Core-and-shell nature of Stöber silica particles
Autor(a) principal: | |
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Data de Publicação: | 2001 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000400013 |
Resumo: | Two different samples of monodisperse Stöber silica particles were examined in the analytical transmission electron microscope, using different imaging modes: bright-field, dark-field, energy-loss and elemental distribution maps. The particles (effective diameters = 141 and 36 nm) are formed by domains of variable O/Si ratio, which is consistent with a variable degree of hydration, and they coexist with particles with a high O/Si ratio measuring a few nanometers only, which appear dispersed in the picture background. Bright-field and energy-loss images of the larger particles show a core-and-shell morphology, and the shells have a higher amount of high-O/Si domains as well as contaminating carbon compounds. On the other hand, the smaller particles (effective diameter = 36 nm) are also formed by distinct domains, but their morphology is neither spherical or core-and-shell. The mechanisms for particle formation presented in the literature are discussed, considering the present findings. |
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Core-and-shell nature of Stöber silica particlescolloidal silicatransmission electron microscopyenergy-filtered imagingsilica particle microchemistryTwo different samples of monodisperse Stöber silica particles were examined in the analytical transmission electron microscope, using different imaging modes: bright-field, dark-field, energy-loss and elemental distribution maps. The particles (effective diameters = 141 and 36 nm) are formed by domains of variable O/Si ratio, which is consistent with a variable degree of hydration, and they coexist with particles with a high O/Si ratio measuring a few nanometers only, which appear dispersed in the picture background. Bright-field and energy-loss images of the larger particles show a core-and-shell morphology, and the shells have a higher amount of high-O/Si domains as well as contaminating carbon compounds. On the other hand, the smaller particles (effective diameter = 36 nm) are also formed by distinct domains, but their morphology is neither spherical or core-and-shell. The mechanisms for particle formation presented in the literature are discussed, considering the present findings.Sociedade Brasileira de Química2001-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000400013Journal of the Brazilian Chemical Society v.12 n.4 2001reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50532001000400013info:eu-repo/semantics/openAccessLeite,Carlos A. P.Souza,Elizabeth F. deGalembeck,Fernandoeng2001-10-17T00:00:00Zoai:scielo:S0103-50532001000400013Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2001-10-17T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Core-and-shell nature of Stöber silica particles |
title |
Core-and-shell nature of Stöber silica particles |
spellingShingle |
Core-and-shell nature of Stöber silica particles Leite,Carlos A. P. colloidal silica transmission electron microscopy energy-filtered imaging silica particle microchemistry |
title_short |
Core-and-shell nature of Stöber silica particles |
title_full |
Core-and-shell nature of Stöber silica particles |
title_fullStr |
Core-and-shell nature of Stöber silica particles |
title_full_unstemmed |
Core-and-shell nature of Stöber silica particles |
title_sort |
Core-and-shell nature of Stöber silica particles |
author |
Leite,Carlos A. P. |
author_facet |
Leite,Carlos A. P. Souza,Elizabeth F. de Galembeck,Fernando |
author_role |
author |
author2 |
Souza,Elizabeth F. de Galembeck,Fernando |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Leite,Carlos A. P. Souza,Elizabeth F. de Galembeck,Fernando |
dc.subject.por.fl_str_mv |
colloidal silica transmission electron microscopy energy-filtered imaging silica particle microchemistry |
topic |
colloidal silica transmission electron microscopy energy-filtered imaging silica particle microchemistry |
description |
Two different samples of monodisperse Stöber silica particles were examined in the analytical transmission electron microscope, using different imaging modes: bright-field, dark-field, energy-loss and elemental distribution maps. The particles (effective diameters = 141 and 36 nm) are formed by domains of variable O/Si ratio, which is consistent with a variable degree of hydration, and they coexist with particles with a high O/Si ratio measuring a few nanometers only, which appear dispersed in the picture background. Bright-field and energy-loss images of the larger particles show a core-and-shell morphology, and the shells have a higher amount of high-O/Si domains as well as contaminating carbon compounds. On the other hand, the smaller particles (effective diameter = 36 nm) are also formed by distinct domains, but their morphology is neither spherical or core-and-shell. The mechanisms for particle formation presented in the literature are discussed, considering the present findings. |
publishDate |
2001 |
dc.date.none.fl_str_mv |
2001-08-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000400013 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000400013 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50532001000400013 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.12 n.4 2001 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318164526235648 |