A tree-grapes-like PTFE fibrous membrane with super-hydrophobic and durable performance for oil/water separation

Abstract

• Ultrafine tree-grapes-like PTFE fibrous membrane was fabricated. • The size and number of grapes can be controlled. • Superhydrophobic (154.6°) and high porosity (94.2%). • Ultrahigh permeability (3200 L m -2 h −1 ) and high efficiency (greater than99%). • The membrane showed long-term, stable and efficient separation ability. Recently, the membranes with durable and highly efficient separation performances for the purification of oil/water emulsions have drawn wide concern due to the great potential application in solving the problem of offshore oil spill and the discharge of oily wastewater. However, the crucial issues of low-permeability and severe membrane fouling seriously affect their application. Herein, we created an ultrafine tree-grapes-like poly(tetrafluoroethylene) (PTFE) fibrous membrane (UTPFM), which aimed to provide a fibrous membrane with ultrahigh permeability and separation efficiency. The fibrous membrane with regular grapes on fiber surface was fabricated by sintering electro-centrifugal spinning ultrafine fibrous poly(vinylpyrrolidone) (PVP)/PTFE membranes. The size and number of grapes could be simply controlled by the PVP/PTFE ratios, and brought water contact angle (WCA) of obtained fibrous membrane up to 154.6°. As a result, the obtained fibrous membrane presented ultrahigh permeability up to 3200 L m -2 h −1 and high separation efficiency more than 99%. Moreover, the grape structures on fiber surface were demonstrated to bring without any changes after 1000 cycles of abrasion. Therefore, the obtained membrane exhibits a great potential application in the long-term, stable and efficient oily wastewater separation.