Extraction, identification and adsorption-​kinetic studies of a natural color component from G. sepium

In the present work, the major color component isolated from the pods of G. sepium plant is morin, which is a flavonoid moiety. The dyeing behavior of this component on silk yarn was investigated. Mordanting studies have indicated that the post-​mordanting method was found to be a better method than pre-​mordanting. Variation of pH on dye ext. pointed out that the max. absorbance was at pH 4 and hence all the dyeing studies have been carried out at that pH. Thermodn. parameters were detd. by studying the dyeing process at different temps. The heat of dyeing was pos., indicating that the dyeing process was endothermic. The adsorption process of morin on silk was tested with Langmuir, Freundlich, and Tempkin-​Pyzhev isotherm models. The adsorption process followed both the Langmuir and Freundlich isotherms. The value of the regression coeff., however, indicated that the Langmuir isotherm gave the best fit. These results signified that the adsorption of morin on silk yarn was homogeneous in nature with the formation of a monolayer. Hence, the dye obtained from the pods of G. sepium plant may be an alternative source to synthetic dye for the dyeing of silk as well as other textile fabrics