Calorimetric study of the effect of water quantity on tetramethoxysilane hydrolysis under ultrasound stimulation
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
20/05/2014
20/05/2014
03/04/2003
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Resumo |
The ultrasound stimulated and oxalic acid-catalyzed hydrolysis of tetramethoxysilane (TMOS) was studied by means of a heat flux calorimetric method as a function of the initial water/TMOS molar ratio (r) ranging from 2 to 10. The method is based on the time recording of the hydrolysis exothermic heat peak. which takes place in acidulated heterogeneous water-TMOS mixtures under ultrasonic stimulation, accounting for the instantaneous hydrolysis rate. The hydrolysis rate increases from zero up to a maximum value during the heterogeneous step of the process and then diminishes naturally according to the reactant consumption. The total hydrolyzed quantity was found to be slightly increasing with r. The immiscibility gap of the TMOS- water system in the presence of the hydrolysis products has been inferred from the evaluation of the reacted quantity during the heterogeneous step of the reaction and it has been represented in a ternary diagram in the studied r-range. |
Formato |
3091-3094 |
Identificador |
http://dx.doi.org/10.1021/jp0273629 Journal of Physical Chemistry B. Washington: Amer Chemical Soc, v. 107, n. 13, p. 3091-3094, 2003. 1520-6106 http://hdl.handle.net/11449/33607 10.1021/jp0273629 WOS:000181922300031 |
Idioma(s) |
eng |
Publicador |
Amer Chemical Soc |
Relação |
Journal of Physical Chemistry B |
Direitos |
closedAccess |
Tipo |
info:eu-repo/semantics/article |