Polymer and Organic Materials Commons^™

Elucidating The Mechanical And Transport Properties Of Lignin-Based Hydrogel Composites, Nicholas Gregorich

All Dissertations

The use of lignin in the fabrication of soft composites has become an emerging area of research in polymer science and polymer chemistry. These lignin-based materials present numerous benefits, notably, a reduction in the use of petroleum-based precursor, improved structural benefits to otherwise soft host polymers, as well as the inherent antimicrobial and antioxidant properties of lignin, making it suitable for biomaterials. Herein, we present two chemical reaction pathways of incorporating lignin that was fractionated and cleaned using the Aqueous Lignin Purification with Hot Agents (ALPHA) process into poly(vinyl alcohol) (PVA) hydrogel composites for aqueous-based separations. By leveraging the ALPHA …

Poly(Ether Imide)S: Synthesis And Properties, Rachel Price

Honors College Theses

The synthesis of strong polymers is crucial to the creation of heat-resistant, durable, and mechanically useful plastics that we use every day. Poly(ether imide)s are used in applications such as food service, aerospace, automotive, and many more. This thesis will discuss the synthesis and properties of these plastics to help express a larger understanding of these polymers.

Bottom-Up Morphological Control Of Biphasic Polymer Particles Via Heterogeneous Polymerization, Heather S.C. Hamilton

Doctoral Dissertations

Heterogeneous polymerization techniques are industrially relevant, scalable methods to synthesize polymer colloids and they have emerged in recent decades as viable methods to produce biphasic and morphologically complex polymer particles. The overarching goal of this thesis is to understand how heterogeneous polymerization techniques can be modified and optimized to control particle morphology through the systematic study of process parameters. Chapter 1 introduces relevant nomenclature and provides a brief historical perspective on the development of heterogeneous polymerization. This chapter also reviews the state-of-the-art techniques used to prepare morphologically complex polymer particles, with an emphasis on the heterogeneous polymerization processes studied in …

Study Of Nanocomposite Materials Using Molecular Dynamics, Prashik Sunil Gaikwad

Dissertations, Master's Theses and Master's Reports

There is an increase in demand for new lightweight structural materials in the aerospace industry for more efficient and affordable human space travel. Polymer matrix composites (PMCs) with reinforcement material as carbon nanotubes (CNTs) have shown exceptional increase in the mechanical properties. Flattened carbon nanotubes (flCNTs) are a primary component of many carbon nanotube (CNT) yarn and sheet materials, which are promising reinforcements for the next generation of ultra-strong composites for aerospace applications. These flCNT/polymer materials are subjected to extreme pressure and temperature during curing process. Therefore there is a need to investigate the evolution of properties during the curing …

Exploring The Effect Of Environmental Degradation On The Shape Memory Properties Of Polymers, Jorge Mario Avila

Open Access Theses & Dissertations

A key detriment of the use of polymers by our society is the negative effect this material class has had on the environment. A category of polymers known as shape memory polymers (SMP)s have the ability to return to a programmed original shape form after deformation to a temporary shape by using stimuli such as temperature, electrical pulses and even magnetism. The shape memory effect allows for some polymers to heal if they are damaged. This ability to heal means that components made from these materials can be reused rather than thrown away if they are damaged. The work presented …

Contact Dewatering Of Cellulose Nanofibers For Biopolymer Composite Applications, Alexander Collins

Electronic Theses and Dissertations

Cellulose Nanofibrils (CNFs) are promising materials for reinforcement of polymer matrices attributable to their impressive physical and mechanical properties, as well as their biodegradability. However, the utilization of these materials in composites is made challenging by the water content of CNF slurries, the tendency of CNFs to agglomerate as they dry, and incompatibility between hydrophilic CNFs and hydrophobic polymer matrices. The most commercially viable drying methods to produce small-scale dry CNFs, such as spray drying, are very energy intensive, can only dry the materials down to micron-scale agglomerates, and do not preserve fibrillar aspect ratios. “Contact dewatering,” or the removal …

