Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols
The use of correlation analysis of photoacoustic signal changes during the sol-gel-aging evolution of titania sols prepared from the hydrolysis of titanium n-butoxide in alcoholic, aqueous, and micellar media which provide different initial conditions and different evolution pathways is proposed. Th...
Guardado en:
Autores principales: | , , , , |
---|---|
Formato: | JOUR |
Materias: | |
Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_0195928X_v25_n2_p491_Marchi |
Aporte de: |
id |
todo:paper_0195928X_v25_n2_p491_Marchi |
---|---|
record_format |
dspace |
spelling |
todo:paper_0195928X_v25_n2_p491_Marchi2023-10-03T15:09:41Z Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols Marchi, M.C. Castañeda-Guzmán, R. Pérez-Pacheco, A. Bilmes, S.A. Villagrán-Muniz, M. Correlation analysis Oscillating reactions Phase transition Photoacoustic Sol-gel TiO 2 Ceramic materials Crystallization Gelation Heat treatment Hydrolysis Phase transitions Photoacoustic effect Sintering Thermoanalysis Thermogravimetric analysis Distinguishable transition Gelation time Oscillating reactions Particle solvent interactions Sol-gels The use of correlation analysis of photoacoustic signal changes during the sol-gel-aging evolution of titania sols prepared from the hydrolysis of titanium n-butoxide in alcoholic, aqueous, and micellar media which provide different initial conditions and different evolution pathways is proposed. The photoacoustic experiments were done either at constant temperature for monitoring the initial evolution of the system, or under heating at 2°C·min -1 for monitoring molecular processes related to drying, sintering, and crystallization. Results obtained from photoacoustic measurements display higher sensibility when compared with those from differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The evolution of these systems shows instabilities below and above gelation, as well as during thermal treatment. These stabilities are minimized when the thermal treatment is performed on gels aged several months, and can be associated to molecular rearrangements or oscillating chemical reactions. For all the systems studied, the sensitivity of the correlation analysis recovered from photoacoustic signals permits detection of a transition in the 100 to 150°C range. Fil:Marchi, M.C. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0195928X_v25_n2_p491_Marchi |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Correlation analysis Oscillating reactions Phase transition Photoacoustic Sol-gel TiO 2 Ceramic materials Crystallization Gelation Heat treatment Hydrolysis Phase transitions Photoacoustic effect Sintering Thermoanalysis Thermogravimetric analysis Distinguishable transition Gelation time Oscillating reactions Particle solvent interactions Sol-gels |
spellingShingle |
Correlation analysis Oscillating reactions Phase transition Photoacoustic Sol-gel TiO 2 Ceramic materials Crystallization Gelation Heat treatment Hydrolysis Phase transitions Photoacoustic effect Sintering Thermoanalysis Thermogravimetric analysis Distinguishable transition Gelation time Oscillating reactions Particle solvent interactions Sol-gels Marchi, M.C. Castañeda-Guzmán, R. Pérez-Pacheco, A. Bilmes, S.A. Villagrán-Muniz, M. Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
topic_facet |
Correlation analysis Oscillating reactions Phase transition Photoacoustic Sol-gel TiO 2 Ceramic materials Crystallization Gelation Heat treatment Hydrolysis Phase transitions Photoacoustic effect Sintering Thermoanalysis Thermogravimetric analysis Distinguishable transition Gelation time Oscillating reactions Particle solvent interactions Sol-gels |
description |
The use of correlation analysis of photoacoustic signal changes during the sol-gel-aging evolution of titania sols prepared from the hydrolysis of titanium n-butoxide in alcoholic, aqueous, and micellar media which provide different initial conditions and different evolution pathways is proposed. The photoacoustic experiments were done either at constant temperature for monitoring the initial evolution of the system, or under heating at 2°C·min -1 for monitoring molecular processes related to drying, sintering, and crystallization. Results obtained from photoacoustic measurements display higher sensibility when compared with those from differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The evolution of these systems shows instabilities below and above gelation, as well as during thermal treatment. These stabilities are minimized when the thermal treatment is performed on gels aged several months, and can be associated to molecular rearrangements or oscillating chemical reactions. For all the systems studied, the sensitivity of the correlation analysis recovered from photoacoustic signals permits detection of a transition in the 100 to 150°C range. |
format |
JOUR |
author |
Marchi, M.C. Castañeda-Guzmán, R. Pérez-Pacheco, A. Bilmes, S.A. Villagrán-Muniz, M. |
author_facet |
Marchi, M.C. Castañeda-Guzmán, R. Pérez-Pacheco, A. Bilmes, S.A. Villagrán-Muniz, M. |
author_sort |
Marchi, M.C. |
title |
Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
title_short |
Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
title_full |
Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
title_fullStr |
Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
title_full_unstemmed |
Photoacoustic analysis of the evolution from sols to aged gels: Comparison of different initial titania sols |
title_sort |
photoacoustic analysis of the evolution from sols to aged gels: comparison of different initial titania sols |
url |
http://hdl.handle.net/20.500.12110/paper_0195928X_v25_n2_p491_Marchi |
work_keys_str_mv |
AT marchimc photoacousticanalysisoftheevolutionfromsolstoagedgelscomparisonofdifferentinitialtitaniasols AT castanedaguzmanr photoacousticanalysisoftheevolutionfromsolstoagedgelscomparisonofdifferentinitialtitaniasols AT perezpachecoa photoacousticanalysisoftheevolutionfromsolstoagedgelscomparisonofdifferentinitialtitaniasols AT bilmessa photoacousticanalysisoftheevolutionfromsolstoagedgelscomparisonofdifferentinitialtitaniasols AT villagranmunizm photoacousticanalysisoftheevolutionfromsolstoagedgelscomparisonofdifferentinitialtitaniasols |
_version_ |
1807320127679496192 |