Improving Natural Dye Uptake in Tencel Fabrics Through Ozone Treatment

This research examined the impact of ozone surface alteration on the dye absorption of Tencel textiles using natural dyes devoid of mordants. Fabric specimens received ozonation at two distinct gas flow rates (5 L/min and 15 L/min) for two different durations (30 min and 60 min) before being dyed with madder and barberry root dyes. Dye uptake, oxycellulose content, color properties, and staining-based fastness of the dyed fabrics were examined. Chemical and morphological changes were characterized by FTIR and SEM analyses. The results revealed that ozone surface modification altered the surface properties of the fabrics, leading to an increase in dye uptake and an improvement in color strength. For both natural dyes, the highest color yield was observed at the ozonation condition of 15 L/min for 30 min. Under optimum conditions, the maximum K/S value was determined as 1.61 for madder dyeing and 3.28 for barberry root dyeing. Furthermore, it was determined that the mechanical and staining-based fastness properties of the fabrics remained within acceptable limits under the selected optimum conditions. This enhancement is consistent with the increase in surface roughness observed in SEM analyses and the formation of oxygen-containing functional groups identified in FTIR spectra. The morphological irregularities formed on the fiber surface as a result of ozone treatment increased the effective surface area, while the increase in carbonyl and hydroxyl groups enhanced fiber polarity, thereby strengthening the intermolecular interactions between the dye and the fiber. The research findings show that ozone-based surface modification is an environmentally friendly pretreatment method that reduces chemical consumption while improving the dyeability of cellulose-based fabrics with natural dyes, and holds promise for future sustainable textile applications and natural dyeing research.