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Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study

The nucleation and growth of niobium pentaethoxide (NPE)-derived clusters in ethanol, through acid-catalyzed hydrolysis/condensation in the presence and absence of the silsesquioxane 1,2-bis(triethoxysilyl)ethane (BTESE), was monitored at 298–333 K by small-angle X-ray scattering. The data were anal...

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Detalles Bibliográficos
Autores principales: Besselink, Rogier, ten Elshof, Johan E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: International Union of Crystallography 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180739/
https://www.ncbi.nlm.nih.gov/pubmed/25294980
http://dx.doi.org/10.1107/S1600576714017105
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author Besselink, Rogier
ten Elshof, Johan E.
author_facet Besselink, Rogier
ten Elshof, Johan E.
author_sort Besselink, Rogier
collection PubMed
description The nucleation and growth of niobium pentaethoxide (NPE)-derived clusters in ethanol, through acid-catalyzed hydrolysis/condensation in the presence and absence of the silsesquioxane 1,2-bis(triethoxysilyl)ethane (BTESE), was monitored at 298–333 K by small-angle X-ray scattering. The data were analyzed with a newly derived model for polydisperse mass-fractal-like structures. At 298–313 K in the absence of BTESE the data indicated the development of relatively monodisperse NPE-derived structures with self-preserving polydispersity during growth. The growth exponent was consistent with irreversible diffusion-limited cluster agglomeration. At 333 K the growth exponent was characteristic for fast-gelling reaction-limited cluster agglomeration. The reaction yielded substantially higher degrees of polydispersity. In the presence of BTESE the growth exponents were substantially smaller. The smaller growth exponent in this case is not consistent with irreversible Smoluchowski-type agglomeration. Instead, reversible Lifshitz–Slyozov-type agglomeration seems to be more consistent with the experimental data.
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spelling pubmed-41807392014-10-07 Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study Besselink, Rogier ten Elshof, Johan E. J Appl Crystallogr Research Papers The nucleation and growth of niobium pentaethoxide (NPE)-derived clusters in ethanol, through acid-catalyzed hydrolysis/condensation in the presence and absence of the silsesquioxane 1,2-bis(triethoxysilyl)ethane (BTESE), was monitored at 298–333 K by small-angle X-ray scattering. The data were analyzed with a newly derived model for polydisperse mass-fractal-like structures. At 298–313 K in the absence of BTESE the data indicated the development of relatively monodisperse NPE-derived structures with self-preserving polydispersity during growth. The growth exponent was consistent with irreversible diffusion-limited cluster agglomeration. At 333 K the growth exponent was characteristic for fast-gelling reaction-limited cluster agglomeration. The reaction yielded substantially higher degrees of polydispersity. In the presence of BTESE the growth exponents were substantially smaller. The smaller growth exponent in this case is not consistent with irreversible Smoluchowski-type agglomeration. Instead, reversible Lifshitz–Slyozov-type agglomeration seems to be more consistent with the experimental data. International Union of Crystallography 2014-09-04 /pmc/articles/PMC4180739/ /pubmed/25294980 http://dx.doi.org/10.1107/S1600576714017105 Text en © Rogier Besselink et al. 2014 http://creativecommons.org/licenses/by/2.0/uk/ This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
spellingShingle Research Papers
Besselink, Rogier
ten Elshof, Johan E.
Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title_full Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title_fullStr Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title_full_unstemmed Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title_short Mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle X-ray scattering study
title_sort mass-fractal growth in niobia/silsesquioxane mixtures: a small-angle x-ray scattering study
topic Research Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4180739/
https://www.ncbi.nlm.nih.gov/pubmed/25294980
http://dx.doi.org/10.1107/S1600576714017105
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