Functional modification of breathable polyacrylonitrile/polyurethane/TiO2 nanofibrous membranes with robust ultraviolet resistant and waterproof performance

Superhydrophobic PAN/PU/TiO2 multiple functional membranes are imparted with UV resistance, water repellency and moisture breathability through electrospinning and doctor-blading coating modification. The modified membranes exhibit double UV resistant function with both reflection and absorption. [Display omitted] Exploiting high-added-value textiles equipped with multiple functionalities like ultraviolet (UV) resistance, waterproofness, and thermal-moisture comfort is facing tremendous demand by a more discerning consumer market. However, the major challenge is to realize the equilibrium among the multifunction. Herein, a new attempt of fabricating superhydrophobic electrospun polyacrylonitrile (PAN)/polyurethane (PU)/titanium dioxide (TiO2) nanofibrous membranes has been tried, and the membranes exhibited multifunction of UV resistance, waterproofness and breathability by coating modification with 2-hydroxy-4-n-octoxybenzophenone (UV531) and fluorinated acrylic copolymer (FAC). TiO2 NPs as inorganic blocker and UV531 as organic absorber were utilized to impart the excellent double UV resistant function for the modified nanofibrous membranes. The hydrophobic coating with FAC endowed the pristine membranes with enhanced superhydrophobic wettability and the advancing contact angle was 152.1°. Regulating the addition amount of TiO2 NPs, the UV531 and FAC concentration, the multiple functionalities of the modified PAN/PU/TiO2 were systemically optimized: robust tensile strength (14.6MPa), good ultraviolet protection factor of 1485, modest waterproofness (62kPa), and moisture breathability (12.9kgm−2 d−1). The equilibrium among the multifunction of the as-prepared membranes indicated their diverse possibilities can be used in various applications, including high-altitude garments, protective clothing, covering materials, self-cleaning materials, and other medical products.