Improve of Direct Dye (Direct Orange 46) Sorption on Pretreated Cotton Fabric by Cationic Agent

The sorption properties of direct dye on bleached cotton and cationized cotton (treated with CibafixWFF) was studied. Cationization of cotton fabric at different conditions (time and cationic agentconcentration) wasinvestigated. Nitrogen content of cotton samples pretreated with cationic agentwere determined by Kjeldahl method. The results showed that at higher cationizing treatment time andinitial cationic agent concentration lead to higher nitrogen content on cotton fabric. The adsorptionisotherm of Direct Orange 46 (D046) on cationized cotton was tested by fitting the adsorption datawith Langmuir and Frendlich. Standard adsorption affinity of direct dyes on cationized cotton wasmeasured. The results showed that standard affinity value is negative. This indicated that the adsorption of D046 on cationized cotton is an exothermic process. According to results, the adsorption of direct dye on cationized cotton is more than bleached cotton. It is clear that the present of cationic group on cationized cotton fabric causes more attractionf or sorption of inionic dyes.