Physical properties of CdS-poly (vinyl alcohol) nanoconducting composite synthesized by organosol techniques and novel application potential

A nanocomposite of poly (vinyl alcohol) (PVA) reinforced with various contents of CdS was synthesized by organosols reaction with particle size in the range of nanoscale. The influence of CdS content on the network structure of PVA matrix such as particle size distribution, gel fraction (GF), equilibrium water content (EWC), water absorption (WA), extent of filler reinforcement (gamma), volume fraction of polymer (V-s) number of elastically effective chains (NEC), and X-ray diffraction (XRD) were investigated. The affine and phantom models for physical crosslinks were used to predict the nature of crosslinks. The thermal behavior of PVA-CdS composites has been studied by differential thermal analysis (DTA), Thermogravimetry (TG) and differential scanning calorimetry (DSC). The dc conductivity of the PVA system reinforced with CdS as a function of concentration and temperature has been presented. The PVA composite exhibits considerably high electronic conductivity which increases linearly with the increase of CdS content. The conduction mechanism in PVA-CdS composites is governing by hopping mechanism. The effects of CdS loading and temperature on the thermal conductivity (lambdaSigma) and specific heats (C-p) were investigated. The antistatic properties and electromagnetic wave shielding effectiveness (EMI) of PVA-CdS composites has been also investigated. The optical properties such as absorbance and transient photo current under applied voltage of PVA-CdS composites were tested. The mechanical properties of PVA-CdS composites were investigated in details. It is proved that the PVA-CdS composites can be effectively used for linear thermistors, antistatic charge dissipation, EMI in the encapsulation of electronic devices, in woven texturing, optical switch and solar cell fabrication. (C) 2003 Elsevier Ltd. All rights reserved.