▎ 摘　　要

In this study, cotton fabrics were coated with silica (SiO2)/reduced graphene oxide (RGO) nanocomposites to obtain the asymmetric wettability (i.e., two surfaces present different wetting properties), excellent air permeating and thermal insulating properties. The coating process was conducted in three steps, i.e., preparing SiO2/GO nanocomposite inks with different SiO2 weight ratios, coating the SiO2/GO inks on cotton fabrics by spray coating and getting the SiO2/RGO fabrics using hot pressing method at a temperature of 180 degrees C. Morphology, chemical structures, thermal stability, wettability, air permeating and thermal insulating properties of the SiO2/RGO coated fabrics were measured. Results indicated that the SiO2 nanoparticles were evenly distributed on the surface of the fabric and enhanced its roughness, and RGO reduced its surface energy. SiO2/RGO fabric with SiO2 weight ratio of 20% showed larger water contact angle (i.e., 151.4 degrees) than both the uncoated and coated fabrics with other SiO2 weight ratios. Besides, it had excellent stability of hydrophobicity, which could maintain the spherical shape of water droplets for 80 min in air (20 degrees C and 65% RH). SiO2/RGO coated fabrics also exhibited better thermal insulation performance than that of the uncoated fabrics, and the SiO2/RGO coating did not impact the air permeability of the cotton fabrics. The study provides a fast and simple spray coating method for developing fabrics with multifunctional properties, which can be used in the development of functional clothing such as winter outdoor clothing that is waterproof and provides better thermal insulation while maintaining breathability.