Physical Sciences and Mathematics Commons^™

Syneresis And Rheology Mechanisms Of A Latex-Heur Associative Thickener System, Travis Bruno Smith

Master's Theses

Rheology modifiers are used in paints and coatings to ease their application to a surface, prevent sagging once applied, and allow the leveling of brushstrokes, among other benefits. The early rheology modifiers were hydroxyethyl celluloses (HECs), a type of non-associative thickener that is relatively inexpensive and synthesized from cellulose, which is abundant. However, coatings that are modified with HECs tend to suffer from poor leveling and syneresis (phase separation). HECs have since been replaced with associative thickeners (ATs). These thickeners, when properly formulated, produce stable dispersions that have improved rheological properties, yet, unlike HECs, are sensitive to changes to the …

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 …

Two-Ply Channels For Faster Wicking In Paper-Based Microfluidic Devices, Conor K. Camplisson, Kevin M. Schilling, William L. Pedrotti, Howard A. Stone, Andres W. Martinez

Chemistry and Biochemistry

This article describes the development of porous two-ply channels for paper-based microfluidic devices that wick fluids significantly faster than conventional, porous, single-ply channels. The two-ply channels were made by stacking two single-ply channels on top of each other and were fabricated entirely out of paper, wax and toner using two commercially available printers, a convection oven and a thermal laminator. The wicking in paper-based channels was studied and modeled using a modified Lucas–Washburn equation to account for the effect of evaporation, and a paper-based titration device incorporating two-ply channels was demonstrated.

Revision-Polyurethane-Graphene Nanocomposites For Corrosion-Resistant Coatings, Alexandra Rose Stevenson

Master's Theses

Corrosion is a prevalent concern throughout the world, causing significant monetary and safety concerns. Research has been dedicated to developing cost-effective solutions for corrosion that will also meet increasingly stringent environmental regulations. The recently discovered nanomaterial graphene has been proposed as a potential component in anticorrosion technology due to its strong air and water barrier properties. However, graphene is a relatively expensive, difficult to synthesize material. By incorporating it into nanocomposites, its properties can be exploited even at low concentrations. Previous work has been conducted involving the preparation of anticorrosive polystyrene-graphene nanocomposites; these materials were found to be effective long-term …

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 (MOFs) are synthetic materials made of a cage-like lattice of metal nodes connected by organic linkers. The pores between the nodes define the characteristics of the material. A MOF, MIL-101, has shown great capacity in the adsorption of carbon dioxide and methane, as well as in hydrogenation catalysis with palladium. While there has been success in synthesizing MIL-101 and other MOFs, 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. Using MIL-101 as a prototypical …

Effect Of Surface Omniphobicity On Drying By Forced Convection, Madani A. Khan, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Low energy surfaces can strongly repel both oil and water. Recently these surfaces have been fabricated on various substrates including fabric, aluminum, stainless steel and many other materials. In this experiment we explore the use of low energy surface deposition on aluminum alloy, stainless steel and silicon substrates, to enhance the drying rate of liquids removed from the surface by forced convection. We control surface roughness by substrate abrasion and by the growth of Al₂O₃ nanograss to enhance liquid repellence by use of a hierarchical texture. Liquid repellence of the substrates is measured by contact angles of …

Wet Chemical Synthesis And Characterization Of Nanomaterials For Solar Cell Applications, Krystle N. Sy, Ramprasad Gandhiraman, Jessica E. Koehne

STAR Program Research Presentations

During long term space missions, it is necessary to have a reliable source of energy. Solar cells are an easy and reliable way to convert energy from the sun to electrical energy. NASA has used solar cells manufactured on Earth as an energy source for many of its missions. In order to develop technologies that will enable high efficiency solar cells, we are synthesizing nanostructured materials. A range of nanostructured materials, such as titanium dioxide nanowires, nickel nanoparticles, copper nanoparticles, and silver nanoparticles/nanowires, are synthesized. In this work, we are reporting on the synthesis of these nanomaterials and the electron …

Composition Effects On Sheen And Spread Rate Of An Interior Flat, One Coat Latex Paint Formulation, Dana James Christensen Ii

Master's Theses

Interior flat, white latex paint is a common coating applied to walls around the world. Development of a coating with one coat hide capability is a pinnacle achievement for paint formulators as it has the potential to save consumers both time and money. One coat paints already exist on the market, but they are limited in color, coverage, and often have many disclaimers. Work done was part of a project initiated by ChemoursTM Titanium Technologies.

