Rational design of dopamine-decorated gradient structure membrane with novel hydrophibic/underwater-oleophobic for oil/water separation

Abstract

The shortage of water resources and the aggravation of water pollution have become global environmental problems. The improvement of the separation performance and flux is still a key challenge that restrict the preparation of high-performance filtration membrane. The gradient structure fibrous membranes were designed and prepared using electrospinning nanofiber and polypropylene/low-melt- point polyester (PP/LPET) micro-fibrous and reinforced via needle-punching and hot-pressing. And the as-prepared membrane was functionalized and directly decorated by dopamine copolymerizes. The novel gradient membrane turned from a hydrophobic state to hydrophilic state, and had excellent mechanical and water transmission properties. Mostly importantly, the as-prepared hydrophilic gradient membranes showed durable oil-fouling repellency and the separation efficiency of oil/water mixture approximate 99% and the flux reach 10,278 ± 1512 L m−2 h−1. This method provides a feasible solution to overcome the high filtration resistance of electrospinning nanofiber membrane, as well as for the preparation of low-cost and high-performance composite membranes and structural regulation of functional membranes.

Keywords

• Needle-punching
• Dopamine
• Gradient structure
• Oil/water separation