Membrane Science Commons^™

A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, Yueming Wu

Murray State Theses and Dissertations

ABSTRACT

The polymerization process of, and gas absorption by, imidazolium-containing thiol:ene poly (ionic liquid)s (PILs), prepared from bisallylimidazolium bis(trifluoromethyl sulfonyl)imide [NTf₂^-] and pentaerythritoltetrakis(3 mercaptopropionate), was studied. The thiol:ene PILs examined were recently reported by groups at Murray State University. The advantage of thiol:ene PILs over other reported PILs is that thiol:ene polymers are made rapidly by UV exposure and exhibit high mechanical and thermal stability due to high cross-linking. The properties of interest for the thiol:ene PILs were studied using a quartz crystal microbalance (QCM). QCM techniques are based on the piezoelectric effect, where certain crystals (e.g., …

Hollow Fiber Membranes For Artificial Lung Applications, Lauren Reed

Chemical Engineering Undergraduate Honors Theses

Artificial lungs are in use, but difficult issues remain in the field of membrane development related to fouling issues. Currently there are external artificial lungs circulating blood outside the body, taking out the carbon dioxide, and inserting oxygenated blood back into the body. An example of this type of machine is the ExtraCorporeal Membrane Oxygenation (ECMO) machine currently used in hospitals. The ECMO takes over the functions for both the lungs and the heart but is only available for short term use by patients with respiratory failure due to infections [1]. The fibers in the machine develop fouling due to …

Plasmonic Pervaporation For Sustainable Mixture Separation, Ty Austin

Chemical Engineering Undergraduate Honors Theses

The U.S. Department of Energy suggests that ca. 40% of the total energy consumed in the chemical and refining industries is used for distillation.¹ One potentially energy efficient alternative is pervaporation, a membrane separation process that uses differences in solvent permeability and vaporization rates to encourage mixture separation. Pervaporation has become a valuable tool in the processes of producing biofuels, recovering water, and removing solvent.^2,3 However, implementation has been hindered by heating the feed to the membrane and cooling the unpermeated retentate to increase membrane throughput at a higher energy cost. Preliminary research has shown that locally heating …

Biopolymer Electrospun Nanofiber Mats To Inactivate And Remove Bacteria, Katrina Ann Rieger

Doctoral Dissertations

The persistence of antibiotic resistance in bacterial pathogens remains a primary concern for immunocompromised and critically-ill hospital patients. Hospital associated infections can be deadly and reduce the successes of medical advancements, such as, cancer therapies and medical implants. Thus, it is imperative to develop materials that can (i) deliver new antibiotics with accuracy, as well as (ii) uptake pathogenic microbes. In this work, we will demonstrate that electrospun nanofiber mats offer a promising platform for both of these objectives because of their high surface-to-volume ratio, interconnected high porosity, gas permeability, and ability to contour to virtually any surface. To provide …

Polymer And Small Molecule Designs For Anion Conducting Membranes: Connected Ion-Channel Morphologies And Highly Alkaline Stable Ammonium Cations, Sedef P. Ertem

Doctoral Dissertations

Fuel cells are one of the oldest sustainable energy generation devices, converting chemical energy into electrical energy via reverse-electrolysis reactions. With the rapid development of polymer science, solid polymer electrolyte (SPE) membranes replaced the conventional liquid ion transport media, rendering low-temperature fuel cells more accessible for applications in portable electronics and transportation. However, SPE fuel cells are still far from commercialization due to high operation cost, and insufficient lifetime and performance limitations. Anion exchange membrane fuel cells (AEMFCs) are inexpensive alternatives to current proton exchange membrane fuel cell (PEMFC) technology, which relies on utilizing expensive noble-metal catalysts and perfluorinated SPE …

Preparation Of Nano-Size Ceramic Membrane From Industrial Waste, Shereen K. Amin, Mai H. Roushdy, Chakinaz Aly El-Sherbiny, Heba Mohamed Abdallah, Magdi F. Abadir

Chemical Engineering

Industrial ceramic wastes are becoming an increasing problem worldwide. Recently, this problem has attracted social concern due to the growing amounts of waste despite the measures and precautions that have been taken worldwide aiming at managing such wastes. One promising solution that has been recently researched consists incorporating such wastes in ceramic bodies which besides minimizing the waste load often improve the quality of the ceramic body. Roller kilns used in the production of ceramic tiles are routinely ground to remove traces of contamination. The fine ground powder is usually discarded as a useless waste. In the present paper, the …

Koh Etching Of (100) Si Wafer, No 2, Inayat Bajwa

Protocols and Reports

This report describes KOH etching of (100) Si wafer through a hard mask of silicon oxide, and reveals that the scattered etch rate is ascribed to the etch rates of the different crystal planes exposed during the etching.

Mass And Charge Transport In Hydrated Polymeric Membranes, Marshall T. Mcdonnell

Doctoral Dissertations

Mass and charge transport through hydrated polymer membranes has significant importance for many areas of engineering and industry. Multi-scale modeling and simulation techniques were used to study transport in relation to two specific membrane applications: (1) food packaging and (2) additives for polymer electrolytes.

Chitosan/chitin films were studied due to their use as a sustainable, biodegradable food packaging film. The effects of hydration on the solvation, diffusivity, solubility, and permeability of oxygen molecules in these films were studied via molecular dynamics and confined random walk simulations. With increasing hydration, the membrane was observed to have a more homogeneous water distribution …

Directed Self-Assembly Of Block Copolymer, No1, Hiromichi Yamamoto

Protocols and Reports

The PS-rich and neutral PS-b-PMMA block copolymer (BCP) films were spin coated on the neutral random copolymer hydroxyl-terminated PS-r-PMMA layers grafted on the native oxide and 50 nm thick PECVD amorphous silicon oxide layers. Relationship between the grafting density of BCP and surface density of hydroxyl moiety on silicon oxide is discussed. Furthermore, optimization of annealing BCP films is reported, and wetted and de-wetted BCP films are shown in optical microscope images. In addition, finger print and nanopore structures of BCP films are also indicated in SEM images.

