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Dynamics and Disorder in Surfactant-Templated Silicate Layers Studied by Solid-State NMR Dephasing Times and Correlated Line Shapes

Authors :
Jan D. Epping
Lyndon Emsley
Sylvian Cadars
Anne Lesage
Nicolas Mifsud
Bradley F. Chmelka
Niklas Hedin
Conditions Extrêmes et Matériaux : Haute Température et Irradiation (CEMHTI)
Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université d'Orléans (UO)
Laboratoire de Chimie - UMR5182 (LC)
Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)-Institut de Chimie du CNRS (INC)
Stockholm University
Dept Chem Engr, Univ. California, Santa Barbara
Dept Chem Engr
Université d'Orléans (UO)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL)
Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Source :
Journal of Physical Chemistry C, Journal of Physical Chemistry C, American Chemical Society, 2008, 112 (25), pp.9145-9154. ⟨10.1021/jp711398h⟩, Journal of Physical Chemistry C, 2008, 112 (25), pp.9145-9154. ⟨10.1021/jp711398h⟩
Publication Year :
2008
Publisher :
HAL CCSD, 2008.

Abstract

Surfactant-templated layered silicates are shown to possess complex compositional, structural, and dynamic features that manifest rich and interrelated order and disorder at molecular length scales. Temperature-dependent 1D and 2D solid-state Si-29 NMR measurements reveal a chemical-exchange process involving the surfactant headgroups that is concomitant with reversible broadening of Si-29 NMR line shapes under magic-angle-spinning (MAS) conditions at temperatures in the range 205-330 K. Specifically, the temperature-dependent changes in the Si-29 transverse dephasing times T-2' can be quantitatively accounted for by 2-fold reorientational dynamics of the surfactant headgroups. Variable-temperature analyses demonstrate that the temperature-dependent Si-29 shifts, peak broadening, and 2D Si-29{Si-29} correlation NMR line shapes are directly related to the freezing of the surfactant headgroup dynamics, which results in local structural disorder within the silicate framework.

Details

Language :
English
ISSN :
19327447 and 19327455
Database :
OpenAIRE
Journal :
Journal of Physical Chemistry C, Journal of Physical Chemistry C, American Chemical Society, 2008, 112 (25), pp.9145-9154. ⟨10.1021/jp711398h⟩, Journal of Physical Chemistry C, 2008, 112 (25), pp.9145-9154. ⟨10.1021/jp711398h⟩
Accession number :
edsair.doi.dedup.....68fc03a4f813f01bca00432527dec55d
Full Text :
https://doi.org/10.1021/jp711398h⟩