Preparation of conductive polyaniline/graphene nanocomposites via in situ emulsion polymerization and product characterization

This work, which is a part of our ongoing studies on developing conductive scaffolds for nerve tissue engineering, reports synthesis of highly conductive binary-doped polyaniline nanoparticles and polyaniline/graphene nanocomposites. The samples were synthesized through chemical oxidation of aniline via in situ emulsion polymerization method in presence of hydrochloric acid and sodium dodecyl sulfate. Graphene nanosheets were also prepared via modified Hummer's method followed by chemical reduction using hydrazine monohydrate. Electrical conductivity measurements using a standard four-point probe technique with FUR and UV-vis studies revealed that conductive binary-doped emeraldine salt polyaniline had been successfully produced. The results also showed that incorporation of less than 1 wt.% of graphene nanosheets into polymeric matrix had improved electrical conductivity of polyaniline from 2 to 7 S cm(-1). The SEM micrographs illustrated that the synthesized polyaniline had spherical morphology with particle size of 10-15 nm. The results of the investigated thermal properties showed that binary doping process and also incorporation of graphene into polymeric matrix had improved thermal stability of polyaniline main chains. Finally, this work supported proper morphological, electrical, and thermal properties of prepared PANI/graphene nanocomposites and their potential use in different biomedical applications such as tissue engineering, biosensor, controlled drug delivery systems, and surface coating. (C) 2014 Elsevier B.V. All rights reserved.