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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...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
International Union of Crystallography
2014
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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. |
format | Online Article Text |
id | pubmed-4180739 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2014 |
publisher | International Union of Crystallography |
record_format | MEDLINE/PubMed |
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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