In situ formation of ultrathin polyampholyte layer on porous polyketone membrane via a one-step dopamine co-deposition strategy for oil/water separation with ultralow fouling

Fouling caused by oils or other pollutants is one of the most important obstacles for membrane application in oil/water separation. To improve the anti-oil-fouling property, a new polyampholyte layer of poly (2-meth-acryloyloxyethyl phosphorylcholine-co-2-aminoethyl methacrylate hydrochloride) (MPC-co-AEMA) was in situ formed on the porous polyketone membrane via an extremely simple one-step dopamine co-deposition strategy. The MPC-co-AEMA layer was firmly immobilized on a polyketone membrane via polydopamine (PDA) adhesion and covalent crosslinking between MPC-co-AEMA and polydopamine. Thus, a robust superhydrophilic and underwater superoleophobic surface was formed on the PDA&MPC-d-PK membrane. The ultrathin polydopamine/MPC-co-AEMA layer on PDA&MPC-d-PK membrane endowed it with a high water permeance of 10,700 L m(-2) h(-1) bar(-1), as well as high emulsion permeance of 10,100 L m(-2) h(-1) bar(-1), and oil rejection of 99.9%. Owing to the unique design of the superhydrophilic polydopamine/MPC-co-AEMA layer combined with intrinsically hydrophilic polyketone membrane, high fouling-resistance and fouling-releasing properties of PDA&MPC-d-PK membrane were achieved even for the viscous surfactant-stabilized soybean oil-in-water emulsion.

Automated summary

By forming a new polyampholyte layer on a porous polyketone membrane, the anti-fouling property of the membrane in oil/water separation was improved, resulting in a superhydrophilic and underwater superoleophobic surface with high water permeance, emulsion permeance, and oil rejection.