Dispersion of rGO in polymeric matrices by thermodynamically favorable self-assembly of GO at oil–water interfaces

Abstract

Various approaches have been employed to disperse graphene in polymers. We introduce a new method which takes advantage of the amphiphilic nature of graphene oxide (GO). This feature results in the spontaneous self-assembly of monolayers at the oil–water interface. Thermodynamically favorable adsorption of GO sheets on the liquid droplets serves as the first step in the fabrication of well-dispersed composites. It eliminates the need for sonication and further compounding, which can destroy the structure of the graphene layers. Another equally important consideration is how to vaporize the liquid medium to preserve appropriate dispersion in the dried masterbatch. Microwave radiation is employed to vaporize the liquids and also to partially reduce GO while keeping it well-dispersed in the polymer. As a challenging matrix, the dispersion of GO in natural rubber is studied here. XRD and SEM results confirm appropriate dispersion of the particles. Improvements in the modulus and ultimate strength were observed without any significant reduction in elongation at break.