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Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee 2018 Michigan Technological University

Recent Approaches In Designing Bioadhesive Materials Inspired By Mussel Adhesive Protein, Pegah Kord Forooshani, Bruce P. Lee

Bruce Lee

Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhe-sion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized poly- mers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface ...


Computational Investigation Of The Ring-Opening Homo- And Co-Polymerizations Of Lactide And Ε-Caprolactone, Diego Garcia, Benjamin Wilson, Joe Fritsch 2018 Pepperdine University

Computational Investigation Of The Ring-Opening Homo- And Co-Polymerizations Of Lactide And Ε-Caprolactone, Diego Garcia, Benjamin Wilson, Joe Fritsch

Seaver College Research And Scholarly Achievement Symposium

The mechanism for the ring-opening polymerization of lactide and ε-caprolactone is presented here with an aluminum-centered catalyst featuring a tridentate ligand and two alkoxide initiating ligands. In each homopolymerization, the addition of electron-withdrawing groups on the tridentate ligand lowers the activation energy of the reaction by increasing the electrophilicity of the central Aluminum. We further investigated the polymerizations by comparing the energy difference between copolymerization and homopolymerization following the initial ring opening as well as the potential for dual polymer chains from the insertion of both initiating ligand. Single chain polymerization is favored in every case, due to lower bond ...


Synthesis Of Dimeric Zinc Complexes For Use As Ring Opening Polymerization Catalysts, Kyle D. Brooks, Arnlold Rheingold, David B. Green, Joe Fritsch 2018 Pepperdine University

Synthesis Of Dimeric Zinc Complexes For Use As Ring Opening Polymerization Catalysts, Kyle D. Brooks, Arnlold Rheingold, David B. Green, Joe Fritsch

Seaver College Research And Scholarly Achievement Symposium

No abstract provided.


Light-Harvesting And Light-Responsive Materials For Optoelectronic And Biological Applications, youngju bae 2018 University of Massachusetts Amherst

Light-Harvesting And Light-Responsive Materials For Optoelectronic And Biological Applications, Youngju Bae

Doctoral Dissertations

In photodynamic therapy, several critical standards are required of photosensitizers including high singlet oxygen quantum yield, biocompatibility in dark, and long term photochemical stability. In addition, current PDT systems lack active targeting strategies to tumor cells, and instead mainly rely on the natural distribution of PS in the body following injection and application of near-infrared light treatment in the tumor region. This thesis describes a series of BODIPY-based molecules that were designed, synthesized and studied as photosensitizers with high singlet oxygen generation capacity through utilizing the heavy atom effect. Additionally, aqueous solubility and active targeting capability were introduced by photosensitizer ...


Preparation And Characterization Of Poly(Ethylene Oxide)(Mw 35k And 100k)/ Silica Nanoparticle Composites, Reem Alfinaikh 2017 Atlanta University Center

Preparation And Characterization Of Poly(Ethylene Oxide)(Mw 35k And 100k)/ Silica Nanoparticle Composites, Reem Alfinaikh

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

In recent years, polymer-inorganic nanoparticle compositions have been a subject of considerable interest in order to achieve desired chemical, physical properties and mechanical properties. In this study a polymer nanocomposites have been prepared by incorporating silica nanoparticles (~20 nm) as fillers into poly(ethylene oxide) matrix. The composites of poly(ethylene oxide) and silica nanoparticles were prepared by solution blending. The product composites were powders. The thermal properties of the composites were investigated using the Differential Scanning Calorimetry. The Nuclear Magnetic Resonance (13C solid state, T), Atomic Force Microscopy, X-ray diffraction and Fourier Transform Infrared Spectroscopy were used ...


Construction And Evaluation Of Novel Molecularly Imprinted Polymers (Mips) Using Helical Poly(3-Methyl-4-Vinylpyridine), Fatmah Alshareef 2017 Atlanta University Center

Construction And Evaluation Of Novel Molecularly Imprinted Polymers (Mips) Using Helical Poly(3-Methyl-4-Vinylpyridine), Fatmah Alshareef

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

A novel chiral helical imprinted polymer (MIP) has been prepared by bulk copolymerization of 3-methyl-4-vinylpyridine and a crosslinker using chiral S-mandelic acid as template. The resulting MIPs after removing the template show optical activity that is derived from the presence of chiral helical structures of poly(3-methyl-4-vinylpyridine) (P3M4VP) embedded within the MIP matrix. The basic functional monomer 3-methyl-4-vinylpyridine (3M4VP) was utilized with the acidic template to ensure good interaction between the template and the polymer. Divinylbenzene (DVB) and ethyleneglycoldimethacrylate (EGDMA) with widely varying degree of rigidity, flexibility, and polarity were selected as crosslinking agents. Using two different crosslinkers, it was ...


