Polymer Science Commons^™

Peptoid Microsphere Coatings To Improve Performance In Sandwich Elisa Microarrays, Jesse L. Roberts, German R. Perez Bakovic, Shannon L. Servoss

Chemical Engineering Faculty Publications and Presentations

Enzyme-linked immunosorbent assay (ELISA) microarray performance is limited by low assay sensitivity and dynamic range. Increasing the surface area for reagent binding can help to improve performance, but standard techniques such as roughening the surface or adding a polymer coating lead to increased non-specific fluorescence and do not have reproducibly improved performance. Another approach to increase surface area is adding a microsphere coating on the surface. Poly-N-substituted glycine (peptoid) microspheres are ideal for this application due to low immunogenicity, protease-resistance, and biocompatibility. Peptoids are polymers with a backbone similar to peptides, but with the side chains appended to nitrogen rather …

Melamine Derivatives As Highly Flame Retardant Additives For Bio-Based Rigid Polyurethane Foams, Niloofar Arastehnejad

Electronic Theses & Dissertations

MELAMINE DERIVATIVES AS HIGHLY FLAME RETARDANT ADDITIVES FOR BIO-BASED RIGID POLYURETHANE FOAMS

Rigid foams, which are mainly used in construction, refrigerators, automotive industries are one of the important types of polyurethanes with great potential in insulation and energy efficiency. Unfortunately, rigid polyurethane foams are highly flammable and catch fire in a short amount of time as well as spread the flame quickly. Hence, rigid foams are considered hazardous materials due to life-threatening situations and environmental issues.

To counter that, nitrogen-based compounds as non-halogenated flame retardants are an effective, low-cost, and eco-friendly option. It has been shown that melamine derivates as …

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, …

Abiotic Sensor For Electrochemical Determination Of Chlorpyrifos In Natural Water Based On The Inhibition Of Silver Nanoparticles Oxidation, Ziad Khalifa, Moustafa Zahran, Magdy Zahran, Magdi Abdelazzem

Chemical Engineering

Chlorpyrifos, organophosphorus pesticide, is a persistent organic pollutant that may cause serious health problems. Herein, a simple, green, and sensitive electrochemical inhibition sensor based on silver nanoparticles (AgNP)-modified glassy carbon (GC) electrode was developed for the determination of chlorpyrifos in natural water for the first time. The chemical reduction technique based on natural reducing and capping agents such as dissolved organic matter (DOM), natural latex (NL) and mucilage was employed for AgNP synthesis. DOM-AgNP, NL-AgNP, and Mucilage-AgNP were immobilized on GC by sticking technique under the same voltammetric and electrolytic conditions. The oxidation behavior of the three modified electrodes was …

Cellulose-Based Polymer Electrolyte Derived From Waste Coconut Husk: Residual Lignin As A Natural Plasticiser, Chua Kai Ying

Student Works (2020-2029)

Polymer electrolyte (PE) finds many applications in the fabrication of electrochemical devices such as batteries, solar cells, supercapacitors, and electrochromic windows. The usage of cellulose from the waste of coconut husk is one alternative in using natural polymer as a green electrolyte. However, due to its high crystallinity, the usage of plasticiser is advantageous to reduce the crystallinity of cellulose. Lignin which co-exists with cellulose in the cell walls of the plants could act as a natural plasticiser in preparing a good polymer electrolyte. In this work, cellulose was isolated from waste coconut husk (Cocos nucifera), modified into water-soluble carboxymethylcellulose …

Performance Of Waterborne Intumescent Coating With Hybrid Industrial And Biofillers For Steel Protection, Khairunisa Md Nasir

Student Works (2020-2029)

In recent decades, the disastrous accidents caused by damaged steel structure in the event of the fire have reminded people of the risk of fire in industrial buildings. The use of intumescent coatings is one of the most efficient methods to protect materials against fire. The coating comprises three active elements bounded together with a binder, which then reacts together at higher temperatures. Under the action of heat, the coating expands and forms a thick porous char layer to insulate the substance, thereby prolonging the building from collapsing under severe fire conditions. Considering ecological issues, the use of waterborne resin …

Valorization Of Xylan In Agroforestry Waste Streams, Harrison Appiah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Valorization of Xylan in Agroforestry Waste Streams.