Production Of Acetic Acid In Kraft Pulp Mill Biorefinery Using Bi-Polar Membrane Electrodialysis, Ravikant Amogisidha Patil

Electronic Theses and Dissertations

The objective of this dissertation was to develop a process for the production of acetic acid in kraft mills. Acetyl groups in hardwood can be hydrolyzed using alkali at 50 °C. The product from this process contains about 15 g/L of sodium acetate and was determined to be suitable for the production of acetic acid.

Experiments performed using aqueous sodium acetate to evaluate the ability of electrodialysis (ED) to separate and concentrate sodium acetate showed that sodium acetate can be concentrated up to 275 g/L starting with an initial concentration of 17 g/L. The transport of water with sodium and …

Synthesis And Characterization Of Polymeric Anion Exchange Membranes, Wenxu Zhang

Doctoral Dissertations

As alkaline anion exchange membrane fuel cells (AAEMFC) are regarded as promising and important energy devices, the development of high performance anion exchange membranes are in urgent need, as well as fundamental investigation on the structure-property relationship, which are the motivation of this dissertation. Three different polymer systems are presented and focused on polymer synthesis, material morphology, and ion transport phenomena.

Crosslinked membranes are promising as practical materials, however, the understanding and further improvement of its performance is hindered by the lack of an ordered morphology or well-defined chemical structure. In Chapter 2, a series of crosslinked membranes were design …

Metal Assisted Chemical Etching, Inayat Bajwa

Protocols and Reports

No abstract provided.

Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson

Biomedical Engineering Undergraduate Honors Theses

Amyloid Beta (Aβ) was the major focus of this study. It is a peptide that is present in the brain with a high tendency to self-aggregate. When this protein aggregates, it forms oligomers and protofibrils which in turn are deposited as senile plaques in the brain. The reason for the concern with these plaques is their association with the neurological disorder Alzheimer’s disease. It has been found that the most dangerous oligomers are formed in a portion of the plasma membrane known as lipid rafts. The purpose of this study was to understand how micelles affect the aggregation properties of …

Koh Etching Of (100) Si Wafer, No 1, Inayat Bajwa

Protocols and Reports

No abstract provided.

Development Of Pvdf Membrane Nanocomposites Via Various Functionalization Approaches For Environmental Applications, Douglas M. Davenport, Minghui Gui, Lindell E. Ormsbee, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

Membranes are finding wide applications in various fields spanning biological, water, and energy areas. Synthesis of membranes to provide tunable flux, metal sorption, and catalysis has been done through pore functionalization of microfiltration (MF) type membranes with responsive behavior. This methodology provides an opportunity to improve synthetic membrane performance via polymer fabrication and surface modification. By optimizing the polymer coagulation conditions in phase inversion fabrication, spongy polyvinylidene fluoride (PVDF) membranes with high porosity and large internal pore volume were created in lab and full scale. This robust membrane shows a promising mechanical strength as well as high capacity for loading …

Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere

Publications

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane …

An Overview Of Production And Development Of Ceramic Membranes, Shereen Kamel Amin, Heba Mohamed Abdallah, Mai H. Roushdy, Chakinaz Aly El-Sherbiny

Chemical Engineering

Ceramic membranes became one of the most important ceramic products because of their numerous benefits. Many attempts have been made by researchers to produce ceramic membranes with modified properties by varying their raw materials. Some of these attempts included incorporating wastes into their production process. Examples of such waste are fly ash wastes, glass waste, mud resulting from the hydro cyclone laundries, cortical bone animal, coal gangue, sawdust, construction waste and rice husk. An ideal waste would be priceless waste while at the same time assisting minimizing pollution. Such a situation deals with a dual economic and environmental aspect. This …

Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson

Graduate Theses and Dissertations

The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks. This process has created large volumes of brackish water that is very difficult to process and is often disposed of into injection wells. Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the reuse of flowback in future hydraulic fracturing operations.

Nanofiltration, a membrane separation …

Separation Of Oil From A Brackish Water Stream, Kayli A. Quinton

Chemical Engineering Undergraduate Honors Theses

In the past 40 years, a variety of enhanced oil recovery (EOR) methods have been developed and applied to mature and mostly depleted oil reservoirs. Chemical and sonic stimulation are two enhanced oil recovery methods in which emulsions are created either as a primary or secondary effect. The resulting emulsion viscosity is considerably lower than that of dry crude thus increasing permeability of and recovery from pay zones. During Chemical enhanced oil recovery, caustic or preformed surfactants are injected into oil reservoirs, which results in flooding and periodic breakthrough of stable oil-water emulsions. The emulsions from chemical enhanced oil recovery …

Evapoporometry: An Effective Analytical Technique For Membrane Pore Size Characterization Of Hollow Fiber Membranes, Alex J. Moix

Chemical Engineering Undergraduate Honors Theses

A new analytical technique called evapoporometry has shown to be an effective and inexpensive method for membrane pore size characterization. This technique is based on the correlation between vapor pressure and pore size as described by the Kelvin equation. Evapoporometry has many advantages over tradition pore size characterization techniques. This technique allows for large sample sizes, uses minimal equipment, is capable of analyzing membranes within a wide range of pore sizes, and provides a highly descriptive representation of the pore distribution. This research looks at the application of evapoporometry as a technique for characterization of hollow fiber membranes. Using the …