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Membranes For Food And Bioproduct Processing, Alexandru Marius Avram 2017 University of Arkansas, Fayetteville

Membranes For Food And Bioproduct Processing, Alexandru Marius Avram

Theses and Dissertations

Modified membranes for process intensification in biomass hydrolysis

Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to ...


Membrane Surface Engineering For Biochemical Applications, Anh T. Vu 2017 University of Arkansas, Fayetteville

Membrane Surface Engineering For Biochemical Applications, Anh T. Vu

Theses and Dissertations

Synthetic membranes have been frequently used for many fields, such as, the food and beverage, biopharmaceutical, and biofuel industries. In the beer industry, microfiltration frequently suffers from fouling due to the interaction between different species. It is shown that polyphenols can form cross-links with protein molecules, forming insoluble aggregates. However, by adding an optimal amount of polysaccharides these aggregates can be disrupted thus reducing fouling by the aggregates. Confocal laser scanning microscopy (CLSM) is a powerful technique to locate the foulants inside the wet membrane in order to understand more about the behavior of fouling in microfiltration.

Membrane surface modification ...


Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz 2017 University of Arkansas, Fayetteville

Removal Of Endocrine Disrupting Compounds Using Membrane Bioreactor, Mohanad Ali Abdulsahib Kamaz

Theses and Dissertations

The presence of endocrine disrupting compounds (EDCs) and pharmaceutically active compounds (PhAC) such as pesticides, personal care products, antibiotics and pharmaceutical compounds, in sewage, industrial, and domestic waters has extensively become the major concern for health and environmental organizations. These compounds have the ability to interact with mammalian endocrine system and disrupting their functions. The traditional activated sludge processes are designed to degrade solids, organic carbon and nitrogen loading. Although several treatment steps in a wastewater treatment plant can contribute to partial removal of EDCs, effective removal has been a challenge due to their resistant chemical and biological degradation and ...


Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton 2017 University of Maine

Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton

Electronic Theses and Dissertations

In the processing industry, fouling due to the accumulation of bioparticles or bacteria on the surface of membranes results in decreased capacity, and subsequently requires filtration membranes to require periodic cleaning, causing increased operating costs. In this work, we evaluate the recently discovered concept of liquid-gated membranes (LGMs) in both filtration characteristics, as well as their ability to facilitate passive cleaning of membranes fouled with whey proteins. Additionally, we show that biofilms formed on the surface of these membranes can be removed through exposure to an air-water interface through a simple dipping step. We further analyze the mechanisms of fouling ...


Biomass Utilization Of Carbon, Kathryn M. Hopfensperger, Catherine Brame, Mary Uselmann, Traci Reusser 2017 University of Wyoming

Biomass Utilization Of Carbon, Kathryn M. Hopfensperger, Catherine Brame, Mary Uselmann, Traci Reusser

Honors Theses AY 16/17

The goal of this project was to address the environmental implications of an algae biomass system that sequesters carbon dioxide to produce economically valuable products. The Algalrithm, a theoretical company driven by reducing CO2 emissions, chose a final product based upon the results of economic analyses that considered potential carbon capture and utilization incomes, as well as the value of diverse products under various commodity pricing constraints. Many algae-based bio-products were considered before narrowing in on a specific product that would encompass the volume of typical utility-scale electricity producing plants, a wide range of future carbon costs, and the ...


Morphological And Photoelectrochemical Characterization Of Membrane Reconstituted Photosystem I (Psi), Seyedeh Hanieh Niroomand 2017 University of Tennessee, Knoxville

Morphological And Photoelectrochemical Characterization Of Membrane Reconstituted Photosystem I (Psi), Seyedeh Hanieh Niroomand

Doctoral Dissertations

The robust structural and photoactive electrochemical properties of Photosystem I (PSI), a transmembrane photosynthetic protein complex, make it an ideal candidate for incorporation into solid state bioelectronic or hybrid photovoltaic devices. However, the first step towards the successful fabrication of such devices requires systematic assembly of oriented and functional PSI onto desired bio-abio interfaces via suitable protein scaffoldings. Hence, this dissertation focuses on utilizing the cyanobacterial PSI for integration into organic/inorganic interfaces that mediate photo-electrochemical energy conversions for electricity and/or solar fuel production. To this end, in this study the effect of systematic incorporation of PSI complexes into ...


