Polymer Science Commons^™

Engineered Porous Structures For Propellants Using Additive Manufacturing, Elbert Caravaca

Dissertations

Foamed polymers are widely used today for shock absorption and packaging materials to prevent damage to their contents. Typical foamed densities vary from 0.1 g/cm³ to 0.4 g/cm³ depending on the polymeric materials used. There is a need to explore foaming densities above 0.4 g/cm³ for propellants with highly engineered surface area progression for increased combustion performance. One way to achieve this is through highly controlled and engineered graded foam structures. To further exploit this approach, additive manufacturing coupled with a tunable means to generate foamed structures is the target of this work. To generate foam structures …

Experimental Evaluation Of Membranes In The Recovery Of Hydrogen From Serpentinization, Rafael Dos Santos

LSU Master's Theses

Natural hydrogen generated through serpentinization reactions has emerged as a promising low-carbon energy resource. However, serpentinization-derived gas streams commonly contain methane (CH₄) and carbon dioxide (CO₂), requiring purification before hydrogen can be utilized in industrial applications. Membrane-based gas separation technologies offer a potentially cost-effective solution for hydrogen recovery; however, to the best of the author's knowledge, no previous studies have specifically investigated their application to serpentinization-derived gas streams.

This work evaluates the performance of two commercial polymeric membrane modules (Evonik and Generon) and one palladium-copper (Pd-Cu) membrane module (Okaya) for hydrogen recovery from gas compositions representative of serpentinization environments. An …

Glass Transition Temperature Of Plga Nanoparticles And The Application In Drug Delivery, Guangliang Liu

Dissertations

The glass transition temperature (T_g) of poly(D,L-lactic-co-glycolic acid) (PLGA) nanoparticles plays a crucial role in governing molecular mobility, diffusion, and consequently, drug release kinetics. However, the interaction among residual surfactant, drug effect, nanoscale confinement, and release medium on T_g remains insufficiently characterized. This study aims to bridge this gap by correlating the thermal behavior of PLGA nanoparticles with their drug release behavior under physiologically relevant conditions.

In the present study, PLGA nanoparticles were synthesized using both nano-emulsion and surfactant-free nano-precipitation approaches. The influence of residual surfactants - poly(vinyl alcohol) (PVA) and didodecyldimethylammonium bromide (DMAB) - was systematically …

Strengthening Kidney Dialysis One Membrane At A Time: Enhancing Tempo-Oxidized Nanocellulose And Ionic Liquid Membrane Strength Through The Variation Of Cosolvents, Bailey M. Butler

Chemical Engineering Undergraduate Honors Theses

Chronic kidney disease occurs when the kidneys lose the ability to effectively filter the blood, which causes waste build up. End-stage kidney disease (ESKD) is the most severe case of kidney disease and requires either dialysis or a kidney transplant. Hemodialysis, the most common form of dialysis, is an extremely time-intensive and physically burdensome process that is currently limited by membrane performance. The polysulfone (PSf) membranes that are widely used for dialysis today have many limitations, including fouling, toxin rejection, and essential protein loss. Recently, new membranes made from TEMPO-Oxidized nanocellulose dissolved in 1-ethyl-3-methylimidazolium acetate (EMIM-Ac) have shown promising characteristics, …

Adsorption Of Pfas On Bridged Functionalized Organosilica Materials, Elisha Lawerh Kabutey

Electronic Theses and Dissertations

PFAS are hazardous contaminants that have a devastating impact on human health and the environment. Their hazardous nature has led to the development of various adsorption methods for removing these contaminants from water sources. In this study, functionalized organosilica materials were synthesized from bis[3-(trimethoxysilyl)propyl] amine using the sol-gel method. The surface amino groups of the organosilica were converted into amine hydrochloride groups. Their adsorption properties were evaluated using salts of perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorobutanesulfonic acid. Results showed excellent adsorption capacity of the materials. Adsorption of PFAS leads to particle agglomeration and flotation of the spent material. A column …

Polymer Charge Effects On Scaling In Membrane Distillation, Lucia Milans Del Bosch

Chemical Engineering Undergraduate Honors Theses

This research evaluates the effectiveness of polymeric inhibitors at suppressing scaling during direct contact membrane distillation (DCMD). Anionic polyacrylic acid (PAA), neutral polyethylene glycol (PEG), and cationic polyethyleneimine (PEI), were investigated. Experiments were conducted using both hypersaline single-salt and multi-component mixed-salt feeds to determine how the presence of different ions influences performance. Results from single-salt experiments showed that PAA and PEG effectively maintained permeate flux through chelation and steric hindrance, respectively, while PEI caused rapid membrane failure due to interfacial aggregation and pore wetting. In complex mixed-salt solutions, PEG was the additive, maintaining a steady flux with only a 7.33% …

