Solution Properties of Mixed Fluorocarbon and Hydrocarbon Surfactants and their Solubilization Behavior

Critical micelle concentration from a lattice gas model

“…This sudden change is not a true phase transition; it is conveniently pictured as an arrested phase separation [6]. To the best of our knowledge, our calculation is the first one for a lattice model which shows the variation of the CMC with T(the dashed line in figure 1) in qualitative agreement with experiments [2]. Other theoretical treatments of micellar solutions based on more phenomenological approaches exist [7].…”

“…In our model, as in experiments [2], the onset of micellisation, i.e. the formation of large aggregates as a function of n,, occurs abruptly at the CMC.…”

“…Our model (2) also exhibits the phenomenon of micellisation, in which the surfactant molecules start to form large aggregates called micelles; we interpret as a micelle a connected cluster of vacancies, immersed in water and surrounded by a boundary layer of surfactants. The vacancies represent in a rough way the exclusion of water from the micelle core, i.e., the region occupied by the hydrocarbon tails of the surfactants.…”

“…Binary mixtures of water and surfactant molecules often exhibit (1) a 'critical micelle concentration' (CMC) [ 1,2] of surfactants at which these molecules form large aggregates called micelles, and (2) a closed-loop coexistence curve [ 1,3] in the n,-Tphase diagram; n, is the density of surfactant molecules. If, in addition, oil is added to the watersurfactant mixture, a variety of phases, including microemulsions, and phase equilibria can be obtained.…”