Membrane Science Commons^™

High Temperature Polymer Electrolytes For Hydrogen Fuel Cells And Electrochemical Pumps, Gokul Venugopalan

LSU Doctoral Dissertations

Hydrogen fuel cell and separation technologies such as proton exchange membrane fuel cells (PEMFCs) and electrochemical hydrogen pump (ECHP) offer a profound advantage in the transition to a low-carbon economy. An imperative hitch in hydrogen fuel cells and ECHP technology has been the electrocatalyst poisoning by carbon monoxide (CO) and other contaminants in the reactant mixture. By operating, hydrogen fuel cells and ECHPs at high temperatures (>200 °C), the effect of CO adsorption on the electrocatalyst surface could be curtailed. The high-temperature operation of devices necessitates a proton exchange membrane (PEM) to operate under anhydrous conditions.

In this work, …

Synthesis Of Inorganic Porous Materials With Tunable Morphology For Molecular Adsorption And Separation, Sanket Sabnis

Doctoral Dissertations

Global industrial and economic development over the past century has largely relied on combustion of non-renewable fossil fuels, such as petroleum, coal, and natural gas, which are also harmful to environment because of the release of CO₂, responsible for global warming and climate change. Establishing eco-friendly, energy-efficient and cost-effective processes to reduce environmental impact is currently one of the most urgent issues for the sustainable development of our society. Inorganic porous materials have found applications in the fields of renewable energy and environmental protection such as biomass conversion, fuel cells, thermal energy storage, CO₂ capture and conversion, …

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, …

Assessing The Impact Of Block-Selective Homopolymers On The Diffusion Of Payload Through Polymeric Organogels, Ian Coates

Honors Theses

Styrenic polymer gels have received recent attention for their application in transdermal patches due to their unique properties. Previous research in the pharmaceutical industry has identified that polymeric gels, specifically styrenic gels, have the potential to encompass multiple functions of the transdermal delivery patch including controlling mechanical and delivery properties. To tailor styrenic gels either the gel nanostructure or the drug complex can be controlled. Specifically, this thesis investigated the effect of gel nanostructure in an attempt to control the gel diffusivity and mechanical properties. To control gel nanostructure a phase selective styrene homopolymer was used at varying concentrations. It …

Understanding Absorption, Supersaturation, And Drug Activity In Solution: Working Towards Developing A More Biorelevant Media, Freddy Arce

Theses and Dissertations--Pharmacy

With the looming dominance of poorly water-soluble chemical entities within the pharmaceutical pipeline, the pharmaceutical industry has leaned on the use of supersaturating drug delivery systems (SDDSs) to achieve efficacious concentrations within the gastrointestinal fluids. SDDSs aim to achieve concentrations in solutions greater than the solubility of the lowest energy crystalline form. However, the generation of supersaturated solutions of active pharmaceutical ingredients (APIs) creates a strong crystallization potential, which is undesirable.

In product development, supersaturating products often fail in Phase I and Phase II clinical trials due to poor oral bioavailability and a lack of in vivo efficacy. Pre-clinical testing …

Simulation Of Water Loading In Filter Medium, Anthony Mole

Williams Honors College, Honors Research Projects

This research will model fluid flow through a filter plugged with water droplets using FlexPDE software. After simulations are run at various initial conditions, curves will be developed to correlate the permeability of the filter to variables like water droplet distribution and size.

Wetting Transition On 3d-Printed Featured Surface, Hannah Pineault

Williams Honors College, Honors Research Projects

The primary objective of this research project was to gain a better understanding of surface characteristics to produce a long-lasting superhydrophobic or superhydrophilic surface. In other words, when will a droplet of water remain on top of a featured surface and when does the transition occur to water filling the grooves of the surface? This research focused on how to best fabricate porous structures that would stay completely dry at all times by preventing the liquid from penetrating. In particular, we followed the behaviors of water droplets placed on top of 3-D printed featured surfaces with various geometries and surface …

Interactions Of Lignin Dimers With Engineered Surfaces And Model Cell Membranes For Design Of Lignin-Based Materials, Mahsa Moradipour

Theses and Dissertations--Chemical and Materials Engineering

Capitalizing on byproducts of industrial and agricultural economies is among the utmost goals of sustainability. Of particular interest for commercial upgrading is lignin, a phenolic biopolymer found in the cell walls of plants which is the second most abundant biopolymer on Earth after cellulose. Due to its heterogeneous structure, deconstructing lignin to selected small molecules for use as chemicals or advanced materials has been elusive. This work capitalizes on a “bottom up” approach to the synthesis of lignin oligomers of known bond chemistry to better understand their interfacial interactions.