Cationic Polymer-Grafted Magnetic Nanoparticles For Enhanced Removal Of Anionic Dyes From Wastewater, Joia A. Traver

Chemical Engineering Undergraduate Honors Theses

Water scarcity and pollution are escalating global challenges, with textile industry wastewater often enriched with toxic dyes posing significant risks to environmental and human health. These contaminants increase turbidity, reduce dissolved oxygen levels, and ultimately impair aquatic ecosystems. This thesis focuses on the remediation of dye-contaminated water using nanoscale polymeric adsorbents. Methyl orange, a common anionic dye widely used in textile and leather industries, was selected as the model contaminant due to its terminal sulfonate group, which enables strong electrostatic and hydrogen-bonding interactions with cationic functional materials.

In this work, magnetic nanoparticles grafted with cationic polymers were synthesized and evaluated …

Electrochemical And Mechanical Evaluation Of Cellulose Acetate Electrolyte Films As A Function Of Polyetherimide And Polyethylene Glycol Additives For Supercapacitor Applications, Chase E. Golden

Chemical Engineering Undergraduate Honors Theses

Polymer electrolytes for supercapacitor applications require a balance between mechanical robustness and electrochemical performance. In this study, cellulose acetate (CA) films were modified with additives such as polyetherimide (PEI) and polyethylene glycol (PEG) to test how compositional changes influence mechanical performance, ionic conductivity, and electrochemical charge storage. Films were cast using phase inversion, soaked in a 1 M NaCl aqueous solution, and characterized using Fourier-transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and tensile testing. Films were also evaluated based on fluid uptake for insight into electrolyte retention.

Characterizations show that the addition of PEI increased ionic …

Fly Ash Proppant Developed For Hydraulic Fracturing, Raz Rzgar Haydar

Theses and Dissertations

Proppants are critical components in hydraulic fracturing, used to maintain fracture conductivity and enhance reservoir stimulation. In high-pressure and harsh reservoir environments, the use of high-strength proppants is essential to ensure well performance. Conventional proppants, being sand, ceramic, and sintered bauxite can be expensive, and their use often requires costly fracture fluids. This study investigates the possibility of utalizing fly ash geopolymers as a sustainable alternative that is also cost-effective for proppants manufacturing. Fly ash, a by-product from the combustion of coal and other materials, was explored as a base material for proppants, utilizing an alkaline solution as an activator …

Made On Mars: Design And Manufacturing Of Structural Polymer-Regolith Composites, Pailey M. Vitale

Williams Honors College, Honors Research Projects

Human exploration of Mars is constrained by harsh environmental conditions and the prohibitive cost of transporting materials from Earth. Long-term sustainability requires the local production of mechanical and structural components using resources available on Mars, thereby minimizing payload mass. This project investigates polymer–regolith composites derived from atmospheric CO₂ and mineral-rich regolith as a pathway toward in-situ manufacturing. These composites, when compatible with additive manufacturing, could replace imported plastics, enable on-demand fabrication, and support closed-loop recycling systems. The objective is to design and evaluate polymer–regolith composites that maintain mechanical integrity and environmental resistance under Martian conditions, including extreme temperature swings, radiation …

Energy Efficient Windows Using Pvme, James S. Bronstrup

Williams Honors College, Honors Research Projects

This Honors Project aims to improve window energy efficiency using the thermoplastic polymer PVME (polyvinyl methyl ether), which displays temperature-dependent transparency that can be adjusted by mixing it with water and salt to reduce heat transfer through a window. The objective is to determine the optimal PVME water-salt ratios for placement inside a windowpane, evaluate energy savings compared to a traditional argon-filled window, and compare estimated costs. A small-scale model will test different concentrations for various climates, with heat transfer measured by temperature indicators via a LabQuest. Building on research by Yang Zhou at Nanyang Technological University, who used a …

Microscopic Insights On Shear Rheology Of Polyampholyte Ionomers Via Molecular Simulations, Kyle Vonscio