Harrison Appiah

Microwave-assisted deep eutectic solvent and gamma-valerolactone metallic chloride catalyzed conversion of xylan to furfural were investigated using a 2x3 factorial experimental design at two levels of percent microwave power, reaction time, and catalyst concentration. The levels of each factor studied were (20%, 60% microwave power, 2, 4 minutes, and 10, 20mg) respectively. The effect of three metallic chloride catalysts (LiCl, FeCl3.6H20, CuCl2) on the conversion of xylan to furfural was also investigated. The gamma-valerolactone-ferric chloride sent system exhibited the highest mean yield of furfural (56.50%). The next highest furfural yield of …

Complementary Techniques To Study The Behavior Of Water And The Effect On Diffusion And Degradation In Hydrogels, Paige Rockwell

Master’s Theses

Hydrogels exhibit biocompatibility in a range of biomedical applications, including drug delivery. This thesis aims to develop complementary techniques to measure the diffusion and degradation behaviors within an injectable, hydrolytically degradable hydrogel, formed via the covalent crosslinking of ethoxylated trimethylolpropane tri-3- mercaptopropionate (ETTMP) and poly(ethylene glycol) diacrylate (PEGDA), to determine its suitability as a drug delivery matrix. The characterization of water as either free, within the network openings of the hydrogel, or bound, tightly associated with the polymer chains, was determined using differential scanning calorimetry (DSC). The mobility of each type of water within the hydrogels was determined via nuclear …

Extraction Of Micro- And Nano-Plastic Particles From Water Using Hydrophobic Natural Deep Eutectic Solvents, Jameson R. Hunter

Theses and Dissertations--Biosystems and Agricultural Engineering

The production of plastic and the amount of waste plastic that enters the environment increases every year. Synthetic polymers will gradually break down into particles on the micro- and nano-scale. The micro- and nano-plastics pose a significant ecological harm by transporting toxic chemicals and causing inflammation and cellular damage when ingested. Two common plastics are polyethylene terephthalate (PET) and Polystyrene (PS), and a newer bioplastic polylactic acid (PLA) that has become a popular alternative. Deep eutectic solvents are a recently discovered solvent composed of a hydrogen bond donor and hydrogen bond acceptor and have been proposed as a cheaper alternative …

Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin

Master’s Theses

Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …

Helicopter Shaft Heating Parameters For Polyamide-11 Coating, Selim Kevran Ph.D, Uğur Ati̇ci̇

International Journal of Aviation, Aeronautics, and Aerospace

In this study, the heating parameters required for polyamide-11 (P11) coating of the helicopter shaft were investigated. The torsion value created by the force applied to the middle of the helicopter's shaft is measured. Heating before coating affects the torsion value of the shaft. A new heating mechanism has been designed to cover the shaft surface without changing the torsion value of the shaft. Thus, the coating surface is left inside the furnace and the torsion measurement area outside of the furnace. Taguchi method was used to determine heating parameters such as furnace type, initial temperature and heating time. The …

The Critical Role Of Dynamic Surface Tension Of Surfactants On The Impact Dynamics Of Water Droplets, Amir Esmaeili, Reza Mohammadi

Graduate Research Posters

Due to their time-dependent surface tension, the addition of surface-active agents or surfactants to water for specific applications has made controlling the impact dynamics of these droplets a complex phenomenon. This work investigates the influence of the molecular weight, concentration, and ionic nature of the surfactants as well as the substrate surface characteristics on the impact dynamics of surfactant-laden droplets using a high-speed camera at 10000 frames per second. Sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, and n-decanoyl-n-methylglucamine were used as anionic, cationic, and nonionic surfactants, respectively. We used hydrophilic glass slides, hydrophobic polytetrafluoroethylene, and superhydrophobic alkyl ketene dimer (AKD) as substrates. …

Assessing Solvent Viscosity Impact On The Physical Characteristics Of Polymeric Organogels, Cameron Hong

Honors Theses

Traditionally, studies of polymeric organogels focus on the impact of polymer factors (e.g., molecular weight and polymer concentration) on the gels’ mechanical and transport properties. Alternatively, this study seeks to assess the impact of altering solvent viscosity, while holding polymer factors constant. The gels in this study were composed of different viscosity mineral oils, styrene-ethylene-butylene-styrene (SEBS) triblock copolymer as a gelator, and oleic acid (OA) as a model drug. Samples were formulated to have 6.5, 11.2, and 15.7 wt% SEBS copolymer for each mineral oil, varying in viscosity from ≈30 mPa*s to ≈500 mPa*s. Uniaxial mechanical testing was performed to …