The potential pharmacological mechanism of lignin deconstruction components and their toxicological …

The Effects Of Solution Condition On Virus Filtration Performance, Fnu Namila

Graduate Theses and Dissertations

Virus filtration is an integral part of the downstream purification of mammalian cell culture-derived biotherapeutics to assure the viral safety of the products. Virus filtration membranes remove viruses based on a size-exclusion mechanism. Commercial parvovirus filers possess unique membrane structure and are designed to remove smaller non-enveloped parvoviruses with size 18-26 nm. However, some filters face issues, such as pre-mature fouling, the decline of filtrate flux, and reduction in virus retention. This doctoral dissertation focused on identifying the factors that influence the filtrate flux and the virus retention capability of commercial virus filters. The effects of solution pH and ionic …

Investigation Of Electrospun Nanofibers For Separation Applications, Shu-Ting Chen

Graduate Theses and Dissertations

Electrospun membranes are an attractive alternative to flat sheet membranes as absorbent with numerous advantages like high porosity, large specific surface area and ease of functionalization. This doctoral dissertation focuses on fabricating novel polymeric membrane adsorbents for protein separations and ammonium ion removal. Three distinctly different preparation methods including UV-initiated polymerization, atom transfer radical polymerization, and mixed-matrix formation, have been employed to fabricate the electrospun membranes. Overall, this study aimed to develop electrospun membranes with excellent separation efficiency for application in protein purification and ammonium ion removal.

Chapter 2 details the stepwise development of weak anion exchange membranes and subsequent …

Optimizing Membrane Distillation With Solar Thermal Collectors, Andrew Mason, Ben Shulders, Siamak Nejati

UCARE Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination including 100% rejection of solute (salt, heavy metals, etc.) and mergeability with other affordable energy sources (solar heat, electric resistance, etc.) However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar‐assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits the low cost of water production in comparison …

Nanohybrid Membrane Synthesis With Phosphorene Nanoparticles: A Study Of The Addition, Stability And Toxicity, Joyner Eke, Philip Alexander Mills, Jacob Ryan Page, Garrison P. Wright, Olga V. Tsyusko, Isabel C. Escobar

Center of Membrane Sciences Faculty Publications

Phosphorene is a promising candidate as a membrane material additive because of its inherent photocatalytic properties and electrical conductance which can help reduce fouling and improve membrane properties. The main objective of this study was to characterize structural and morphologic changes arising from the addition of phosphorene to polymeric membranes. Here, phosphorene was physically incorporated into a blend of polysulfone (PSf) and sulfonated poly ether ether ketone (SPEEK) doping solution. Protein and dye rejection studies were carried out to determine the permeability and selectivity of the membranes. Since loss of material additives during filtration processes is a challenge, the stability …

Probing Counterion Condensation Phenomena In Nanostructured Thin Film Block Copolymer And Random Copolymer Electrolytes, Qi Lei

LSU Doctoral Dissertations

This dissertation describes advanced metrology and molecular dynamics simulations for quantifying counterion condensation in block copolymer electrolyte thin films. The fraction of condensed counterions (f_c) were quantified in nanostructured block copolymer electrolyte (BCE) and random copolymer electrolyte (RCE) thin films with new and established experimental techniques. The transition between the osmotic-controlled regime and condensation-controlled regime in BCEs and RCEs was identified using solution uptake measurements via a quartz crystal microbalance (QCM) and environmental grazing incidence small-angle x-ray scattering (GI-SAXS). The activity coefficients of ions in thin film were quantified experimentally and these values matched predictions from Manning’s Theory …

Toxicant Disruption Of Immune Defenses Potential Implications For Fetal Membranes And Pregnancy, Sean M. Harris, Erica Boldenow, Steven E. Domino, Rita Loch-Caruso

