Synergistic effects of Janus graphene oxide and surfactants on the heavy oil/water interfacial tension and their application to enhance heavy oil recovery

The interfacial activities of graphene oxide (GO) and two kinds of Janus graphene oxide (JGO150 and JGO400), i.e., GO with one side being modified by two different amount of dodecylamine, were evaluated in various oil/water systems. Based on the results of IFT measurement, JGO showed the greater interfacial activity than original GO, especially for JGO400 which greatly reduced the heavy oil/water IFT to 0.12 mN/m. Molecular dynamic simulations were employed to illustrate the interfacial interaction between GO/JGO and oil molecules. Furthermore, the interaction between three kinds of nano-sheet materials and three types of surfactants, including dodecyltrimethylammonium bromide (DTAB), sodium dodecyl sulfate (SDS), and Triton X-100 (TX-100), were systematically investigated in the heavy oil/water system. The JGO400/DTAB system exhibited excellent synergistic effects to dramatically decrease the heavy oil/water IFT to 8 × 10 −3  mN/m, which was responsible for its remarkable ability to improve heavy oil recovery (19.5%) in core flooding tests.