Solubilisation of Red Pigments from Canna Indica Flower in Different Media and Cotton Fabric Dyeing

摘要

Background: Dissolution of partially insoluble natural pigment is generally a major problem. Thus attempts were made to dissolve pigments from canna flowers in different media. Aqueous, oil/water micro-emulsion, ethanolic and its oil/water micro-emulsion were prepared and used for dyeing cotton. RESULTS: Oil/water/surfactant emulsion was used for this particular plant pigment. The role of oii/water/surfactant emulsion in dye migration at the micelles for dissolution of canna pigments from the ethanolic extract and its release for better dyeability for dyeing cotton was observed. The ease of solubilisation of canna pigments in oil/water micro-emulsion and its influence in dye exhaustion and fixation on cotton fabric was found to be the better than aqueous extractant. Extraction of 25g/50m! fresh red canna flower was used to dye 10g cotton piece to the desired colour. Use of higher amounts did not yield substantial colour strength. CONCLUSION: The condition of the flower-fresh or frozen - was found to have significant effect on colorant content and colour strength, thus in an optimised o/w microemulsion of ethanolic extract of frozen flower best results were observed. Microemulsions are also proposed as standard dye formulation for canna pigments, which can be diluted as per the dyeing requirements. Fastness properties were evaluated for aqueous and ethanolic o/w emulsion dyed samples, showing marked difference. Better solubility of plant pigments causes better adherence through oii/water/surfactant microemulsion. Keywords: Canna indica, Extraction methods. Oil/water microemulsion, Natural dyeing, Cotton Fabric.