Binary nanofibrous membranes with independent oil/water transport channels for durable emulsion separation

Oil fouling threatens the stability of water permeability for oil-water separation membrane. Homogeneous hydrophilic surface modification provided an opportunity to prevent oil pollution, but failed to maintain stable water traverse due to oil accumulation. Here we report a binary nanofibrous membrane (BNM) through co-electrospinning technique and Michael addition reaction, where hydrophilic polyacrylonitile (mPAN) and hydrophobic poly (vinylidene fluoride) (mPVDF) nanofibers with certain ratio constructed independent water/oil transport channels respectively. The fabricated binary nanofibrous membrane provides stable permeance and high separation efficiency (>99.5%) for viscous oily emulsions in continuous cross-flow filtration. The oil droplets transport experienced deposition, migration, coalescence and removal to significantly alleviate fouling. The binary nanofibrous membrane with heterogenous wetting property provides durable permeation and separation efficiency for durable emulsion separation, which sheds light on a new approach for the development of ideal oil/water separation membranes.