  We present a coarse-grained model for ionic surfactants in explicit aqueous
solutions, and study by computer simulation both the impact of water content on
the morphology of the system, and the consequent effect of the formed
interfaces on the structural features of the adsorbed fluid. On increasing the
hydration level at ambient conditions, the model exhibits a series of three
distinct phases: lamellar, cylindrical and micellar. We characterize the
different structures in terms of diffraction patterns and neutron scattering
static structure factors. We demonstrate that the rate of variation of the
nano-metric sizes of the self-assembled water domains shows peculiar changes in
the different phases. We also analyse in depth the structure of the
water/confining matrix interfaces, the implications of their tunable degree of
curvature, and the properties of water molecules in the different restricted
environments. Finally, we discuss our results compared to experimental data and
their impact on a wide range of important scientific and technological domains,
where the behavior of water at the interface with soft materials is crucial.
