Photostability of TiO₂-Coated Wool Fibers Exposed to Ultraviolet B, Ultraviolet A, and Visible Light Irradiation

Abstract

This study is to investigate the role of the coating of TiO2 nanoparticles deposited on wool fibers against high-intensity ultraviolet B (UVB), ultraviolet A (UVA), and visible light irradiation. The properties of tensile and yellowness and whiteness indices of irradiated TiO2-coated wool fibers are measured. The changes of TiO2-coated wool fibers in optical property, thermal stability, surface morphology, composition, molecular structure, crystallinity, and orientation degree are characterized using diffuse reflectance spectroscopy, thermogravimetric analysis, scanning electronic microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction techniques. Experimental results show that the tensile properties of anatase TiO2-coated wool fibers can be degraded under the high-intensity UVB, UVA, and visible light irradiation for a certain time, resulting in the loss of the postyield region of stress–strain curve for wool fibers. The coating of TiO2 nanoparticles makes a certain contribution to the tensile property, yellowness and whiteness indices, thermal stability, and surface morphology of wool fibers against high-intensity UVB, UVA, and visible light irradiation. The high-intensity UVB, UVA, and visible light can result in the photo-oxidation deterioration of the secondary structure of TiO2-coated wool fibers to a more or less degree. Meanwhile, the crystallinity and orientation degree of TiO2 coated wool fibers decrease too.

Effects of UV radiation on natural and synthetic materials

“…UV-absorbing oxide particles used either as a nanofiller or surface application to decorate the fibres can decrease the UV transmittance of fabrics incorporating them [193][194][195][196], as shown in Fig. 6.…”