Application of Copper Nanoparticles on Cotton Fabric to Improve Dyeing Properties with Punica granatum

Natural dyes produce very uncommon, soothing and soft shades on cotton fabric. But these dyes are fugitive, even when applied in conjunction with a heavy metal mordant. Thus, their colour fastness performance ratings are inadequate and somehow pollute the environment with the release of heavy metallic mordants. Nanotechnology has helped in limiting both of the demerits tremendously by engineering the modification on the fabric surface. This study deals with application of copper nanoparticles (CuNPs) as mordant on cotton fabric followed by dyeing with the rind of Punica granatum (pomegranate). CuNPs with the average size of 6-8nm, are synthesized by a greener process and the morphology is examined by SEM, TEM techniques and UV-Visible spectroscopy. Pre-mordanting and simultaneous mordanting are employed with copper sulphate and CuNPs. The results show that simultaneous mordanting using CuNPs enhances the colour strength (i.e, K/S value) to 56% and in case of pre-mordanting, it increases to 47% when compared with that of copper sulphate as mordant. On increasing the temperature from 45 0 C to 60 0 C, a further increase in 10-14% of K/S value is observed in both the cases. Also, wash fastness and light fastness properties have enhanced simultaneously.