The solidndash;liquid phase transition temperatures and heats of fusion Dgr;Hfof nonpolar organic solids confined in the pores of controlled pore glasses were measured by differential scanning calorimetry. The pore diametersdwere in the range of 40ndash;730 Aring; and the organics studied werecishyphen;decalin,transhyphen;decalin, cyclohexane, benzene, chlorobenzene, naphthalene, and heptane. In accordance with previous reports on studies of primarily inorganic materials, the melting point of the pore solidT(d) decreased with decreasing pore diameter. In addition, a large reduction in the bulk enthalpy of fusion Dgr;Hfof the pore solid was measured, which apparently has not been studied in detail by other workers. A linear correlation was found between the melting point depression (Dgr;Tm) and the reciprocal diameter, as predicted by theories of solidification in a capillary. The calculated values of the solidndash;liquid interfacial energy sgr;slwere in reasonable agreement with values reported in the literature based on other methods of measurement.
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