Membrane Science Commons^™

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 …

Meshless Discrete Velocity Boltzmann Model For Porous Media Flow, Amandine Maidenberg

Doctoral Dissertations and Master's Theses

This dissertation explores the combination of two sophisticated techniques for addressing computational fluid dynamics: the discrete velocity Boltzmann equation (DVBE) and the localized collocation meshless model with upwinding (U-LCMM). The DVBE is a high-level model that describes the foundations of transport phenomena by addressing the microscale motions of particles themselves and the effect of their aggregate behaviors on continuum principles. This equation integrates multiple scales of phenomena; while it can be used for fluid flow at Navier-Stokes scales, it can also resolve fine features that can only be described at the molecular level. This type of model is necessary for …

Superhydrophobic Cerium-Based Metal–Organic Frameworks/Polymer Nanofibers For Water Treatment, Samar A. Salim, Hani Nasser Abdelhamid,

Nanotechnology Research Centre

No abstract provided.

Anion Exchange Membrane Transport And Accelerated Testing Methods For Co2 Electrolyzers With Cu-Based Electrocatalyst, John C. Hendershot

LSU Doctoral Dissertations

Electrocatalytic carbon dioxide (CO₂) reduction to C₂₊ products holds promise for low carbon intensity fuels, chemicals, and food; however, durability challenges, particularly bicarbonate (HCO₃^-)and carbonate (CO₃^2-) salt precipitation, hinder their commercialization. This report considers water (H₂O) and ion transport properties of conventional anion exchange membranes (AEMs) in zero-gap membrane electrode assembly (MEA) configurations using Cu electrocatalysts. Transport characterization includes H₂O diffusion, permeability, potassium (K⁺) diffusion, and transference numbers using three commercial AEMs, including piperidinium-based (Versogen), quaternary ammonium-based (Fumasep), and imidazolium-based (Dioxide Materials) membranes. Accelerated lifetime …

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, …

Anion Exchange Membrane Durability For Electrochemical Co2 Reduction In Membrane Electrode Assembly Cells, Soundarzo Tasnim

LSU Master's Theses

The electrochemical reduction of CO₂ using membrane electrode assembly (MEA) cells has emerged as a promising approach for carbon capture and conversion into valuable products. This study investigates the degradation mechanisms of anion exchange membranes (AEMs) in CO₂ reduction applications, focusing on Sustainion X37-50, PiperION, and FAA-3-50. The research analyzes the impact of chemical and mechanical degradation on membrane performance, highlighting key stability challenges in long-term operation. Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were employed to monitor functional group stability and ionic conductivity loss over extended operation. The results indicate that hydroxide-induced degradation leads to nucleophilic …

Modeling Cell Buildup And Release In An Ultrafiltration Cartridge, Holiday B. Derosier

Chemical Engineering Undergraduate Honors Theses

While membrane filtration has improved greatly and has been incorporated into many modern practices, there isn’t much data on material exchange in and out of the lumen and how that effects the overall efficiency of the process. This data may help to accurately measure the reliability and efficiency of a filtration membrane system, which can lead to improvements in filtration sustainability, process lifespan, and product quality.

This project aims to model the material balance within a perfusion bioreactor ultrafiltration system in MATLAB, with a focus on bioreactors and cell buildup and release from the lumen. The results of this study …

Measuring Selectivity Of Ion Exchange Resin For Use In Activated Wafer Electrodeionization, Hope M. Coffman

Chemical Engineering Undergraduate Honors Theses

Ion exchange resins are a type of ion exchange material used throughout industry. Their insolubility allows for the exchange of ions and an easy separation of the resin itself. They are used alone in industry, but they are also found in processes such as electrodialysis and electrodeionization. This research investigates the selectivity of chloride form ion exchange resin in the presence of solutions of lactate and formate ions. The work of this thesis is a part of a larger study investigating the conversion and separation of glucose into lactic acid via coupled electrocatalysis and electrodialysis. The results of this study …

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 …

Modern Ir-Spectroscopic Methods For The Analysis Of Hydroxybenzene-Methanal Resin Obtained On The Basis Of 2,5-Furandion, Sherali Anvarovich Umarov, Ravshan Israilovich Ismailov Ismailov

Technical science and innovation

The chemical changes occurring during the synthesis of hydroxybenzene-methanal resins obtained on the basis of 2,5-furandion under various ratios and temperature conditions were investigated using the IR spectroscopic method. Analysis of the compositional changes in the resin during the production of the thermoreactive resin revealed that the content of hydroxyl groups (~3300–3500 cm⁻¹) decreased, while the aldehyde groups (~1700–1750 cm⁻¹) increased; moreover, the presence of ether groups (~1050–1150 cm⁻¹) indicated that the process was successful. The synthesis of resins based on thermoreactive hydroxybenzene-methanal resins was carried out at high temperatures (70°C, 80°C, 95°C). During the identification of the functional groups …

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 …

Optimization And Dft Study For Boosted Electooxidation Of Formic Acid At Niox Modified Pt Using Urea Derivatives As Blending Fuels, Aya Saada

