Evaluation of correlated studies using liquid cell and cryo‐transmission electron microscopy: Hydration of calcium sulphate and the phase transformation pathways of bassanite to gypsum

• DOI: 10.1111/jmi.13102
• Publication Date: 2022-03-29T09:31:58Z
• Authors: M. Ilett; H. M. Freeman; Z. Aslam; J. M. Galloway; D. P. Klebl; S. P. Muench; I. J. McPherson; O. Cespedes; Y‐Y. Kim; F. C. Meldrum; S. R. Yeandel; C. L. Freeman; J. H. Harding; R. M. D. Brydson
• Keywords: Microscopy, Electron, Transmission; QH; TN; Themed Issue Articles; QD; Crystallization; Calcium Sulfate; 01 natural sciences; 0104 chemical sciences

Insight into the nucleation, growth and phase transformations of calcium sulphate could improve performance construction materials, reduce scaling in industrial processes aid understanding its formation natural environment. Recent studies have suggested that pseudo polymorph, gypsum (CaSO4 ·2H2 O) can form aqueous solution via a bassanite ·0.5H2 intermediate. Some situ experimental work has also transformation to occur through an oriented assembly mechanism. In this work, we exploited liquid cell transmission electron microscopy (LCTEM) study undersaturated sulphate. This was benchmarked against cryogenic TEM (cryo-TEM) validate internally data obtained from two techniques. When coupled with Raman spectroscopy, real-time generated by LCTEM, structural cryo-TEM show transform more than one pathway, predominant being dissolution/reprecipitation. Comparisons between LCTEM is slower within confined region as compared bulk solution. highlights important role correlated approach for dynamic such crystallisation if are extract true mechanistic understanding.