Self-aligned and bundled electrospun fibers prepared from blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairt-rod polyphenylene copolymer

Cataloged from PDF version of article.Bundled and self-aligned fibers were obtained by electrospinning blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairy-rod polyphenylene-g-polystyrene/poly(a-caprolactone) (PP-g-PS/PCL) copolymer. The self-alignment and bundling characteristics of these electrospun fibers were ascribed to the unique molecular architecture of the conjugated polymer, PP-g-PS/PCL, and its interactions with the solvent and the polymer matrixes used for the electrospinning. The self-alignment and bundling was found to be much more pronounced for PP-g-PS/PCL-PS blend when compared to PP-g-PS/PCL-PMMA blend. Furthermore we found that the degree of self-alignment of the fiber bundles was enhanced by increasing the amount of PP-g-PS/PCL in the blends but the alignment completely disappeared when the solvent dimethylformamide was changed to chloroform. © 2009 Elsevier B.V. All rights reserved

Immobilization of cholesterol oxidase in a conducting copolymer of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

Cholesterol oxidase has been immobilized in conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole (CM/PPy) and polypyrrole (PPy) via electropolymerization. p-Toluene sulphonic acid was used as the supporting electrolyte. Kinetic parameters (V-max and K-m) and operational stability of enzyme electrodes were investigated. Surface morphology of the films was examined by scanning electron microscope

Neonatal Fc Receptor: From Immunity to Therapeutics

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn

Immobilization of invertase and glucose oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole

WOS: 000236451300007In this study, immobilizations of invertase and glucose oxidase were achieved in conducting thiophene functionalized copolymers of vinyl alcohol with thiophene side groups and pyrrole (PVATh/PPy) via electrochemical polymerization. The kinetic parameters, V-max (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on the enzyme activity and film morphologies was examined. The optimum temperature, operational and storage stabilities of immobilized enzymes were determined. PVATh/PPy copolymer was found to exhibit significantly enhanced properties compared to pristine polypyrrole. (c) 2005 Elsevier B.V. All rights reserved

Synthesis and characterization of conducting copolymers of menthyl ester of 3-thiophene acetic acid with pyrrole

A new thiophene derivative containing menthyl group (MM) was synthesized and polymerized via chemical and electrochemical (constant current) methods. Polymers obtained and MM itself were used to synthesize copolymers with pyrrole under conditions of constant potential electrolyses. Cyclic voltammetry (CV), thermal analysis (DSC, TGA) and scanning electron microscopy (SEM) analyses were performed for the characterization of samples

Novel poly(phenylene vinylenes) with well-defined poly(ε-caprolactone) or polystyrene as lateral substituents: Synthesis and characterization

New macromonomers containing dialdehyde functionalities placed at the middle or at the end of the chains were synthesized in two reaction steps. First, using ring-opening polymerization (ROP) of ε-caprolactone (CL) or atom transfer radical polymerization (ATRP) of styrene (St) in the presence of proper initiators provided well-defined low molecular weight polymers with dibromobenzene moieties. In the second step, using Suzuki couplings of these dibromobenzene functions with 4-formylphenyl boronic acid, macromonomers having 4,4‘-dicarbaldehyde terphenyl moieties were obtained. Poly(phenylenevinylene)s (PPVs), with lateral subtituents PSt or PCL chains respectively, were synthesized by following a Wittig polycondensation in combination with bis(triphenylphosphonium) salts in the presence of potassium tert-butoxide. The resulting PPVs were soluble in common organic solvents at room temperature as were the starting macromonomers. All of the starting and intermediate polymers and the final PPVs were characterized by using 1H and 13C NMR, IR, GPC, DSC, and TGA measurements. Optical properties of the polymers were followed by UV and fluorescence spectroscopy. The studied PPVs show a blue or green fluorescence in solution

Synthesis and characterization of conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

A new polythiophene containing a cholesteryl side chain in the beta-position was chemically polymerised in nitromethane/carbontetrachloride using FeCl3 as the oxidizing agent. Polymerisation was also achieved by constant current electrolysis in dichloromethane. Subsequently, conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester (CM), PCM1 (obtained from chemical polymerisation method) and PCM4 (obtained from constant current electrolysis) with pyrrole were synthesized using p-toluene sulfonic acid and sodium dodecyl sulfate as the supporting electrolytes via constant potential electrolyses. Characterizations of the samples were performed by CV, FTIR, NMR, DSC, TGA and SEM analyses. Electrical conductivities were measured by the four-probe technique. (C) 2002 Kluwer Academic Publishers

Synthesis, characterization and electrochromic properties of a conducting copolymer of pyrrole functionalized polystyrene with pyrrole

A well-defined polystyrene (PSt) based polymer containing at one end-chain 3.5-dibromobenzene moiety. prepared by atom transfer radical polymerization (ATRP), was modified in two reaction steps. First one constitutes a Suzuki coupling reaction between aromatic dibromine functional polymer and 3-aminophenylboronic acid, when a diamino-containing intermediate was obtained. The second step is a condensation reaction between the diamino functional polystyrene and 2-pyrrole alclehyde. Thus, a polymer containing a conjugated sequence having pyrollyl groups at the extremities was synthesized. The presence of oxidable pyrrole groups in the structure of the polymer permitted further electropolymerization. The structures of intermediate polymers were analyzed by spectral methods (H-1 NMR, FTIR). Electrochemical copolymerization of pyrrole functionalized polymer (PStPy) with pyrrole was carried out in acetonitrile (ACN)-tetrabutylammonium tetrafluoroborate (TBAFB) solvent electrolyte Couple. Characterization of the resulting copolymer were performed via Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC). scanning electron microscopy (SEM), spectroclectrochemical analysis, and kinetic study. Spectroelectrochemical analysis show that the copolymer of PStPy with Py has an electronic band gap (due to pi-pi* transition) of 2.4 eV at 393 nm, with a yellow color in the fully reduced form and a blue color in the fully oxidized form. Via kinetic studies. the optical contrast %Delta T was found to be 20% for P(PStPy-co-Py). Results showed that the time required to reach 95% of the ultimate T was 1.7 s for the P(PStPy-co-Py)