Shama Islam

Synthesis, Electrical Conductivity, and Dielectric Behavior of Polyaniline/V2O5 Composites

Conducting polymer composites of polyaniline/vanadium pentaoxide PANI/V2O5 (with different initial weight percentage of V2O5) has been synthesized by in situ polymerization method. DC conductivity of compressed pellets has been analyzed in the temperature range 300–550 K and was found to increase with V2O5 doping. This increase in conductivity is mainly due to band conduction. It has also been observed that the dielectric constant and dielectric loss increase with the level of doping of V2O5 but remain independent of the frequency (50 KHz–1 MHz). X-ray diffraction pattern shows some order of crystallinity of composites due to interaction of polyaniline with V2O5. UV-visible spectroscopy shows an increase in the optical band gap with doping.

Enhancement in the dielectrics of poly( o -toluidine)/single wall carbon nanotubes (POT/SWCNTS) polymer nanocomposites for electrical energy storage

Present study focuses on influence of carbon nanotubes in POT polymer, in order to improve performance of energy storage devices. (POT/SWCNTS) nanocomposites are synthesized by situ polymerization with different concentrations of SWCNTS. POT had long chain of qunoid and benzoined rings provide together large transport of charge along with SWNTs resulting to store large amount of electric charge. Synthesized samples are characterized by dc conductivity; UV–Vis studies, FTIR, X-ray diffraction (XRD) and dielectric techniques. Electrical conductivity enhances up to four orders with dopant concentrations. Incorporation of dopant into polymer matrix is confirmed by FTIR studies. XRD analysis revealed crystallinity of nanocomposites. Present consequences of synthesized polymer nanocomposites shows meaningful impact with changes in dielectric properties due to better dispersion of SWCNTS in polymer matrix. As results enhancements in dielectric parameters values, highlights their great potential for supercapacitors. These nanocomposites do not need any binding substance that is an important practical advantage.

Engineering the Optical Properties of insitu Polymerized poly (o-toluidine/V2O5) Composites

Conducting polymer composites of poly (o-toluidine)/vanadium pentoxide (POT/V2O5) were synthesized by polymerization of o-toluidine with V2O5 using (NH4)2 S2O8) as an oxidant. The optical properties as photoluminescence, UV–visible absorption, optical band gap, UV–visible reflection and refractive index are studied. The optical band gap of composites found to decrease with increase in the weight percent of V2O5 and the PL intensity has been found to increase with V2O5. From UV–visible absorption and reflection studies, the dielectric constant has been estimated and found to increase with V2O5. The PL emission intensity of all the polymer/V2O5 composites makes them suitable for various optoelectronic devices.