Stabilization and desestabilization of model colloids after adsorption of Triton X-100

The colloidal stability of polystyrene particles with different surface fun ctional groups (sulfate and carboxyl) has been studied after adsorption of Triton X-100. The coverage degree and the medium pH were the main factors i n this study. Three different types of colloidal stabilization were found, which can be clasified as a function of the relationship between the atract ive interaction energy (V-A, Van der Waals type) and the steric interaction energy (V-S, repulsive type): electrostatic (V-S = 0), electrosteric (V-S < \V-A\), and steric (V-S > \V-A\). The main difference between these stabi lization types is the response against the electrolyte concentration: the f irst and second cases are affected by electrolyte addition, while the third one does not.