Kinetic and adsorption studies of Indian siris (<i style="">Albizia lebbeck</i>) natural dye on silk

Abstract

Spectral techniques have been used to identify and characterize the color constituent of the bark of <i style="">Albizia lebbeck</i>. The dyeing potential and color fastness properties of the extract have been evaluated on silk yarn. Pre-mordanting of the dye is found to be better than post-mordanting, particularly with alum which gives higher color strength values. The color co-ordinates of dyed samples lie in the yellow-red quadrant of color space diagram. The kinetic and adsorption studies on the dye uptake by silk yarn have also been carried out. The positive standard affinity indicates a spontaneous adsorption. During the dyeing process the enthalpy change is positive, indicating an endothermic process with large negative entropy change. This implies an uniform ordered distribution of dye on silk. The adsorption of the dye fits into the Langmuir model of isotherm having high regression coefficient. These findings indicate that the color extract of the bark of <i style="">Albizia lebbeck</i> serves as a potential natural dye for silk fabrics.