Radiation Induced Assessment of Dye Yielding Plants as Potential Soruce of Colourant For Textile Dyeing

Abstract

The revival of natural dyes in different walks of life is due to stringent environmental standards imposed by many associations. For current study, three plants such as Arjun bark, Neem bark and Harmal seeds have been selected for dyeing of cotton, wool and silk fabrics under the influence of microwave, ultrasonic and gamma radiation. For this purpose, powder, liquid extracts and fabrics were exposed to microwave (1 to 6 min.), ultrasonic (15 to 60 min.) and gamma radiation (2 to 10 kGy). These treated and un-treated dye extracts obtained in respective media were employed to dye the irradiated and un-irradiated fabrics. The characterization of extract and untreated and undyed irradiated fabric samples were done. For introduction of new shades and improvement of colourfastness properties, different concentrations of chemical and bio-mordant were employed. All dyed fabrics were subjected to CIE LAB System for evaluation of colour strength (K/S) and colour coordinates (Lab values) using Spectraflash SF600 and to rate colourfastness properties using ISO standard methods for light, washing, rubbing, dry cleaning and perspiration fastness. Finally, the results obtained from extraction of colourants from plants in optimal medium and after dyeing parameters have been analyzed statistically through 2-way Anova design. It has been found that using arjun bark, microwave radiation has given very good results after isolation of colourant in acidified methanolic medium followed by dyeing and mordanting onto silk fabric as compared to other radiations and fabrics used. Using neem bark as source of colourant, microwave radiation has also given very good results after isolation of colourant in acidified methanolic medium followed by dyeing and mordanting onto silk fabric as compared to other radiations and fabrics used. Using harmal seeds, it has been observed that ultrasonic radiation has given promising results after isolation of colourant in acidified methanolic medium followed by dyeing and mordanting onto wool fabric as compared to other radiations and fabrics used. It has been inferred that these radiations have not only given the extraction yield of colourant more promisingly in suitable solvents and tuned the fabric surface for enhancing its substantivity towards extracted dye but also along with inclusion of bio-mordants contributed a great role in improving the colour characteristics of dyed fabric with introduction of new shades.