Williams Honors College, Honors Research Projects

Ionomers are polymers that contain a small fraction of charged groups. The ionic attraction of charged groups allows ionomers to act similarly to crosslinked polymers. Depending on the strength of electrostatic interactions and structure of the ionomers, different dynamics and rheological responses can be observed. With moderate attraction between ions, these noncovalent crosslinks can be broken when heated, allowing ionomers to flow and show the strength of a crosslinked network at low temperatures. Nonequilibrium molecular dynamics (NEMD) simulations will be performed under shear in the xy-plane and the macroscopic rheology and conformation of the polyampholyte ionomer will be determined. The …

Analyzing The Effect Of Network Properties On Self-Assembly Of Polymer Grafted Nanoparticles In Vitrimer Nanocomposites, Tyler Eakin

Williams Honors College, Honors Research Projects

This project aims to show the how polymer grafted nanoparticles behave in a vitrimer composite network. The effect of varying the network parameters such as the grafting density, the volume fraction of nanoparticles, and the ratio of polymer chain length : graft chain length will be studied. The assemblies formed by the polymer grafted nanoparticles will be visually analyzed and assigned one of 5 possible conformations. A phase diagram of grafting density vs network chain length / graft length will be constructed. The phase diagram will provide valuable insight into how nanoparticle self-assembly can be manipulated through changing network parameters

Effects Of Hofmeister Ions On Lower Critical Solution Temperatures Of Poly(N-Isopropylacrylamide) And Poly(Vinyl Methyl Ether), Joseph Joaquin

Williams Honors College, Honors Research Projects

The goal of this study is to compare how four different Hofmeister anions (Cl-, SCN-, F-, and I-) affect the Lower Critical Solution temperature (LCST) on two thermo-responsive polymers: poly(N-isopropylacrylamide) (pNIPAAM) and poly(vinyl methyl ether) (PVME). pNIPAAm is commonly used in the environmental applications such as monitoring, oil-water separations, or antifouling materials, and in medical industry from drug delivery to tissue engineering. When pNIPAAM or PVME reaches a temperature above their LCST, they become hydrophobic, and the polymer chains coiled, leading to their aqueous solutions turn opaque. PVME exhibits a similar LCST as that of pNIPAAM, so it can be …

Surface Immobilization Of Stimuli-Responsive Polymers Using A Network Of Aminopropyltriethoxysilane, Walter Bungard, Ryan Nixon

Williams Honors College, Honors Research Projects

The goal of this honors project is to develop a cost-effective and accessible method for entrapping stimuli-responsive polymers onto solid substrates using aminopropyltriethoxysilane (APTES). The entrapment network process will first be replicated on glass or silicon using APTES and poly(N-isopropylacrylamide), involving spin coating and thermal annealing to chemically bond the polymer to the substrate. Once validated, the method will be applied to other stimuli-responsive polymers, including thermo-responsive, electroactive, and pH-sensitive types, with APTES as a control. For each sample, film stability, responsiveness, and surface behavior will be evaluated using contact angles, optical microscopy, and spectroscopic analysis, followed by statistical evaluation. …

Purifying Circular Rna Therapeutics, Karen Guillen-Cuevas

All Dissertations

Circular RNA (circRNA) has emerged as a promising therapeutic modality due to its enhanced stability and resistance to exonuclease degradation compared with linear mRNA. However, its stability and functionality depend strongly on achieving high purity, and current methods such as size-exclusion chromatography suffer from peak overlap, low yields, and poor scalability. This dissertation addresses these limitations by developing ultrafiltration-based strategies to purify circRNA directly from in vitro transcription (IVT) and self-splicing (circularization) reactions. First, the feasibility of ultrafiltration was demonstrated using polyethersulfone membranes, where sieving coefficients and critical flux values of circRNA, precursor RNA, and nicked RNA were measured to …

Polymer-Enhanced Nanopore Sensing, Eugene Gyasi Agyemang

Graduate Theses and Dissertations

The resistive pulse technique characterizes single analytes by detecting fluctuations in the ion current as they pass through a narrow orifice connecting two electrolyte-filled chambers, each containing a single electrode. The amplitude, shape, frequency, and duration of these fluctuations primarily provide information about the analyte’s size, shape, concentration, and net surface charge, respectively. One configuration for resistive pulse measurements is of an electrolyte-filled nanopipette immersed in a bath, where the nanopipette tip acts as the nanoscale orifice. It was previously shown that incorporating the large quantities polymer polyethylene glycol (PEG 8K, 50% w/v) into the external electrolyte bath dramatically enhanced …

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 …

Removal Of Fluoroquinolones From Water Systems Employing Rice Husk Composited Sponges Via Nanoadsorption, Dalia Kanaa

