Abstract
This study was designed to investigate the relationship between the dispersion stability of particles and the detergency of particulate soil as functions of pH, ionic strength, electrolytes, and surfactants using $\alpha$-Fe$_2$O$_3$ particles as a model of particulate soil. The dispersion stability of particles was estimated by suspending power and the detergency of particulate soil was determined by the adhesion of hematite particles to polyester fabrics and their removal from the fabrics. The dispersion stability of particles was biphases and minimum at pH 6~7. The suspending power decreased with the addition of electrolytes and increased with decreasing ionic strength, and the effect of surfactant on the suspending power was insignificant. Although some deviation exists in the effect of surfactant on detergency of particular soil, the general trend of detergency of particulate soil was similar to that of dispersion stability of particles. Therefore, it appears that the detergency of particulate soil correlates with the dispersion stability of particles.