文献类型：期刊文献

英文题名：Decoupling Ca2+ and SO42? effects on α-calcium sulfate hemihydrate hydration by thermokinetics and molecular dynamics

作者：Lei, Xiaohu[1]; Qiu, Chunlong[1]; Chen, Hang[1]; Song, Xingfu[1]

机构：[1] National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, China

年份：2026

卷号：109

期号：1

外文期刊名：Journal of the American Ceramic Society

收录：EI(收录号：20254219332040)

语种：英文

外文关键词：Calcium sulfate - Compressive strength - Dissolution - Growth kinetics - Gypsum - Hydration - Ions - Kinetics - Process control - Supersaturation

摘要：The mechanistic roles of Ca2+ and SO42? as key ions governing hydration kinetics and gypsum-based materialsperformance remain unresolved. Ion-specific effects of exogenous Ca2+/SO42? on α-calcium sulfate hemihydrate (α-HH) hydration were systematically examined through thermokinetic analysis, experimental validation, and molecular dynamics simulations. Hydration acceleration was not induced by Ca2+, whereas SO42? demonstrated concentration-dependent enhancement. The Krstulovi??Dabi? model revealed that the hydration process transitions from nucleation and crystal growth to interphase reactions and diffusion control. While both ions enhanced the thermodynamic driving force, Ca2+ retarded hydration kinetics by inhibiting the dissolution process via the common ion effect and adsorption onto the HH surface. In contrast, under high supersaturation, SO42? dynamically promoted dissolution by accelerating nucleation and crystal growth, thereby maintaining a high supersaturation level. The elevated SO42? concentration in later stages further alleviated diffusion-controlled limitations, enhancing overall hydration kinetics. This ion-specific mechanism led to microstructural differences: exogenous Ca2+ resulted in coarsened calcium sulfate dihydrate crystals and a 21% decrease in compressive strength, whereas SO42? promoted refined, densely interlocked crystals and a 16% strength increase compared to the control. The elucidated mechanism provides critical guidance for regulating hydration, tailoring microstructure, and optimizing performance in gypsum-based materials. ? 2025 The American Ceramic Society.