The effect of bentonite microparticles in the washing of cotton fabric

Abstract

The primary aim of this work is to attain improvement of the softness of cotton fabric during the washing process with ecological surfactants. To attain that improvement, sodium bentonite microparticules was added to the detergent formulations to produce a softening effect during washing and obtain the so called “soft detergent” effect. Sodium bentonite (a mineral composed mainly of hydrated aluminium silicates) was mixed with the surfactants used in ecological detergents. Two types of particle size of these microparticles with ammoniumsilicone softener treatment for improving this effect on their behaviour were used. The surfactants used were an anionic surfactant, namely LAS, and two non-ionic surfactants, namely APG and AE, used separately and as mixtures, without builders, to demonstrate their detersive power in one wash and repeated washes, depending on the nature of the surfactants and on their separate mixtures and mixtures in different proportions of anionic and non-ionic surfactants in combination in all cases with a constant concentration of sodium bentonite with two particle sizes. Evaluation was performed of the subjective softness (by handle) of pairs of samples by several observers and also of changes in whiteness after deposition of the bentonite during washing, which was checked with scanning electron microscopy (SEM) images of the fibres of the cotton fabric.