Polymer and Organic Materials Commons^™

Investing In Maine Research Infrastructure: Sustainable Forest Bioproducts, Michael Eckardt, Stephen Shaler, Hemant P. Pendse, Adriaan R. P. Van Heiningen, Robert G. Wagner

University of Maine Office of Research Administration: Grant Reports

The University of Maine, the University of Southern Maine, several baccalaureate institutions in the state, along with other federal, state and local public, private, and non-profit institutions will collaborate to create the Forest Bioproducts Research Institute (FBRI) at the University of Maine. The vision of the FBRI is to advance understanding about the scientific underpinnings, system behavior, and policy implications for the production of forest-based bioproducts that meet societal needs for materials, chemicals, and fuels in an economically and ecologically sustainable manner.

The research plans Integrate three themes. They are (1) forest sustainability modeling of life cycle assessment, (2) integrated …

Self-Organized Nanolayers Of Organosilane Molecules, Ocelio V. Lima

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

There is a high degree of interest in organic thin films for lightweight, low power, rugged and flexible electronics. Conjugated organic molecules with polycyclic rings are being considered a major enabler of such applications. Due to a surface tension mismatch between the organic molecule with the inorganic support (mainly silicon oxides), molecular packing inside these thin films is often disordered, which suppresses the device performance. There are major efforts focused on modifying the bulk properties, for instance, maximizing orbital overlaps in the solid state, little attention was paid to receive long-range ordered thin films. A novel approach to afford conjugated …

Modeling Of Metal-Ferroelectric-Insulator-Semiconductor Structures Based On Langmuir–Blodgett Copolymer Films, Timothy J. Reece, Stephen Ducharme

Stephen Ducharme Publications

Among the ferroelectric thin films used in field-effect transistor devices; the ferroelectric copolymer of polyvinylidene fluoride PVDF –CH2–CF2–, with trifluoroethylene TrFE –CHF–CF2–, has distinct advantages, including low dielectric constant, low processing temperature, low cost, and compatibility with organic semiconductors. The operation of a metal-ferroelectric insulatorsemiconductor structure with PVDF-TrFE as the ferroelectric layer was analyzed and optimized by numerical solution of the Miller and McWhorter model. A model device consisting of 20 nm PVDF/TrFE on a 10-nm-thick high-k dielectric buffer exhibits a memory window of 5 V with an operating voltage of 15 V. The operating voltage can be reduced to …

Novel Design Of A Portosystemic Shunt Occluder, Tommy Lee Washington

Masters Theses

In some breeds of dog, specifically the Yorkshire Terrier, a genetic defect exists that causes a hepatic portosystemic shunt to form. A hepatic portosystemic shunt is a vessel that when present cause blood to bypass the liver, which is responsible for filtering waste from the digestive system and moving it out of the body. An implantable polymeric device was constructed that would slowly occlude the hepatic portosystemic shunt and force the blood to stop flowing through the bypassing vessel and flow through the vessel to the liver over 3-4 months time.

The portosystemic shunt occluder device consist of three polyoxymethylene …

Feasibility Of Ellipsometric Sensor Development For Use During Pecvd Siox Coated Polymer Product Manufacturing, Daniel Lynn Helms

Master's Theses

Polymeric materials have provided pathways to products that could not be manufactured otherwise. A new technology which merges the benefits of ceramics into these polymer products has created materials ideally suited to many different industries, like food packaging. Nano Scale Surface Systems, Inc. (NS3), a company which coats polymers with ceramic oxides like SiO2 through a process known as plasma enhanced chemical vapor deposition (PECVD), was interested in the feasibility of an in line measurement system for monitoring the deposited films on various polymer products. This project examined two different coated polymer products, polyethylene terephthalate (PET) beverage containers and biaxially …

Dielectric Nanocomposites: An Inside-Out Approach To Storing Electrostatic Energy, Stephen Ducharme

Stephen Ducharme Publications

The ability to achieve high-energy densities is the central challenge in energy storage and recovery. A promising strategy for increasing energy storage is to use highperformance dielectric materials, such as highly polarizable nanoparticles or polymers, or nanocomposites of the two. In this issue, Kim et al. use a molecular coating and clever chemistry to combine oxide nanoparticles with a polymer matrix, thereby producing an improved nanocomposite dielectric. Some advantages and challenges of using nanocomposites as improved dielectric materials are presented in this Perspective.

