Physical Sciences and Mathematics Commons^™

Pressure Driven Desalination Membranes: Lyotropic Liquid Crystals Containing Single Walled Carbon, Matteo A. Del Giudice, Samantha Castillo Merigold

Materials Engineering

This project presents a potential alternative desalination technique that utilizes the ion rejection properties of single walled carbon nanotubes dispersed in a lyotropic liquid crystal (LLC) matrix. Previous research has pointed to the polymerizable surfactant methacryloxy ethyl hexadecyl dimethyl ammonium bromide (C16MA) having capabilities of filtering molecular components smaller than a nanometer, when oriented in cylindrical micelles. SWCNTs were dispersed in deionized water by probe sonication and addition of surfactant cetyltrimethylammonium bromide (CTAB) due to SWCNTs’ hydrophobic properties. Membranes were produced containing 55wt% C16MA, 37wt% DI water, 0.1wt% with respect to the monomer (WRM) SWCNTs, 1.9 wt% WRM 2,2-dimethoxy-2-phenylacetophenone (photointiator), …

Pressure Driven Desalination Utilizing Nanomaterials, Fangyou Xie

Master's Theses

Nanomaterials such as graphene oxide and carbon nanotubes, have demonstrated excellent properties for membrane desalination, including decrease of maintenance, increase of flux rate, simple solution casting, and impressive chemical inertness. Here, two projects are studied to investigate nanocarbon based membrane desalination. The first project is to prepare hybrid membranes with amyloid fibrils intercalated with graphene oxide sheets. The addition of protein amyloid fibrils expands the interlayer spacing between graphene oxide nanosheets and introduces additional functional groups in the diffusion pathways, resulting in increase of flux rate and rejection rate for the organic dyes. Amyloid fibrils also provide structural assistance to …

Beam Loss Analysis Through Particle Tracking Simulation, Marvin Valverde

STAR Program Research Presentations

Water soluble-polymers are commonly used to build detergents or other types of surfactants. These polymers are important because water soluble-polymers used in the development of surfactants have become an essential new factor in the cleaning of oil. However, the development of these surfactants has been constrained by the difficulty of producing them. For this synthesis, phenolic maleimide was used as starting material for a water-soluble polymer. This polymer will be able to break apart at set temperatures and self-assemble into a surfactant.

A Comparison Of Solvent And Water-Borne Alkyd Coatings And The History Of Voc Regulations In The United States, Molly Elise Burns

Master's Theses

A Comparison of Solvent and Water-Borne Alkyd Coatings Abstract

Conventional solvent based alkyd coatings have gone out of favor due to concerns over volatile organic compound (VOC) content. However, due to recent focus on renewable raw materials, alkyds are making a comeback in waterborne form. Water based alkyd coatings are known to have poor shelf stability and corrosion resistance, as well as other problems during the formulation process. This project focused on comparing solvent borne to two types of water-borne alkyds, water reducible alkyds and alkyds emulsions. The purpose was to understand the differences between the three types of alkyds …

Calculating The Energy Barriers Required To Join Metal-Organic Framework Synthesis Intermediates With Non-Equilibrium Molecular Simulation, Marcus A. Tubbs, David Cantu, Roger Rousseau, Vassiliki-Alexandra Glezakou

STAR Program Research Presentations

Metal organic frameworks are synthetic porous materials with great capacity for adsorption of carbon dioxide and methane. They chemically appear as a chain-link fence with nodes of metal connected by organic linkers. The pores between the nodes define the characteristics of the material, allowing gas particles of specific size to pass through while blocking larger particulates. While there has been success in synthesizing small amounts of metal organic frameworks, the mechanistic details behind their assembly remain unknown. Understanding the synthesis mechanism is necessary to understand the kinetics involved and be able to produce this useful material on an industrial scale. …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Lipid Production By Microalgae Treating Municipal Wastewater, James Edward Kelley

