The effect of drying modes on aqueous dispersion of graphene oxide solids

Abstract

The graphene oxide solids are derived from four representative drying methods, denoted as AGO (air drying), HGO (heat-vacuum drying), VGO (vacuum drying) and FGO (freezing drying), studied in view of aqueous dispersion. Their dispersion stability was found in order of FGO [Formula: see text] VGO [Formula: see text] AGO [Formula: see text] HGO, corresponding to the increasing C/O ratio of 1.771, 1.778, 2.337 and 2.483 indicated by XPS, respectively. The variation in structure and composition of GO solids caused by different drying processes was further characterized through Raman, XRD, SEM and HR-TEM. By such, the mechanism interpreting the rationale between dispersion and drying for GO was proposed.