Characterization and application of blue pea flower (clitoria ternatea) natural dyes on cotton fabrics through a study of three pre-treatment techniques

This paper has explored the use of Clitoria ternatea (Blue Pea Flower) as natural dye of cotton fabrics, and it has focused on enhancing the dye uptake, colour intensity and fastness attributes using chemical pre-treatment and mordanting. An aqueous method was used to extract fresh blue pea flowers. Three treatment conditions were applied to cotton fabrics, first were not treated (control), second were copper mordanting, and the third one were hydrogen peroxide pre-treatment with copper mordanting. Evaluation test of the dyed fabrics consisted of ISO based on colourfastness tests, semi-field exposure to sunlight and rain and through UV-Vis spectrophotometric analysis. These findings showed that the pre-treatment of the tissue using hydrogen peroxide and copper mordanting gave the dark and most consistent blue coloration and the best resistance to washing, rubbing, exposure to light and environmental effects. Based on UV-Vis analysis, an increase in absorbance intensity of dye baths and spectral changes in copper-treated dye baths indicate that the anthocyanin has been more stable as a result of metal-ligand coordination. Overall, the results demonstrate that proper fibre surface alteration and mordanting have a significant impact on the performance of Clitoria ternatea dyes, which can justify their possible utilisation as an alternative to dye textile application in terms of sustainability