UV-assisted stabilization of superhydrophobic nanofibrous membranes for waterproof, breathable and thermal insulation applications

Polyacrylonitrile (PAN)/polyurethane (PU)/hydrophobic silicon dioxide (SiO 2 ) nanofibrous membranes were prepared by electrospinning combined with a UV-induced stabilization method. The PAN/PU/SiO 2 membranes possessed excellent self-cleaning performance because the introduction of SiO 2 nanoparticles endowed the nanofibrous membranes with high surface roughness and good hydrophobicity . In addition, SiO 2 nanoparticles could also promote the waterproof performance of nanofibrous membranes because hydrophobicity improved and pore size decreased with the increase of SiO 2 content. Water vapor transmission rate of the membranes decreased from 10.8 to 9.2 kg m −2 d −1 with increasing of SiO 2 concentration because SiO 2 nanoparticles could fill the spaces among the adjacent nanofibers . Reflectance to sunlight of the PAN/PU/SiO 2 membrane was much higher than that of the PAN/PU membrane, indicating an obvious radiative cooling effect due to loading of SiO 2 nanoparticles. This facile fabrication of fluorine-free superhydrophobic membranes provides advantages for potential applications in self-cleaning materials and versatile protective clothing.