Thin films were developed, characterized, and optimized for optical absorbance from blends of organic polymer poly (3-hexylthiophene-2, 5-diyl) (P3HT) and the fullerene derivative [6, 6] phenyl-C 61 -butyric acid methyl ester (PCBM). The materials of both pristine and blends were analyzed using X-ray diffraction spectroscopy and high resolution transmission electron microscopy for structural properties, and fourier transform infra-red and UV-VIS spectroscopy for optical properties. The study evaluated the effects of altering the blend ratio and annealing temperature on absorption. The ratios were made by varying the weight of PCBM whilst keeping that of P3HT constant. Eleven different ratios were made with each exhibiting its own optimal annealing temperature and absorption. The optimum ratio was determined and found to be at 1:1 with an annealing temperature of 100ºC for 30 min duration.

We report on the preparation, characterization and property evaluation of molecularly imprinted polyaniline nanoparticles that can be used for selective recognition of aldrin. Molecularly imprinted polyaniline (MI-PANI) nanoparticles were prepared by inverted emulsion polymerization using aldrin as a template and aniline as a functional monomer. Materials prepared were characterized using UV-VIS, FTIR and NMR for structural elucidation. Comparison of spectra data from UV-VIS, FTIR and NMR confirmed that aldrin was incorporated successfully into the polymer matrix. AFM and SEM were used to evaluate morphological characteristics. Both AFM and SEM revealed that the particles prepared were spherical in nature. The particle size was in range 60-100 nm for non-imprinted which increased to between 500-1500 nm for the imprinted. The surface morphology was observed to change from smooth to rough on incorporating aldrin molecules. Electrical properties were evaluated using a four-point probe coupled to a source meter. Non-imprinted materials showed an electrical conductivity of 4.149 S/cm that reduced to 0.546 S/cm in MI-PANI. The values of KD and Bmax were found to be 0.6 ng/L and 0.799 ng/L respectively. Adsorption characteristics of aldrin and DDT were investigated to ascertain the selectivity of the imprinted nanoparticles. The results showed the distribution coefficient of for DDT and Aldrin to be 0.76 ng/ng and 1.31 L/ng respectively. This is indicative that the imprinted nanoparticles had a stronger affinity for Aldrin than DDT.

The preparation of polyester resin blends consisting of an unsaturated polyester resin matrix and rubbery particles comprising three radially-alternating glassy and rubbery layers is described. The morphology of the resin blends was examined by transmission electron microscopy (TEM) while thermal properties were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The results show that the particles were prepared with good control of particle size and morphology. DMTA results showed no reduction in the Tg of the matrix whilst the shear modulus of modified materials was found to be lower than that of the matrix material.

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Abstract:Polymer blends comprising an unsaturated polyester resin and dispersed particles were prepared. Rubbery particles were synthesized by sequential emulsion polymerization and had core-shell morphology. Curing of materials was carried out at ambient temperature and subsequently post cured at elevated temperatures to obtain materials of consistent properties. Materials made of different particle content were prepared and their tensile properties evaluated. Effect of matrix ductility was investigated by inclusion of ethyl acrylate in the polyester resin composition. Deformation mechanisms involved in these materials were examined using transmission electron microscopy (TEM) and real-time small angle X-ray spectroscopy (RT-SAXS). Incorporation of rubbery particles in the polyester resin was found to generally improve the tensile properties of the materials. Furthermore, the deformation mechanisms were found to involve cavitation/debonding processes as evidenced from stress whitening in the failed specimen and from real-time small angle X-ray scattering experiments.