Membrane Science Commons^™

Performance And Fouling During Bioreactor Harvesting, Da Zhang

Graduate Theses and Dissertations

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 …

Defining Interactions Between Deformable Dna Origami And Lipid Bilayers Through Molecular Dynamics Simulation, Zachary A. Loyd

Chancellor’s Honors Program Projects

No abstract provided.

Reactive Thin Film Polymers And Thin Film Composite Membranes For The Rapid Screening Of Uranium Isotopes, Abenazer W. Darge

All Dissertations

Traditional radiochemistry approaches for the detection of trace-level alpha-emitting radioisotopes in water require lengthy offsite sample preparations and do not lend themselves to rapid quantification. Therefore, a novel platform is needed that combines onsite purification, concentration, and isotopic screening with a fieldable detection system. My dissertation research objective was to develop novel reactive thin polymer films and thin film composite membranes for the selective separation of uranium from environmental water followed by direct isotopic analysis by alpha spectroscopy. Chapter 1 reviews progress made on uranium separation from aqueous matrices and discusses methods used for the determination of isotopic composition.

Chapter …

Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster

All Dissertations

The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …

Optimizing Virus Prefiltration For Biopharmaceutical Manufacturing, Solomon Isu

Graduate Theses and Dissertations

Virus filters are single-use devices that use a size-based separation process. In virus filters, contaminating virus particles are retained while the therapeutic molecules pass through the membrane pores. Virus filters are an essential component of the overall virus clearance strategy. Sections 1 and 2 of this dissertation provide an introduction and extensive review of monoclonal antibody (mAb) process development, where virus filtration is pivotal. In section 3, prefiltration studies were performed with an industrially relevant IgG1 type mAb using adsorptive and size-exclusion-based prefilters with different mechanisms of action. This mAb has an isoelectric point range of 7.1 to 8.0 and …

Isolation And Production Of Tandem Collagen Binding Domain From Clostridial Collagenase Colg And Developments In C1q Reagent Production For Future Molecule Characterization Work, Stephanie Beitle

Chemical Engineering Undergraduate Honors Theses

This thesis covers a two part project: the production methods to create a double collagen binding domain molecule with a growth factor for wound healing applications and the development of a new in-house production method for isolating C1q from bovine blood. The wound healing molecule was created using transformation, sonication, and purification before being tested via electrophoresis SDS page and Western blots to confirm the molecule’s presence. The C1q in-house production method utilizes an ultrafiltration flow cell rather than dialysis at a critical point in the process, allowing for researchers to not only be able to use a single small …

Tuning Electrochemical Interactions And Polymer Electrolyte Interfaces For Enhanced Organic Acid Separations Using Electrodeionization, Matthew Leo Jordan

LSU Doctoral Dissertations

Chemical separations are critical processes for chemical and industrial plants to purify and isolate products however current separation technologies, such as distillation, rely on energy intensive processes. Electrochemical separation processes, such as electrodialysis and electrodeionization, are an energy efficient alternative that are emerging as an alternative for thermal-based separations. Organic acids are weakly ionizable species and susceptible for purification from process streams using electrochemical processes. Recently the fermentation route has garnered greater attention as a means for producing value-added chemicals, such as organic acids, from a renewable feedstock and aiding the circular economy. Some of the challenges electrodialysis faces for …

Small-Pore Zeolite Membranes: A Review Of Gas Separation Applications And Membrane Preparation, Zishu Cao, Ninad Anjikar, Shaowei Yang

Chemical & Biomedical Engineering Faculty Publications

There have been significant advancements in small-pore zeolite membranes in recent years. With pore size closely related to many energy- or environment-related gas molecules, small-pore zeolite membranes have demonstrated great potential for the separation of some interested gas pairs, such as CO2/CH4, CO2/N-2 and N-2/CH4. Small-pore zeolite membranes share some characteristics but also have distinctive differences depending on their framework, structure and zeolite chemistry. Through this mini review, the separation performance of different types of zeolite membranes with respect to interested gas pairs will be compared. We aim to give readers an idea of membrane separation status. A few representative …

Design And Control Of Intensified Membrane Reactor Systems Through Module-Based Design Approach, Brent Bishop

Graduate Theses, Dissertations, and Problem Reports

As interest in the modularization and intensification of chemical processes continues to grow, more research must be directed towards the modeling and analysis of intensified process units. Intensified process units such as membrane reactors pose unique challenges pertaining to design and operation that have not been fully addressed in the reported literature. This work aims to address the design and control challenges caused by the integration of phenomena and the loss of degrees of freedom (DOF) that occur in the intensification of modular membrane reactor units.