The goal of the project presented in this article was to create an interior flat, white latex paint that yields a spread rate of greater …

Poly(N-Isopropylacrylamide) Hydrogels For Storage And Delivery Of Reagents To Paper-Based Analytical Devices, Haydn T. Mitchell, Spencer Schultz, Philip Costanzo, Andres W. Martinez

Chemistry and Biochemistry

The thermally responsive hydrogel N,N'-methylenebisacrylamide-cross-linked poly(N-isopropylacrylamide) (PNIPAM) was developed and evaluated as a reagent storage and delivery system for microfluidic paper-based analytical devices (microPADs). PNIPAM was shown to successfully deliver multiple solutions to microPADs in specific sequences or simultaneously in laminar-flow configuration and was found to be suitable for delivering four classes of reagents to the devices: Small molecules, enzymes, antibodies and DNA. PNIPAM was also able to successfully deliver a series of standard glucose solutions to microPADs equipped to perform a colorimetric glucose assay. The results of these tests were used to produce an external calibration …

A Lego® Brewster Angle Microscope For Quantitative Monolayer Film Analysis, Nicholas Benz

Physics

In order to study single-molecule thick films and their phase behavior we built a Brewster Angle Microscope (BAM). BAM’s are inherently expensive due to their accuracy and precision. We built a fully functional BAM using Lego® Mindstorm® kits for the fraction of the price of a commercial BAM. And by utilizing the 10µm patented Lego® tolerance, comparable accuracy was attained. The BAM was mounted to a Langmuir-trough and will be used for laboratory experiments for optics and physical chemistry along with research on lung surfactant and on liquid crystals.

Effect Of Surfactant Architecture On Conformational Transitions Of Conjugated Polyelectrolytes, Greg A. Braggin

Master's Theses

Water soluble conjugated polyelectrolytes (CPEs), which fall under the category of conductive polymers, possess numerous advantages over other conductive materials for the fabrication of electronic devices. Namely, the processing of water soluble conjugated polyelectrolytes into thin film electronic devices is much less costly as compared to the processing of inorganic materials. Moreover, the handling of conjugated polyelectrolytes can be performed in a much more environmentally friendly manner than in the processing of other conjugated polymers because conjugated polyelectrolytes are water soluble, whereas other polymers will only dissolve in toxic organic solvents. The processing of electronic devices containing inorganic constituents such …

Reagent Pencils: A New Technique For Solvent-Free Deposition Of Reagents Onto Paper-Based Microfluidic Devices, Haydn T. Mitchell, Isabelle C. Noxon, Cory A. Chaplan, Samantha J. Carlton, Cheyenne H. Liu, Kirsten A. Ganaja, Nathaniel W. Martinez, Chad Immoos, Philip Costanzo, Andres W. Martinez

Chemistry and Biochemistry

Custom-made pencils containing reagents dispersed in a solid matrix were developed to enable rapid and solvent-free deposition of reagents onto membrane-based fluidic devices. The technique is as simple as drawing with the reagent pencils on a device. When aqueous samples are added to the device, the reagents dissolve from the pencil matrix and become available to react with analytes in the sample. Colorimetric glucose assays conducted on devices prepared using reagent pencils had comparable accuracy and precision to assays conducted on conventional devices prepared with reagents deposited from solution. Most importantly, sensitive reagents, such as enzymes, are stable in the …

Chloroamino Acids As A Chemical Explanation For Viking Labeled Release Soil Activity On Mars, John C. Hironimus

STAR Program Research Presentations

The Viking missions to Mars, which took place in the 1970’s, performed several experiments on martian soil in an attempt to discern if there was microbial life present. In one set of experiments, a nutrient solution containing amino acids and organic substrates tagged with carbon-14 was injected into sample cells containing martian soil, and the evolution of labeled CO2 was monitored. The evolution of labeled CO2 indicated that there was a process occurring that broke down the nutrients in solution and released CO2 as a byproduct. Cellular metabolism releases CO2, so this result supported the idea of microbial life on …

Stability Of Lidocaine Tested By Forced Degradation And Its Interactions With Serum Albumin, Lindsay Nichols

STAR Program Research Presentations

A concern for future long-term manned space expeditions is the ability to treat illnesses with appropriate pharmaceuticals. However, pharmaceuticals degrade faster in space than on Earth presumably due to an abundance of space radiation. The stability of Lidocaine was investigated because it is a common pain reliever currently used on the International Space Station. One of the most common proteins in blood is serum albumin, which acts as a carrier to distribute drugs throughout the body. It is important to know how well the drug binds to serum albumin so that the rate of distribution of Lidocaine-bound protein in blood …

Fabrication And Characterization Of A Vertically-Oriented Graphene Supercapacitor, Patrick R. Rice, Jiaxin Cui, Ahmad Badr, Michael M. Oye, Jessica E. Koehne, Meyya Meyyappan

STAR Program Research Presentations

Supercapacitors, otherwise known as electrical double layer capacitors, are a new type of electrochemical capacitor whose storage capacity is governed by two principals: the electrostatic storage achieved by a separation of charge at the interface of an electrode with an electrolytic solution, and pseudocapacitance, whose electrical energy is achieved by faradaic redox reactions. This project reports the synthesis and characterization of vertically-oriented graphene grown on copper substrates as electrodes in electric double-layer capacitor. Graphene is a two-dimensional pure carbon material with a high potential for energy storage. With vertically-grown graphene, an exponentially-larger surface area is made available, allowing an increase …