Three dimension-printed membrane for ultrafast oil/water separation as driven by gravitation

Facing millions of tons of discharged oily wastewater each year worldwide, it is highly desired to develop eco-friendly, cost-effective and high-efficiency oil/water separation technology with antifouling performance. Herein, three-dimensional (3D) printing technology is applied to develop an eco-friendly acrylonitrile-butadiene-styrene (ABS) membrane that is modified by an eco-friendly plasma strategy without chemical consumption. The modified membrane demonstrates excellent hydrophilicity and oleophobicity, with a water contact angle of 8.8° and underwater oil contact angle of 137.6°. Only driven by tiny gravitation force, the modified membrane exhibits an ultra-high flux of 1.17 × 105 L·m-2·h-1 with 99.60% rejection for five typical oil/water systems. The rejection maintains 99.40% after 100 cycling tests during a four-month period, demonstrating superior stability and recyclability of the membrane. To our knowledge, this membrane largely outperforms all the state-of-the-art membranes for oil/water separation. In particular, the electron transfer of liquid and solid (L-S) surface during the contact electrification (CE) process is firstly introduced to interpret the membrane separation process. This work opens an avenue to fabricate appealing performance membranes for oil/water separation.