Fluid Phase Equilibria
Reverse micelles are an important class of nanoreactors providing an array of applications. The structure and dynamics of aqueous reverse micelles have been intensely investigated, yet there are many subtleties involved in characterizing the arrangement of water and ionic species within these aggregates. The interfacial arrangement of water and dopants added to bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reverse micelles were investigated by fully atomistic molecular dynamics simulations. Reverse micelles of increasing water to surfactant ratio were doped with concentrations of KCl from 0.0 to 1.0 M to analyze the partitioning of ions and water. Detailed analysis of pair density functions reveals that Cl− ions are embedded deep in the aqueous interior, and the K+ ions display a remarkable affinity for the interface. Our results confirm the existence of multiple layers of water, and an ordered multi-layer ionic arrangement that is driven by the negatively charged surfactant headgroup.
Crowder, Max; Lizarraga, Isabel; Patterson, Joshua D.; and Sharma, Arun K., "Ionic partitioning of KCl in AOT reverse micelles from molecular dynamics simulations" (2023). Biology and Chemistry Faculty Publications and Presentations. 15.