Physical Sciences and Mathematics Commons^™

Studies Of Tribotechnical Properties Of Composite Polymeric Materials Of Machine Designation, Tojiboy O. Almataev, Nozimbek T. Almataev

Scientific Bulletin. Physical and Mathematical Research

In the given work are experimentally investigated tribotechnical properties as intensity of wear process and factor of a friction composite epoxy the polymeric materials processed by ultrasound. Results of influence of a kind and the maintenance loading on tribotechnical properties composite epoxy polymeric materials depending on modes of ultrasonic processing are received. Correlation dependence of intensity of wear process and factor of a friction composite epoxy coverings from modes of ultrasonic processing is established. It is shown in the work that with an increase in the duration of ultrasonic exposure, the wear rate and the friction coefficient of the coatings …

Towards Completely Automated Glycan Synthesis, Matteo Panza

Dissertations

Carbohydrates are ubiquitous both in nature as biologically active compounds and in medicine as pharmaceuticals. Although there has been continued interest in the synthesis of carbohydrates, chemical methods require specialized knowledge and hence remain cumbersome. The need for development of rapid, efficient and operationally simple procedures has come to the fore. This dissertation focuses on the development of a fully automated platform that will enable both experts and non-specialists to perform the synthesis of glycans. Existing automated methods for the synthesis of oligosaccharides are highly sophisticated, operationally complex, and require significant user know-how. By contrast, high performance liquid chromatography (HPLC) …

Progress Toward Durable Icephobic Materials, Matthew J. Coady

Electronic Thesis and Dissertation Repository

Ice accumulation is a major engineering challenge in many fields including aerospace, power generation, transportation, and infrastructure. A variety of solutions are being researched to address this challenge. Perhaps the most promising method of combating ice accumulation is by applying coatings with low values of interfacial ice adhesion strength, τ_ice. Icephobic materials are those with ice adhesion below 100 kPa, and it has been shown that passive delamination can occur on surfaces with τ_ice below 20 kPa. While various low adhesion surfaces have been prepared, durability concerns pervade applications where surfaces experience repeated icing or freeze-thaw cycles, …

An Analysis Of The Potential Toxicological Effects Of Marine Plastics And Associated Organic And Inorganic Toxic Compounds On Six Commercially Significant Fishery Species, Nicole Marie Jackson

HCNSO Student Capstones

Marine plastics are a global issue which has garnered significant support for mitigation efforts in recent history. Research on the prevalence of plastic polymers in the marine environment has also come to the forefront of the scientific community, however studies on the toxicological impacts of their presence remains to be a little studied matter to date. In this study an intensive critical review of existing data was conducted to compile profiles (including: stability ranks, sorption capacities, organic and inorganic toxic constituent concentrations, bioaccumulations scores per constituent, biomagnification scores per constituent, and totaled threat scores out of five) for the three …

Active Polymeric Materials For 3d Shaping And Sensing, Adebola Oyefusi

Theses and Dissertations

Part I: Reprogrammable Chemical 3D Shaping for Origami, Kirigami, and Reconfigurable Molding

Origami- and kirigami-based design principles have recently received strong interest from the scientific and engineering communities because they offer fresh approaches to engineering of structural hierarchy and adaptive functions in materials, which could lead to many promising applications. Herein, we present a reprogrammable 3D chemical shaping strategy for creating a wide variety of stable complex origami and kirigami structures autonomously. This strategy relies on a reverse patterning method that encodes prescribed 3D geometric information as a spatial pattern of the unlocked phase (dispersed phase) in the locked phase …

Effects Of Disorder On Thermoelectric Properties Of Semiconducting Polymers, Zlatan Aksamija, Dhandapani Venkataraman, Connor J. Boyle, Meenakshi Upadhyaya

Zlatan Aksamija

Synthesis And Characterization Of Degradable Polymers, Christopher Collins

Mahurin Honors College Capstone Experience/Thesis Projects

A degradable polymer with proposed applications in drug delivery was synthesized and characterized. This polymer was grown from a difunctional initiator, a "core" that is able to grow two polymer chains and able to degrade in the presence of oxidizing agents such as peroxides. During the first part of this project, poly(methyl methacrylate) was synthesized via atom transfer radical polymerization using commercially-available reagents in order to develop an optimal synthesis technique. This technique was then used to synthesize the degradable polymer. After introducing hydrogen peroxide, the molecular weight of the degradable polymer decreased in two different experiments, confirming its hypothesized …

Selective Catalysis By Polymer-Supported Ruthenium Nanoparticlesand New Ligand Design For Cooperative And Bimetallic Catalysis, Seyed Hadi Nazari

Theses and Dissertations

The abstract is the summary of three different projects all centered around the generalidea of catalysis which is the general theme of research in the Michaelis laboratory. The firstproject focuses on development of a new heterogeneous catalyst for selective catalysis. In theMichaelis lab, we were interested in the potential of nanoparticle catalysts for regioselectivetransformations. We showed that polymer supported ruthenium nanoparticles performed as areliable catalyst for regioselective reduction of azide to amine. In our study of regioselectivereduction of multiple azide containing substrates, we observed that in presence of ourruthenium nanoparticle catalysts, the least sterically hindered azide group reduced to aminefunctional …