Theses and Dissertations

A novel nanocomposite of polyvinyl alcohol formaldehyde (PVF) sponge loaded with green zinc oxide nanoparticles (ZnONP) and referred to as (NP-PVF) was fabricated as a potential adsorbent of ciprofloxacin from water. A simple mechanical foaming process was used to synthesize the adsorbent. Rice husk extract was used to synthesize zinc oxide nanoparticles (ZnONP) for its phytochemicals as reducing agents. A facile and low-energy-dependent extraction method was used that did not require the use of high-temperature annealing. The synthesized nanoparticles showed a maximum UV absorption at 347 nm, which corresponds to a 3.58 eV band gap energy. FTIR confirmed the successful …

Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins, Joey Velasquez

Master's Theses

The effect of household oil and agricultural soil contamination on catalyst performance during polyolefin pyrolysis was simulated on mixed virgin plastic pellets by evaluating contamination influence on mixed plastic degradation temperatures. Three phyllosilicate nanocatalysts including Fulcat435, Fulcat22F and Y-Zeolite were evaluated in this work based on a literature review of catalyzed plastic pyrolysis and these catalysts’ ability to lower plastic decomposition temperature by 50 °C – 100 °C. These findings were confirmed in this research through thermogravimetric analysis of a polyolefin mixture and further developed in furnace experiments containing household oil and agricultural contamination. Household oil contamination deactivated each of …

Chemical Recycling Of Pet Plastic Waste, Charlie Parker, Benjamin Puga, Jake Verschoor

Materials Engineering

The growing accumulation of plastic waste, specifically polyethylene terephthalate (PET), has driven the need for more efficient and scalable chemical recycling methods. This study investigated the methanolysis of PET using zinc oxide (ZnO) nanoparticles as a catalyst and tetrabutylammonium chloride (NBu₄Cl) as an ionic liquid, aiming to reduce methanol consumption while achieving high PET conversion efficiency. ZnO nanoparticles were synthesized via wet chemistry and characterized using Dynamic Light Scattering (DLS), which showed an average particle size of 13.5 nm with a polydispersity index of 0.1556, indicating a moderately-high monodisperse distribution of particles sufficient for reactions. The main conversion product, dimethyl …

Interfacial Phenomena Of Plastics: From Surface Modifications To Environmental Impacts, Kennedy Guillot

LSU Doctoral Dissertations

Plastic is a ubiquitous part of everyday life since its introduction in the previous century. Global production continues to exponentially increase, establishing plastics as one of the most dominant materials in modern manufacturing. Within the scope of academia, plastic is essential due to its low cost and sterility, particularly for minimizing contamination. Beyond the laboratory, plastic use spans numerous industries, and its use and disposal has since raised many environmental concerns. Once valued for its durability, plastics now pollute the environment in landfills and natural ecosystems. In recent decades, the consequences of this pollution have been investigated, yet the full …

Multifunctional Pvdf Ionogels With Magnetic Nanoparticles For Electroactive And Magnetic Actuation, Alfredo Carrillo Valverde

Chemical Engineering Undergraduate Honors Theses

The fast development of compact and multifunctional electronics has driven interest in smart materials capable of responding to multiple stimuli. Ionogels, polymers that have been swollen with ionic liquids (IL), offer several favorable electrochemical and thermal properties due to their intrinsic ion conductivity, wide electrochemical window, non-flammability, and high thermal stability. However, their poor mechanical properties (e.g., modulus and strength) limit their use in applications. In this work, multifunctional PVDF ionogel composites were made by blending magnetically responsive iron oxide nanoparticles (Fe₃O₄ MNPs) into the polymer matrix. The influence of MNP concentration (9-21 wt%) on composition, ionic …

Tuning The Morphology Of Triblock Copolymers Via Homopolymer Blending, John F. Searles

Honors Theses

Morphology plays an important role in the physical properties of block copolymer (BCP) materials. Depending on the type of morphology and chemical composition of the blocks, BCPs are used in applications ranging from soft biomaterials for biomedical devices to rigid materials for ballistics protection. Due to incompatibility between comonomers and required block weight ratios to achieve targeted morphologies, it is generally necessary to use complex, time-consuming, and expensive synthetic techniques to prepare BCPs. As a result, there is increased interest in the development of new processing methods to tailor block copolymer morphology without the need for additional synthesis. The morphological …

Mechanistic Insights Into Polymer-Assisted Graphene Exfoliation: The Roles Of Velocity, Adhesion, Cohesion, Temperature, Peeling Mode, And Edge Defect Via Coarse-Grained Molecular Dynamics, Linjiale Dai

