Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route
Silica matrices synthesized from a pre-hydrolysis step in ethanol followed by alcohol removal at low pressure distillation, and condensation in water, are suitable for encapsulation of biomolecules and microorganisms and building bioactive materials with optimized optical properties. Here we analyze...
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paper:paper_09280707_v59_n1_p174_Perullini2023-06-08T15:52:10Z Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route Perullini, Ana Mercedes Jobbagy, Matias Aldabe Bilmes, Sara Alfonsina Dora Candal, Roberto Jorge Optical quality SAXS microstructure characterization Silica hydrogels TEOS alcohol-free Bioactive material Cluster densities Gyration radii Low pressures Optical qualities SAXS microstructure characterization Silica concentrations Silica matrix Sol-gel routes Synthesis conditions TEOS alcohol-free Visible light Coagulation Condensation Distillation Elementary particles Ethanol Fractal dimension Gelation Gels Hydrogels Optical properties Pressure effects Silica Sol-gel process Microstructure Silica matrices synthesized from a pre-hydrolysis step in ethanol followed by alcohol removal at low pressure distillation, and condensation in water, are suitable for encapsulation of biomolecules and microorganisms and building bioactive materials with optimized optical properties. Here we analyze the microstructure of these hydrogels from the dependence of I(q) data acquired from SAXS experiments over a wide range of silica concentration and pH employed in the condensation step. From the resulting data it is shown that there is a clear correlation between the microscopic parameters-cluster fractal dimension (D), elementary particle radius (a) and cluster gyration radius (R)-with the attenuation of visible light when the condensation step proceeds at pH < 6. At higher pHs, there is a steep dependence of the cluster density (~R D-3 ) with the condensation pH, and non-monotonous changes of attenuance are less than 20%, revealing the complexity of the system. These results, which were obtained for a wide pH and silica concentration range, reinforce the idea that the behavior of gels determined in a restricted interval of synthesis variables cannot be extrapolated, and comparison of gelation times is not enough for predicting their properties. © 2011 Springer Science+Business Media, LLC. Fil:Perullini, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Jobbágy, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Bilmes, S.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Candal, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09280707_v59_n1_p174_Perullini http://hdl.handle.net/20.500.12110/paper_09280707_v59_n1_p174_Perullini |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Optical quality SAXS microstructure characterization Silica hydrogels TEOS alcohol-free Bioactive material Cluster densities Gyration radii Low pressures Optical qualities SAXS microstructure characterization Silica concentrations Silica matrix Sol-gel routes Synthesis conditions TEOS alcohol-free Visible light Coagulation Condensation Distillation Elementary particles Ethanol Fractal dimension Gelation Gels Hydrogels Optical properties Pressure effects Silica Sol-gel process Microstructure |
| spellingShingle |
Optical quality SAXS microstructure characterization Silica hydrogels TEOS alcohol-free Bioactive material Cluster densities Gyration radii Low pressures Optical qualities SAXS microstructure characterization Silica concentrations Silica matrix Sol-gel routes Synthesis conditions TEOS alcohol-free Visible light Coagulation Condensation Distillation Elementary particles Ethanol Fractal dimension Gelation Gels Hydrogels Optical properties Pressure effects Silica Sol-gel process Microstructure Perullini, Ana Mercedes Jobbagy, Matias Aldabe Bilmes, Sara Alfonsina Dora Candal, Roberto Jorge Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| topic_facet |
Optical quality SAXS microstructure characterization Silica hydrogels TEOS alcohol-free Bioactive material Cluster densities Gyration radii Low pressures Optical qualities SAXS microstructure characterization Silica concentrations Silica matrix Sol-gel routes Synthesis conditions TEOS alcohol-free Visible light Coagulation Condensation Distillation Elementary particles Ethanol Fractal dimension Gelation Gels Hydrogels Optical properties Pressure effects Silica Sol-gel process Microstructure |
| description |
Silica matrices synthesized from a pre-hydrolysis step in ethanol followed by alcohol removal at low pressure distillation, and condensation in water, are suitable for encapsulation of biomolecules and microorganisms and building bioactive materials with optimized optical properties. Here we analyze the microstructure of these hydrogels from the dependence of I(q) data acquired from SAXS experiments over a wide range of silica concentration and pH employed in the condensation step. From the resulting data it is shown that there is a clear correlation between the microscopic parameters-cluster fractal dimension (D), elementary particle radius (a) and cluster gyration radius (R)-with the attenuation of visible light when the condensation step proceeds at pH < 6. At higher pHs, there is a steep dependence of the cluster density (~R D-3 ) with the condensation pH, and non-monotonous changes of attenuance are less than 20%, revealing the complexity of the system. These results, which were obtained for a wide pH and silica concentration range, reinforce the idea that the behavior of gels determined in a restricted interval of synthesis variables cannot be extrapolated, and comparison of gelation times is not enough for predicting their properties. © 2011 Springer Science+Business Media, LLC. |
| author |
Perullini, Ana Mercedes Jobbagy, Matias Aldabe Bilmes, Sara Alfonsina Dora Candal, Roberto Jorge |
| author_facet |
Perullini, Ana Mercedes Jobbagy, Matias Aldabe Bilmes, Sara Alfonsina Dora Candal, Roberto Jorge |
| author_sort |
Perullini, Ana Mercedes |
| title |
Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| title_short |
Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| title_full |
Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| title_fullStr |
Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| title_full_unstemmed |
Effect of synthesis conditions on the microstructure of TEOS derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| title_sort |
effect of synthesis conditions on the microstructure of teos derived silica hydrogels synthesized by the alcohol-free sol-gel route |
| publishDate |
2011 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09280707_v59_n1_p174_Perullini http://hdl.handle.net/20.500.12110/paper_09280707_v59_n1_p174_Perullini |
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AT perullinianamercedes effectofsynthesisconditionsonthemicrostructureofteosderivedsilicahydrogelssynthesizedbythealcoholfreesolgelroute AT jobbagymatias effectofsynthesisconditionsonthemicrostructureofteosderivedsilicahydrogelssynthesizedbythealcoholfreesolgelroute AT aldabebilmessaraalfonsinadora effectofsynthesisconditionsonthemicrostructureofteosderivedsilicahydrogelssynthesizedbythealcoholfreesolgelroute AT candalrobertojorge effectofsynthesisconditionsonthemicrostructureofteosderivedsilicahydrogelssynthesizedbythealcoholfreesolgelroute |
| _version_ |
1768543569721688064 |