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Electrical properties of PVC, PMMA and their 1 : 1 polyblends, before and after adding paranitroaniline into them, have been investigated as a function of temperature, electric field and dopant concentration, to study the mechanism of electrical conduction. The current was measured by applying d.c. voltage in the range 25-800 V at various thermostatically controlled temperatures (313-373 K). The results obtained predict the Schottky-Richardson conduction mechanism to be operative and d.c. conductivity of the blend lies intermediate between those of individual components. Further, the conductivity of the blend increases with temperature and applied electric field and also with the increase in concentration of dopant. To identify the mechanism governing the conduction, the activation energies in low temperature (LTR) and high temperature (HTR) regions have been calculated. The dielectric constant of the sample at various temperatures have been calculated which increased with increase in temperature. This is indicative of the diffusion of ions in space charge polarization at higher temperature. The study of XRD and FTIR supports the changes occurring in the conductivity of the blend.

The ZnO nanostructures have been synthesized and studied as the sensing element for the detection of H 2 S. The ZnO nanostructures were synthesized by hydrothermal method followed by sonication for different interval of time i.e. 30, 60, 90 and 120 min. By using screen printing method, thick films of synthesized ZnO nanostructure were deposited on glass substrate. Gas sensing properties of ZnO nanostructure thick films were studied for low concentration H 2 S gas at room temperature. The effects of morphology of synthesized ZnO nanostructure on gas sensing properties were studied and discussed. ZnO nanostructure synthesized by this method can be used as a promising material for semiconductor gas sensor to detect poisonous gas like H 2 S at room temperature with high sensitivity and selectivity.