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for …

Chameleon Coatings: Adaptive Surfaces To Reduce Friction And Wear In Extreme Environments, Christopher Muratore, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10−10 to 10−4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment …

Structure And Properties Of Nanoclay Reinforced Polymer Films, Fibers And Nonwovens, Raghavendra Ratnakar Hegde

Doctoral Dissertations

In this research, influence of different levels of Closite Na⁺ additives on the microstructure, morphology and mechanical properties of polymer products was studied. Importance was given to understand the additive level, extent of dispersion in matrix, change in microstructure and respective property observed in the end product. Polypropylene spunbond and meltblown web samples with various levels of Closite Na⁺ additives were produced and characterized. Injection molded polypropylene nanocomposite with 1 to 15 wt% nanoclay additives were also prepared and characterized for microstructure and mechanical properties.

Crystallization kinetics studies showed significant increase in crystallization rates on nylon 6 even …

Morphological Characterization Of Irradiated Ultra High Molecular Weight Polyethylene (Uhmwpe), Christopher Phillip Stephens

Doctoral Dissertations

Effects of radiation (gamma and proton) on Ultra High Molecular Weight Polyethylene (UHMWPE) is studied for prosthetic joints and for radiation shielding for manned space missions. The first section of the dissertation will cover gamma radiation effects on UHMWPE by means of solubility, hardness, three-phase model, crystallite thickness, and molecular mobility studies. The second part will cover proton radiation effects on UHMWPE by means of solubility, three-phase crystallite model, and crystallite thickness study. The combined studies of the gamma irradiated samples shows that chain scission occurs on the surface and crosslinking in the center. The combined studies of the proton …

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Polarization Switching Kinetics Of Ferroelectric Nanomesas Of Vinylidene Fluoride-Trifluoroethylene Copolymer, R. V. Gaynutdinov, O. A. Lysova, S. G. Yudin, A. L. Tolstikhina, A. L. Kholkin, V. M. Fridkin, Stephen Ducharme

Stephen Ducharme Publications

The polarization switching kinetics of ferroelectric polymer nanomesas was investigated using piezoresponse force microscopy. The nanomesas were made by self-organization from Langmuir–Blodgett films of a 70% vinylidene fluoride and 30% trifluoroethylene copolymer. The polarization switching time exhibits an exponential dependence on reciprocal voltage that is consistent with nucleation-type switching dynamics.

Evaluating The Electrical Response Of Polyaniline To Mechanical Strain, Matthew L. Goebel

Master's Theses

This thesis focuses on the electrical output of polyaniline films subjected to uniaxial strain in hydrochloric acid solutions. Polyaniline belongs to novel class of materials known as conducting polymers. Alternating single and double bonds in the backbone of conducting polymers allow them to transmit electric charge when they are doped with negatively charged ions. Modifying the degree of doping and other electrical/chemical treatments allow conducting polymers to exhibit conducting, semi-conducting, or insulating electrical properties. Resilient mechanical properties, good processability, and low cost make conducting polymers good candidates for applications traditionally held by metals and semi-conductors.

When tensile strain is applied …

Interfacial Energy Between Carbon Nanotubes And Polymers Measured From Nanoscale Peel Tests In The Atomic Force Microscope, Mark C. Strus, Camilo I. Cano, R. Byron Pipes, Cattien V. Nguyen, Arvind Raman

Other Nanotechnology Publications

The future development of polymer composite materials with nanotubes or nanoscale fibers requires the ability to understand and improve the interfacial bonding at the nanotube-polymer matrix interface. In recent work [Strus MC, Zalamea L, Raman A, Pipes RB, Nguyen CV, Stach EA. Peeling force spectroscopy: exposing the adhesive nanomechanics of one-dimensional nanostructures. Nano Lett 2008;8(2):544–50], it has been shown that a new mode in the Atomic Force Microscope (AFM), peeling force spectroscopy, can be used to understand the adhesive mechanics of carbon nanotubes peeled from a surface. In the present work, we demonstrate how AFM peeling force spectroscopy can be …

