A mussel inspired highly stable graphene oxide membrane for efficient oil-in-water emulsions separation

In this work, a simple coating method was employed to prepare a highly stable graphene oxide (GO) membrane for oil-in-water emulsions separation. By using mussel inspired polydopamine (PDA) as covalent linker, mixed cellulose ester membrane (MCEM) was successfully modified with PDA layer by self-polymerize, then GO nanosheets were attracted onto PDA/MCEM by simple vacuum filtration method, lead to the formation of GO/PDA/MCEM. The as-prepared membranes were characterized by FT-IR, TEM, AFM and contact angle, respectively. The results indicated that GO layer was uniformly coated on the support, and GO/PDA/MCEM had a rough surface and good hydrophilic property. Attributing to both the high adhesive ability of PDA and possible covalent interaction between GO and PDA, GO/PDA/MCEM was highly stable by being immersed in water environment for 12 h. GO/PDA/MCEM was employed to separate Tween-80 stabilized oil-in-water emulsions. The results showed that the prepared GO/PDA/MCEM had effective separation performance and reusability in the oil-in-water emulsions filtration for four cycles. This study provided a feasible, simple and economical way to prepare a highly stable GO-based membrane for oil-in-water emulsions filtration.