A Strategy Towards Synergy by Combining Long Vertically-Aligned Carbon Nanotubes and Graphene in Epoxy Nanocomposites

In this work, we report the remarkable synergy achieved by combining in-house CNTs, which are grown as highly-aligned 'forests' (aspect ratio ~30,000), and are highly dispersible, with graphene, in randomly dispersed epoxy nanocomposites, at low combined wt%. The hybrid CNTs/graphene/epoxy nanocomposites resulted in a significant enhancement in dielectric and mechanical properties. For example, the dielectric constant of the composite with 0.5 wt% hybrid nanofiller (50:50) is 35 times higher than that of the pure epoxy, about 1.8 times higher than that of the epoxy filled with either 0.5wt% graphene or 0.5wt% CNTs separately. In hybrid samples, CNTs bridge graphene particles creating a continuous co-supported network. At such low loadings, these CNTs and CNT-graphene materials become economically feasible for large volume production of nanocomposites. The reported strategy provides an effective route for the development of high-performance multifunctional polymer-based composite materials