INFLUENCE OF PH ON SURFACE-POTENTIAL AND WETTING OF QUARTZ BY CETYLTRIMETHYLAMMONIUM BROMIDE SOLUTIONS

Contact angles of aqueous solutions of cationic surfactant cetyltrimet hylammonium bromide (CTAB) in air and oil media were measured at vario us pH values of background electrolyte solution. Dependences of the su rface potentials of quartz psi(1) and oil psi(2) in contact with the s olution on CTAB concentration were obtained to elucidate the mechanism of influence of pH on wetting. The obtained values of Delta psi = psi (1), - psi(2) were employed for the estimation of the contribution of electrostatic forces to the forming contact angles on the basis of the theory of wetting using disjoining pressure isotherms of the wetting films.