Effect of organic functional groups on the phase transition of organic liquids in silica mesopores

The phase transition behaviors of organic liquids condensed in the silica mesopores which modified with organic functional groups have been investigated. Three organic liquids, n-hexane, 1-hexanol and acetonitrile, were employed. The melting points of the organic liquids in the pores with and without the organic functional groups decreased with decreasing the pore size. The effect of the organic functional groups on the change in the physical properties of the organic condensed liquids in the pores was estimated from a depression of the melting point. The phase transition behaviors of the organic liquids in the pores closely related to the interaction between the organic molecules and the pore surfaces.