Multifunctional Graphene-Silicone Elastomer Nanocomposite

We show that functionalized graphene sheet (FGS) as a multifunctional reinforcing filler in silicone elastomer (SE) can impart simultaneous improvements in modulus, strain at failure, tensile strength, electrical conductivity and barrier property. In the concentration range investigated, FGS performs superior to other fillers previously reported at improving the mechanical properties of SE. Distributed deformation and load transferring introduced by FGS in SE are proposed to explain the improvements in mechanical properties. Electrical percolation occurs between 0.05 wt.% (0.022 vol.%), second only to one case of multiwall carbon nanotube-SE nanocomposite. The low electrical percolation threshold is attributed to the agglomerated FGS morphology. At a loading of 3 wt.% (1.31 vol.%), the electrical conductivity of FGS-SE nanocomposite reaches 0.89 S/m and meets the conductivity requirement for electrostatic painting applications. Oxygen and nitrogen permeability is reduced by half at 3 wt.% (1.31 vol.%) FGS loading.