Text Summarization Towards Scientific Information Extraction, Abigail Keller

College of Computing and Digital Media Dissertations

Despite the exponential growth in scientific textual content, research publications are still the primary means for disseminating vital discoveries to experts within their respective fields. These texts are predominantly written for human consumption resulting in two primary challenges; experts cannot efficiently remain well-informed to leverage the latest discoveries, and applications that rely on valuable insights buried in these texts cannot effectively build upon published results. As a result, scientific progress stalls. Automatic Text Summarization (ATS) and Information Extraction (IE) are two essential fields that address this problem. While the two research topics are often studied independently, this work proposes to …

Monitoring Of State Transitions In Extreme Environment Application Materials Using Fiber Bragg Grating Sensors, Sabuj Khadka

Electronic Theses and Dissertations

By embedding both a single fiber Bragg grating (FBG) sensor and a thermocouple (TC) during the manufacturing for extreme environment applications of certain classes of materials such as metals and polymers, a novel in-situ approach was developed to precisely monitor their entire manufacturing processes. This novel monitoring technique was able to identify many characteristic points during the curing of room and high-temperature epoxies and the solidification processes of metal alloys composed of tin and bismuth which were selected in this research purely for verification purposes. Some of the characteristic points identified for the epoxies were: (i) the gel point, (ii) …

Utilizing The Oxygen-Barrier Properties Of Poly(Isobutylene) To Enhance Photon Upconversion In Thermoplastic Elastomers, Haley Carroll

Honors Theses

Upconversion (UC) is the conversion of low energy light to higher energy light. It is utilized for a broad range of applications such as solar energy harvesting, microscopy of cellular biology, and cancer therapy. Specifically, triplet-triplet annihilation UC (TTA-UC) involves two dye species, a sensitizer and an annihilator, which are capable of upconverting noncoherent light such as sunlight. Traditionally, TTA-UC is achieved in solution, rubbers, or glasses, however, this work probes the capabilities of a thermoplastic elastomer (TPE) matrix to examine the effect of phase-separated morphology on the energy transfers necessary for TTA-UC. The system herein consists of poly(styrene-isobutylene-styrene) (SIBstar) …

Characterization, Immobilization, And Polymer Related Applications Of Watermelon Seed Powder, A Practical Source Of Urease Enzyme, Anthony Quan Quoc Mai

LSU Doctoral Dissertations

Urease enzyme was crystallized almost a century ago, and to this day its intrinsic stability is not ideal for everyday applications. This work introduces a new process by which a naturally encapsulated material, watermelon seed powder (WMSP), is characterized for its stability and activity. WMSP enzymatic activity has been measured for over a year at various storage conditions—exposed to ambient atmosphere for a year, WMSP retained above 90% activity. In aqueous conditions, the enzyme maintained above 60% activity after two months; with the addition of a preservative that number stays at about 90%. There is a pH shift of the …

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 …

Hydrolytic Degradation Study Of Polyphosphazene-Plga Blends, Riley Blumenfield

Honors Scholar Theses

The synthesis and in vitro degradation analysis of thin films of poly[(glycineethylglycinato)₇₅(phenylphenoxy)₂₅phosphazene]
(PNGEG₇₅PhPh₂₅) and poly[(ethylphenylalanato)₂₅(glycine-
ethylglycinato)₇₅phosphazene] (PNEPA₂₅GEG₇₅) blended with poly(lactic-co-glycolic acid) (PLGA) was conducted to determine the blends’ potential for use as scaffolding materials for tissue regeneration applications. The samples were synthesized with glycylglycine ethyl ester (GEG) acting as the primary substituent side group, with cosubstitution by phenylphenol (PhPh) and phenylalanine ethyl ester (EPA) to make the final product [1]. Blends of 25% polyphosphazene, 75% PLGA and 50% polyphosphazene, 50% PLGA were …

