Confinement effects on freezing of binary mixtures

We report molecular simulations and experimental measurements of the freezing and melting of mixtures confined in nanopores. Dielectric relaxation spectroscopy was used to determine the experimental phase diagram of mixtures confined in activated carbon fibers. Grand Canonical Monte Carlo simulations combined with the parallel tempering technique were used to model the freezing of several Lennard - Jones mixtures in graphite slit pores. The effect of confinement is discussed for mixtures having a simple solid solution or an azeotropic solid - liquid phase diagram. We also investigate how the competition between the wall -fluid and fluid - fluid interactions affects the freezing temperature of the confined system. The structure of the crystal phase in the simulations is also investigated by means of positional and bond-orientational pair correlation functions and bond-order parameters.