Superhydrophobic and Ultraviolet-Blocking Cotton Textiles
mediaposted on 27.04.2011, 00:00 by Lingling Wang, Xintong Zhang, Bing Li, Panpan Sun, Jikai Yang, Haiyang Xu, Yichun Liu
Cotton textile was coated with ZnO@SiO2 nanorods in order to obtain superhydrophobic and ultraviolet (UV)-blocking properties. The coating process was conducted in mild conditions, which involved the low-temperature preparation of ZnO seeds, hydrothermal growth of ZnO nanorods, bioinspired layer-by-layer deposition of a SiO2 shell on the surface of ZnO nanorods, and hydrophobic modification of ZnO@SiO2 nanorods with octadecyltrimethoxysilane. Despite the highly curved morphology of cotton fibers, the ZnO@SiO2 nanorods coated the textile densely and uniformly. The treated cotton textile was found to have a large UV protection factor (UPF = 101.51) together with UV-durable superhydrophobicity, as determined by contact-angle measurement under long-term UV irradiation. The good UV-blocking property can be ascribed to the high UV absorbance and scattering properties of ZnO nanorods, and the UV-durable superhydrophobicity is a result of suppression of the photoactivity of ZnO nanorods by a SiO2 shell.