Doping behavior and occurrence state of Na impurity in α-calcium sulfate hemihydrate prepared in Na2SO4 solution

IF 1.7 4区材料科学 Q3 CRYSTALLOGRAPHY

Journal of Crystal Growth Pub Date : 2024-11-10 DOI:10.1016/j.jcrysgro.2024.127993

Lusong Wang , Xianbo Li , Yuqi He , Hu Huang , Yawen Du

引用次数: 0

Abstract

α-calcium sulfate hemihydrate (α-CSH) is a green building material. The synthesis of α-CSH from industrial phosphogypsum (PG) in Na₂SO₄ solution is a promising technique, but Na impurity may be introduced into α-CSH crystal. In this study, the doping behavior of Na into α-CSH was investigated, and the occurrence state of Na in α-CSH was clarified. The results show that Na impurity was doped into α-CSH in the form of Na₂Ca₅(SO₄)₂·3H₂O, and the doping content of Na₂O in α-CSH increases with the Na₂SO₄ concentration and reaction time. Density functional theory (DFT) calculation shows Na impurity is likely to be doped into α-CSH crystal through interstitial filling. Unfortunately, the doping of Na into α-CSH could cause a visible frost phenomenon for the hardened plaster, which has a negative impact on the practical utilization of α-CSH.

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在 Na2SO4 溶液中制备的α-半水硫酸钙中 Na 杂质的掺杂行为和发生状态

半水硫酸钙（α-CSH）是一种绿色建材。以工业磷石膏（PG）为原料在 Na2SO4 溶液中合成 α-CSH 是一种很有前景的技术，但 Na 杂质可能会引入 α-CSH 晶体中。本研究考察了 Na 在 α-CSH 中的掺杂行为，并阐明了 Na 在 α-CSH 中的出现状态。结果表明，Na杂质以Na2Ca5(SO4)2-3H2O的形式掺入α-CSH中，且α-CSH中Na2O的掺入量随Na2SO4浓度和反应时间的增加而增加。密度泛函理论（DFT）计算表明，Na 杂质很可能是通过间隙填充掺杂到 α-CSH 晶体中的。遗憾的是，Na 在 α-CSH 中的掺杂会导致硬化石膏出现明显的结霜现象，这对α-CSH 的实际应用产生了负面影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Crystal Growth 化学-晶体学

CiteScore

3.60

自引率

11.10%

发文量

373

审稿时长

65 days

期刊介绍： The journal offers a common reference and publication source for workers engaged in research on the experimental and theoretical aspects of crystal growth and its applications, e.g. in devices. Experimental and theoretical contributions are published in the following fields: theory of nucleation and growth, molecular kinetics and transport phenomena, crystallization in viscous media such as polymers and glasses; crystal growth of metals, minerals, semiconductors, superconductors, magnetics, inorganic, organic and biological substances in bulk or as thin films; molecular beam epitaxy, chemical vapor deposition, growth of III-V and II-VI and other semiconductors; characterization of single crystals by physical and chemical methods; apparatus, instrumentation and techniques for crystal growth, and purification methods; multilayer heterostructures and their characterisation with an emphasis on crystal growth and epitaxial aspects of electronic materials. A special feature of the journal is the periodic inclusion of proceedings of symposia and conferences on relevant aspects of crystal growth.