Liquid Organic Electrolytes: Blends Of Low Molecular Weight Methoxyoligooxyethylene (Mpegs)/Litfsi Salt, Rasha Alshahrani 2017 Atlanta University Center

Liquid Organic Electrolytes: Blends Of Low Molecular Weight Methoxyoligooxyethylene (Mpegs)/Litfsi Salt, Rasha Alshahrani

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

Blends containing methoxyoligooxyethyleneglycol (MPEGs) (MW 350 and 550) and bis(trifluoromethane)sulfonimide lithium (LiTFSI) salt were prepared by solution blending process using tetrahydrofuran (THF) as a solvent. The ionic conductivity of the blends of different compositions were determined at four temperatures i.e. 25°C, 40°C, 60°C and 70°C. A maximum ionic conductivity value of 3.9x10-3 S cm-1 at 25°C was obtained for the blends containing MPEG-350 at an ethylene oxide to lithium salt ratio of 1:10. The ionic conductivity increases with increasing temperature and shows that the ion transport is aided ...


Electrophilic Cleavage And Functionalization Of Polyisobutylenes Bearing Unsaturations In The Backbone And Synthesis Of Polymers For This Process, Christopher Campbell 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

Dissertations

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 ...


Cellulose Nanofiber-Reinforced Impact Modified Polypropylene: Assessing Material Properties From Fused Layer Modeling And Injection Molding Processing, Jordan Elliott Sanders 2017 University of maine

Cellulose Nanofiber-Reinforced Impact Modified Polypropylene: Assessing Material Properties From Fused Layer Modeling And Injection Molding Processing, Jordan Elliott Sanders

Electronic Theses and Dissertations

The purpose of this research was to investigate the use of cellulose nanofibers (CNF) compounded into an impact modified polypropylene (IMPP) matrix. A IMPP was used because it shrinks less than a PP homopolymer during FLM processing. An assessment of material properties from fused layer modeling (FLM), an additive manufacturing (AM) method, and injection molding (IM) was conducted. Results showed that material property measurements in neat PP were statistically similar between IM and FLM for density, strain at yield and flexural stiffness. Additionally, PP plus the coupling agent maleic anhydride (MA) showed statistically similar results in comparison of IM and ...


Synthesis And Electrochemical Characterization Of Pani/Ni And Pani/Au/Ni Composites, Morgan Emily Pacini 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 ...


Reintroducing Explicit Solvent To A Solvent-Free Coarse-Grained Model, Seung Ha Kim, Monica H. Lamm 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.


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 2017 Paul Scherrer Institut

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, Sunny Kwan, Sunny Kwan 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 ...


Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi 2017 University of Southern Mississippi

Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi

Dissertations

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, David William Bilger, David William Bilger 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, 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 2017 Georgia Institute of Technology

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, Daniel Jonwal Denmark 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 ...


Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger 2017 Duquesne University

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles ...


Molecular And Polymeric Materials Based On Asymmetrically Substituted Bf2 3-Cyanoformazanates, Samantha Novoa 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 ...


Silanol-Assisted Carbinolamine Formation In An Amine-Functionalized Mesoporous Silica Surface: Theoretical Investigation By Fragmentation Methods, Ana P. de Lima Batista, Federico Zahariev, Igor I. Slowing, Ataualpa A. C. Braga, Fernando R. Ornellas, Mark S. Gordon 2017 Instituto de Química

Silanol-Assisted Carbinolamine Formation In An Amine-Functionalized Mesoporous Silica Surface: Theoretical Investigation By Fragmentation Methods, Ana P. De Lima Batista, Federico Zahariev, Igor I. Slowing, Ataualpa A. C. Braga, Fernando R. Ornellas, Mark S. Gordon

Igor I. Slowing

The aldol reaction catalyzed by an amine-substituted mesoporous silica nanoparticle (amine-MSN) surface was investigated using a large molecular cluster model (Si392O958C6NH361) combined with the surface integrated molecular orbital/molecular mechanics (SIMOMM) and fragment molecular orbital (FMO) methods. Three distinct pathways for the carbinolamine formation, the first step of the amine-catalyzed aldol reaction, are proposed and investigated in order to elucidate the role of the silanol environment on the catalytic capability of the amine-MSN material. The computational study reveals that the most likely mechanism involves the silanol groups actively participating in the reaction, forming and breaking covalent bonds in the carbinolamine ...


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