The anionic surfactant bis(2-ethylhexyl) sodium sulfosuccinate (Aerosol OT or AOT) is studied by atomic-level molecular modeling, using the second-generation ESFF (extensible systematic force field). The
geometries of seven representative conformers are analyzed. The energies of these conformers correspond
to those of the most probable ones based on random-sampling statistics and differ by, at most, 10 kcal/mol.
Thus, these conformers should be available for the system under typical ambient conditions. Interactions
with water and carbon tetrachloride modify the geometries only to a modest extent. The solvation by water
is found to be exoergic, and the analysis of individual AOT−water interactions identified four strongly
bound water molecules (with >10 kcal/mol of interaction energy), in accordance with experimental results.
A CCl4 box was generated for the investigation of the effects of carbon tetrachloride as a solvent. A truncated-cone-geometry model of the AOT molecule yields 14.5 as the estimated aggregation number N of AOT
reverse micelles in CCl4, in good agreement with the experimental value of the mean aggregation, 〈n〉 =
15−17, of the solution. The predicted diameter of the dry reverse micelles d = 2.8 nm is comparable with
the experimental apparent hydrodynamic diameter, 〈D
h〉 = 3.2 nm (at w
o = 0.8).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.