Superhydrophobic and breathable polydimethylsiloxane/nano-SiO2@polylactic acid electrospun membrane with core-sheath fiber structure

Polylactic acid (PLA) has great potential to replace traditional petroleum-based polymers, especially in membrane production, due to its biocompatibility, degradability, and renewability. However, there are rare reports of superhydrophobic and breathable PLA membranes. In this work, a multifunctional PDMS/SiO2@PLA membrane with superhydrophobicity and breathability was prepared by coaxial electrospinning method to coat the surface of PLA fiber with a thin layer of biocompatible polydimethylsiloxane (PDMS) and nano-silica particles. The prepared membrane has a water contact angle (WCA) of 151.8 ± 1.3° and a water sliding angle (WSA) of 5.7 ± 0.3°. Thanks to its superhydrophobicity, it can support a water column of 195 cm. The membrane has excellent breathability that its water vapor transmission rate is ~14.7 kg·m−2·24 h−1. Moreover, the freezing time of the membrane is 2.25 times longer than that of the original PLA membrane. In addition, it has an oil-water separation efficiency of 99.9 % and a flux of ~12,300 L·m−2·h−1. The overall performance of this multi-functional PDMS/SiO2@PLA membrane is one of the best among the fluorine-free electrospun membranes.