Morphology and Fluctuations of Suspended Graphene Oxide Sheets*

We study the morphology and fluctuations of suspended graphene oxide sheets by phase contrast and confocal microscopy. The morphology of graphene oxide sheets is manipulated by changing solvent pH. Labeling the graphene oxide sheets with quantum dots permits further study of morphology, as well as the possible study of the fluctuations, through the use of confocal microscopy. The direct imaging studies of the morphology are complimented by light scattering studies, conventionally used to characterize morphology of colloidal membranes. These direct imaging studies can lead to measurements of the mechanical properties of graphene oxide in solution.