In-situ grown SiO2 on amino-silane modified polyacrylonitrile nanofibrous membranes and its waterproof-breathable and light-shielding properties

Waterproof and breathable (W&B) materials with light-shielding properties are expected to provide new choices for outdoor clothing. Herein, SiO2@PAN nanofibrous membranes were fabricated by a facile and eco-friendly strategy. Firstly, amino-silane modified polyacrylonitrile (PAN-APS) nanofibrous membranes were prepared by electrospinning. Subsequently, a hierarchical rough structure and robust superhydrophobic surface were formed by a one-step in-situ growing SiO2 and coating with hexadecyltrimethoxysilane (HDTMS). The results showed that SiO2@PAN nanofibrous membranes displayed durable water repellency (the water contact angle above 150° and the sliding angle of about 5.3°), and high breathability (the air permeability of 47.23 mm/s and the moisture permeability of 3.92 kg·m−2·d-1). And SiO2@PAN nanofibrous membranes had a certain durability, which water repellency could maintain even after mechanical abrasion, or after 24 h of immersion in acid-base solutions with pH values of 1, 4, 7, 10 and 13. Moreover, SiO2@PAN nanofibrous membranes showed light-shielding properties. After 10 min exposure to sunlight irradiation, the surface temperature of SiO2@PAN membrane was about 10 °C lower than that of PAN membrane and 20 °C lower than the temperature of the surface without covering membrane. This work provides a promising candidate for protective clothing.