Superhydrophobic Polyvinylidene Fluoride Nanofibrous Membranes with Stable Hierarchical Structures for Protective Textiles

Waterproof and breathable (W&B) membranes, resisting the intrusion of liquid water while allowing trans-mission of vapor, have been widely applied in various applications. However, there are still great challenges to construct superhydrophobic and mechanically robust W&B membranes. Here, we present a facile strategy to prepare superhydrophobic nanofibrous membranes by combining humidity-induced electrospinning with thermal-pressing treatment. The hierarchical rough structures generated by humidity-induced phase separation of polyvinylidene fluoride jets endow the fiber with superhydrophobicity. Meanwhile, the thermal-pressing manipulation ensures that strong physical bonding exists between nanofibers, which greatly improves the membrane's mechanical and waterproof performances. Significantly, the resulted membranes exhibited desir-able superhydrophobicity with water contact angle of 151 degrees, remarkable water and oil intrusion pressures of 81.8 and 36.2 kPa, respectively, high water vapor transmission rate of 7948 g m- 2 d-1, and satisfactory tensile strength of 8.1 MPa. The successful development of such membranes provides a new inspiration for the manufacture of superhydrophobic protective membranes.