A Simple And Robust Approach To Reducing Contact Resistance In Organic Transistors, Zachary A. Lamport, Katrina J. Barth, Hyunsu Lee, Eliot Gann, Sebastian Engmann, Hu Chen, Martin Guthold, Iain Mcculloch, John E. Anthony, Lee J. Richter, Dean M. Delongchamp, Oana D. Jurchescu

Chemistry Faculty Publications

Efficient injection of charge carriers from the contacts into the semiconductor layer is crucial for achieving high-performance organic devices. The potential drop necessary to accomplish this process yields a resistance associated with the contacts, namely the contact resistance. A large contact resistance can limit the operation of devices and even lead to inaccuracies in the extraction of the device parameters. Here, we demonstrate a simple and efficient strategy for reducing the contact resistance in organic thin-film transistors by more than an order of magnitude by creating high work function domains at the surface of the injecting electrodes to promote channels …

Gnygrens18.Pdf, Garrett Nygren

Garrett Nygren

Light Intensity-Induced Phase Transitions In Graphene Oxide Doped Polyvinylidene Fluoride, Yuri A. Barnakov, Omari Paul, Akinwunmi Joaquim, April Falconer, Richard Mu, Vadim Y. Barnakov, Dmitriy Dikin, Vitalii P. Petranovskii, Andre Zavalin, Akira Ueda, Frances Williams

Electrical and Computer Engineering Faculty Research

The coupling of light with low-frequency functionalities of dielectrics and liquid crystals and an ability to turn “on” and “off” the pyro-, piezo-, or ferro- electric properties of materials on demand by optical means leads to fascinating science and device applications. Moreover, to achieve all-optical control in nano-circuits, the coupling of the light with mechanical degrees of freedom is highly desirable and has been elusive until recently. In this work, we report on the light intensity-induced structural phase transitions in graphene oxide doped piezoelectric polyvinylidene fluoride (PVDF) film observed by micro-Raman spectroscopy. Increasing the laser power results in a steady …

New Methods For Understanding And Controlling The Self-Assembly Of Reacting Systems Using Coarse-Grained Molecular Dynamics, Stephen Thomas

Boise State University Theses and Dissertations

This research aims at developing new computational methods to understand the molecular self-assembly of reacting systems whose complex structures depend on the thermodynamics of mixing, reaction kinetics, and diffusion kinetics. The specific reacting system examined in this study is epoxy, cured with linear chain thermoplastic tougheners whose complex microstructure is known from experiments to affect mechanical properties and to be sensitive to processing conditions. Mesoscale simulation techniques have helped to bridge the length and time scales needed to predict the microstructures of cured epoxies, but the prohibitive computational cost of simulating experimentally relevant system sizes has limited their impact. In …

Imaging The Three-Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri-Spot Point Spread Function, Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Fluorescence photons emitted by single molecules contain rich information regarding their rotational motions, but adapting single-molecule localization microscopy (SMLM) to measure their orientations and rotational mobilities with high precision remains a challenge. Inspired by dipole radiation patterns, we design and implement a Tri-spot point spread function (PSF) that simultaneously measures the three-dimensional orientation and the rotational mobility of dipole-like emitters across a large field of view. We show that the orientation measurements done using the Tri-spot PSF are sufficiently accurate to correct the anisotropy-based localization bias, from 30 nm to 7 nm, in SMLM. We further characterize the emission anisotropy …

Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, Leila Malekmotiei

LSU Doctoral Dissertations

The first aim of this work is developing a procedure for experimental and analytical characterization of nano-scale microstructures which mediate large scale deformation in amorphous polymers. Glassy polymers are extensively used as high impact resistant, low density, and clear materials in industries. Nevertheless, their response under severe loading conditions is yet to be appropriately unraveled. Due to the lack of long-range order in the microstructures of glassy solids, their plastic deformation is different from that in crystalline solids. Shear Transformation Zones (STZs) are believed to be the main plasticity carriers in amorphous solids and defined as the localized atomic or …

