Understanding the Water-in-Salt to Salt-in-Water Characteristics across the Zinc Chloride : Water Phase Diagram.

Using a series of time- and temperature-resolved synchrotron diffraction experiments, the relationship between multiple polymorphs of ZnCl and its respective hydrates is established. The δ-phase is found to be the pure anhydrous phase, while the α, β, and γ phases result from partial hydration. Diffraction, gravimetric, and calorimetric measurements across the entire ZnCl· HO, 0 > > ∞ composition range using ultrapure, doubly sublimed ZnCl establish the ZnCl : HO phase diagram.