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 …

Determination Of Hydrogel Degradation By Passive Mechanical Testing, Avery Rosh-Gorsky

Honors Theses

This paper details a new technique to measure the mechanical properties of ETTMP PEGDA hydrogels using Hertz Contact Theory and simultaneously analyze both the model drug release and gel erosion in situ. This method involves curing a drug loaded hydrogel in a standard cuvette and placing a glass bead and phosphate buffer solution (PBS). Over time, the cross-linked network of the hydrogel breaks down, and, as a result, the ball sinks into the hydrogel. This method provides a macroscopic and inexpensive way to continuously and passively measure properties of the hydrogel as the hydrogel degrades. By plotting both the …

Doping Graphene With Substitutional Mn, Pin-Cheng Lin, Renan Villarreal, Simona Achilli, Harsh Bana, Maya N. Nair, Antonio Tejeda, Ken Verguts, Stefan De Gendt, Manuel Auge, Hans Hofsäss, Steven De Feyter, Giovanni Di Santo, Luca Petaccia, Steven Brems, Guido Fratesi, Lino M. C. Pereira

Advanced Science Research Center

We report the incorporation of substitutional Mn atoms in high-quality, epitaxial graphene on Cu(111), using ultralow-energy ion implantation. We characterize in detail the atomic structure of substitutional Mn in a single carbon vacancy and quantify its concentration. In particular, we are able to determine the position of substitutional Mn atoms with respect to the Moiré superstructure (i.e., local graphene-Cu stacking symmetry) and to the carbon sublattice; in the out-of-plane direction, substitutional Mn atoms are found to be slightly displaced toward the Cu surface, that is, effectively underneath the graphene layer. Regarding electronic properties, we show that graphene doped with substitutional …

Evaluating The Thermoresponsive Properties Of Hydroxypropyl Cellulose Solutions For Smart Window Applications, Adam Reed

Williams Honors College, Honors Research Projects

With HVAC and building energy usage expected to increase, there is a strong need for autonomous thermal management solutions. In particular, there has been a growing interest in thermoresponsive (TR) smart windows that are activated by ambient temperature changes. Most TR smart windows contain a liquid solution between two panes. The goal of this research project was to develop a self-supporting smart window by forming a gel that maintained its TR properties. A gel is less prone to spilling in the case of window breakage. It was also desired to tune the phase transition to occur at environmentally relevant conditions …

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 …

Comparison Of The Effects Of Hofmeister Ions On Transition Temperature Of Two Thermoresponsive Polymers, Ashley Knight

Williams Honors College, Honors Research Projects

It has been hypothesized that poly(vinylmethylether) (PVME) could be used to replace poly(N-isopropylacrylamide) (pNIPAAM) in various thermoresponsive applications based on literature searches and previous lab experiments. PVME is cheaper and easier to process, and would make pNIPAAM applications more cost effective. In order to verify this, experimental data was gathered on the effects of four anions from the Hofmeister series (SO₄₂-, Cl-, I-, and SCN-) on the lower critical solution temperature (LCST) of pNIPAAM and compared to previous data collected on PVME. Commercial pNIPAAM from Sigma Aldrich and Polysciences were used. The reported LCST range for pNIPAAM is …

Investigation Of Surface Charge Using Faraday Bucket Measurements: Analysis On Electrospun Polyvinylidene Fluoride Fiber Mats, Ryan Kantenwein

Williams Honors College, Honors Research Projects

Piezoelectric polymer materials such as polyvinylidene fluoride exhibit beneficial properties for use in personal protective equipment (PPE) against viral contaminants and other foreign microparticles. The electrospinning process of this material allows for surface charge to develop over a controlled surface area. Kynar 761 at 10 wt% demonstrates increased surface charge after withstanding a flow of aerated NaCl particles from a TSI 8130 instrument. Utilizing voltage measurements from a Faraday bucket, 18 wt% Kynar 761 and MG-15 exhibit surface charge when undergoing an electrospinning process; however, Kynar MG-15 displays lower charge values than that of Kynar 761. Several critical factors such …