Synthesis and characterization of electrical conducting chitosan-graft-polyaniline

Synthesis of Chemical Responsive Chitosan–Grafted-Polyaniline Bio-Composite

A polysaccharide based bioplolymer, chitosan was grafted with polyaniline through a simple room temperature oxidative-radical copolymerization method employing CuSO4 as a polymerizing agent. The grafting conditions were optimized by varying different parameters. The optimized experimental findings have been discussed and proposed a probable mechanism for the graft copolymerization. The representative sample of chitosan-graft-polyaniline (CHIT-g-PANI) was characterized using UV-vis, FTIR, X-ray diffraction and Scanning electron microscopy techniques taking chitosan as reference material. The result revealed the formation of grafted composite. Which exhibited highly improved electrical conductivity , in the order of ~ 10 -6 times due to the grafting of PANI onto chitosan backbone. Further , composite was found responsive in nature for H+ ion , which will be a suitable properties for its use in fabrication of bio-sensor.

Charge transport mechanism in thin cuticles holding nandi flame seeds

Metal-sample-metal sandwich configuration has been used to investigate DC conductivity in 4 mum thick Nandi flame [Spathodea campanulata P. Beauv.] seed cuticles. J-V characteristics showed ohmic conduction at low fields and space charge limited current at high fields. Charge mobility in ohmic region was 4.06 x 10(-5) (m(2)V(-1)s(-1)). Temperature-dependent conductivity measurements have been carried out in the temperature range 320 K < T > 450 K. Activation energy within a temperature of 320 K-440 K was about 0.86 eV. Variable range hopping (VRH) is the main current transport mechanism at the range of 330-440 K. The VRH mechanism was analyzed based on Mott theory and the Mott parameters: density of localized states near the Fermi-level N(E(F)) approximately 9.04 x 10(19) (eV(-1)cm(-3)) and hopping distance R approximately 1.44 x 10(-7) cm, while the hopping energy (W) was in the range of 0.72 eV-0.98 eV.