Colorant-free coloration and superhydrophilic modification of poly(ethylene terephthalate) fabric surface by H 2 O 2 and nano-TiO 2 ultraviolet photocatalysis

Abstract

In the paper, synchronous colorant-free coloration and superhydrophilic modification of poly(ethylene terephthalate) (PET) fabric surface were successfully investigated. PET fabric surface treated by nano-TiO₂-H₂O₂/ultraviolet light becomes both a brilliant kelly with a color strength (K/S) value of 3.0147 and superhydrophilic with a water contact angle of 0° in a short time. The coloration parameters were optimized and PET fabric can be uniformly colored without colorant used. The wash fastness, rub fastness and light fastness of treated PET fabric were similar to the control PET fabric. The mechanical properties of modified PET fabric were hardly affected. The chemical structure of modified PET surface was investigated by X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform infrared spectra, demonstrating –COOH, >C = O, −NO and –NO₂ new groups. The mechanisms of coloration and superhydrophilic modification of PET surface were proposed. Scanning electron microscopy images showed that new materials were formed on the surface of modified PET fibers. X-ray diffraction and thermogravimetric analysis indicated that the crystallinity increased a little and the thermal stability of modified PET fibers clearly increased. This novel method exhibited highly efficient and eco-friendly advantages for both coloration and superhydrophilic modification of PET fabric surface.