Jose Sebastian; Dr. Eby Thomas Thachil(September 23, 2015)
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Abstract:
Organic-inorganic nanocomposites combine unique properties of
both the constituents in one material. Among this group of materials,
clay based as well as ZnO, TiO2 nanocomposites have been found to
have diverse applications. Optoelectronic devices require polymerinorganic
systems to meet certain desired properties. Dielectric
properties of conventional polymers like poly(ethylene-co-vinyl acetate)
(EVA) and polystyrene (PS) may also be tailor tuned with the
incorporation of inorganic fillers in very small amounts. Electrical
conductivity and surface resistivity of polymer matrices are found to
improve with inorganic nanofillers. II-VI semiconductors and their nano
materials have attracted material scientists because of their unique
optical properties of photoluminescence, UV photodetection and light
induced conductivity. Cadmium selenide (CdSe), zinc selenide (ZnSe)
and zinc oxide (ZnO) are some of the most promising members of the IIVI
semiconductor family, used in light-emitting diodes, nanosensors,
non-linear optical (NLO) absorption etc. EVA and PS materials were
selected as the matrices in the present study because they are
commercially used polymers and have not been the subject of research
for opto-electronic properties with semiconductor nanomaterials
Transition metal-loaded (3%) nanocrystalline sulfated titania (ST) powders are prepared using the sol–gel technique. Anatase is found as the active phase in all the samples. Sulfate ion impregnation decreases the crystallite size and stabilizes the anatase phase of TiO2. Acidity of the samples is found to increase by the incorporation of sulfate ion and also by the modification by transition metal ions. All the prepared catalysts are found stable up to 700 °C.