Spontaneous exfoliation of graphite oxide in polar aprotic solvents as the route to produce graphene oxide - organic solvents liquid crystals

It is highly desirable for many applications including liquid crystal formation to have nonaqueous dispersion of graphene oxide (GO). Here, we report our findings on spontaneous exfoliation of graphite oxide flakes into GO in the general class of polar aprotic solvents, which similar to water, induce chemical transformations in GO. We further proposed solvent exchange method as a complementary step to widen the range of organic dispersing media for GO. Having dispersions of very large GO particles results in lyotropic nematic liquid crystalline phases formation for all those solvents at very low GO concentration (typically 0.1 wt%). Suspensions with liquid crystalline phases of GO, provide a basis for fabrication of highly ordered and conductive graphene-based composite materials. For a polymer-graphene composite with layered structure, an exceptionally high electrical conductivity (1050 S m(-1)) is obtained using liquid crystalline GO dispersion in the polymer solution. (C) 2013 Elsevier Ltd. All rights reserved.