Color Performance, Durability and Handle of Inkjet-Printed and UV-Cured Photochromic Textiles for Multi-Colored Applications

The development and design of novel functional and smart textile materials such as textile sensors and multicolored systems based on photochromic dyes necessitate controls of color intensities, switching speeds, and material durability. Precise control and synchronization of dye kinetics are important for multi-colored photochromic applications especially. However, durability towards abrasion and washing should not be compromised on if we aim to design reliable future textile products. In this study, two different commercial photochromic dyes — a naphthopyran and a spirooxazine-based dye — have been applied on PET fabric by inkjet printing and UV-LED curing. The photochromic textiles’ color behavior, fastness to abrasion and washing, and handle are evaluated using spectrophotometry, scanning electron microscopy, and Kawabata evaluation system. Despite a decrease in color performance after washing, the photochromic inkjet print is effective and barely influences the textile structure. Reduced rigidity of the host matrix promoted higher color yields and faster dye kinetics, but also improved durability towards abrasion and washing. In order to synchronize kinetics of the different dye types for multi-colored applications, distinct curing conditions are preferable, which, however, result in varying print durability. In the design of multi-colored photochromic textiles, dye kinetics, and durability have to be balanced.