Shift of triple point in confined systems with curved interfaces

The unified thermodynamic approach to the analysis of melting/freezing phenomena in confined systems is proposed. The approach relates the shift of the triple point in a confined system in comparison with the bulk system with the physico-chemical parameters of the bulk system and the boundary layer. The application of general equations to particular types of confinement is illustrated for small particles and substance embedded inside porous matrices. The analysis of equations derived indicates that for the systems considered the shift of triple point in the boundary layers and in the uniform core part of the system in the general case differ from each other. The shift of triple point may be either positive or negative and may be controlled for paricles by variation of the interfacial energy, and for the pores by variation of interfacial energy and/or pore walls wettability.