Abstract
This study was designed to investigate the relationship between the interaction energy between two particles and the dispersion stability of particles as functions of pH, ionic strength, and electrolytes using $\alpha$-Fe$_2$O$_3$particle as a model of particulate soil. The ξ-potential of $\alpha$-Fe$_2$O$_3$particles in the surfactant solution was measured to calculate the potential energy of interaction between two particles using Verwey-Overbeek theory and to estimate dispersion stability of particles. Suspending power and particle size were determined by UV-Vis spectrometer and by light scattering using the polarization ratio method, respectively. The interaction energy between two particles decreased with the addition of electrolytes and increased with decreasing ionic strength. The interaction energy was minimum at neutral pH. Although some deviation exist, the general trend of the dispersion stability of particles was similar to that of potential energy of interaction between two particles regardless of solution conditions. Therefore, it appears that the dispersion stability of particles correlates well with the interaction energy of two particles.