FACTORS AFFECTING CRYSTALLIZATION PRESSURE

摘要

Crystallization pressure arises when the growth of a crystal is frustrated by an obstacle, such as a pore wall. At equilibrium, the crystallization pressure is inversely related to the size of the pore in which it grows. However, the equilibrium is unstable with respect to growth in a larger pore: if there is a path connecting small and large pores, small crystals will dissolve and the solute will diffuse to a larger pore where the chemical potential of the crystal will be lower. If the supersaturation is high, there can be abundant growth of small crystals that produce a high transient stress, while diffusion is transferring solute to the largest accessible pores. In the case of DEF, it is argued that expansion results from growth of crystals in mesopores, and macroscopic crystals appear subsequently as the solute redistributes.