Dynamic Surface Tension and Adsorption Kinetics in Finite Systems

• Published in: Journal of colloid and interface science Vol. 187; no. 2; pp. 352 - 362
• Main Authors: Filippov, Leonid K., Filippova, Nadezhda L.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.03.1997; Elsevier
• Subjects: adsorption kinetics; Chemistry; diffusion of surfactants; dynamic surface tension; Exact sciences and technology; finite systems (liquid spherical drop, liquid spherical drop surrounded by liquid phase, liquid spherical drop surrounded by spherical liquid shell); Gas-liquid interface and liquid-liquid interface; General and physical chemistry; relaxation times; Surface physical chemistry; relaxation times; finite systems (liquid spherical drop, liquid spherical drop surrounded by liquid phase, liquid spherical drop surrounded by spherical liquid shell); adsorption kinetics; diffusion of surfactants; dynamic surface tension; Dynamic surface tension; Spherical shape; Adsorption; Liquid liquid interface; Theoretical study; Kinetics; Surfactant; Diffusion; Drop
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.1996.4704

A quantitative theory is developed to describe the dynamic surface tension and the adsorption kinetics at a liquid–liquid interface, taking into account the molecular diffusion in both bulk phases and the adsorption isotherm for surfactant on the interface. Asymptotic analytical solutions are obtained in the following finite systems: (i) a liquid spherical drop, (ii) a liquid spherical drop surrounded by a liquid phase, and (iii) a liquid spherical drop surrounded by a spherical liquid shell. The behavior of the dynamic surface tension and interfacial adsorption over a wide range of times is predicted for cases (i) through (iii). The conditions under which the dynamic surface tension passes through a minimum below the steady state value are found. The theoretical model developed allows a qualitative interpretation of the experimental data obtained for a viscous crude oil containing natural acids after contact with aqueous alkali.