Molecular dynamics simulations of crystallization under confinement at triple point conditions

Molecular dynamics computer simulations of crystallization of a Lennard-Jones system under confinement conditions in the vicinity of the triple point are reported. We calculate the force exerted on a crystal by a melt when it crystallizes. The force due to crystallization is reflected in the disjoining pressure isotherms as a characteristic peak. We find that at conditions of high confinement, i.e., pore thicknesses of ≈1 nm, the disjoining pressure can rise up to ≈108 Pa. We also analyze the dependence of the crystallization under confinement as a function of temperature. Confinement can stabilize the crystal phase at temperatures significantly higher than the melting temperature. For the systems studied in this work, a pore of 1 nm thickness stabilizes the crystal phase at temperatures up to 45% higher than the normal melting temperature. In addition we consider the disjoining pressure profile along confining pore slits of finite lengths. The finite size effects due to the pore length modifies the value...