Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides

The structure of several crystalline Ni(II)-Al(III) and Mg(II)-Al(III) layered double hydroxides (LDHs) intercalated with nitrate anions was studied as a function of the relative humidity. For low charge density LDHs, the electrostatic attraction between the anions and the positive LDH layers prevai...

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Detalles Bibliográficos
Autor principal: Jobbagy, Matias
Publicado: 2010
Materias:
Divalent cation
Dry atmospheres
Electrostatic attractions
Hydration process
Layer charge density
Layered double hydroxides
Nitrate anions
Relative humidities
Structural feature
Water activity
Water molecule
Atmospheric humidity
Ions
Charge density
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n42_p18153_Jobbagy
http://hdl.handle.net/20.500.12110/paper_19327447_v114_n42_p18153_Jobbagy
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_19327447_v114_n42_p18153_Jobbagy
record_format dspace
spelling paper:paper_19327447_v114_n42_p18153_Jobbagy2023-06-08T16:31:30Z Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides Jobbagy, Matias Divalent cation Dry atmospheres Electrostatic attractions Hydration process Layer charge density Layered double hydroxides Nitrate anions Relative humidities Structural feature Water activity Water molecule Atmospheric humidity Ions Charge density The structure of several crystalline Ni(II)-Al(III) and Mg(II)-Al(III) layered double hydroxides (LDHs) intercalated with nitrate anions was studied as a function of the relative humidity. For low charge density LDHs, the electrostatic attraction between the anions and the positive LDH layers prevails over any other interaction, and the anions remain flat, F, with their C 3 axis perpendicular to the xy planes, irrespective of water activity. For LDHs bearing higher charge densities, the incoming water molecules drive an abrupt phase expansion in which the anions tilt their C3 axis with respect to the interlamellar xy plane, thus resulting in an expanded, T, form. The structural F-T transition is discontinuous, and involves a second staging phase intermediate, with alternated F and T galleries. For intermediate charge density LDHs, the hydration process easily reverts, once the samples are resubmitted to a dry atmosphere. Dehydration of high charge density LDHs is however kinetically hindered; this behavior is explained in terms of the structural features of the involved phases. For all samples, the maximum net gallery expansion is proportional to the layer charge density, irrespective of the nature of the divalent cation. © 2010 American Chemical Society. Fil:Jobbágy, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n42_p18153_Jobbagy http://hdl.handle.net/20.500.12110/paper_19327447_v114_n42_p18153_Jobbagy
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Divalent cation
Dry atmospheres
Electrostatic attractions
Hydration process
Layer charge density
Layered double hydroxides
Nitrate anions
Relative humidities
Structural feature
Water activity
Water molecule
Atmospheric humidity
Ions
Charge density
spellingShingle Divalent cation
Dry atmospheres
Electrostatic attractions
Hydration process
Layer charge density
Layered double hydroxides
Nitrate anions
Relative humidities
Structural feature
Water activity
Water molecule
Atmospheric humidity
Ions
Charge density
Jobbagy, Matias
Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
topic_facet Divalent cation
Dry atmospheres
Electrostatic attractions
Hydration process
Layer charge density
Layered double hydroxides
Nitrate anions
Relative humidities
Structural feature
Water activity
Water molecule
Atmospheric humidity
Ions
Charge density
description The structure of several crystalline Ni(II)-Al(III) and Mg(II)-Al(III) layered double hydroxides (LDHs) intercalated with nitrate anions was studied as a function of the relative humidity. For low charge density LDHs, the electrostatic attraction between the anions and the positive LDH layers prevails over any other interaction, and the anions remain flat, F, with their C 3 axis perpendicular to the xy planes, irrespective of water activity. For LDHs bearing higher charge densities, the incoming water molecules drive an abrupt phase expansion in which the anions tilt their C3 axis with respect to the interlamellar xy plane, thus resulting in an expanded, T, form. The structural F-T transition is discontinuous, and involves a second staging phase intermediate, with alternated F and T galleries. For intermediate charge density LDHs, the hydration process easily reverts, once the samples are resubmitted to a dry atmosphere. Dehydration of high charge density LDHs is however kinetically hindered; this behavior is explained in terms of the structural features of the involved phases. For all samples, the maximum net gallery expansion is proportional to the layer charge density, irrespective of the nature of the divalent cation. © 2010 American Chemical Society.
author Jobbagy, Matias
author_facet Jobbagy, Matias
author_sort Jobbagy, Matias
title Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
title_short Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
title_full Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
title_fullStr Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
title_full_unstemmed Interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
title_sort interplay of charge density and relative humidity on the structure of nitrate layered double hydroxides
publishDate 2010
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n42_p18153_Jobbagy
http://hdl.handle.net/20.500.12110/paper_19327447_v114_n42_p18153_Jobbagy
work_keys_str_mv AT jobbagymatias interplayofchargedensityandrelativehumidityonthestructureofnitratelayereddoublehydroxides
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