Effect of Surfactants on Decoloration of Various Dyes by Peroxide Bleaching Agents

Abstract

The effect of three surfactants, dodecylbenzenesulfonate (DBS), n-hexadecyltri methylammonium bromide (HTAB), and polyethylene glycol mono-p-octylphenyl ether (PEOPE), on the decoloration rates of C.I. Acid Orange 7, C.I. Basic Green 4, and C.I. Basic Orange 33 by peroxide bleaching agents such as sodium percarbonate and hy drogen peroxide is examined. The decoloration rate of Acid Orange 7 by peroxide bleaching agents accelerates in the presence of DBS, HTAB and PEOPE, especially near the cmc, with the maximum rate being observed in the presence of HTAB. However, the decoloration rate of Basic Orange 33 by hydrogen peroxide accelerates only when DBS is present near the cmc. There is no or less enhanced decoloration in the presence of HTAB or PEOPE. Interestingly, the decoloration rate of Basic Green 4 by hydrogen peroxide accelerates with increasing HTAB concentration, and in contrast, the rate de creases when DBS is present. These results indicate that decoloration rates by peroxide bleaching agents largely depend on interactions between the dyes and surfactants.