First, a novel first-principles approach for modeling membrane reactors is developed using the AVEVA …

Scale-Up Of Flow-Electrode Capacitive Deionization Method For Hard Water Softening, Noah Henry

Williams Honors College, Honors Research Projects

This study’s purpose is to further document a capacitive deionization design that could be capable of purifying H₂O at a household scale where clean water is otherwise unobtainable in applicable regions of the world. The hypothesis behind this study was continuously larger scaled electrochemical cell-units would increase their water softening capabilities in sustainable fashion. The trend at which performance will scale is currently unknown. The units studied were constructed using graphite plates, anion exchange membranes, cation exchange membranes, and Teflon channels. Three streams, two being CaCl₂ solutions in DI H₂O (one being concentrated with CaCl …

Amine-Functionalized Interpenetrating Polymer Networks For Co2 Capture, James Wills

Williams Honors College, Honors Research Projects

The research performed looked to advance the studies of vacuum swing absorption of Carbon Dioxide to help combat global climate change issues. The focus of the project was to create an anime-polymer sorbent that will weakly absorb and desorb CO2. The sorbent must be durable and be able to withstand multiple uses. The creation of a porous polymer matrix aided in the amines' ability to absorb CO2. Created samples underwent several qualitative and quantitative tests to determine their usefulness as an industrial sorbent. Infrared spectroscopy was used to study the effectiveness of the amine sorbents. Studying the changes in the …

Water Recovery From Bioreactor Mixed Liquors Using Forward Osmosis With Polyelectrolyte Draw Solutions, Calen Raulerson

All Theses

The objective of this research was to test the feasibility of using forward osmosis (FO) with polyelectrolyte draw solutions to recover water from bioreactor mixed liquors. When combined with an Anaerobic Osmotic Membrane Bioreactor (AnOMBR), such a system could process fecal and food waste from astronauts aboard the International Space Station (ISS) and reclaim important nutrients and water. This project focused on measuring the obtainable water recovery rates from bioreactor effluent, and the identifying challenges associated with the operation.

AnOMBRs feature several advantages over aerobic bioreactors, and non-osmotic anaerobic membrane bioreactors (AnMBR). Anaerobic bioreactors avoid the significant energy costs of …

Atomically Thin Nanoporous Graphene Membranes For Fluid Separation, Anika O. K. Wong

Electronic Thesis and Dissertation Repository

Membrane separation applications such as water desalination and carbon capture require high permeance and selectivity. For such processes, nanoporous graphene membranes promise 100-fold higher permeance at comparable selectivity to conventional polymer membranes, but remain under development. This thesis reports fluid permeance through both simulated and experimental graphene nanopores. Molecular dynamics simulations were performed to investigate liquid advection-diffusion through graphene nanopores and how the transport rates differ from continuum predictions. Furthermore, a technique for measuring the gas permeance of nanoscopic areas of graphene was developed. Here, a single layer of graphene seals a ~10 nm diameter hole in a multi-layer graphene …

Investigation Of Electrochemical And Hybrid Microbial Desalination Cells For Environmental Applications, Shawn Nicholas Hamilton

Electronic Thesis and Dissertation Repository

ABSTRACT

Road salt is a global problem especially in cold countries that are focused on road safety in urbanized and big cities. On an average approximately 5 million tonnes of road salt is applied on Canadian highways annually. Road salt impacts aquatic ecosystems, bridges, buildings and corrodes metal structures. Therefore the treatment of road salt is important and needs to be studied.

