A study of stable graphene oxide dispersions in various solvents

The work on processibility and practical use of graphene is expanding,so the need for stable dispersion of graphene in different solvents is ever increasing. the dispersion behavior of graphene oxide (go) prepared by modified hummer's method was studied in ten different solvents namely water,tetrahydofuran(thf),dimethyl formamide(dmf),ethylene glycol,acetone,pyridine,2-propanol,methanol,ethanol,and dimethyl sulfoxide (dmso). the effect of sonication and addition of surfactant (sodium cholate) on dispersion behavior was also investigated. homogeneous dispersions were found in all freshly prepared go solutions but they were short lived. the dispersions were then left as such for three weeks and after three weeks they were observed again. it was found that stable dispersions were left only in some solvents like water,thf,dmf,ethylene glycol and pyridine. finally in a separate set of experiment we treated the go solutions in all these solvents with surfactant (sodium cholate) and sonication (400 hrs) to see the dispersion behavior. it was observed that stable dispersion remained only in few solvents like water,dmf,ethylene glycol and pyridine. these were most stable and showed no sedimentation or settling down of go even after three weeks. these solvents are easily available and can be effectively used for dispersion formation and further processing of graphene. © 2015,chemical society of pakistan. all rights reserved.