Spinodal for NaCl nucleation from solution in confined environment
Dr. Noushine Shahidzadeh, Associate Professor University of Amsterdam
Van der Waals-Zeeman Institute- IOP
15 octobre à 14h, amphithéâtre Nougaro
The nucleation of crystals from solution is widely used in physics, chemistry and pharmacology. Recently, the principle of Classical Nucleation Theory have been called into question by an increasing number of studies of electrolyte solutions that reported so-called non-classical pathways of nucleation, which involve the aggregation of either pre-nucleation clusters of ions or of primary particles.
We study the nucleation and growth of sodium chloride, the most common and abundant salt, for different degrees of confinement in microcapillaries in which the liquid phase is trapped by capillary forces. Our results show that contrary to what is assumed for this salt, crystallization always happens around a reproducible spinodal point independent of the shape, size and chemical nature of the microcapillaries. The spinodal concentration is found to be almost twice the solubility and leads to the growth of only one single crystal in the solution with a peculiar morphology : a Hopper crystal.