Superlyophobic graphene oxide/polydopamine coating under liquid system for liquid/liquid separation, dye removal, and anti-corrosion

It is highly desirable to develop superlyophobic surfaces under liquid system that can act as a versatile platform for separation of both oil/water and oil/oil mixtures and removing dye from water, but it is still hard to achieve. Herein, a graphene oxide/polydopamine (GO/PDA) coating with superlyophobicity under liquid system was fabricated through the self-polymerization of dopamine anchored on the GO sheet surface. The obtained GO/PDA coating possessed both under-water superoleophobicity and under-oil superhydrophobicity. Utilizing its dual superlyophobicity under an oil/water system, the GO/PDA coated fabric was applied to on-demand oil/water separation. Amazingly, the GO/PDA coated fabric exhibited dual superoleophobicity under an immiscible oil/oil system, which allowed it to separate oil/oil mixtures effectively. Due to the water affinity, layered texture, and absorption effect of the GO/PDA coating, the GO/PDA coated fabric can be served as a filtration module for removing dye from water efficiently. Moreover, the GO/PDA coating could also serve as a barrier to protect metal against corrosion.