Interaction of oil droplets with silica surfaces

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 1994-11, Vol.91, p.97-112
• Main Authors: Churaev, N.V., Ershov, A.P., Esipova, N.E., Iskandarjan, G.A., Madjarova, E.A., Sergeeva, I.P., Sobolev, V.D., Svitova, T.F., Zakharova, M.A., Zorin, Z.M., Poirier, J.-E.
• Format: Article
• Language: English
• Subjects: Interactions; Oil droplets; Silica surfaces
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/S0927-7757(94)80048-0

Measurements of contact angles, emulsion film thicknesses, movement of oil droplets in thin capillaries and surface charges are used for investigation of oil droplet interaction with silica surfaces in aqueous solutions of the cationic surfactant cetyltrimethylammonium bromide (CTAB) of various concentrations from 10 −7 and 10 −3 M. As model systems tetradecane and silicone oil, polished optical quartz plates and quartz capillaries were used. Surface charges were obtained from measurements of streaming potentials in thin capillaries. In this case a paraffin wax coating on the inner capillary surface was used as the oil/solution interface. Emulsion film stability and oil adhesion to silica surfaces are determined by electrostatic and hydrophobic attraction forces influenced by addition of cationic surfactants. Strong adhesion takes place when the quartz surface is hydrophobized owing to CTAB adsorption, and electrical potentials of emulsion film interfaces become different in magnitude. In the case under investigation, the strongest adhesion of oils takes place at 10 −5 M CTAB. In general, the results of these experiments offer the possibility of controlling oil adhesion, depending on the surface properties of porous bodies and oils.