A photochemical approach for preparing graphene and fabrication of SU-8/graphene composite conductive micropatterns.

We proposed herein a facile, fast and low cost metal-free photochemical method for preparing reduced graphene oxide (rGO) by ultraviolet (UV) irradiation of a solution containing mixture of a photoinitiator such as phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (GR-XBPO) and a triethylamine (TEA) in ethanol. Free radicals are generated via photoinitiator decomposition under UV irradiation. In this process, graphene oxide (GO) rapidly reduced to graphene via extensively removal of oxygen-containing functional groups (OFGs) by free radicals in the presence of anti-oxide inhibitor such as TEA exists. Furthermore, we prepared flexible conductive micropatterns over rGO/SU-8 composites deposited on several substrates (e.g., glass, polyethylene terephthalate (PET), aluminum, and silicon) by dispersing rGO into a photocurable SU-8 resin by means of a photolithography technique. The incorporation of rGO changed the properties of the composites. Thus, the behavior of SU-8 resin shifted from insulating to conductive/antistatic upon incorporation of rGO nanocomposites. This preliminary study provides us with the opportunity to not only develop an efficient metal-free photochemical reduction route towards GO but also obtain a processable conductive micropattern by optimizing the overall processing parameters, and maximizing the advantages of them for future carbon-based nanocomposites at large scale. [ABSTRACT FROM AUTHOR]