天美传媒

Abstract

Synthesis and processing of polymer based materials through green friendly methods involving supercritical fluids particularly supercritical carbon dioxide (SCC) has recently received substantial technological importance because of the commercial and industrial benefits involved. In the present work, a SCC assisted green and sustainable process has been developed to synthesize Polyacrylonitrile/Barium Titanate Nanocomposites (PNCs). The process of synthesis has been conducted through 2,2-azobisisobutyronitrile initiated in situ polymerization of acrylonitrile in presence of nanobarium titanate (1 phr) at temperature ranging 60 to 120癈, 1200 psi over 18 hours in SCC. Polymerization below 70oC afforded PNCs in semi solid products whereas polymerizations conducted at 120oC under identical conditions have afforded the end products in well solid state. The structure and properties of PNCs has been evaluated through ultraviolet-visible absorption, X-ray diffraction and fourier transformed infrared spectra, scanning electron and atomic force microscopy, simultaneous thermogravimetric- differential thermal analysis-differential thermogravimetry and four point probe electrical conductivity methods. With temperature, all the polymerization reactions has been progressed resulting in PNCs with enhanced polymerization yield, rheoviscosity, dispersion of nanobarium titanate into polyacrylonitrile matrix and thermal stability. This has contributed a simultaneous loss in the electrical conductivity of PNCs. Cyclic voltammetry in coherence with electrical conductivity reveals the excellent potential of the PNCs modified glassy carbon electrodes towards amperometric detection of doxorubicin (DOX) in phosphate buffer (pH 7.4). A supercritical carbon dioxide assisted process has been developed to synthesize series of polymer nanocomposites (PNCs) has been synthesized through 2,2 azobisisobutyronitrile initiated polymerization of acrylonitrile (AN) in presence of nanobarium titanate powder (NBT) under various microwave power ranging 25 to 100W over 10 min. The microstructure and composition of the obtained PNCs were characterized by FT-IR, UV and XRD. In this work, doxorubicin (DOX) has been studied by means of cyclic voltametry on a glassy carbon electrode in aqueous solution containing phosphate buffer (pH 7.4) as supporting electrolyte. In addition, we also employed atomic force microscopy (AFM) to investigate the surface texture of samples and thermogravimetric/differential temperature analysis (TG/DTA) to determine the stabilization temperature of the samples performed at a heating rate of 10癈/min in air. It was found that the nanocomposite materials possess much higher heat resistance and low moisture content than the PAN.

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