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

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorDonatti, D. A.
dc.creatorVollet, D. R.
dc.date2014-05-20T15:23:56Z
dc.date2016-10-25T17:57:59Z
dc.date2014-05-20T15:23:56Z
dc.date2016-10-25T17:57:59Z
dc.date2000-01-01
dc.date.accessioned2017-04-05T23:44:32Z
dc.date.available2017-04-05T23:44:32Z
dc.identifierJournal of Sol-gel Science and Technology. Dordrecht: Kluwer Academic Publ, v. 17, n. 1, p. 19-24, 2000.
dc.identifier0928-0707
dc.identifierhttp://hdl.handle.net/11449/34615
dc.identifierhttp://acervodigital.unesp.br/handle/11449/34615
dc.identifier10.1023/A:1008748702656
dc.identifierWOS:000083802900003
dc.identifierhttp://dx.doi.org/10.1023/A:1008748702656
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/878503
dc.descriptionThe 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.
dc.languageeng
dc.publisherKluwer Academic Publ
dc.relationJournal of Sol-Gel Science and Technology
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectTEOS
dc.subjectsono-hydrolysis
dc.subjectwater
dc.titleEffects of the water quantity on the solventless TEOS hydrolysis under ultrasound stimulation
dc.typeOtro


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