Inorganic/organic composites of polyaniline (PANI) with zinc oxide (ZnO) nanoparticles as inorganic filler have been prepared by solution casting method using N-methyl-2-pyrrolidone (NMP) as solvent. These composites are studied for their electrical conductivity and stability in terms of DC electrical conductivity retention using four-in-line probe technique under isothermal and cyclic heating of the test samples. The composites have also been characterized by Fourier Transform Infrared (FTIR) spectroscopy. It has been found that in composites, there exist two conduction phases, as electrical conductivity first decreases with decrease in concentration of PANI. However, with the increase in concentration of ZnO nanoparticles further, the electrical conductivity of the composites increases. All the samples follow Arrhenius equation for the temperature dependence of electrical conductivity and support the semiconducting nature of the doped state. The conductivity of the as-prepared composites has been found to be in the semiconducting region. The studied samples showed good electrical conductivity stability up to the temperature of 90 °C.

Mutual interactions between inorganic semiconductors and conducting polymers may give rise to interesting properties which are significantly different from those of individual components (Dutta et al., 2009). Nanostructures and nanocomposites of conducting polymers have emerged as a new field dedicated to the creation of smart materials for use in future technologies (Malinauskas et al., 2005; and Rajesh et al., 2009). Blending or encapsulation of inorganic nanoparticles in intrinsically conducting polymer matrix is believed to be an easy route to prepare and design nanocomposites where delocalizedp-electrons can interact with inorganic nanoparticles, resulting in materials of unique or better properties (Lei and Su, 2007). Many studies on polymer nanocomposite preparation have been reported in the quest to develop new advanced materials with improved mechanical, electrical, optical and catalytic properties or to improve conduction mechanism in electronic devices. These materials have found their use in many electronic and nanoelctronic devices.

Polyaniline (PANI) is a promising conducting polymer due to its easy synthesis, environmental stability and high electrical conductivity on doping with protonic acids (Ahmed et al., 2004; and Qiang et al., 2008). The preparation of PANI composites with various materials has received great attention because of their unique properties and applications in various electrical and electronic devices. Several reports dealing with the preparation of conducting composites such as Fe₃O₄:PANI, MnO₂:PANI, TiO₂:PANI and ZrO₂:PANI (Gok et al., 2007; and Yavuz and Gok, 2007), as well as preparation and characterization of ZnO:PANI composites have been published (Paul et al., 2007; Jeng et al., 2008; and Zhang, 2009). However, in the present work, we have studied the electrical properties of the ZnO:PANI composites based on ZnO nanoparticles as inorganic filler material and PANI as the main matrix. We have studied the effect of ZnO nanoparticles on the electrical conductivity of PANI and its thermal stability in terms of electrical conductivity retention in two slightly different conditions.

Chemistry Journal, Electrical Studies, Zinc Oxide Nanoparticles, Fourier Transform Infrared Spectroscopy, Electrical Conductivity, Nanoelctronic Devices, Oxidative Polymerization, Electrical Conductivity, FTIR Spectrum, ZnO Nanoparticles, Electronic Devices.