Fabrication of palygorskite coated membrane for multifunctional oil-in-water emulsions separation

Abstract With the rapid development of industrial growth, the issue of severe water pollution risen from oily waste water, dye waste water, and frequent oil spill accidents has become a bottleneck for hindering the global sustainable development. Herein, we report the facile fabrication of a superhydrophilic/underwater superoleophobic multifunctional separation membrane by vacuum assisted filtration technology using palygorskite (Pal) as raw material. The Pal coated membrane show excellent thermal， chemical stability, and mechanical strength with 300 bending times. As expected, the membrane has excellent separation performance, e.g. it exhibits an enhanced permeation flux of 477.7 ± 5.0 L m−2 h−1 bar−1 and a high separation efficiency of up to 99.6% ± 0.05%. In addition, it can separate different oil-in-water emulsions in harsh environments. Interestingly, the as-prepared membrane can also remove organic dyes in the water phase during the separation process, making it multifunctional and promising membrane for water treatment, by combination with its simple and cost-efficient manufacture, excellent physicochemical properties. More importantly, our work may also open a new way for high-increment utilization of palygorskite mineral with a “green” method.