Eco-friendly production of anti-UV and antibacterial cotton fabrics via waste products

Abstract

A new and simple method based on natural dyeing was developed for producing antibacterial and biodegradable cotton fabrics. Using the aqueous extraction procedure, a natural dye was extracted from boiled pomegranate rinds and prepared into a fine powder. The whey protein isolate was used as an ecofriendly mordant to increase the affinity of cotton fabrics to the pomegranate rind extract. The different dyeing parameters, including dye concentration, temperature, time, and dyeing bath pH, were optimized via reflectance spectrophotometry using the three different pre-mordanting, simultaneous mordanting, and post-mordanting dyeing methods. The pre-mordanting method performed at a temperature of 80 °C yielded the best overall efficiency in terms of dye color strength and depth of shade under the optimized dyeing conditions of a concentration of 70%, pH = 4.5, time = 80 min, a material to liquid ratio of 1:20, and a temperature of 90 °C. The bio-fabrics thus produced exhibited excellent wash and light fastness. The results of FTIR spectroscopy confirmed the chemical interaction between cotton fabrics and the combination of WPI/dye agents. Moreover, SEM micrographs revealed the homogeneous surface morphology of the bio-fabrics without any microscopic cracks or discontinuities in the sample surface. Results also revealed that, with 18 h of contact time, the proposed ecofriendly method was able to produce bio-fabrics that maintained desirable antibacterial properties against pathogenic and spoilage bacteria, even after 10 washing cycles and also exhibited excellent protection against ultraviolet radiation. The results confirmed that this procedure is promising for producing dyed fabrics for biomedical applications without adverse environmental effects and that the natural mordant used is a good replacement for the commonly used metallic ones.