Electrophilic Cleavage And Functionalization Of Polyisobutylenes Bearing Unsaturations In The Backbone And Synthesis Of Polymers For This Process, 2017 The University of Southern Mississippi
Electrophilic Cleavage And Functionalization Of Polyisobutylenes Bearing Unsaturations In The Backbone And Synthesis Of Polymers For This Process, Christopher Campbell
In the first project, we demonstrated a new reaction, which is a subset of the Friedel‑Crafts alkylation reaction, in which the alkylating carbocation undergoes a cleavage reaction prior to reaction with the aromatic substrate. This reaction was discovered by the observation that when a PIB containing a large amount of coupled fraction was subjected to a mixture of protic and Lewis acids (HCl/TiCl4) in the presence of an alkoxybenzene compound, the coupled fraction was quantitatively converted to its constituent monofunctional chains, which became functionalized by the alkoxybenzene.
In the second project, a commercial polymer, poly(isobutylene-co ...
Synthesis And Electrochemical Characterization Of Pani/Ni And Pani/Au/Ni Composites, 2017 University of Nevada, Las Vegas
Synthesis And Electrochemical Characterization Of Pani/Ni And Pani/Au/Ni Composites, Morgan Emily Pacini
UNLV Theses, Dissertations, Professional Papers, and Capstones
The purpose of this research is to show that the electrochemically controlled formation of monometallic and bimetallic catalysts in polyaniline (PANI) can directly influence the efficiency and reproducibility of the catalytic oxidation of methanol. PANI is a conductive polymer that provides a three-dimensional template for the metallic catalysts deposition at nitrogen sites. The controlled deposition of metallic species can be achieved using the normal oxidation/reduction cycles of PANI. The deposition of metallic species relies on anion precursors that are electrostatically bound by the polymer during the oxidation cycle. The precursor is reduced directly at the nitrogen sites in the ...
Development Of High-Performing Polydimethylsiloxane-Based Membranes For Carbon Dioxide Separation, 2017 University of Tennessee, Knoxville
Development Of High-Performing Polydimethylsiloxane-Based Membranes For Carbon Dioxide Separation, Tao Hong
Membrane separation is highlighted as one of the most promising approaches to mitigate the excessive CO2 [carbon dioxide] emission, due to its significant reduction of energy cost compared with many conventional separation techniques. Unfortunately, the separation performance of current membranes does not meet the practical CO2/N2 [nitrogen] separation requirements. And due to the huge volume of industrial flue gas, membranes with exceptionally high permeability are needed for practical reasons.
Currently, the separation mechanism of most polymeric membranes is based on size-sieving. However, this method is not sufficient for CO2/N2 separations due to the ...
Barrier Properties Of Polymer Nanocomposites With Graphene Oxide And Its Derivatives: Mechanism And Applications In Anticorrosive Coatings, 2017 University of Southern Mississippi
Barrier Properties Of Polymer Nanocomposites With Graphene Oxide And Its Derivatives: Mechanism And Applications In Anticorrosive Coatings, Yidan Guan
Metallic devices made from steel or aluminum are subjected to deterioration by environmental contaminants over time. As one of the corrosion control methods, organic coatings show many advantages due to their low cost, versatility, decoration aesthetics and effective protections. Corrosion protection theories and failure modes of organic coatings are still not fully understood due to complicated interactions in the coating-metal-environment system, however, it is widely agreed that the barrier nature of polymeric materials towards aggressive species, such as oxygen, water, electrolyte, plays a key role. Improved barrier property of polymer nanocomposites (PNCs) with two-dimensional (2D) carbon filler, graphene and graphene ...
Development And Implementation Of Redox-Active Olefin Polymerization Catalysts, 2017 University of Tennessee, Knoxville
Development And Implementation Of Redox-Active Olefin Polymerization Catalysts, William Curtis Anderson Jr.
Investigating homogeneous polymerization catalysts has been a thriving area of chemistry in the academic realm for several decades now, and has helped drive the development of a range of materials, from designer plastics to cheap commodity polymers. Billions of pounds of these materials are produced every year, which ensures that continuing research in the area will be necessary to improve current processes and enable more economic use of our resources.
This dissertation showcases the Long group’s research in homogeneous polymerization catalysis and our impact on the field thus far. We show that intelligent design of redox-active catalysts allows for ...
