@article{pillai_wilcox_hillis_losey_martin_2022, title={Understanding the Water-in-Salt to Salt-in-Water Characteristics across the Zinc Chloride : Water Phase Diagram}, volume={126}, ISSN={["1520-5207"]}, url={https://doi.org/10.1021/acs.jpcb.1c10530}, DOI={10.1021/acs.jpcb.1c10530}, abstractNote={Using a series of time- and temperature-resolved synchrotron diffraction experiments, the relationship between multiple polymorphs of ZnCl2 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 ZnCl2·R H2O, 0 > R > ∞ composition range using ultrapure, doubly sublimed ZnCl2 establish the ZnCl2 : H2O phase diagram. The results are consistent with the existence of crystalline hydrates at R = 1.33, 3, and 4.5 and identify a mechanistic pathway for hydration. All water is not removed from hydrated ZnCl2 until the system is heated above its melting point. While hydration/dehydration is reversible in concentrated solutions, dehydration from dilute aqueous solutions can result in loss of HCl, the source of hydroxide impurities commonly found in commercial ZnCl2 preparations. The strong interaction between ZnCl2 and water exerts a significant impact on the solvent water such that the system exhibits a deep eutectic at a composition of about R = 7 (87.5 mol %) and a eutectic temperature below -60 °C.}, number={11}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, publisher={American Chemical Society (ACS)}, author={Pillai, Shelby B. and Wilcox, Robert J. and Hillis, Berkley G. and Losey, Bradley P. and Martin, James D.}, year={2022}, month={Mar}, pages={2265–2278} }
 @article{hillis_losey_weng_ghaleb_hou_martin_2017, title={From rate measurements to mechanistic data for condensed matter reactions: a case study using the crystallization of [Zn(OH2)(6)][ZnCl4]}, volume={7}, ISSN={2073-4352}, url={http://dx.doi.org/10.3390/cryst7010011}, DOI={10.3390/cryst7010011}, abstractNote={The kinetics of crystallization of the R = 3 hydrate of zinc chloride, [Zn(OH2)6][ZnCl4], is measured by time-resolved synchrotron x-ray diffraction, time-resolved neutron diffraction, and by differential scanning calorimetry. It is shown that analysis of the rate data using the classic Kolmogorov, Johnson, Mehl, Avrami (KJMA) kinetic model affords radically different rate constants for equivalent reaction conditions. Reintroducing the amount of sample measured by each method into the kinetic model, using our recently developed modified-KJMA model (M-KJMA), it is shown that each of these diverse rate measurement techniques can give the intrinsic, material specific rate constant, the velocity of the phase boundary, vpb. These data are then compared to the velocity of the crystallization front directly measured optically. The time-resolved diffraction methods uniquely monitor the loss of the liquid reactant and formation of the crystalline product demonstrating that the crystallization of this hydrate phase proceeds through no intermediate phases. The temperature dependent vpb data are then well fit to transition zone theory to extract activation parameters. These demonstrate that the rate-limiting component to this crystallization reaction is the ordering of the waters (or protons) of hydration into restricted positions of the crystalline lattice resulting in large negative entropy of activation.}, number={1}, journal={Crystals}, publisher={MDPI AG}, author={Hillis, B. G. and Losey, B. P. and Weng, J. and Ghaleb, N. and Hou, F. and Martin, J. D.}, year={2017}, pages={11} }