Functional Polymers Through Mechanochemistry, Stephen Schrettl, Diedrik W.R. Balkenende, Céline Calvino, Marc Karman, Ana Lavrenova, Laura N. Neumann, Yoshimitsu Sagara, Ester Verde-Sesto, Michela Di Giannantonio, Yoan C. Simon, Katharina M. Fromm, Marco Lattuada, Christoph Weder

Faculty Publications

While coupling mechanical and chemical processes is widespread in living organisms, the idea to harness the mechanically induced dissociation of weak covalent and non-covalent bonds to create artificial materials that respond to mechanical stimulation has only recently gained attention. Here we summarize our activities that mainly revolve around the exploitation of non-covalent interactions in (supramolecular) polymeric materials with the goal to translate mechanical stresses into useful, pre-defined events. Focusing on mechano- chromic polymers that alter their optical absorption or fluorescence properties, several new operating principles, mechanosensitive entities, and materials systems were developed. Such materials are expected to be useful for …

Properties And Applications Of Tetraalkylphosphonium Alkylsulfate Ionic Liquids And 3d Printed Polymerized Ionic Liquids, Mustafa Mohammed Alhussain

Murray State Theses and Dissertations

Ionic liquids (ILs) are defined as pure salts with a melting temperature below 100 °C with a subset called room-temperature ILs (RTILs) with melting temperatures at or below room temperature. The sizes of the cation and anion play a critical role in determining the properties, with smaller ions forming stronger ionic forces and packing better, raising viscosity and lowering conductivity of the IL. At the same time, intermolecular forces such as van der Waals and hydrogen bonding can play a role in IL properties as well. Our research described herein is focused on three tetraalkylphosphonium-based cations coupled with three alkylsulfate …

Designed Conducting Polymer Composites That Facilitate Long-Lived, Light-Driven Oxygen And Hydrogen Evolution From Water In A Photoelectrochemical Concentration Cell (Pecc), Mohammed Alsultan, Khalid Zainulabdeen, Pawel W. Wagner, Gerhard F. Swiegers, Holly Warren

Australian Institute for Innovative Materials - Papers

Light-driven water-splitting to generate hydrogen and oxygen from water is typically carried out in an electrochemical cell with an external voltage greater than 1.23 V applied between the electrodes. In this work, we examined the use of a concentration/chemical bias as a means of facilitating water-splitting under light illumination without the need for such an externally applied voltage. Such a concentration bias was created by employing a pH differential in the liquid electrolytes within the O2-generating anode half-cell and the H2-generating cathode half-cell. A novel, stretchable, highly ion-conductive polyacrylamide CsCl hydrogel was developed to connect the two half-cells. The key …

Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson

Williams Honors College, Honors Research Projects

Chemonic™ CCG-6 surfactant is a water-soluble poly(ethylene glycol) (PEG) conjugated alkyl glyceride emollient. This surfactant exists as a complex mixture of a glycerol cores conjugated with poly(ethylene glycol) branches (PEGylation) that were partially esterified with caprylic (C8) and capric (C10) acids. These may be esterified on one, two, or all three arms of the glyceride. The architecture of the structures in this mixture was studied using multidimensional mass spectrometry (MS). Mass spectrometry was interfaced with ultra-performance liquid chromatography (UPLC) and ion mobility (IM) separation. The mixture was separated by reversed-phase LC, oligomers of the star-branched polymer were separated according to …

The Solvation Energy Of Ions In A Stockmayer Fluid, Cameron John Shock

Dissertations, Master's Theses and Master's Reports

The solvation of ions in polar solvents has been a long studied system since the early twentieth century. A common technique to calculate the energy associated with ion solvation is the Born Solvation energy equation. This equation assumes an ion is placed in an incompressible, homogeneous dielectric, which is not necessarily representative of a real system. In this work the Stockmayer Fluid Model is used in a molecular dynamics simulation through the software LAMMPS to check the quantitative correctness of the Born equation. It is also shown how solvation energies of ions placed in polymerized and non-polymerized solvents differ. It …

Increased Utility Of Ph Sensitive Indicators As High Concentration Co2 Detectors Through The Use Of Polyelectrolyte Complexes As Stabilizing Media, Camden James Johnson

All Master's Theses

Development of plastic materials which produce visible color change when exposed to different environments has recently attracted attention for many biomedical applications.^1,2Many biomedical devices are packaged under high concentrations of carbon dioxide (CO₂) which can lower the pH of the packaging environment. This is similar to the CO₂ chemistry responsible for ocean acidification.³ Dye molecules that are sensitive to environmental changes in pH (known as pH indicators) can be encapsulated in plastics and produce a visible color change when a medical device is removed from the sterile CO₂ environment. Plastics made from large …

Multifunctional Microgels For Nanoparticle-Based Detection Methodologies, Alyson Silva

WWU Graduate School Collection

In this study, pH-responsive microgel particles, comprised of 2-vinyl pyridine (P2VP) and styrene (PS), are explored as scaffolds to assemble metallic nanoparticles (NPs) for ultrasensitive detection strategies. Microgel particles serve as size-tunable scaffolds to assemble metal (silver or gold) NPs for surface-enhanced Raman scattering (SERS) vibrational spectroscopy. The high sensitivity of SERS arises from the enormous enhancement of the Raman scattering cross sections of molecules adsorbed to roughened metal surfaces, such as metal NPs. Using a sterically stabilized latex of random copolymers of PS and P2VP (PSxP2VPy), this polymer is capable of transitioning to a microgel state through acid-base titration. …