The Effect Of Plant Source On Lignin-Based Polyurethanes And The Interdiffusion Dynamics Of Semi-Rigid Polymers, 2017 University of Tennessee, Knoxville
The Effect Of Plant Source On Lignin-Based Polyurethanes And The Interdiffusion Dynamics Of Semi-Rigid Polymers, Jason Michael Lang
The work reported in this thesis increases our understanding of the effect of lignin plant source on the mechanical and morphological properties of lignin-based polyurethanes and the interdiffusion of glassy/liquid bilayer thin films. The interdiffusion of glassy/liquid polymer pairs has received much less attention than liquid/liquid bilayers, leading to conflicting results and unresolved discrepancies. Therefore, the reported study of interdiffusion between polysulfone glassy/liquid polymer layers provides insight into the dynamics of these systems.
This thesis first reports the correlation between the mechanical properties of lignin-based polyurethanes and the lignin plant source. Lignin is a molecule that ...
Responsive Nanogel Probe For Ratiometric Fluorescent Sensing Of Ph And Strain In Hydrogels, 2017 University of Manchester
Responsive Nanogel Probe For Ratiometric Fluorescent Sensing Of Ph And Strain In Hydrogels, Mingning Zhu, Dongdong Lu, Shanglin Wu, Qing Lian, Wenkai Wang, Amir H. Milani, Zhengxing Cui, Nam T. Nguyen, Mu Chen, L. Andrew Lyon, Daman J. Adlam, Anthony J. Freemont, Judith A. Hoyland, Brian R. Saunders
Engineering Faculty Articles and Research
In this study a new pH-responsive nanogel probe containing a complementary nonradiative resonance energy transfer (NRET) fluorophore pair is investigated and its ability to act as a versatile probe of network-related changes in three hydrogels demonstrated. Fluorescent sensing using NRET is a powerful method for studying relationships between Angstrom length-scale structure and macroscopic properties of soft matter. Unfortunately, inclusion of NRET fluorophores into such materials requires material-specific chemistry. Here, low concentrations of preformed nanogel probes were included into hydrogel hosts. Ratiometric photoluminescence (PL) data for the gels labeled with the nanogel probes enabled pH-triggered swelling and deswelling to be studied ...
Reintroducing Explicit Solvent To A Solvent-Free Coarse-Grained Model, 2017 Iowa State University
Reintroducing Explicit Solvent To A Solvent-Free Coarse-Grained Model, Seung Ha Kim, Monica H. Lamm
Monica H. Lamm
A unique coarse-grained modeling scheme that combines a systematic, solvent-free multiscale coarse-graining algorithm for a complex macromolecule with an existing coarse-grained solvent model is proposed. We show that this procedure efficiently and reliably describes the interactions for complex macromolecules, using the specific example of dendrimers binding phenanthrenes in water. The experimentally measured binding capacity is predicted by the unique coarse-grained modeling approach; the conditions for this simulation are beyond what could be reasonably simulated with an all-atom molecular dynamics simulation.
Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, 2017 Amir Chamaani
Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani
FIU Electronic Theses and Dissertations
The transition from fossil fuels to renewable resources has created more demand for energy storage devices. Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical energy densities. They, however, are still in their infancy and several fundamental challenges remain to be addressed. Advanced analytical techniques have revealed that all components of a Li-O2 battery undergo undesirable degradation during discharge/charge cycling, contributing to reduced cyclability. Despite many attempts to minimize the anode and cathode degradation, the electrolyte remains as the leading cause for rapid capacity fading and poor cyclability in Li-O2 batteries. In this ...
Phase Behavior Of Binary And Polydisperse Suspensions Of Compressible Microgels Controlled By Selective Particle Deswelling, A. Scotti, U. Gasser, E. S. Herman, Jun Han, A. Menzel, L. Andrew Lyon, A. Fernandez-Nieves
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We investigate the phase behavior of suspensions of poly(N-isopropylacrylamide) (pNIPAM) microgels with either bimodal or polydisperse size distribution. We observe a shift of the fluid-crystal transition to higher concentrations depending on the polydispersity or the fraction of large particles in suspension. Crystallization is observed up to polydispersities as high as 18.5%, and up to a number fraction of large particles of 29% in bidisperse suspensions. The crystal structure is random hexagonal close-packed as in monodisperse pNIPAM microgel suspensions.We explain our experimental results by considering the effect of bound counterions. Above a critical particle concentration, these cause deswelling ...
Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, 2017 Murray State University
Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, Sunny Kwan, Sunny Kwan
Honors College Theses
Polymers made from thiol-ene reactions are versatile – they can be made from a variety of easily obtainable starting materials and show promise as biomedical materials, hydrogels, resins, and nanoparticles. Ionic liquids (ILs) have uniquely exploitable physical and chemical properties, and polymerization of ILs into polymeric ionic liquids (PILs) enhances or changes these properties, allowing an even wider range of potential applications of ILs in technologies such as fuel cells, solar cells, and even artificial muscles. Bisimidazolium thiol-ene PIL (BITPIL) networks are polymers with each monomer consisting of two moles of bis-imidazolium bridged together with either an alkyl or poly(ethylene ...
Poly(Ethyl Glyoxylate) Solid-Core Particles For Drug Delivery, 2017 The University of Western Ontario
Poly(Ethyl Glyoxylate) Solid-Core Particles For Drug Delivery, Michael Thomas Gambles
Electronic Thesis and Dissertation Repository
The ability to trigger the degradation of polymeric nanoparticles (NPs) by a specific stimulus can provide a method of improved drug targeting and selective release capabilities in vivo. The challenge for most polymeric drug delivery systems remains the necessity for many stimuli events to trigger the release of cargo. Polymeric nanotechnology containing “self-immolative polymers” looks to alleviate the reliance on high concentrations of stimuli by undergoing complete end-to-end depolymerization via a single stimulus-mediated reaction of an end-cap. Herein, NPs were developed using poly(ethyl glyoxylate) (PEtG) blended with poly(d,l-lactic acid) (PLA) to encapsulate a hydrophobic cargo to be ...
Synthesis, Characterization, And Reactive Modification Of 2-Vinyl-4,4-Dimethyl Azlactone Polymers, 2017 University of Tennessee, Knoxville
Synthesis, Characterization, And Reactive Modification Of 2-Vinyl-4,4-Dimethyl Azlactone Polymers, Bethany Michelle Aden
Polymeric materials possessing specific functionality have been designed for use in applications such as membranes, biocompatible coatings, lubricants, and tissue engineering. Because the chemical nature of the repeat units set the properties offered by the polymer, the ability to reactively modify polymer chains to integrate specific functionality expands the range of potential applications. Thus, reactive modification of polymer thin films provides a useful route to confer new properties to the underlying material, with the range, strength and type of interaction across the interface dictated by the display of functional groups decorating the surface. To address the links between design, in ...
Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, 2017 University of Southern Mississippi
Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi
Over the past two decades, the increasing concern about the negative environmental impacts of synthetic materials has led to rising interests in utilizing renewable natural resources to develop polymer materials with comparable properties and performance to their synthetic counterparts. One of the major fields of interest is polymer composites where the replacement of synthetic fibers with bio renewable natural fibers is of great potential. However, the processing difficulties, in terms of fiber dispersion and thermal stability have limited the application of cellulosic fibers to polymers with low processing temperatures which are mostly hydrophobic polymers. As a result, the true reinforcing ...
Multi-Scale Assembly Methodologies Of Poly(3-Hexylthiophene) Derivative Systems For Enhanced Optoelectronic Anisotropy, 2017 California Polytechnic State University - San Luis Obispo
Multi-Scale Assembly Methodologies Of Poly(3-Hexylthiophene) Derivative Systems For Enhanced Optoelectronic Anisotropy, David William Bilger
Master's Theses and Project Reports
Conjugated polymers represent a class of semi-conducting materials with numerous applications in optoelectronic devices, including organic light-emitting diodes, field-effect transistors, and photovoltaics. Because of the numerous advantages of macromolecular systems, including solution processing and mechanical flexibility, conjugated polymers have become a burgeoning field of research with the hopes of producing cost-effective solution-based electronics. Importantly, optoelectronic device performance is heavily influenced by conjugated polymer backbone orientation and overall thin film morphology. As such, the processing conditions of these systems are important to the construction of high- performance optoelectronics. Polythiophenes are model conjugated polymers that have been studied extensively in halogenated organic ...