All Theses

Graphene exfoliation is a critical step in the fabrication of high-quality graphene

layers. However, the underlying fracture mechanisms remain poorly understood. In this

work, I employed coarse-grained (CG) molecular dynamics (MD) simulations to

investigate how factors such as interfacial binding energy, substrate cohesion, temperature,

peeling mode, and edge defects influence the outcome of the exfoliation process. To model

polymer-assisted mechanical exfoliation, I used a finite-size system in which multilayer

graphene (MLG) is sandwiched between two thin polymer films. Leveraging the

spatiotemporal efficiency of the CG model, I performed fifty simulation iterations per

parameter set and analyzed the results from a …

Incorporating Recycled And Repurposed Plastic Into 100% Reclaimed Asphalt Pavement, Basant Bhatt

Graduate Theses and Dissertations (2019 - present)

The increasing awareness of sustainability in the asphalt industry has driven the use of recycled materials like reclaimed asphalt pavement (RAP) and waste plastic. This study examines the incorporation of recycled polypropylene (rPP), recycled high-density polyethylene (rHDPE), and recycled low-density polyethylene (rLDPE) at 0.3%, 0.6%, and 0.8% dosages into 100% RAP, along with the warm mix asphalt additive Evotherm® P25. Laboratory tests were conducted to evaluate the mechanical and durability performance of the modified asphalt mixtures while rutting and fatigue life were evaluated using mechanistic-empirical (ME) analysis in PerRoad software. Both plastic type and dosage had a statistically significant impact …

Design And Characterization Of Lignin-Based, Thermoresponsive Soft Composites With Improved Mechanical And Transport Properties, Missoury D. Wolff

All Dissertations

In an attempt to reduce reliance on petroleum-based polymers, lignin – an abundant biopolymer – has gained popularity as a sustainable alternative. However, research on lignin-containing soft composites – i.e., hydrogel (bio)composites – has largely been heuristic, providing limited insight into the fundamental structure-processing-property relationships that govern performance improvements in this emerging class of ‘green’ soft composites. As such, this dissertation presents a systematic investigation of how lignin molecular weight (MW), composite composition, and the concentrations of crosslinker and accelerator impact the mechanical and transport characteristics of soft composites composed of lignin, poly(N-isopropylacrylamide) (PNIPAm), and poly(vinyl alcohol) (PVA).

In the …

Development Of Ex-Situ Accelerated Chemical Stress Test Protocol For Common Anionic Exchange Membrane Chemistries, Michael D. Friend, Michael D. Friend

Master's Theses

The development of sustainably produced hydrogen fuel (“green hydrogen”) is key for the transition to clean energy sources. Green hydrogen is produced via water electrolysis. As with many clean energy sources, one of the major barriers for scaling water electrolysis is cost. A newer category of water electrolysis is Anionic Exchange Membrane (AEM) water electrolysis. AEM electrolysis systems have the potential to cost less as they do not require the expensive precious metal catalysts the current high preforming Proton Exchange Membrane water electrolysis technologies do. However, AEM lifetimes must be long enough to be cost competitive and AEM chemical durability …

Prediction Of Glass Transition Temperature Of Polymers Using Structure-Based Models, Nicholas Wolfe

Williams Honors College, Honors Research Projects

The focus for this study is prediction of glass transition temperatures of polymers using machine learning models. The preprocessing of the data included the generation of descriptors, the scaling of the data, the principal component analysis for dimensionality reduction, and the clustering of the data. Three methods of property predictions were utilized including Linear Regression, Random Forest, and a Feedforward Neural Network. The dataset consisted of over 7000 polymers each with their respective glass transition temperatures. This study found that the Random Forest model returned the best results followed by the Feedforward Neural Network then the Linear Regression model. Each …

Modeling The Thermodynamics Of Butadiene And Carbon Dioxide Coupling Reactions, Alexis Sarantos

Williams Honors College, Honors Research Projects

This project will analyze the synthesis reaction of ethenylated 𝛿-valerolactone (EVL), specifically to determine certain thermodynamic properties of EVL and its coproducts. The thermodynamic properties of the reaction products can then be utilized to make the development of a large-scale process simpler and safer. The properties that will be determined are the heats of formations, heat capacities, and changes in enthalpy caused by each product during the reaction, and these will be used to determine whether the energy produced by the reaction is sufficient to maintain formation of the desired product. Additionally, a process model of heat flows and energy …