Advanced search
1 file | 2.45 MB

UV-Raman and 29Si NMR spectroscopy investigation of the nature of silicate oligomers formed by acid catalyzed hydrolysis and polycondensation of tetramethylorthosilicate

(2011) JOURNAL OF PHYSICAL CHEMISTRY C. 115(22). p.11077-11088
Author
Organization
Abstract
Tetramethylorthosilicate (TMOS) was hydrolyzed and polymerized under strongly acidic conditions in the presence of substoichiometric quantities of water. The polymerization reaction was monitored during 64 h using Si-29 NMR and UV-Raman spectroscopy. The nature of the oligomers and the condensation reaction pathways were unraveled using this combination of experimental techniques together with molecular modeling. Si-29 NMR and UV-Raman signals which previously were not documented in literature could be assigned. TMOS rapidly was converted into short straight methoxylated silicate chains. Subsequently the growth of oligomers proceeded by condensations between a hydrolyzed middle group of a chain with an end-group of another chain. Larger oligomers were attached to each other via condensations between middle groups generating multiply branched structures. Rings were formed late in the reaction scheme through internal condensations of sizable silicate molecules. Oligomers that were characteristic of the different stages of the polymerization process were proposed. Oligomerization pathways starting from tetramethylorthosilicate and tetraethylorthosilicate (TEOS) are significantly different. While with TMOS rings are formed only late in the oligomerization scheme, with TEOS rings are formed at early stages through cyclo-dimerization. This insight into the different nature of the oligomers obtained from TMOS and TEOS will assist the design of new silica sol gel materials.
Keywords
SOL-GEL POLYMERIZATION, ALKOXIDES, GLASS, CHEMISTRY, FRAMEWORK, AB-INITIO, SI/AL RATIO, FAUJASITIC ZEOLITES, CHEMICAL-SHIFTS, VIBRATIONAL-SPECTRA

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 2.45 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Depla, Anouschka, Elke Verheyen, An Veyfeyken, Marc Van Houteghem, Kristof Houthoofd, Veronique Van Speybroeck, Michel Waroquier, Christine EA Kirschhock, and Johan A Martens. 2011. “UV-Raman and 29Si NMR Spectroscopy Investigation of the Nature of Silicate Oligomers Formed by Acid Catalyzed Hydrolysis and Polycondensation of Tetramethylorthosilicate.” Journal of Physical Chemistry C 115 (22): 11077–11088.
APA
Depla, A., Verheyen, E., Veyfeyken, A., Van Houteghem, M., Houthoofd, K., Van Speybroeck, V., Waroquier, M., et al. (2011). UV-Raman and 29Si NMR spectroscopy investigation of the nature of silicate oligomers formed by acid catalyzed hydrolysis and polycondensation of tetramethylorthosilicate. JOURNAL OF PHYSICAL CHEMISTRY C, 115(22), 11077–11088.
Vancouver
1.
Depla A, Verheyen E, Veyfeyken A, Van Houteghem M, Houthoofd K, Van Speybroeck V, et al. UV-Raman and 29Si NMR spectroscopy investigation of the nature of silicate oligomers formed by acid catalyzed hydrolysis and polycondensation of tetramethylorthosilicate. JOURNAL OF PHYSICAL CHEMISTRY C. 2011;115(22):11077–88.
MLA
Depla, Anouschka, Elke Verheyen, An Veyfeyken, et al. “UV-Raman and 29Si NMR Spectroscopy Investigation of the Nature of Silicate Oligomers Formed by Acid Catalyzed Hydrolysis and Polycondensation of Tetramethylorthosilicate.” JOURNAL OF PHYSICAL CHEMISTRY C 115.22 (2011): 11077–11088. Print.
@article{1267369,
  abstract     = {Tetramethylorthosilicate (TMOS) was hydrolyzed and polymerized under strongly acidic conditions in the presence of substoichiometric quantities of water. The polymerization reaction was monitored during 64 h using Si-29 NMR and UV-Raman spectroscopy. The nature of the oligomers and the condensation reaction pathways were unraveled using this combination of experimental techniques together with molecular modeling. Si-29 NMR and UV-Raman signals which previously were not documented in literature could be assigned. TMOS rapidly was converted into short straight methoxylated silicate chains. Subsequently the growth of oligomers proceeded by condensations between a hydrolyzed middle group of a chain with an end-group of another chain. Larger oligomers were attached to each other via condensations between middle groups generating multiply branched structures. Rings were formed late in the reaction scheme through internal condensations of sizable silicate molecules. Oligomers that were characteristic of the different stages of the polymerization process were proposed. Oligomerization pathways starting from tetramethylorthosilicate and tetraethylorthosilicate (TEOS) are significantly different. While with TMOS rings are formed only late in the oligomerization scheme, with TEOS rings are formed at early stages through cyclo-dimerization. This insight into the different nature of the oligomers obtained from TMOS and TEOS will assist the design of new silica sol gel materials.},
  author       = {Depla, Anouschka and Verheyen, Elke and Veyfeyken, An and Van Houteghem, Marc and Houthoofd, Kristof and Van Speybroeck, Veronique and Waroquier, Michel and Kirschhock, Christine EA and Martens, Johan A},
  issn         = {1932-7447},
  journal      = {JOURNAL OF PHYSICAL CHEMISTRY C},
  keyword      = {SOL-GEL POLYMERIZATION,ALKOXIDES,GLASS,CHEMISTRY,FRAMEWORK,AB-INITIO,SI/AL RATIO,FAUJASITIC ZEOLITES,CHEMICAL-SHIFTS,VIBRATIONAL-SPECTRA},
  language     = {eng},
  number       = {22},
  pages        = {11077--11088},
  title        = {UV-Raman and 29Si NMR spectroscopy investigation of the nature of silicate oligomers formed by acid catalyzed hydrolysis and polycondensation of tetramethylorthosilicate},
  url          = {http://dx.doi.org/10.1021/jp200568j},
  volume       = {115},
  year         = {2011},
}

Altmetric
View in Altmetric
Web of Science
Times cited: