Quantitative evaluation of coloration and functionalization efficiency for surface modification of regenerated cellulose fabrics

Globally, the ever-growing demand for sustainable, functionalized cellulosic textile fabrics has increased, steering interest towards a new generation of eco-friendly regenerated cellulosic fibers. In this study, sustainable dyed and multi-functionalized Tencel and bamboo fabrics were developed via eco-friendly surface modification, followed by dyeing with natural dyes in the presence or absence of essential oils to fabricate multi-functionalized cellulosic dyeings in a single step. First, Tencel and Bamboo fabrics were modified using biopolymers, namely gelatin (10 g/L) /β-cyclodextrin (7 g/L) in the presence of citric acid/sodium hypophosphite as an environmentally benign crosslinking system via a pad-dry-cure technique. Subsequently, the pre-modified fabrics were dyed with turmeric dye or Natural Brown 6 dye with or without essential oils, namely clove, cinnamon, and tulsi (20 g/L). FT-IR analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, along with quantitative and qualitative evaluations, were performed. The results obtained revealed a significant improvement in antibacterial activity with bacterial reduction percentages exceeding 90%. In addition, excellent ultraviolet protection properties were achieved. The integration of natural dyes and essential oils within the biopolymers resulted in durable coloration, improved functionality, and enhanced performance properties while maintaining air permeability within a reasonable range. The developed approach represents an environmentally benign and effective strategy for producing added-value sustainable textiles with combined aesthetic and protective functionality.