High-strength corrosion resistant membranes for the separation of oil/water mixtures and immiscible oil mixtures based on PEEK

Nowadays, PEEK, as a kind of high performance polymer characterized with high strength, great corrosion resistance and thermal stability is regarded as a promising membrane material. In this study, PEEK fibers were prepared by melt spinning and then woven into textiles. Furthermore, interface reduction was utilized to give a more hydrophilic textile (PEEK-OH textile). In addition, considering to make full use of the huge membrane pores of the textile, a liquid-infused method was employed to regulate its surface energy and to establish an under-water oleophobic surface. Surprisingly, PEEK-OH textile functioned in not only oil/water separation, but also separating immiscible organic liquids with different polarities just through a liquid-infused approach. More importantly, we firstly introduced ‘mediator effect’ during the pre-wetting process before separation, taking ethanol as a ‘mediator’. Furthermore, according to the ‘mediator effect’, an under-oil hydrophobic membrane was established using dichloromethane as a ‘mediator’. As we expected, both PEEK and PEEK-OH textiles revealed features such as high flux, admirable selectivity, competitive strength, great corrosion resistance and thermal stability, herein, they promised to be used for oil/water separation in practical environment.