University Faculty Publications and Creative Works

In addition to providing a physical compartment for gestation, the fetal membranes (FM) are an active immunological barrier that provides defense against pathogenic microorganisms that ascend the gravid reproductive tract. Pathogenic infection of the gestational tissues (FM and placenta) is a leading known cause of preterm birth (PTB). Some environmental toxicants decrease the capacity for organisms to mount an immune defense against pathogens. For example, the immunosuppressive effects of the widespread environmental contaminant trichloroethylene (TCE) are documented for lung infection with Streptococcus zooepidemicus. Group B Streptococcus (GBS; Streptococcus agalactiae) is a bacterial pathogen that is frequently found in the female …

Engineering Ionomer Materials For Addressing Ohmic Resistances In Electrochemical Desalination And Waste Heat Recovery, Varada Menon Palakkal

LSU Doctoral Dissertations

Water scarcity and energy availability present important challenges that need to be addressed in the coming centuries. In the front of water technologies, desalting brackish water is of extreme importance for thermal electric power plants, chemical manufacturing plants, and other industrial operations that treat and reuse their water utilities. Membrane capacitive deionization (MCDI) is an energy efficient desalination technique that has drawn attention from commercial entities. Most material research studies on MCDI focus on enhancing electrode performance while little emphasis is given to rationale design of ion-exchange membranes (IEMs). In this work, the ionic conductivity, permselectivity, and thickness for three …

Analysis Of Blood Purification Studies On Oxone Mediated Tempo-Oxidized Nano Cellulose Mixed-Matrix Membranes, Tony Roller

Biomedical Engineering Undergraduate Honors Theses

End-stage renal disease (ESRD) is currently the ninth leading cause of death in the United States, and of the 661,00 Americans diagnosed with ESRD, approximately 468,800 were on hemodialysis in 2016. Hemodialysis refers to a technique where a machine combined with a membrane, often referred to as an artificial kidney, is used to clean blood by removing any waste such as urea, potassium, and other smaller waste products while preserving the concentrations and integrity of cells and proteins in the blood. It has been shown in artificial blood studies that cellulose nanomaterials, like TEMPO/Oxidized cellulose nanoparticles (TOCNs), can be integrated …

Characterization Of Oxone Mediated Tempo-Oxidized Nano Cellulose Mixed-Matrix Membranes During Ultrafiltration And Hemodialysis, Kristyn Robling

Biomedical Engineering Undergraduate Honors Theses

The ninth leading cause of death in the United States is kidney disease, and hemodialysis is the process most commonly prescribed for treatment. It utilizes a selectively permeable membrane filter to remove toxins such as urea from the blood and retain necessary protein levels. However, traditional filters, such as cellulose triacetate, used during dialysis can be inefficient in terms of separation performance and reduction of fouling. Recent exploration of nanoparticles has resulted in the creation of Oxone Mediated TEMPO-Oxidized Nano Cellulose which has properties that are believed to increase hydrophilicity, increase tensile capacity, decrease membrane resistance and lower fouling, making …

Scale-Up Of Polyaniline Cellulose Membranes, Isaac Bodemann

Chemical Engineering Undergraduate Honors Theses

Polyaniline coated cellulose membranes show impressive conductive properties that may be used to innovate traditional charged separation techniques, such as electrodeionization. However, these membranes are not sold to consumers, so they cannot be easily integrated into such systems. This research focuses on the scale-up and development of positively charged anion exchange membranes to be used in EDI cells. Novel cellulose membranes were made using lab-specific cellulose. These membranes were then coated using a polyaniline technique adopted from a paper titled, “Flexible Electrically Conductive Nanocomposite Membrane Based on Bacterial Cellulose and Polyaniline." This paper details the methods used to add the …

Pollution Prevention Via Recovery Of Cerium (Iv) Oxide In Optics Company, Eugene Park, William Gallagher, Sydor Optics, Flint Creek Resources

Articles

Pollution prevention methods were applied at an optics manufacturer in an effort to improve recovery of a valuable polishing component, cerium oxide (ceria), 77% of which was lost to dragout and sewer discharge. Centrifugation and microfiltratiion were evaluated to develop a process that would increase recovery of used ceria, which would then be sent back to the ceria supplier for reclamation and reuse. Full-scale implementation included a high-speed centrifuge that operates continuously with a microfiltration system through recirculation in a single process tank. Sydor Optics has improved ceria recovery from 23% to 48%, saving thousands of dollars annually.

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …