Effect of surfactant structure on interfacial properties

¹ Department of Chemistry, Norwegian University of Science and Technology N-7491 Trondheim, Norway
² Department of Chemical Engineering, University of Amsterdam Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands

Corresponding author: live.rekvig@phys.chem.ntnu.no

Received: 15 April 2003
Accepted: 11 July 2003

Abstract

We study surfactants at the oil/water interface using Dissipative Particle Dynamics simulations at constant . The interfacial tension depends on the surfactant branching in a subtle way. For a given interfacial concentration, a double-tail surfactant is more efficient than its single-tail isomer only if the oil-head repulsion is sufficiently strong. For a given concentration in the bulk water phase, the single-tail surfactants are more efficient in both cases. We interpret these results in light of the molecular packing at the interface and free-energy considerations.