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Different route of hydroxide incorporation and thermal stability of new type of water clathrate: X-ray single crystal and Raman investigation.

ABSTRACT: 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: (^O2O^2-?+? ^W Cl^-)???3?×? ^O2aOH. 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 ^O2aOH^-???^O2O^2- + ^W OH^- + ^gH₂O occurs at temperature range from 355?K to 598?K.

SUBMITTER: Dulski M

PROVIDER: S-EPMC5567383 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

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Different route of hydroxide incorporation and thermal stability of new type of water clathrate: X-ray single crystal and Raman investigation.

Dulski Mateusz M Marzec Katarzyna M KM Kusz Joachim J Galuskina Irina I Majzner Katarzyna K Galuskin Evgeny E

Scientific reports 20170822 1

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 ...[more]

PMID: 28831152

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Dataset Information

Different route of hydroxide incorporation and thermal stability of new type of water clathrate: X-ray single crystal and Raman investigation.

Publications

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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