Ultrasound assisted miniemulsion synthesis of polyaniline/Ag nanocomposite and its application for ethanol vapor sensing

Polyaniline-silver (polyaniline/Ag) nanocomposite was prepared by an ultrasound assisted in situ miniemulsion polymerization of aniline along with different loading of silver nanoparticles. Colloidal silver nanoparticles were synthesized by reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4) using sodium dodecyl sulfate (SDS). Films of Polyaniline/Ag were casted using 1-methyl-2-pyrrolidone (NMP) by spin coating, which were further tested for ethanol vapor sensing. The nanocomposite was characterized using FTIR and TEM analysis techniques. In-house prototype batch set-up was fabricated for ethanol vapor sensing. The response in terms of change in electrical conductivity on exposure to ethanol vapors was reported. Ethanol vapor sensing ability of the nanocomposite was found to increase on addition of silver nanoparticles in the polymer matrix. Response time of the sensor for different loadings of Ag were also studied, which show decrement in response time with increase in amount of Ag. (C) 2011 Elsevier B.V. All rights reserved.