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Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide
Supercritical carbon dioxide (scCO(2)) treatments of a montmorillonite (MMT) intercalated with ammonium cations bearing two long hydrocarbon tails (organo-modified MMT, OMMT) led to OMMT exfoliation, with loss of the long-range order in the packing of the hydrocarbon tails and maintenance of the lon...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982576/ https://www.ncbi.nlm.nih.gov/pubmed/24790956 http://dx.doi.org/10.3389/fchem.2013.00028 |
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author | Longo, Simona Mauro, Marco Daniel, Christophe Galimberti, Maurizio Guerra, Gaetano |
author_facet | Longo, Simona Mauro, Marco Daniel, Christophe Galimberti, Maurizio Guerra, Gaetano |
author_sort | Longo, Simona |
collection | PubMed |
description | Supercritical carbon dioxide (scCO(2)) treatments of a montmorillonite (MMT) intercalated with ammonium cations bearing two long hydrocarbon tails (organo-modified MMT, OMMT) led to OMMT exfoliation, with loss of the long-range order in the packing of the hydrocarbon tails and maintenance of the long-range order in the clay layers. The intercalated and the derived exfoliated OMMT have been deeply characterized, mainly by X-ray diffraction analyses. Monolithic composite aerogels, with large amounts of both intercalated and exfoliated OMMT and including the nanoporous-crystalline δ form of syndiotactic polystyrene (s-PS), have been prepared, by scCO(2) extractions of s-PS-based gels. Also for high OMMT content, the gel and aerogel preparation procedures occur without re-aggregation of the exfoliated clay, which is instead observed for other kinds of polymer processing. Aerogels with the exfoliated OMMT have more even dispersion of the clay layers, higher elastic modulus and larger surface area than aerogels with the intercalated OMMT. Extremely light materials with relevant transport properties could be prepared. Moreover, s-PS-based aerogels with exfoliated OMMT could be helpful for the handling of exfoliated clay minerals. |
format | Online Article Text |
id | pubmed-3982576 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-39825762014-04-30 Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide Longo, Simona Mauro, Marco Daniel, Christophe Galimberti, Maurizio Guerra, Gaetano Front Chem Chemistry Supercritical carbon dioxide (scCO(2)) treatments of a montmorillonite (MMT) intercalated with ammonium cations bearing two long hydrocarbon tails (organo-modified MMT, OMMT) led to OMMT exfoliation, with loss of the long-range order in the packing of the hydrocarbon tails and maintenance of the long-range order in the clay layers. The intercalated and the derived exfoliated OMMT have been deeply characterized, mainly by X-ray diffraction analyses. Monolithic composite aerogels, with large amounts of both intercalated and exfoliated OMMT and including the nanoporous-crystalline δ form of syndiotactic polystyrene (s-PS), have been prepared, by scCO(2) extractions of s-PS-based gels. Also for high OMMT content, the gel and aerogel preparation procedures occur without re-aggregation of the exfoliated clay, which is instead observed for other kinds of polymer processing. Aerogels with the exfoliated OMMT have more even dispersion of the clay layers, higher elastic modulus and larger surface area than aerogels with the intercalated OMMT. Extremely light materials with relevant transport properties could be prepared. Moreover, s-PS-based aerogels with exfoliated OMMT could be helpful for the handling of exfoliated clay minerals. Frontiers Media S.A. 2013-11-13 /pmc/articles/PMC3982576/ /pubmed/24790956 http://dx.doi.org/10.3389/fchem.2013.00028 Text en Copyright © 2013 Longo, Mauro, Daniel, Galimberti and Guerra. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Chemistry Longo, Simona Mauro, Marco Daniel, Christophe Galimberti, Maurizio Guerra, Gaetano Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title | Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title_full | Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title_fullStr | Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title_full_unstemmed | Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title_short | Clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
title_sort | clay exfoliation and polymer/clay aerogels by supercritical carbon dioxide |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3982576/ https://www.ncbi.nlm.nih.gov/pubmed/24790956 http://dx.doi.org/10.3389/fchem.2013.00028 |
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