  In this paper we explore the self-assembly patterns in a two dimensional
colloidal system using extensive Langevin Dynamics simulations. The pair
potential proposed to model the competitive interaction have a short range
length scale between first neighbors and a second characteristic length scale
between third neighbors. We investigate how the temperature and colloidal
density will affect the assembled morphologies. The potential shows aggregate
patterns similar to observed in previous works, as clusters, stripes and porous
phase. Nevertheless, we observe at high densities and temperatures a porous
mesophase with a high mobility, which we name fluid porous phase, while at
lower temperatures the porous structure is rigid. triangular packing was
observed for the colloids and pores in both solid and fluid porous phases. Our
results show that the porous structure is well defined for a large range of
temperature and density, and that the fluid porous phase is a consequence of
the competitive interaction and the random forces from the Langevin Dynamics.
