Graphene Dissolution at High Concentrations and Formation of Liquid Crystals

Graphene is a promising new material with a wide number of potential applications, including electronics and nanocomposites, which often require that the graphene be dispersed and processed as single layers in a fluid phase. Here we show that in chlorosulfonic acid, pristine graphene is spontaneously exfoliated and dissolved at isotropic concentrations as high as ~1000 ppm without the need for covalent functionalization, surfactant stabilization, or sonication. At higher concentration, a liquid-crystalline phase spontaneously forms. Cryo-TEM and AFM show evidence of single-layer to few-layer dissolution. We show that these isotropic and liquid crystalline phases can be leveraged for making flexible electronics as well as multifunctional fibers.