Quantifying Gauche Defects And Phase Evolution In Self-Assembled Monolayers Through Sessile Drops, Jiahao Chen, Boyce Chang, Stephanie Oyola-Reynoso, Zhengjia Wang, Martin M. Thuo 2017 Iowa State University

Quantifying Gauche Defects And Phase Evolution In Self-Assembled Monolayers Through Sessile Drops, Jiahao Chen, Boyce Chang, Stephanie Oyola-Reynoso, Zhengjia Wang, Martin M. Thuo

Materials Science and Engineering Publications

Self-assembled monolayers (SAMs) are widely used in surface modifications, specifically in tuning the surface chemistry of materials. The structure and properties of SAMs have been extensively studied often with sophisticated tools, even for the simplest n-alkanethiolate SAMs. In SAMs, especially in linear n-alkanethiolates, the properties are dependent on the chain length, which is best manifested in the so-called odd–even effect, a simple yet not fully understood phenomenon. One main challenge is fully delineating the origin of length-dependent properties, which can be due to the structure (ideal SAMs), defect evolution, or substrate-molecule effects. This study demonstrates that utilizing ...


Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick 2017 University of Kentucky

Functionalization Of Silver Nanoparticles On Membranes And Its Influence On Biofouling, Conor G. Sprick

Theses and Dissertations--Chemical and Materials Engineering

Ultrafiltration (UF) processes are often used as pretreatment before more retentive/costly processes, such as nanofiltration and reverse osmosis. This study shows the results of low-biofouling nanocomposite membranes, loaded with casein-coated silver nanoparticles (casein-Ag-NPs). Membranes were cast and imbedded with Ag-NPs using two approaches, physical blending of Ag-NPs in the dope solution (PAg-NP/CA membranes) and chemical attachment of Ag-NPs to cast membranes (CAg-NP/CA membranes), to determine their biofouling control properties. The functionalization of Ag-NPs onto the CA membranes was achieved via attachment with functionalized thiol groups with the use of glycidyl methacrylate (GMA) and cysteamine chemistries ...


Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou 2017 University of Kentucky

Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou

Theses and Dissertations--Chemical and Materials Engineering

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through ...


Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra 2017 University of Kentucky

Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra

Theses and Dissertations--Chemical and Materials Engineering

Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.

Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these ...


Investigating The Synergistic Effects Of Combined Modified Alginates On Macrophage Phenotype, Hannah C. Bygd, Kaitlin M. Bratlie 2016 Iowa State University

Investigating The Synergistic Effects Of Combined Modified Alginates On Macrophage Phenotype, Hannah C. Bygd, Kaitlin M. Bratlie

Materials Science and Engineering Publications

Understanding macrophage responses to biomaterials is crucial to the success of implanted medical devices, tissue engineering scaffolds, and drug delivery vehicles. Cellular responses to materials may depend synergistically on multiple surface chemistries, due to the polyvalent nature of cell–ligand interactions. Previous work in our lab found that different surface functionalities of chemically modified alginate could sway macrophage phenotype toward either the pro-inflammatory or pro-angiogenic phenotype. Using these findings, this research aims to understand the relationship between combined material surface chemistries and macrophage phenotype. Tumor necrosis factor-α (TNF-α) secretion, nitrite production, and arginase activity were measured and used to determine ...


Hollow Fiber Membranes For Artificial Lung Applications, Lauren Reed 2016 University of Arkansas, Fayetteville

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 2016 University of Arkansas, Fayetteville

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 ...


Koh Etching Of (100) Si Wafer, No 2, Inayat Bajwa 2016 Quattrone Nanofabrication Facility

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 2016 University of Tennessee, Knoxville

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 ...


Production Of Acetic Acid In Kraft Pulp Mill Biorefinery Using Bi-Polar Membrane Electrodialysis, Ravikant Amogisidha Patil 2016 University of Maine

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 ...


Directed Self-Assembly Of Block Copolymer, No1, Hiromichi Yamamoto 2016 Singh Center

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.


Metal Assisted Chemical Etching, Inayat Bajwa 2016 Quattrone Nanofabrication Facility

Metal Assisted Chemical Etching, Inayat Bajwa

Protocols and Reports

No abstract provided.


Micellular Electrokinetic Chromatography For Studying Amyloid Beta Oligomer Membrane Affinity, Andrew Bryson 2016 University of Arkansas, Fayetteville

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 ...


Koh Etching Of (100) Si Wafer, No 1, Inayat Bajwa 2016 Quattrone Nanofabrication Facility

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

Protocols and Reports

No abstract provided.


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