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Updated: Sep 23, 2025

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Effect of Cu2+ on the nucleation kinetics and crystallization of rod-shaped CaSO4·2H2O in aqueous solution
Xiangbin Sun1, Xianshun Wang1, Genlei Zhang1,2,3
1School of Chemistry and Chemical Engineering, Anhui Province Key Laboratory of Controllable Chemistry Reaction and Material Chemical Engineering, Hefei University of Technology Hefei 230009 China genleizhang@hfut.edu.cn cuipeng@hfut.edu.cn.
Abstract:
In this study, a simple and efficient strategy is developed to synthesize rod-like CaSO4·2H2O (DH) crystals with tunable aspect ratio in aqueous solution using Cu2+ as modifier. The aspect ratio and length of the DH crystals are effectively reduced to 5.7 : 1 and about 35 μm in the presence of Cu2+, respectively. The interfacial tension value (γ) in the aqueous solution is improved significantly with the assistance of Cu2+, yet the nucleation rate (J) of the DH crystal is decreased sharply. The interfacial tension value (γ) in the aqueous solution is improved and the nucleation rate (J) of the DH crystal is drastically decreased due to the introduction of Cu2+, leading to the induction time of the DH crystallization being extended from 4 min to 25 min. The diversification of morphology for the DH crystals is incited by the changes of nucleation kinetics and Cu2+ incorporated into the crystal lattice, affecting the crystal growth habit, and finally controlling the growth of DH crystals in aqueous solution.
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