Microwave Irradiation Enables Rapid and Direct Dispersion of Highly Conductive Graphene Sheets and Carbon Nanotubes

H.X. He
Rutgers University, US

Keywords: graphene and carbon nanotubes, microwave

Summary:

we report our quick and scalable strategies to directly produce highly conductive graphene sheets with controlled porous structures and controlled sizes from a few nanometers to tens of micrometers. We exploit aromatic oxidation by nitronium ions combined with the unique capability of microwave irradiation. By controlling the duration of microwave irradiation and ratio of nitronium ions and graphite, graphene sheets with controlled sizes from a few nanometers to tens of micrometers. This method has the following advantages for mass production: (1) short production periods (30s); (2) direct production (without requirement of a post-reduction process) of graphene sheets with lower level of oxygen containing groups, which ensures substantial reservation of the outstanding electrical and optical properties; (3) fewer destructive defects such as nanometer sized holes; (4) high-concentration dispersions both in aqueous and organic solvents (without requiring polymeric or surfactant stabilizers); (5) fewer starting materials and low-cost (compared to commonly used Hummers’ and modified Hummers’); and (6) reduced waste from purification steps. The same approach can be used to directly disperse highly conductive carbon nanotubes. This greener, rapid and scalable approach produces high quality solution processible graphene sheets and carbon nanotubes, enabling a broad spectrum of applications by low-cost solution processing techniques.