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标题：Different route of hydroxide incorporation and thermal stability of new type of water clathrate: X-ray single crystal and Raman investigation
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作者：Mateusz Dulski ; Katarzyna M. Marzec ; Joachim Kusz 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2017
卷号：7
期号：1
DOI：10.1038/s41598-017-08152-1
语种：English
出版社：Springer Nature
摘要：Chlormayenite Ca12Al14O32[♦4Cl2] (♦-vacancy) is partially hydrated micro porouss mineral with hydroxide groups situated at various crystallographic sites. There are few mechanisms describing its hydration. The first one assumes Cl(-) substitution by OH(-) at the center of the structural cages (W-site). The second one determines the converting a T1O4 tetrahedron to a T1O3(OH)3 octahedron due to the replacement of oxygen at the O2 site by three OH-groups according to the scheme: ((O2)O(2-) + (W) Cl(-)) → 3 × (O2a)OH. The third mechanism, not considered so far in the case of zeolite-like minerals, includes the hydroxide incorporation in form of hydrogarnet defect due to the arrangement of tetrahedral (OH)4 in vacant cages. This yields a strong hydrated phase containing even up to 35% of water more than in any currently known mineral applicable to Portland cement. Moreover, water molecules present in different structural cages are stable up to 355 K while dehydroxylation linked to the gradual loss of only 8% of OH(-) groups according to 3 (O2a)OH(-) → (O2)O(2-) + (W) OH(-) + (g)H2O occurs at temperature range from 355 K to 598 K.