The Processing And Polarization Reversal Dynamics Of Thin Film Poly(Vinylidene) Fluoride, Noel Mayur Dawson

Nanoscience and Microsystems ETDs

Many ferroelectric devices benefit from the ability to deposit thin ferroelectric layers. Poly(vinylidene) fluoride (PVDF) is the prototypical ferroelectric polymer, but processing of thin film ferroelectric PVDF remains a challenge due to the formation of large voids in the film during traditional thin film processing. The research described in this dissertation starts by investigating the origin of these voids. The cause of these voids is found to be caused by vapor induced phase separation (VIPS). Guided by the thermodynamics of VIPS, a process is then designed to produce void-free ferroelectric PVDF thin films on polar and non-polar substrates. The films …

Structure-Force Field Generator For Molecular Dynamics Simulations, Carlos M. Patiño, Lorena Alzate, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Atomistic and molecular simulations have become an important research field due to the progress made in computer performance and the necessity of new and improved materials. Despite this, first principle simulations of large molecules are still not possible because the high computational time and resources required. Other methods, such as molecular dynamics, allow the simplification of calculations by defining energy terms to describe multiple atom interactions without compromising accuracy significantly. A group of these energy terms is called a force field, and each force field has its own descriptions and parameters. The objective of this project was to develop a …

Electro-Optic Contact Poling Of Polymer Waveguide Devices And Thin Films, Michael Briseno

Dissertations, Master's Theses and Master's Reports

Optical communication is a high speed, large bandwidth, low cost, and power efficient method of transferring data over short-haul and long-haul channels. Optical communication requires devices (optical modulators) that utilize the originating electrical signal information to modulate a corresponding optical signal. State of the art optical modulators can be used for communicating signals at modulation frequencies up to 100 GHz and faster. Polymer modulators are used over lithium niobate due to the large potential electro-optic coefficient, which has been shown to be as high as 226 pm/V in thin films.

Organic electro-optic polymers used in thin film modulators contain nonlinear …

Engineering Polymers Through Impact Modification And Superheated Liquid Processing, Gregory Connor Evans

Doctoral Dissertations

A new approach to toughen anionically polymerized polyamide 6 (aPA6) was applied using reaction induced phase separation (RIPS). This method solved issues with particle dispersion, mixture viscosity, and additive concentration common with conventional rubber toughening thereby making it an ideal candidate for fiber reinforced aPA6 reaction injection molding (RIM). Octamethylcyclotetrasiloxane (D₄) was used as a functional additive that undergoes RIPS during aPA6 polymerization and polymerizes to polydimethylsiloxane (PDMS). Controlled phase separation, modulus retention, and increased crystallinity were achieved at low additive concentrations. Optimal properties were achieved with 2 wt% D₄. Fracture energy was measured at high …

Material Selection And Testing For A Radiation Therapy Catheter, Philip James Wadlow

Master's Theses

Three different polymers (a high-density polymer and two other polymers) were tested for use as an x-ray catheter in a radiation therapy application. This report describes the testing of these three materials to determine which material is the best option for a long use catheter. Tests included tensile, simulated clinical life, and other tests. Some testing was performed using nitrogen and an industrial coolant. Testing revealed significant non-circularities for some catheters. With increasing pressure, the circularity of these catheters increased. The tensile tests were performed on samples with varying doses of radiation. Tensile testing showed significant decreases in ultimate tensile …

Ultra-Thin Polymer Films And Hierarchical Composites: Processing And Mechanical Properties, Yujie Liu

Doctoral Dissertations

Properties and fabrications of ultra-thin polymer films and hierarchical composites are of great interest in packaging, electronics, separations, and other manufacturing fields. However, due to the inherently fragile nature of ultra-thin polymer films, measuring their properties has proven difficult. Additionally, variables controlling thin polymer patterns (e.g. substrate wetting property) and composites (weight percent of particulates in matrix) formation have not been fundamentally well understood. Within this spectrum, fundamental understanding of formation mechanisms of these patterns and composites are needed. Additionally, a new characterization technique is required to be able to measure the mechanical properties of fabricated composites and thin films. …

