Preparation of conductive polyaniline grafted graphene hybrid composites via graft polymerization at room temperature

Abstract

Graphene was covalently functionalized with phenol groups via a 1,3-dipolar cycloaddition reaction without degrading its electronic properties. The most important thing is that two hydroxyl groups can be covalently attached to the graphene sides in a single step. Here, the phenols on the functionalized graphene have been further derivatized with γ-aminopropyltriethoxysilane to form a dense aminopropylsilane self assembled monolayer with active sites for the graft polymerization of aniline. The conductive polyaniline layer was chemically grafted on the surface of the self assembled monolayer coated graphene by in situ polymerization of the aniline monomer in the presence of ammonium peroxodisulfate under acidic conditions. This reaction was found to be extremely efficient for producing conductive polyaniline–graphene hybrid composites, even at room temperature and short reaction times (24 h), and was usually performed using graphene oxide. The chemical grafting of PANI was confirmed using Fourier transform infrared spectroscopy. Thermogravimetric analysis indicated that the polymer functionalized graphene consisted of 24.5 wt% polymer. The morphologies of the polyaniline grafted graphene hybrid composites and hydroxyl functionalized graphene were examined by scanning electron microscopy and transmission electron microscopy, showing relatively uniform polymer coatings on the sides of graphene.