Structural Features of Reverse AOT Micelles in Water/Cyclohexane: Molecular Dynamics Study

Abstract

A study of the structural features of reverse micelles of Na AOT (sodium bis(2-ethylhexyl) sulfosuccinate) molecules in cyclohexane with an aqueous core was carried out using the molecular dynamics method. Reverse AOT micelles are formed in three-component systems containing a non-polar solvent, water, and AOT molecules at certain concentration ratios, expressed as w = [H2O]/[AOT]. A strong hydrogen bond between water molecules and AOT was found at the concentration w=6. For the first time, a sharp decrease in hydrogen bonding between water molecules and AOT at w=7 was shown, caused by a difference in the packing of AOT molecules and the collective dynamics of water molecules in the micelle core. The calculated results are in good agreement with experimental data from other authors. It is shown that, along with the methods of vibrational spectroscopy and dynamic light scattering, the molecular dynamics method is also informative for determining the structural characteristics of supramolecular structures and analyzing the collective dynamics of water molecules.

Keywords

• Molecular dynamics method
• Reverse micelles
• Hydrogen bonding