Hypothesis: By combining the experimental small- and wide-angle x-ray
scattering (SWAXS) method with molecular dynamics simulations and the
theoretical 'complemented-system approach' it is possible to obtain detailed
information about the intra- and inter-molecular structure and dynamics of the
solvation and hydration of the surfactant in organic and mixed solvents, e.g.,
of the nonionic surfactant Brij 35 (C12E23) in alcohols and aqueous
alcohol-rich ternary systems. This first application of the complemented-system
approach to the surfactant system will promote the use of this powerful
methodology that is based on experimental and calculated SWAXS data in studies
of colloidal systems. By applying high-performance computing systems, such an
approach is readily available for studies in the colloidal domain.
Experiments: SWAXS experiments and MD simulations were performed for binary
Brij 35/alcohol and ternary Brij 35/water/alcohol systems with ethanol,
n-butanol and n-hexanol as the organic solvent component at 25 {\deg}C.
Findings: We confirmed the presence of solvated Brij 35 monomers in the
studied organic media, revealed their preferential hydration and discussed
their structural and dynamic features at the intra- and inter-molecular levels.
Anisotropic effective surfactant molecular conformations were found. The
influence of the hydrophobicity of the organic solvent on the hydration
phenomena of surfactant molecules was explained.Comment: 31 pages, 6 figures, 1 tabl