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Dehydration Process of Hofmann-Type Layered Solids.

ABSTRACT: In the present work the dehydration process of layered solids with formula unit M(H?O)?[Ni(CN)?]·nH?O, M = Ni, Co, Mn; n = 1, 2, 4 is studied using modulated thermogravimetry. The results show that water molecules need to overcome an energetic barrier (activation energy between 63 and 500 kJ/mol) in order to diffuse through the interlayer region. The related kinetic parameters show a dependence on the water partial pressure. On the other hand, X-ray diffraction results provide evidence that the dehydration process is accompanied by framework collapse, limiting the structural reversibility, except for heating below 80 °C where the ordered structure remains. Removal of water molecules from the interlayer region disrupts the long-range structural order of the solid.

SUBMITTER: Reyes-Martinez O

PROVIDER: S-EPMC5452313 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

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Dehydration Process of Hofmann-Type Layered Solids.

Reyes-Martinez Omar O Torres-García Enelio E Rodríguez-Gattorno Geonel G Reguera Edilso E

Materials (Basel, Switzerland) 20130409 4

In the present work the dehydration process of layered solids with formula unit M(H₂O)₂[Ni(CN)₄]·<i>n</i>H₂O, M = Ni, Co, Mn; <i>n</i> = 1, 2, 4 is studied using modulated thermogravimetry. The results show that water molecules need to overcome an energetic barrier (activation energy between 63 and 500 kJ/mol) in order to diffuse through the interlayer region. The related kinetic parameters show a dependence on the water partial pressure. On the other hand, X-ray diffraction results provide evid ...[more]

PMID: 28809220

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