Biochemical Engineering

This paper addresses the enhancement of formic acid electrooxidation (FAO) at Pt and Pt-NiOx nanoparticles based-catalysts assisted with urea derivatives as blending fuels. Blending formic acid with various ratios of urea derivatives showed noticeable enhancements of FAO as demonstrated by a favorable negative shift of its onset potential (Eonset) and increase of its peak current density concurrently with suppression of the amount of CO poisoning reaction intermediate. Among all the used derivatives, phenyl urea (PU) showed superior enhancing effect towards the direct FAO with a minimal CO formation together with a favorable negative shift of Eonset by 150 mV. The …

Integrating Medical Plastic Waste Pyrolysis And Circular Economy For Environmental Sustainability, Attia Attia, Mohamed Bassyouni Prof., Reem Nasser Eng., Moataz El-Bagoury Eng., Islam Shaker Eng., Yasser Elhenawy Prof., Dina Aboelela Dr.

Biochemical Engineering

A critical assessment of pyrolysis technologies and reactor designs was discussed, highlighting various reactor configurations. This study explored the influence of catalysts, temperature, heating rate, and residence time on the pyrolysis process, and addressed their effects on product distribution and composition. Safety considerations and strategies for mitigating the potential environmental impacts of pyrolysis were presented. Comparative analyses of the environmental impacts of traditional waste disposal methods versus pyrolysis-based approaches provided insights into the potential reduction of greenhouse gas emissions and other pollutants. The circular economy approach was explored in the context of medical plastic waste pyrolysis. The potential for closing …

Electrical Homeostasis Of The Inner Mitochondrial Membrane Potential, Peyman Fahimi, Lázaro A. M. Castanedo, P. Thomas Vernier, Cherif F. Matta

Bioelectrics Publications

The electric potential across the inner mitochondrial membrane must be maintained within certain bounds for the proper functioning of the cell. A feedback control mechanism for the homeostasis of this membrane potential is proposed whereby an increase in the electric field decreases the rate-limiting steps of the electron transport chain (ETC). An increase in trans-membrane electric field limits the rate of proton pumping to the inter-membrane gap by slowing the ETC reactions and by intrinsically induced electroporation that depolarizes the inner membrane. The proposed feedback mechanism is akin to a Le Chatelier's-type principle of trans-membrane potential feedback control.

How Many Passes Does It Take? An Investigation To Determine The Optimal Number Of Liposome Extrusion Cycles, Kasey Piper

Honors Theses

Liposomes are lipid-based nanoparticles with significant applications in drug delivery and membrane research. One of the most common methods for fabricating liposomes of specific sizes is membrane extrusion, where liposomes are passed through porous membranes to reduce their size. The precise number of passes needed and the factors influencing this process remain unclear. This thesis investigates the relationship between the number of passes through a track-etched polycarbonate membrane and size and lamellarity of extruded liposomes with a focus on lipid type (DOPC, DMPC, Soy PC), membrane pore size (50, 100, 200, 400 nm), and the effect of freeze-thaw cycling. To …

Statistical Investigation Of Gypsum Crystallization Kinetics, Azmain A. Akash

LSU Master's Theses

Gypsum, a naturally occurring mineral salt, is frequently encountered in industrial processes such as seawater desalination and power plant cooling. Over the years, significant effort has been devoted to controlling the crystallization of gypsum through various chemical approaches, including acidification, chelating agents, and antiscalant polymers. Nevertheless, the cost associated with chemical treatments may be reduced by incorporating physical operational strategies to complement chemical methods in regulating gypsum crystallization.

This study systematically examines the comparative roles of chemical and physical entropy in the gypsum crystallization process to elucidate their respective influences on gypsum growth kinetics. Chemical entropy is manipulated by adjusting …

Membrane Reactor Modeling And Optimization For Hydrogen Production, Ayooluwa Tomiwa Akintola

Graduate Theses, Dissertations, and Problem Reports (ETD)

There has been an ongoing trend toward cleaner fuels for more environmentally benign forms of energy generation. Recently, hydrogen has been identified as a clean fuel for energy generation. However, the most established, efficient, and widely utilized technique for producing hydrogen remains the steam methane reforming (SMR) in the presence of catalyst. Unlike other fossil fuels, utilizing methane from natural gas in an SMR process to produce hydrogen emits less, but yet a notable sum of carbon dioxide. Furthermore, the endothermic nature of SMR reactions imply that there is a high energy requirement to obtain a substantial amount of hydrogen …

The Optimization And Manufacturing Scale-Up Of Polymeric Membranes Using Eco-Friendly Solvents, David Lu

Theses and Dissertations--Chemical and Materials Engineering

Polymeric membranes have become a prominent technology applied in water filtration due to the lower cost, energy input, and simpler manufacturing process relative to other separation technologies. However, the environmental impact of polymeric membrane fabrication remains a hindrance due to the use of hazardous solvents derived from fossil fuels (e.g., DMAc, NMP, DMF) that pose a risk to the environment and human health. Whereas recent studies have demonstrated the proof-of-concept of polymeric membrane derived from eco-friendly solvents, the next steps of optimizing and upscaling the production of these membranes remains understudied and a gap between lab-scale studies and the path …