Microwave graphene syntheses and graphene-based artificial muscles

Graphene, a single layer assembly of carbon atoms densely packed into a benzene ring structure have unique properties thus making it a potential material for applications in next-generation electronic devices, reinforced composites for electrical and thermal conduction, transparent electrodes for displays, solar cells, chemical and biological sensors, nano-composites and others. We developed eco-friendly techniques [1] for synthesis of graphene nano-sheets from various precursors like graphite, carbon nanotubes, and carbon fibers. One of our techniques can also be used to facile one-pot synthesis [2] of metal decorated graphene which can be used in variety of applications like sensors, actuators, surface enhanced raman spectra etc.

One advantage of our technique is that the bulk of oxygen impurities are driven away during this process resulting in graphene nano-sheets with minimal defects. In order to improve the yield and efficiency of our technique, we added eco-friendly foaming agent like azodicarbonamide (ADC) to improve the yield of graphene [4]. Under microwave radiation, the intercalated foaming agent plays a key role in the rapid and large expansion of the graphene worm along the thickness direction and in the reduction process of the graphite oxide. Also, with addition of metal precursors to the reactant mixture, this technique can also be extended to a one-pot method to synthesize metal-decorated graphene nano-hybrids. A variety of metal precursors was used to yield iron, platinum, and palladium decorated graphene nano-sheets.