Insights into the dyeing using natural indigo (Indigofera tinctoria): Toward an environmentally friendly garment

Abstract

Currently, the use of natural indigo dye has been treated as an alternative to overcome the environmental pollution caused by synthetic indigo. Irrespective of the indigo dye source, it must be reduced to its soluble form by using reducing agents in a suitable alkaline environment. Herein, bio-sugars such as glucose or fructose were used for this purpose. The results revealed that when fructose was used instead of glucose, colour strength (K/S) values increased. In this work, cotton was cationised with water-soluble chitosan. Water-soluble chitosan in a wide pH range extends the use of chitosan in textiles, which otherwise is limited due to its poor water solubility at pH above 6.0. Colour fastness washing test was conducted to evaluate the efficacy of cotton cationisation. The performance of cationised samples was around 30% higher in comparison to non-cationised samples. Moreover, in this article we have focused on integrating materials and design. We propose a garment, using natural indigo-dyed cotton and a zero-waste modelling approach, as a sustainable fashion product.