Effects Of Interfacial Energy On The Melting Of Nanoscaled Ice

Melting is ubiquitous in nature and is a very important phase transition in materials science. Although studied over a century, it is poorly understood as yet.Recent experiments showed that the melting of crystal started on the crystal surface or interface. That is to say, the properties crystal surfaces or interfaces determined the thermodynamics of melting. As is known, the amount of crystal surfaces or interfaces is associated with crystal sizes:the smaller the crystal, the more surfaces or interfaces. For the size effect of melting, reported research results are available for several systems. In comparison, for the effect of surface or interfacial energy on melting, there are no systematic data, mainly because of the difficulty in controlling the surface or interface state.In this work, mesoporous silica with ordered pores (SBA-15) is used to study the melting of ice in the mesopores of SBA-15. Samples with pore diameters ranging from2to nm are prepared and are treated by using a series of silane-coupling agent to modify the properties of pore surfaces. Finally, the melting behaviour of ice in the above pores with different surface properties are studied by using thermal analysis.Our results show that modifications of pore surface have no detectable influence on the melting of ice.