Effects of the water quantity on the solventless TEOS hydrolysis under ultrasound stimulation

dc.contributor.authorDonatti, D. A.
dc.contributor.authorVollet, D. R.
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-20T15:23:56Z
dc.date.available2014-05-20T15:23:56Z
dc.date.issued2000-01-01
dc.description.abstractThe acid hydrolysis under ultrasound stimulation of solventless tetraethoxysilane(TEOS)-water mixtures was studied at 40 degrees C, by means of a heat flux calorimetric method, as a function of the initial water/TEOS molar ratio (r) ranging from 2 to 10. The method is based on the time record of the exothermic heat peak of hydrolysis, arising after an induction time under ultrasound stimulation, which is a measure of the reaction rate. The hydrolysed quantity was found to be approximately independent of the water/TEOS molar ratio, even for r < 4. Polycondensation reaction takes place mainly for low water/TEOS molar ratio in order to supply water to allow almost complete hydrolysis. The overall process of dissolution and hydrolysis has reasonably been described by a previous modelling. The dissolution process of water in TEOS, under ultrasound stimulation and acid conditions, was found to be rather dependent of the alcohol produced in the hydrolysis reaction instead of the initial water quantity present in the mixture.en
dc.description.affiliationUNESP, IGCE, Dept Fis, BR-13500970 Rio Claro, SP, Brazil
dc.description.affiliationUnespUNESP, IGCE, Dept Fis, BR-13500970 Rio Claro, SP, Brazil
dc.format.extent19-24
dc.identifierhttp://dx.doi.org/10.1023/A:1008748702656
dc.identifier.citationJournal of Sol-gel Science and Technology. Dordrecht: Kluwer Academic Publ, v. 17, n. 1, p. 19-24, 2000.
dc.identifier.doi10.1023/A:1008748702656
dc.identifier.issn0928-0707
dc.identifier.lattes3538107401166553
dc.identifier.lattes2661573794233385
dc.identifier.urihttp://hdl.handle.net/11449/34615
dc.identifier.wosWOS:000083802900003
dc.language.isoeng
dc.publisherKluwer Academic Publ
dc.relation.ispartofJournal of Sol-Gel Science and Technology
dc.relation.ispartofjcr1.745
dc.relation.ispartofsjr0,477
dc.rights.accessRightsAcesso restrito
dc.sourceWeb of Science
dc.subjectTEOSpt
dc.subjectsono-hydrolysispt
dc.subjectwaterpt
dc.titleEffects of the water quantity on the solventless TEOS hydrolysis under ultrasound stimulationen
dc.typeArtigo
dcterms.licensehttp://www.springer.com/open+access/authors+rights
dcterms.rightsHolderKluwer Academic Publ
unesp.author.lattes3538107401166553
unesp.author.lattes2661573794233385
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Geociências e Ciências Exatas, Rio Claropt

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