Fabrication of semiconducting graphene oxide/polyaniline composite particles and their electrorheological response under an applied electric field

Semiconducting graphene oxide/polyaniline (GO/PANI) composite particles for potential electrorheological (ER) fluid applications were synthesized by the in situ dispersion polymerization of aniline in the presence of GO particles, which were prepared using a modified Hummers method. The electroresponsive ER characteristics of the composite when dispersed in silicone oil exhibited a phase transition from a liquid-like to solid-like state under an applied electric field. The morphology and composition of the composite particles were characterized by scanning and transmission electron microscopy and Raman spectroscopy. Its fibrillation phenomenon was observed by optical microscopy during the application of an external electric field. The bulk rheological characteristics of both the flow curve and yield stress were examined using a rotational rheometer equipped with a high voltage generator. The GO/PANI composite showed typical ER behavior, which demonstrated its potential applications as an ER smart material. (C) 2011 Elsevier Ltd. All rights reserved.