microrough

structures on the surface of hydrophobic membranes is a challenge in the oil–water separation process. In this regard,

it is crucial to develop a simple method to prepare stable superhydrophobic membranes. This article prepared superhydrophobic

polyvinylidene fl uoride (PVDF) membranes, employing a combination of thermally induced phase separation (TIPS)

with rolling embossing. The gel state of the membrane surface is the key core for the success of the process, for which the

eff ect of pre-evaporation time on the membrane properties was explored. A turning point in the gel curve occurred at a preevaporation

time of 1.5 min, when the gel state of the membrane was most suitable for rolling. The surface of the embossed

membrane shows a micron–submicron hierarchical structure reminiscent of the lotus leaf surface, and the surface of the

membrane presents a water contact angle of 151° and a solid contact angle of 9.5°. The micrometer submicron hierarchical

structure exhibits excellent mechanical stability in friction experiments, with a water contact angle only reduced by 7.9°

after 50 sandpaper frictions. Cross-fl ow fi ltration was signifi cantly superior to dead-end fi ltration in oil–water separation, the

embossed membrane maintained a high fl ux of 1234 L•m −2 •h −1 and a retention rate (α) of 99.10%. Meanwhile, the embossed

membrane can remove 100% of mechanical impurities and water from waste diesel fuel. This study provides certain ideas

and methods for the preparation of superhydrophobic microporous membranes.