Fabrication of superhydrophobic and UV-resistant surface on cotton fabric via layer-by-layer assembly of silica-based UV absorber

A hybrid UV absorber (SiO2-H) was successfully synthesized by functionalizing nanosilica (SiO2) with 2,4-dihydroxybenzophenone and then was introduced onto the surface of cotton fabric by sequentially depositing in poly (diallyl dimethyl ammonium chloride) (PDDA) aqueous solution and SiO2-H suspension via layer-by-layer assembly method. The SiO2-H particles imparted excellent ultraviolet (UV) resistance property to the cotton fabric, while forming nano- and micro structure on the surface of cotton fabric, making the fabric superhydrophobic after the modification with hexadecyltrimethoxy silane (HDTMS). The surface morphology, wetting behavior, UV resistance and physical properties of cotton fabrics were studied. According to the results, the modified cotton fabric not only showed strong UV-resistant ability with Ultraviolet Protection Factor (UPF) value as high as 500, but also displayed superhydrophobicty with WCA of 153 ± 1°. Moreover, the durability of multifunctional surface was examined by laundering and abrasion tests. The modified fabrics still maintained hydrophobic property and excellent UV resistance after 300 abrasion or 20 laundering cycles, demonstrating outstanding durability.