Poly (aniline-co-aniline-2,5-disulfonic acid) / L-ascorbic acid / Ag@SiO2 / polysafranin nanocomposite: Synthesis, characterization and anomalous electrical behaviour

Abstract

It is well known that modification of polymer properties by incorporating organic dyes usually improves the conductivity; however, the oxidation of safranin dye itself or its blended material impairs the conductivity. In this paper, we report a new finding that the incorporation of the safranin dye with our recently reported sulfonated polyaniline/Ag@SO2 nanocomposite, prepared under modified conditions, achieved better conductivity after heating. The d.c conductivity of the organic oligomer itself varied from 0.06 to 0.016 (s/cm) and that of the composite from 0.008 to 0.016 (s/cm), respectively, with an increasing temperature of up to 363 K and then decreased at 393 K. The material changed from a semiconductor to a metallic nature, and their d.c conductivities were comparable to those of many commercial inorganic or organic composites. The frequency dependence of the permittivity, e¢, showed a remarkable effect on the frequency window under consideration. e¢ was independent of the increment in the frequency and this behaviour confirmed the presence of electrode polarization and space-charge effects. This result, on account of their attractive electrical properties we suggest, is promising for electronic field applications.