A Unique Approach for Functionalization of Cotton Substrate with Sustainable Bio-based Vanillin for Multifunctional Effects

Exploration of novel bio-based materials for value addition of textile substrates is a desirable research trend. In this context, vanillin (4-hydroxy-3-methoxybenzaldehyde), a bio-based material (obtained from vanilla pod) having multifunctional properties, can be a well-suited candidate. In the present article, both the vanillin alone and vanillin–copper (vanillin-Cu) complexes have been incorporated into cotton textiles separately using a high temperature-high pressure (HT-HP) dyeing machine and the quantity of copper has successfully been optimized to demonstrate enhanced properties. The vanillin-treated fabric has shown very good all-round properties like ultraviolet protection factor (UPF), color value (K/S value), and antibacterial activity (AM) in the presence of copper salt. However, only vanillin itself has rendered as such no UPF value but demonstrated 70% antimicrobial activity against E. coli (Gram-negative) bacteria and during washing operation small molecules of vanillin get leached out of fabric (as represented by significant loss in properties). This is the first time that the functional properties of vanillin and vanillin-Cu complex have directly been explored on cotton textile wherein significantly enhanced properties have been achieved on vanillin-Cu complex-treated fabric (i.e. 99% AM, a good UPF factor of 78, K/S value of 11.55, and even 25% antioxidant activity).