Effects of non-toxic solvent microemulsion in washing wool

Abstract

This work studies the detersive power and redeposition of impurities after washing standard wool fabrics with a non-toxic solvent microemulsion added to the conventional washing formulations in order improve the results of conventional washing. The solvent was dimethyl sulfoxide (DMS), emulsified and micro-dispersed with amphoteric surfactant. The fabric was washed using non-ionic surfactants, alcohol ethoxylate (AE-7) with 7 m. E.O. and an alkyl polyglucoside (APG). Detersive power was studied as function of those surfactants and their differing proportions in mixture. Detersive power was potentiated by addition sodium carbonate and sodium chloride as builders, and it was likewise studied under the influence of the salts with different water hardness used in the tests. A sequestering agent, DTPMP, was used to improve the results for detergency. The tensile strength and burst strength of the wool fabric washed with those surfactants and the microdispersed DMS with repeated washes was assessed. With those non-ionic surfactants used in the same programmed washing tests, the redeposition of a solid impurity, namely carbon black, during the washing was also studied, and a notable decrease of redeposition was attained with addition of the microemulsified DMS, which was also observed with the additional use of sodium dodecylbenzenesulfonate (LAS). In order to predict the stability of the particles of carbon black and the particles of DMS in the washing bath, the size of those particles was determined