Facile fabrication of hydrogel coated membrane for controllable and selective oil-in-water emulsion separation.

The facile fabrication of a hydrogel-networks coated membrane for efficient oil-in-water emulsion separation was successfully achieved through the photo-initiated free radical polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS). Due to the combination of the special wettability of the PAMPS hydrogel with the microscale multi-porous structure of the substrate, such a membrane is able to achieve the separation of sundry surfactants stabilized oil-in-water emulsions with high separation efficiency, large permeation flux and excellent stability. In particular, the PAMPS hydrogel coated membrane exhibits selective separation for cationic and nonionic types of surfactants stabilized emulsions via hydrogen bond interactions. The fabrication protocol is facile, cost-efficient and environmentally friendly, which can be scaled up to facilitate its practicability in sewage remediation.