A simple and efficient protocol to develop durable multifunctional property to cellulosic materials using in situ generated nano-ZnO

This article focuses on the development of a durable multi-functional finish for cotton fabric by direct synthesis of nano zinc oxide (nano-ZnO) particles in the pores of the fibres. Anions and cations of zinc nitrate interacted with cellulose molecules and opened up the internal pore structure of cellulosic fibrils that in turn acted as nucleating sites for the formation of nano-ZnO on reaction with sodium hydroxide. The finished fabric was characterized using XRD, FTIR, SEM, TEM, AAS, DSC and AFM. The finished fabric displayed excellent antibacterial activities (>99%) against two pathogens, Staphylococcus aureus (Gram-positive) and Klebsiella pneumoniae (Gram-negative) with 40 UPF even after 30 washes confirming the utility of this method. Inherent physical and mechanical properties of the fabric were found to be unaffected. Low stress mechanical properties evaluated by Kawabata Evaluation System for Fabrics indicated that the total hand value of the finished fabric changed from 3.54 to 3.40. A plausible mechanism for in situ formation of nano-ZnO and its durability on cotton fabric has been proposed.