Simulation of demixing transition for binary fluid within a gel

Monte Carlo simulations are used to study phase separation of binary fluid mixtures in the porous space within a solid gel. The fluid mixture is stimulated by a 3D Ising model, the gel by random percolation. Phase transition and phase separation are then studied for fixed spins and no spin on the percolating clusters and the surface fluid on the perimeter of the clusters with a bulk field on remaining spins. The authors find a non-symmetric miscibility gap and very slow motion towards equilibrium.