Micellar aggregates of ionic surfactants are known to possess a rich variety of interesting thermodynamic as well as structural properties, which are essentially dominated by simple effective interactions between the aggregates. Because of their technological relevance enormous efforts have been invested to understand and characterize their interactions in solution with the goal of developing substances with novel material’s properties. On a theoretical level several approaches have been proposed to describe their effective interactions adequately, generally based on the DLVO theory. However, these approaches do not take into account aspects of stability of the aggregates and therefore fail in the description of several important characteristics, such as, e.g., the re-entrant behavior of the apparent molal heat capacity appearing with increasing density of the micelles. In this paper we study the effective interactions of these systems by investigating the suitability of the Gauss-core model, to reproduce the relevant thermodynamic properties. To this end, we discuss the Gauss-core model in comparison to the standard DLVO model and demonstrate its aptitude to reproduce the results from calorimetric experiments of the ionic surfactant sodium decanoate in water.
aqueous suspensions of ionic surfactants coarse-grained models computer simulation