First application of chlorophyll-a as biomordant: sonicator dyeing of wool with betanin dye

In this research, extraction of dyes from Opuntia ficus-indica was conferred by ultrasound. Dyes extracted and isolated from Opuntia ficus-indica plant were separated by fractional crystallization method and characterized by mass techniques. The dyeing of wool fabric using betanin as natural dye and Chlorophyll-a as biomordant has been studied. Results show an increase in the colour strength values with increasing the concentration of biomordant. The effect of treatment variables on the colour strength of dyed fibres was also examined. It was found that pH and temperature of dyeing influences considerably the results; this is mainly linked to the stability conditions of betanin dye. Dye exhaustion was studied in both conventional and ultrasonic dyeing process. It was shown that sonication improve dye exhaustion from rating 30% to rating 60% in a shorter dyeing time. The fastness properties of dyed wool against washing, light, dry and wet rubbing were evaluated. Un-mordanted and mordanted samples have good fastness properties. (C) 2012 Elsevier Ltd. All rights reserved.