Interfacial Assembly Behavior of Alkylamine-ModulatedGraphene Oxide with Different Oxidation Degrees

Multitudinous studies have been carried out on the controllable functionalization and performance evaluation of graphene oxide (GO). In this study, the correlation between the amount of grafted alkylamine on GO and its interfacial assembly behavior at liquid–liquid and liquid–solid interfaces was studied. GO was modified with n-octylamine through basal functionalization (bGO). The grafting amount of alkylamines was regulated using two GOs varied in oxidation degree (GO_L and GO_H). A study on the oil–water interfacial behaviors shows that bGO_L has better ability to modulate the interfacial tension than that of bGO_H. Grafting alkylamine on GO will not only increase the interaction strength with oil while weaken that with water but also do damage to the graphene lattice and weaken the interaction of π–π stacking; therefore, bGO_L displays a broader capability to modulate interfacial tensions than that of bGO_H. The bGO-based Pickering emulsion was prepared, and the interfacial behavior at the liquid–solid...