  We use Molecular Dynamics simulations to study how the nanopore and the fluid
structures affects the dynamic, thermodynamic and structural properties of a
confined anomalous fluid. The fluid is modeled using an effective pair
potential derived from the ST4 atomistic model for water. This system exhibits
density, structural and dynamical anomalies and the vapor-liquid and
liquid-liquid critical points similar to the quantities observed in bulk water.
The confinement is modeled both by smooth and structured walls. The
temperatures of extremum density and diffusion for the confined fluid show a
shift to lower values while the pressures move to higher amounts for both
smooth and structured confinement. In the case of smooth walls, the critical
points and the limit between fluid and amorphous phases show a non-monotonic
change in the temperatures and pressures when the the nanopore size is
increase. In the case of structured walls the pressures and temperatures of the
critical points varies monotonicaly with the porous size. Our results are
explained on basis of the competition between the different length scales of
the fluid and the wall-fluid interaction.
