, these cell modification or artificial cell construction strategies are expected to generate new mammalian cell-like structures with …

Metabolon-Inspired Design Of Multi-Modal Catalytic Cascade, Madelaine Seow Chavez

Chemical and Biological Engineering ETDs

Developing hybrid catalytic systems has been researched for the past decade in an effort to efficiently incorporate catalysts of different modalities in catalytic cascades. It has become imperative to design a cascade system where the catalysts are spatially organized to control the delivery of precursors, intermediates, and products. In this work, we have shown that a molecular catalyst, biocatalyst, and metallic catalyst can be co-localized using a carbonaceous support to create a hybrid catalytic system and complete the oxidation of oxalic acid to create a microchemical reactor. The molecular, pyrene-TEMPO catalyst oxidizes glyoxalic acid to oxalic acid. The enzyme oxalate …

Reaction Of Titanium Subhydride With Multiple Passivating Gasses, Erik C. Strobert Jr

Chemical and Biological Engineering ETDs

Sandia National Laboratories has used substoichiometric titanium hydride as a pyrotechnic fuel for decades. Production of titanium subhydride requires partial dehydriding of titanium hydride powder and subsequent chemical passivation to render the resultant bare titanium surface nonreactive and the powder non-pyrophoric. Novel passivation techniques, using a gas other than air, have been suggested in the past but have never been investigated. This work examines the reaction kinetics of titanium subhydride with three passivating agents, nitrogen, oxygen, and propane. These passivation experiments took place under isothermal conditions (420 ˚C) with varied dehydriding and passivation time periods. It was found that the …