Materials And Coatings Derived From The Polymerizable Ionic Liquid Surfactants 1-(2-Acryloyloxyundecyl)-3-Methylimidazolium Tetrafluoroborate And 1-(2-Acryloyloxyundecyl)-3-Methylimidazolium 2-Acrylamido-2-Methyl-Propylsulfonate, Hong Gu

Master's Theses and Doctoral Dissertations

Polymerizable ionic liquid surfactants were synthesized and polymerized, yielding engineered advanced polymers that can be tailored for diverse applications. First, 1-(2-acryloyloxyundecyl)-3-methylimidazolium tetrafluoroborate (IL-BF₄) was synthesized and was copolymerized with methyl methacrylate (MMA) via microemulsion polymerization. The resulting polymer gels can be transformed into porous materials by anion exchange, and the porosity of the material can be tuned through the solvent shifting. Second, an ionic liquid composed of a 1-(2-acryloyloxyundecyl)-3- methylimidazolium (IL) cation and 2-acryloamido-2-methyl-propylsulfonate (AMPS) anion was synthesized and polymerized by UV irradiation, and introductory data are illustrated for humidity sensitive preparations suitable for chemFETs, for proton conducting …

Potential Migration Of Ε-Caprolactam To Water And Wine As Affected By Transportation And Storage, Joseph C. Ianneo

Master's Theses

Abstract: Under normal sealing and storage conditions, Nylon-6, poly-caprolactam-based plastic laminates may release impurities to packaged foods and liquids and the application of heat for cooking often increases the rate of migration. Epsilon-caprolactam is one of the main contaminates found to migrate from a Nylon-6 poly-caprolactam plastic film. The objectives of this study were to determine the effects of solvent, transportation and storage time on the migration of ε-caprolactam from a Nylon-6-based lidding material into water or a white wine substitute (12% ethanol). Polypropylene plastic cups were filled, sealed, packaged, stacked and exposed to a simulated 3-day cross-country shipment. Cups …

Oligopeptide-Functionalized Graft Copolymers: Synthesis And Applications In Nucleic Acid Delivery, Rebecca Boudreaux Breitenkamp

Open Access Dissertations

Utilizing the diverse functionality of amino acids, a new class of amphiphilic graft copolymers has been synthesized, characterized, and explored for applications in biomaterials and nucleic acid delivery. This thesis research focused on the syntheses of oligopeptide-functionalized polyesters and polyolefins. Polyester functionalization was geared towards applications in biomaterials, tissue engineering, and drug delivery by incorporating sequences that promote cell-adhesion. These polyester- graft -oligopeptide materials were prepared by a 1,3-Huisgen cycloaddition reaction, "click" chemistry, of an azide-terminated oligopeptide (prepared by Fmoc-based solid phase peptide synthesis (SPPS)) and alkyne-containing polyester (synthesized by ring-opening polymerization). Following the syntheses of these materials, they were …

Polymer Confinement And Translocation, Chiu Tai Andrew Wong

Open Access Dissertations

Single polymer passage through geometrically confined regions is ubiquitous in biology. Recent technological advances have made the direct study of its dynamics possible. We studied the capture of DNA molecules by the electroosmotic flow of a nanopore induced by its surface charge under an applied electric field. We showed theoretically that the DNA molecules underwent coil-stretch transitions at a critical radius around the nanopore and the transition assisted the polymer passage through the pore. To understand how a polymer worms through a narrow channel, we investigated the translocation dynamics of a Gaussian chain between two compartments connected with a cylindrical …

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 …

Effect Of Loading And Process Conditions On The Mechanical Behavior In Sebs Thermoplastic Elastomers (Tpes), Mohit Mamodia

Open Access Dissertations

Styrenic block copolymer thermoplastic elastomers are one of the most widely used thermoplastic elastomers (TPEs) today. The focus of this research is to fundamentally understand the structure-processs-property relationships in these materials. Deformation behavior of the block copolymers with cylindrical and lamellar morphologies has been investigated in detail using unique techniques like deformation calorimetry, transmission electron microscopy (TEM), combined in-situ small angle x-ray and wide angle x-ray scattering (SAXS/WAXS). The research involves the study of structural changes that occur at different length scales along with the energetics involved upon deformation. The structural changes in the morphology of these systems on deformation …

