Abstract:
With the public’s enhanced interest to eco-safety and health concerns, environment friendly and non-toxic bio-resource products are regaining popularity in different spheres of our lives. Natural dyes obtained from plants, insects/animals and minerals are renewable and sustainable bio-resource products used in textiles. As the use of synthetic dyes has detrimental effects on environment so natural dyes re-emerge as an alternative to synthetic dyes. The present study was concerned with extraction of colorant and their characterization from different algal groups. Green algae were collected from Faisalabad Pakistan. Brown and red algae were obtained through the courtesy of Marine Biology Department, University of Karachi, Karachi. Extraction of colorants was carried out using aqueous, alkaline and organic media. Different dyeing parameters such as temperature (30-70⁰C), time (30-70 minutes), pH (4-11), salt concentration (4-12 g/L) and material liquor ratio were optimized. For improvement of color strength on to fabric, different mordants such as iron, copper, alum and tannic acid with concentration were applied. Suggested ISO standard method for color fastness to light, washing and rubbing were employed. The results indicated that different algal species used in the study could be potential source of natural colorants for sustainable textile dyeing. In general, alkaline media (KOH solution) proved to be an efficient media for extraction of natural colorants from all algal species used in the study. Condition optimization experiments indicated that 4g/100 ml salt was optimum exhausting agent in case of cladophora glomerata L., 45 minutes time in case of Laurencia obtuse, 7 pH in case of Laurencia obtuse and 75⁰C optimum temperature in case of Sargassum muticum. All the algal species showed maximum light fastness, rubbing and washing fastness properties and proved to be a excellent source of natural colorant. Antimicrobial activity determination experiments indicated that the cotton fabrics dyed with extract of varying algal species showed differential behavior against the two bacterial species E. coli and Staphylococcus aureus used in the study.
