Preparation and characterization of high concentration graphene aqueous dispersion

Abstract

The high concentration graphene aqueous dispersion was obtained by high-pressure homogenization liquid phase exfoliation (HPH-LPE) of flake graphite in water. The effect of surfactant concentration, HPH pressure and cycle number on the concentration of graphene dispersion CG was studied by UV-Vis spectra. The structure and morphology of graphene were analyzed by Roman spectra, SEM and TEM. The results indicate that CG is obtained up to 324.3mg·L-1 for the first time by the parameters optimization, which is 10 times higher than that obtained by sonication; graphene obtained has few defects, thin thickness and large size, indicating the good quality of graphene production; the conductivity of free-standing film prepared by the obtained graphene dispersion can reach 3.2×104S·m-1.

Keywords

• flake graphite
• high-pressure homogenization liquid phase exfoliation
• graphene aqueous dispersion
• high concentration