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 …

Tailoring Nanoparticles And Polymers For Cooperative Interfacial And Surface Interactions, Irem Bolukbasi

Doctoral Dissertations

This thesis describes the synthesis of chemically functionalized nanoparticles and their behavior at interfaces and in conjunction with polymers. Solid-liquid, liquid-liquid, and air-liquid interfaces are useful platforms for studying nanoparticle assembly, especially when nanoparticles are functionalized to enable their segregation to the interface. At the liquid-liquid interface, double emulsions droplets, both oil-in-water-in-oil and water-in-oil-in-water, stabilized with nanoparticles were prepared. This involved gold nanoparticles stabilizing oil-in-water droplets, and CdSe quantum dots stabilizing water-in-oil droplets. These double emulsion droplets were by simply shaking to give polydisperse droplets, or in a well-defined fashion by microcapillary flow focusing. When nanoparticle-stabilized double emulsions were sized …

Aging Of A Polymer Core Composite Conductor Under Combined Ozone And Temperature Conditions, James M. Middleton

Electronic Theses and Dissertations

The next generation High Temperature Low Sag Polymer Core Composite Conductors (HTLS PCCC) can experience harsh in-service environments including high temperature and highly concentrated ozone. In some extreme cases, it is possible that the conductors will experience temperatures of up to 180°C and ozone concentrations as high as 1% (10,000 ppm). Therefore, the primary goal of this research was to determine the most damaging aging conditions which could negatively affect the in-service life of the conductors. This included characterizing the aging in ozone and at high temperature of the HTLS PCCC hybrid composite rods and neat resin. It was found …

Wireless Temperature Monitoring System For The Cal Poly Pilot Winery, Caitlin Devaney

Materials Engineering

This project, with an interdisciplinary group of two computer engineers and one materials engineer, was seeking to implement an automated temperature monitoring system which is affordable and easy to use, as well as adaptable to any arrangement and scale of a winemaker’s fermentation setup. My goal, as the materials engineer, was to design, fabricate, and test the enclosure, for the wireless nodes that are placed in the wine fermentation tanks, and the materials used for the node enclosure. For the enclosure of the system, materials selection was completed using CES software using limitations of only polymer materials which absorb less …

A Least Squares Closure Approximation For Liquid Crystalline Polymers, Traci Ann Sievenpiper

Mathematics & Statistics Theses & Dissertations

An introduction to existing closure schemes for the Doi-Hess kinetic theory of liquid crystalline polymers is provided. A new closure scheme is devised based on a least squares fit of a linear combination of the Doi, Tsuji-Rey, Hinch-Leal I, and Hinch-Leal II closure schemes. The orientation tensor and rate-of-strain tensor are fit separately using data generated from the kinetic solution of the Smoluchowski equation. The known behavior of the kinetic solution and existing closure schemes at equilibrium is compared with that of the new closure scheme. The performance of the proposed closure scheme in simple shear flow for a variety …

Synthesis And Interfacial Behavior Of Functional Amphiphilic Graft Copolymers Prepared By Ring-Opening Metathesis Polymerization, Kurt E. Breitenkamp

Open Access Dissertations

This thesis describes the synthesis and application of a new series of amphiphilic graft copolymers with a hydrophobic polyolefin backbone and pendent hydrophilic poly(ethylene glycol) (PEG) grafts. These copolymers are synthesized by ruthenium benzylidene-catalyzed ring-opening metathesis polymerization (ROMP) of PEG-functionalized cyclic olefin macromonomers to afford polycyclooctene- graft -PEG (PCOE- g -PEG) copolymers with a number of tunable features, such as PEG graft density and length, crystallinity, and amphiphilicity. Macromonomers of this type were prepared first by coupling chemistry using commercially available PEG monomethyl ether derivatives and a carboxylic acid-functionalized cycloctene. In a second approach, macromonomers possessing a variety of PEG …