Nanofinishing of wool and blended fabrics with TiO 2 for UV protection and photoyellowing reduction

Abstract

The effectiveness of nanocrystalline titanium dioxide (TiO 2 ) (P-25) in enhancing protection against ultraviolet rays and reducing photoinduced yellowing was evaluated through its application to wool fabrics and wool blends (such as wool–polyester and wool–polyester–spandex). The nanofinishing treatment was performed using a pad–dry–cure process, employing TiO 2 concentrations ranging from 0.1 to 5 g/L. After 24 h of accelerated ultraviolet radiation, colorimetric analysis (using the CIELAB system) revealed that the TiO 2 particles effectively reduced the rate of photoinduced yellowing (Δ E ), acting as an ultraviolet absorber that dissipates energy and protects the fibers or textile materials from photo-oxidation. Untreated fabrics showed considerably lower levels of ultraviolet protection than treated samples, and the experimental results demonstrated that all treated samples maintained excellent or very good ultraviolet protection factor ratings (up to 50+). Scanning electron microscopy confirmed the presence of TiO 2 on the fiber surface. Furthermore, Fourier transform infrared spectroscopy and contact angle measurements confirmed that the treatment inhibited the formation of functional groups responsible for yellowing and reduced the increase in hydrophobicity. It can thus be concluded that nano-TiO 2 finishing is an effective method for improving the photostability and performance of wool-based textiles.