Effect Of Salts On The Electrospinning Of Poly(Vinyl Alcohol), Jonathan J. Stanger, Nick Tucker, Mark P. Staiger, Kerry Kirwan, Stuart Coles, Daniel Jacobs, Nigel Larsen

Jonathan J Stanger

Fibres with a diameter in the nanometer range were electrospun from aqueous poly(vinyl alcohol) (PVOH). In order to improve the mass deposition rate and decrease the final fibre diameter salts (NaCl, LiCl, LiBr and LiF) were added to the solution. The aim was to increase the charge density and hence increase the electrostatic forces on the fluid. It was found that with increasing salt concentration the charge density did increase. However the mass deposition rate was found to decrease and the final fibre diameter was found to increase. The decrease in mass deposition rate is explained by considering the concept …

Effect Of Charge Density On The Taylor Cone In Electrospinning, Jonathan J. Stanger, Nick Tucker, Kerry Kirwan, Stuart Coles, Daniel Jacobs, Mark P. Staiger

Jonathan J Stanger

A detailed understanding of charge density and its origins during the electrospinning process is desirable for developing new electrospinnable polymer-solvent systems and ensuring mathematical models of the process are accurate. In this work, two different approaches were taken to alter the charge density in order to measure its effect on the Taylor cone, mass deposition rate and initial jet diameter. It was found that an increase in charge density results in a decrease in the mass deposition rate and initial jet diameter. A theory is proposed for this behaviour in that an increase in charge density leads to the tip …

The Effect Of Electrode Configuration And Substrate Material On The Mass Deposition Rate Of Electrospinning, Jonathan J. Stanger, Nick Tucker, Andrew Wallace, Nigel Larsen, Mark P. Staiger, Roger Reeves

Jonathan J Stanger

Poly(vinyl alcohol) (PVOH) was electrospun using different methods to charge the polymer solution. A positive high voltage relative to the collecting electrode significantly increased the fibre deposition rate. Electron microscopy showed that approximately half of the increase in fibre mass was due to thicker fibres being deposited. The current flowing from the grounded electrode was measured to determine the charge carried on the PVOH jet. This showed that for a positive voltage charging condition there is a much larger current and hence more charge carriers generated in the PVOH solution. As a result, more mass is ejected from the Taylor …

پاسخهای تشریحی سوالات کنکور کارشناسی ارشد رشته شیمی کاربردی-چاپ دوم-ویرایش جدید, A. Khataee, M. H. Rasoulifard, Mir Saeed Seyed Dorraji, V. Vatanpoor

Mir saeed Seyed Dorraji

No abstract provided.

Effect Of Filler Incorporation On The Fracture Toughness Properties Of Denture Base Poly(Methyl Methacrylate), Nidal Elshereksi

Nidal Elshereksi

Poly(methyl methacrylate) (PMMA) is the material of choice for denture base construction. In spite of its many good qualities, the application of PMMA as an ideal dental base material is still restricted by a few limitations. One of these is the difficulty in achieving intrinsic radiopacity in the material. The aim of the present study is to investigate the possibility of using barium titanate (BaTiO3) as a radiopacifier in PMMA. The formulation used in this study composed of PMMA 89.5 wt%, BaTiO3 10 wt% and benzoyl peroxide (BPO) 0.5 wt% as an initiator, methyl methacrylate (MMA) 90 wt% as a …

Effect Of Filler Incorporation On The Fracture Toughness Properties Of Denture Base Poly(Methyl Methacrylate), Nidal Elshereksi

Nidal Elshereksi

Poly(methyl methacrylate) (PMMA) is the material of choice for denture base construction. In spite of its many good qualities, the application of PMMA as an ideal dental base material is still restricted by a few limitations. One of these is the difficulty in achieving intrinsic radiopacity in the material. The aim of the present study is to investigate the possibility of using barium titanate (BaTiO3) as a radiopacifier in PMMA. The formulation used in this study composed of PMMA 89.5 wt%, BaTiO3 10 wt% and benzoyl peroxide (BPO) 0.5 wt% as an initiator, methyl methacrylate (MMA) 90 wt% as a …