ABSTRACTThe properties of water near surfaces are known to differ from those of the bulk. For instance, in 140 A diameter silica pores the density has been found to be 3% lower than that of the bulk while the heat capacity is 25% greater than that the bulk. Etzler [15] has proposed a statistical thermodynamic model for vicinal water. This model has been able to correlate a number of thermodynamic properties of water in silica pores. Furthermore, some of the microscopic implications of the model have been found to be consistent with molecular dynamics simulations. Here we discuss the results of a statistical geometric analysis of a molecular dynamics simulation which, as first suggested by Roentgen (1892), indicates that water indeed exists in “bulky” and “dense” states. Furthermore, recent results concerning the temperature dependence of the heat capacity of water in silica pores is discussed.
