Summary: EUROPHYSICS LETTERS 10 June 1996
Europhys. Lett., 34 (8), pp. 575-580 (1996)
Kinetics of surfactant adsorption at fluid/fluid interfaces:
H. Diamant and D. Andelman
School of Physics and Astronomy
Raymond and Beverly Sackler Faculty of Exact Sciences
Tel Aviv University - Ramat Aviv, Tel Aviv 69978, Israel
(received 16 August 1995; accepted in final form 22 April 1996)
PACS. 68.10Jy Kinetics (evaporation, adsorption, condensation, catalysis, etc.).
PACS. 68.10Cr Surface energy (surface tension, interface tension, angle of contact, etc.).
PACS. 82.65Dp Thermodynamics of surfaces and interfaces.
Abstract. We present a model treating the kinetics of adsorption of soluble surface-active
molecules at the interface between an aqueous solution and another fluid phase. The model
accounts for both the diffusive transport inside the solution and the kinetics taking place
at the interface using a free-energy formulation. In addition, it offers a general method of
calculating dynamic surface tensions. Non-ionic surfactants are shown, in general, to undergo
a diffusion-limited adsorption, in accord with experimental findings.
Surface-active agents (surfactants) play a major role in various fields, including petrochem-
ical technologies, detergents, biological systems, etc. In some important cases, equilibrium