Effects of Three Types of Surfactants on Fabric Dyeing Using a Natural Dye Extracted from Brown Onion Skin

Abstract

The influence of three types of surfactants, the nonionic surfactant polyoxyethylene(23)dodecyl ether (Brij-35), anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant dodecyl trimethyl ammonium chloride (DTAC), on the dyeing of silk fabric with natural dyes extracted from brown onion skin, was investigated. The surface tension, zeta potential and absorbance of aqueous solutions containing different concentrations of the three dodecyl-tail surfactants, with and without the dyes, were measured. The surface tension of the solutions containing SDS and DTAC decreased with the addition of natural dyes, suggesting that attractive interactions between the ionic surfactants and dyes further disrupted the cohesion forces between water molecules. The colors of the fabrics dyed with and without the three types of surfactants were compared and found to be paler with the addition of SDS and DTAC. The absorbance of the dye solutions containing DTAC and the color of the dyed fabrics were compared by varying the DTAC concentration. The absorbance reached a minimum at a DTAC concentration of 15.0 mmol/L, which was same as the critical micelle concentration (CMC). On the other hand, the color of the dyed fabrics became paler with increasing concentration of DTAC. The results are discussed based on the distributed state of the dye molecules in the solution and the interactions among the dye, surfactants, and fibers. This research contributes to understanding the complicated interactions among dyes, fibers and surfactants.