Influence of gamma radiation on the colour strength and fastness properties of fabric using turmeric (Curcuma longa L.) as natural dye Ijaz A. Bhatti a,n , Shahid Adeel a , M. Asghar Jamal b , Muhammad Safdar c , Muhammad Abbas d a Department of Chemistry, University of Agriculture, Faisalabad 38040, Pakistan b Department of Chemistry, G.C. University, Faisalabad 38040, Pakistan c Department of Chemistry, University of A J & K, Muzaffarabad, Azad Kashmir, Pakistan d Haris Dyes and Chemicals, Faisalabad 38040, Pakistan article info Article history: Received 3 July 2009 Accepted 7 December 2009 Keywords: Irradiation Fabric Dyeing Mordanting Fastness properties Spectraflash SF-650 abstract The effect of gamma radiation on the dyeing of cotton with extract of turmeric (Curcuma longa L.) powder has been investigated. Cotton fabric and turmeric powder were irradiated to absorbed doses of 1, 2, 3, 4 and 6 kGy using Co-60 gamma irradiator. Dyeing parameters such as temperature, pH and mordant concentration were optimized. Dyeing was performed using un-irradiated and irradiated cotton with the extracts of un-irradiated and irradiated turmeric powder in order to investigate the effect of radiation treatment on the colour strength of dyed fabric. The reported data of un-irradiated and irradiated fabrics dyed with un-irradiated and irradiated dyes were obtained using the spectraflash SF-650. The colourfastness to light, rubbing- and washing-fastness properties showed that gamma irradiation has improved the dyeing characteristics from fair to good. & 2009 Elsevier Ltd. All rights reserved. 1. Introduction Dyeing was practiced in ancient times and has undergone many changes in reaching todays’ development. In the early age, textiles were dyed using plants and animal sources, but with the advent of synthetic dyes, the use of natural dyes in textiles was eliminated since synthetic dyes give variety of shade and colours (Deo and Desai, 1999). Recent studies show that synthetic dyes are non-biodegradable, allergic and some are carcinogenic. Many countries are reluctant to use, import and export the products that are not eco-friendly. Again the world trend is inclined towards natural dyes in textiles as well as in food processing. Natural dyes are biodegradable, health curing, extracted under mild reaction conditions and have no disposal problem due to their compatibility with environment (Sachan and Kapoor, 2004). Gamma radiation treatment of fabric may facilitate shrinking and wrinkling resistances of fibers, raises the rate of dye uptake, fixes more dye on fibers as well as improve the shade of the dyed fabric (Millington, 2000). Radiation treatment of colouring substances not only improves the extraction of colourant but also deepens the colour of extract without any adverse change in their physiological characteristics (Kim et al., 2006). Turmeric rhizome has been selected as a colouring material in the present study for dyeing of cotton fabric. It is a rich source of phenolic compounds called curcuminoids (Teli et al., 1994). The active colouring ingredient in turmeric rhizome is Curcumin, which is also known as Natural Yellow 3 (C I 75300).Its general formula is given below: It is only the brightest yellow natural dye, which belongs to diaroyl-methane group named as diferuloyle-methane. It is also well known for its anti-carcinogenic, anti-inflammatory, anti-microbial, anti-parasitic, anti-mutagenic, anti-inceptive and anti-cancer properties as well as for the formation of sunscreen products (Jayaprakash, et al. 2002). The aim of this study is to ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/radphyschem Radiation Physics and Chemistry 0969-806X/$ - see front matter & 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.radphyschem.2009.12.006 n Corresponding author. Tel.: + 92 41 9200161x3309; fax: + 92 41 9200187. E-mail address: ijazchem@yahoo.com (I.A. Bhatti). Radiation Physics and Chemistry 79 (2010) 622–625