Polyhydroxy phenolic resin coated polyetherimide membrane with biomimetic super-hydrophily for high-efficient oil–water separation

In terms of treating the problem of oily wastewater, membrane separation technology has always been a simple and efficient method of oil–water emulsion separation. Inspired by the hydrophilic bumps of the desert beetle, the polyetherimide (PEI) fiber membrane with super-hydrophilic/underwater super-oleophobic properties was prepared by electrospinning and subsequent seeded aggregation strategy of resorcinol (R) and formaldehyde (F). The membrane (PEI@RF) demonstrates pearl necklace-like structures and good antifouling properties, oil–water separation performances, as well as good stabilities in a variety of environments (immersed in water at high/low temperature, and in acid/alkali/salt solutions). More importantly, the as-prepared membrane exhibits excellent performance for various kinds of oil–water mixtures separation, and the corresponding separation fluxes and efficiencies are above 2600 L/m2·h and 99 %, respectively.