Abstract:
In this research, the effects of surfactant concentration, surfactant type, type of fabric, and solution pH on the detergency performance in hydrophobic particulate removal were investigated. Carbon black was selected as a model hydrophobic particulate and three types of fabric were used: pure polyester, pure cotton, and blended polyester-cotton. The detergency experiments of carbon black removal were carried out by using sodium dodecyl sulfate, an anionic surfactant, and octyl phenol ethoxylate, a nonionic surfactant. To gain a better understanding of the mechanisms of particulate soil detergency, the adsorption isotherms of surfactants, zeta potential, contact angle, and surface tension were studied. For any given type of surfactant, %detergency increased with in-creasing solution pH and the maximum performance was found at pH 11. In addition, SDS was found to exhibit a better detergency than Triton X-100 since the zeta potential on the carbon black surface in SDS solutions is more negative than those in Triton X-100 solutions. Although the surfactant adsorption density of polyester is lower than cot-ton, carbon black can be removed from polyester better than from cotton.
