We have studied by Molecular Dynamics computer simulations the dynamics of
water confined in ionic surfactants phases, ranging from well ordered lamellar
structures to micelles at low and high water loading, respectively. We have
analysed in depth the main dynamical features in terms of mean squared
displacements and intermediate scattering functions, and found clear evidences
of sub-diffusive behaviour. We have identified water molecules lying at the
charged interface with the hydrophobic confining matrix as the main responsible
for this unusual feature, and provided a comprehensive picture for dynamics
based on a very precise analysis of life times at the interface. We conclude by
providing, for the first time to our knowledge, a unique framework for
rationalising the existence of important dynamical heterogeneities in fluids
absorbed in soft confining environments