Rapid Probing of Self-Cleaning Activity on Polyester Coated by Titania–Natural Silica Nanocomposite Using Digital Image-Based Colorimetry

Titania–silica nanocomposites (TiO2–SiO2) show outstanding performance and is very well applied in photocatalysis. In this research, SiO2 extracted from Bengkulu beach sand will be used as a supporting material of the TiO2 photocatalyst for application to polyester fabrics. TiO2–SiO2 nanocomposite photocatalysts were synthesized using the sonochemical method. The coating of the TiO2–SiO2 material on polyester was carried out using the sol–gel-assisted sonochemistry method. The method of determining self-cleaning activity uses a digital image-based colorimetric (DIC) method, which is much simpler than using an analytical instrument. The scanning electron microscopy–energy dispersive X-ray spectroscopy results showed that the sample particles adhered to the fabric surface and the best particle distribution was shown in pure SiO2 and 1:0.5 TiO2–SiO2 nanocomposites. Analysis of Fourier-transform infrared (FTIR) spectroscopy proved the presence of Ti–O and Si–O bonds as well as the typical spectrum of polyester, which indicated that the fabric had been successfully coated with nanocomposite particles. The analysis of the contact angle of the liquid on the polyester surface showed a significant change in the properties of the TiO2 and SiO2 pure coated fabrics, but changes occur only slightly in the other samples. Self-cleaning activity against the degradation of methylene blue dye has been successfully carried out using DIC measurement. The test results showed that the best self-cleaning activity was shown by TiO2–SiO2 nanocomposite with a ratio of 1:0.5 with the degradation ratio reaching 96.8%. Furthermore, the self-cleaning property remains after the washing process, which shows excellent washing resistance