Thermostimulated sol-gel transition in suspensions of sulfate zirconium oxychloride

Página do item simplificado
dc.contributor.authorChiavacci, L. A.
dc.contributor.authorSantilli, Celso Valentim [UNESP]
dc.contributor.authorPulcinelli, Sandra Helena [UNESP]
dc.contributor.authorCraievich, A. F.
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionUniversidade de São Paulo (USP)
dc.date.accessioned2014-05-20T15:27:08Z
dc.date.available2014-05-20T15:27:08Z
dc.date.issued1997-10-01
dc.description.abstractThe sol-gel transition of an aqueous solution of zirconium oxychloride modified by sulfuric acid (Zr:S 3:1) has been studied by small-angle X-ray scattering (SAXS) performed in situ during one cycle of heating and cooling between 298 and 358 K. The experimental SAXS curves exhibit three regions, at small, medium and high q values, characteristic of the Guinier, 'fractal' and Pored regimes, respectively. The value of 5.5 Angstrom for the radii of the primary particles, obtained from the cross over of the Pored and fractal regimes, is consistent with the size of the inner core of the polynuclear Zr18O4(OH)(38.8)(SO4)(12.6).33H(2)O molecule. These molecules aggregate as small clusters (31 Angstrom) of fractal structure, with a dimensionality D = 2.16 in the sol. The value of the fractal dimensionality, which is characteristic of ideal branched polymers, decreases during heating, attaining a value of 2.0, characteristic of swollen polymers. Above the critical temperature (329 K), the average size of aggregates increases abruptly to 200 Angstrom and the fractal dimensionality decreases to D = 1.75, this value being characteristic of a cluster-cluster aggregation process.en
dc.description.affiliationUNESP, Inst Chem, Araraquara, SP, Brazil
dc.description.affiliationCNPq, Natl Synchrotron Light Lab, Campinas, SP, Brazil
dc.description.affiliationUSP, Inst Phys, BR-09500900 São Paulo, Brazil
dc.description.affiliationUnespUNESP, Inst Chem, Araraquara, SP, Brazil
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.format.extent750-754
dc.identifierhttp://dx.doi.org/10.1107/S0021889897001787
dc.identifier.citationJournal of Applied Crystallography. Copenhagen: Munksgaard Int Publ Ltd, v. 30, n. 2, p. 750-754, 1997.
dc.identifier.doi10.1107/S0021889897001787
dc.identifier.fileWOS000071640900037.pdf
dc.identifier.issn0021-8898
dc.identifier.lattes5584298681870865
dc.identifier.lattes9971202585286967
dc.identifier.orcid0000-0002-8356-8093
dc.identifier.urihttp://hdl.handle.net/11449/37182
dc.identifier.wosWOS:000071640900037
dc.language.isoeng
dc.publisherMunksgaard Int Publ Ltd
dc.relation.ispartofJournal of Applied Crystallography
dc.relation.ispartofsjr1,635
dc.rights.accessRightsAcesso restrito
dc.sourceWeb of Science
dc.titleThermostimulated sol-gel transition in suspensions of sulfate zirconium oxychlorideen
dc.typeArtigo
dcterms.licensehttp://journals.iucr.org/services/copyrightpolicy.html
dcterms.rightsHolderMunksgaard Int Publ Ltd
unesp.author.lattes9971202585286967
unesp.author.lattes5584298681870865[2]
unesp.author.orcid0000-0002-8356-8093[2]
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Química, Araraquarapt

Arquivos

Pacote Original
Agora exibindo 1 - 1 de 1
Imagem de Miniatura
Nome:
WOS000071640900037.pdf
Tamanho:
542.83 KB
Formato:
Adobe Portable Document Format
Baixar
Licença do Pacote
Agora exibindo 1 - 1 de 1
Nenhuma Miniatura disponível
Nome:
license.txt
Tamanho:
1.71 KB
Formato:
Item-specific license agreed upon to submission
Descrição:

Coleções

Artigos - Físico Química - IQ