In this study, a batch lab-scale 3-compartment electrochemical desalination cell was invented and studied to reduce NaCl_(aq) (model of road salt) through the utilization of NaBH₄/H₂O₂ redox reaction. Using of several commercial …

Inherently Porous Atomically Thin Membranes For Gas Separation, Harpreet Atwal

Electronic Thesis and Dissertation Repository

Membranes made from atomically thin materials promise hundreds of times higher production rates than conventional polymer membranes for separation applications. Graphene is impermeable to gases but becomes selectively permeable once pores are introduced into it but creating trillions of nanopores over large areas is difficult. By instead choosing an inherently porous two-dimensional material with naturally identical pores repeated at high density, we may circumvent this challenge. In this work, we explore the potential of two candidate materials, 2D polyphenylene and graphdiyne. We synthesize cyclohexane-m-phenylene, a monomer of 2D polyphenylene. We then develop an atomic force microscopy technique for measuring the …

Characterization Techniques And Cation Exchange Membrane For Non-Aqueous Redox Flow Battery, Kun Lou

Doctoral Dissertations

The motivation of this work comes from one of the major problems of emerging non-aqueous flow battery (NAFB) that a separator or membrane which facilitates conductivity and blocks redox species crossover does not exist. Although many aspects of principles can be mirrored from mature fuel cell and aqueous flow battery, it is found that some well-defined membrane properties in aqueous systems such as swelling, transport and interactions are different in non-aqueous solvents to some extent. However, the approach of this work does follow the way perfluorosulfonate ion exchange membrane (PFSA) facilitated development of fuel cell and aqueous flow battery in …

Lipoprotein-Induced Increases In Cholesterol And 7-Ketocholesterol Result In Opposite Molecular-Scale Biophysical Effects On Membrane Structure, Manuela A.A. Ayee, Irena Levitan

Faculty Work Comprehensive List

Under hypercholesterolemic conditions, exposure of cells to lipoproteins results in a subtle membrane increase in the levels of cholesterol and 7-ketocholesterol, as compared to normal conditions. The effect of these physiologically relevant concentration increases on multicomponent bilayer membranes was investigated using coarse-grained molecular dynamics simulations. Significant changes in the structural and dynamic properties of the bilayer membranes resulted from these subtle increases in sterol levels, with both sterol species inducing decreases in the lateral area and inhibiting lateral diffusion to varying extents. Cholesterol and 7-ketocholesterol, however, exhibited opposite effects on lipid packing and orientation. The results from this study indicate …

Phase-Field Modeling Of The Polymer Membrane Formation Process For Micro- And Ultra-Filtration, Michael Rosario Cervellere

Graduate Theses and Dissertations

Porous polymer membrane filters are widely used in separation and filtration process. Micro- and ultra-filtration membranes are commonly used in biopharmaceutical applications such as filtering viruses and separating proteins from a carrier solution. The formation of these membrane filters via phase inversion is a complex and interconnected process where varying casting conditions can have a wide variety of effects on the final membrane morphol- ogy. Tailoring membrane filters for specific performance characteristics is a tedious and time consuming process. The time and length scales of membrane formation make it extremely difficult to experimentally observe membrane formation. Modeling the membrane formation …

Investigation Of Membrane Based Processes For Biomedical Applications, Efecan Pakkaner

Graduate Theses and Dissertations

As substantial developments were achieved in nanotechnology and polymer engineering, especially in the last few decades, the use of membranes and membrane-based procedures was found to be expanding into more and more research and development areas; including biological engineering, life sciences and biomedical engineering. Not only have they been the main focus of meaningful research, but they have also been the main pieces of the solutions to very thorny problems encountered within a wide range of applications from microfluidics to water treatment, thanks to their versatility, cost-effectiveness and biocompatibility, when compared to conventional separation techniques. To celebrate and embrace these …

Garver Industrial Design Project: Designing A Full-Scale Reverse Osmosis Water Treatment Facility For The City Of Lawton, Oklahoma, Kayliana Warden, Marlando Collins, Sandrina Depaz, Reid Eakin, Reed Leasure, Vera Rodriguez

Chemical Engineering Undergraduate Honors Theses

A groundwater treatment facility was designed for Lawton, Oklahoma to address potential water scarcity due to drought conditions in southwest Oklahoma. The facility will produce five million gallons per day (MGD) of treated water. The plant will have the capacity of treating 4,085 gallons per minute of influent water at an 86% recovery. The water to be treated will come from the Arbuckle-Timbered Hills Aquifer. Studies have been conducted around the aquifer to identify the best well site locations.

A centralized treatment facility using reverse osmosis filtration as the main treatment technology has been designed. To prevent reverse osmosis membrane …

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 …