Self-stabilized polyaniline@graphene aqueous colloids for the construction of assembled conductive network in rubber matrix and its chemical sensing application

Facile dispersion and construction of graphene-based 3D conductive network in polymer matrix are highly attractive for the preparation of conductive polymer composites (CPCs) and flexible electronic devices. In this study, a simple and effective strategy for the fabrication of graphene-based assembled conductive network in natural rubber (NR) matrix is reported. Specifically, polyaniline@graphene nanohybrids were prepared by in situ reduction of graphene oxide using aniline as both reducing and stabilizing agents. The resulted self-stabilized polyaniline@graphene nanohybrids could well disperse in aqueous suspension by electrostatic repulsion. When homogenized with NR through latex assembly technique, they could be located in the interstitial space between the NR latex microspheres and organized into a continuous 3D hierarchical network. The as-prepared CPCs with this 3D conductive network exhibited a very low percolation threshold (3-fold lower than that of the conventional NR/graphene blends), enhanced electrical conductivity (up to 6 orders of magnitude improvement) and meanwhile excellent chemical sensing properties. This work provides a feasible approach to stabilize graphene nanosheets in aqueous media without the use of stabilizer or complicated surface modification and extend their applications in the preparation of CPCs as chemical sensing materials.