Oligo(Ethylene Glycol)-Sidechain Microgels Prepared In Absence Of Cross-Linking Agent: Polymerization, Characterization And Variation Of Particle Deformability, Nicole Welsch, L. Andrew Lyon
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We present a systematic study of self-cross-linked microgels formed by precipitation polymerization of oligo ethylene glycol methacrylates. The cross-linking density of these microgels and, thus, the network flexibility can be easily tuned through the modulation of the reaction temperature during polymerization. Microgels prepared in absence of any difunctional monomer, i.e. cross-linker, show enhanced deformability and particle spreading on solid surfaces as compared to microgels cross-linked with varying amounts of poly(ethylene glycol diacrylate) (PEG-DA) in addition to self-crosslinking. Particles prepared at low reaction temperatures exhibit the highest degree of spreading due to the lightly cross-linked and flexible polymer network ...
Photopolymerization Synthesis Of Magnetic Nanoparticle Embedded Nanogels For Targeted Biotherapeutic Delivery, 2017 University of South Florida
Photopolymerization Synthesis Of Magnetic Nanoparticle Embedded Nanogels For Targeted Biotherapeutic Delivery, Daniel Jonwal Denmark
Graduate Theses and Dissertations
Conventional therapeutic techniques treat the patient by delivering a biotherapeutic to the entire body rather than the target tissue. In the case of chemotherapy, the biotherapeutic is a drug that kills healthy and diseased cells indiscriminately which can lead to undesirable side effects. With targeted delivery, biotherapeutics can be delivered directly to the diseased tissue significantly reducing exposure to otherwise healthy tissue. Typical composite delivery devices are minimally composed of a stimuli responsive polymer, such as poly(N-isopropylacrylamide), allowing for triggered release when heated beyond approximately 32 °C, and magnetic nanoparticles which enable targeting as well as provide a mechanism ...
Molecular And Polymeric Materials Based On Asymmetrically Substituted Bf2 3-Cyanoformazanates, 2017 The University of Western Ontario
Molecular And Polymeric Materials Based On Asymmetrically Substituted Bf2 3-Cyanoformazanates, Samantha Novoa
Electronic Thesis and Dissertation Repository
This thesis outlines the synthesis and characterization of asymmetric and symmetric 3-cyanoformazanate BF2 complexes and their incorporation into polymers. CuAAC chemistry was used to synthesize two additional asymmetric BF2 complexes and a side product that was identified as a symmetric dimer. Spectroscopic and electrochemical properties of these compounds are described.
Incorporation of an asymmetric 3-cyanoformazante BF2 complex into polymers was done by ROMP. This reaction was used to make homo, block, and random copolymers, where the comonomer was an organic norbornene derivative. Spectroscopic studies of these polymers revealed that, as the mole fraction of BF2 (ƒ ...
Fabrication And Applications Of Multifunctional Superhydrophobic Surfaces Based On Surface Chemistry And Morphology, 2017 The Graduate Center, City University of New York
Fabrication And Applications Of Multifunctional Superhydrophobic Surfaces Based On Surface Chemistry And Morphology, Yang Liu
All Dissertations, Theses, and Capstone Projects
Superhydrophobic surfaces are gaining great interests in both fundamental researches and technological applications, because of their unique non-wetting and self-cleaning properties. By mimicking the hierarchical surface structure of the natural superhydrophobic surface, i.e. lotus leaf, numerous artificial surperhydrophobic surfaces were developed. However, the challenge is how to fabricate superhydrophobic surfaces by a scalable and economical method. To address this challenge, our group has developed methodologies that enable the fabrication of superhydrophobic surfaces in inexpensive and potentially scalable ways, such as lamination and 3-D printing. To expand on applications, we also combined other desired functionalities into the superhydrophobic surfaces.
A Comparison Study Of Two Synthesis Methods For Polymer Of Intrinsic Microporosity 1 (Pim-1), 2017 California Polytechnic State University, San Luis Obispo
A Comparison Study Of Two Synthesis Methods For Polymer Of Intrinsic Microporosity 1 (Pim-1), Conor S. Perry
Polymers of Intrinsic Microporosity (PIMs) are an emerging polymeric material class for molecular sieving applications. This study focuses on PIM-1, an alternating copolymer of 5,5’,6,6’-tetrahydroxy-3,3’,3,3’-tetramethyl-1,1’-spirobisindane and tetrafluoroterephthalonitrile synthesized via nucleophilic aromatic substitution. PIM-1 been widely studied as a gas separating material and filtering membrane, but in this case, it is studied as a battery separator material. PIM-1’s microporous (pore diameters less than 2 nm) structure allows smaller favorable ions to transport while preventing larger ions and compounds from transporting. Two synthesis methods, round bottom flask synthesis and ball mill ...