Master's Theses

Microalgae hold much promise as a feedstock in liquid biofuel production. Lipid content of microalgae cells range from 30-80% dry weight of biomass. It is projected that microalgae can produce between 1,000-6,500 gallons/acre/year of oil. Currently, production of industrial algae operates in open raceway ponds that use minimal capital and energy inputs to culture algae. Raceway ponds can also be used to grow microalgae from municipal waste streams. Although high biomass productivity can be achieved in these systems, there remains a large production gap between large volumes of biomass cultivation and high lipid content from microalgae cells. Low lipid content …

Latent Cysteine Residues From Polymers Prepared Via Free And Controlled Radical Polymerizations, Douglas Vincent Amato

Master's Theses

One less commonly used “click” reaction is thiazolidine chemistry. Thiazolidine chemistry is a commonly used reaction used in biological systems because the reaction requires the presence of both cysteine (a common amino acid) and an aldehyde or ketone. If cysteine residues could be incorporated into a polymer then a variety of applications could be developed. Polymers containing free thiols (aka thiomers) have developed in the last decade to become great mucoadhesives. If there was a facile route to control the amount of free thiols along the polymer then more fine-tuned and potentially stronger adhesives could be made. For these reasons …

Re-Healable Coating Based Upon Thermally Responsive Linkages, Dahlia Ningrum Amato

Master's Theses

The goal of this thesis was to design thermally responsive polyol resins that would be compatible with isocyanates. Two approaches were made to reach this goal, the first involved functionalizing soybean oil and the second involved post-polymerization modification of a methacrylate based resin.

A soybean based coating with thermally responsive Diels-Alder linkages has been prepared following an automotive two-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. …

Experimenting With Polymer Blend Solar Cells And Active Layer Thickness, Ryan Blumenthal

Physics

Bulk heterojunction organic photovoltaics utilize the electrical characteristics of semi-conductive polymers. These solution processable materials are beneficial because of their low material cost, light weight, and simple fabrication requirements. Our devices employ multiple photoactive polymers, P3HT and PCPDTBT, to absorb photons over a wide spectral range. We optimized various device characteristics including thickness and thermal anneal usage to reach a power conversion efficiency of 3.0% in AM1.5 sunlight. Device performance degrades over time due to atmospheric water and oxygen, prompting us to investigate device packaging to extend cell lifetime for additional testing.

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …

The Development Of Transparent, Processable, Thermally-Responsive Coatings, Christopher David Roland

Master's Theses

Polymer matrices are commonly used as guest-host systems for organic chromophores for use in non-linear optical materials. The chromophores must be aligned or poled in an electric field in order to impart anisotropy and non-linear activity to the material. This poling process raises several issues, the two largest being the eventual relaxation of the chromophores back into random orientations due to brownian motion, and high molecular weight polymer matrices limiting chromophore mobility during poling. The prevention of this relaxation process is an area of significant interest, especially in applications that require long term coating stability and activity. In this study, …

The Preparation Of Functional Surfaces, Philip Thomas Dirlam

Master's Theses

Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates in reversible manner. Glass slides and capillaries were functionalized with hydrophobic dieneophiles resulting in a non-wetting surface. A retro Diels-Alder reaction facilitated by the thermal treatment of the surface’s function to cleave the hydrophobic dieneophile and resulted in the fabrication of a hydrophilic surface. Contact angle (CA) measurements were used as preliminary measurements for monitoring the changes in surface energy exhibited during the initial hydrophobic state (CA - 70±3°), after attachment of the dieneophile creating a hydrophobic state (CA - 101±9°) followed by reestablishment of the hydrophilic state …

Part A: The Use Of Nonionic Associative Polymers For The Thickening And Emulsifying Of Personal Care Products/ Part B: The Synthesis Of A Manganese Sod Mimetic For Reactive Coatings, Mallory Lynn Mcmahon

Master's Theses

Part A

The use of nonionic associative thickeners was proposed for personal care applications. Various limitations of current rheology modifiers used in personal care were discussed. Nonionic associative polymers were examined as both thickeners and emulsifiers. The structure/property relationship for nonionic polymers and their ability to thicken and emulsify were fully examined. Results showed an increase in thickening efficiency for nonionic associative polymers with higher log(P) (partition coefficient) values. This was due to the formation of smaller aggregates and increased bridging between aggregates. The connection between oil polarity, log(P) of the associative polymer, and emulsion stability showed no relationship however; …