Fig. 2
From: Acid-less direct gram scale exfoliation of graphite to partially oxidized graphene

(a) Digital photograph of POG material, rGO (standard reduction method), and GO (modified Hummers method) water dispersion; all pictures were taken on the same day. (b) zeta potential values for the fresh samples and after 3 months of storage time-duration. The POG material shows a good dispersion behavior, similar to GO in water and exhibits long-term stability than rGO and GO. Few additional digital photographs of the three suspensions are added in SI as Figure S1 (a, b).