Synthesis, characterization and structure-properties relationship of aerogels and aerogel-based composites
During the last few years, cellular materials research has pointed to aerogels as one of the most promising materials. This is due to the combination of properties, such as their low density, large specific surface area, excellent thermal and acoustic insulation, and high porosity. These properties...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Institución: | Universidad de Valladolid |
| Repositorio: | UVaDOC. Repositorio Documental de la Universidad de Valladolid |
| OAI Identifier: | oai:uvadoc.uva.es:10324/59775 |
| Acceso en línea: | https://doi.org/10.35376/10324/59775 https://uvadoc.uva.es/handle/10324/59775 |
| Access Level: | acceso abierto |
| Palabra clave: | Materiales Polyurethane Poliuretano Aerogels Aerogeles 22 Física 33 Ciencias Tecnológicas |
| Sumario: | During the last few years, cellular materials research has pointed to aerogels as one of the most promising materials. This is due to the combination of properties, such as their low density, large specific surface area, excellent thermal and acoustic insulation, and high porosity. These properties are the consequence of their interesting structures characterized by pores and particles in the nanometric scale. This thesis focuses on the synthesis and characterization of aerogels and aerogel-based composites. The main objective has been the development of polyurethane-based organic aerogels obtained by sol-gel technology followed by supercritical drying. These materials present interesting optical properties (transparency to visible light), a thermal conductivity below that of the aerogels previously described for this matrix (included in the superinsulating range), achieving values of 12 mW/mK, and superior mechanical properties than the widely investigated silica aerogels. Additionally, the effect of the addition of infrared blockers on its thermal conductivity has been studied. On the other hand, the incorporation of polyurethane foams with reticulated structures during the synthesis of silica aerogels has allowed the notable improvement of their mechanical properties, providing them with great stiffness and flexibility. In addition, these materials have excellent thermal insulation. As a result of this research, the relationship between formulation-process-structure-properties has been understood, so that, through the analysis of different parameters, their influence on the final properties has been identified. Thus, certain synthesis strategies are established allowing to obtain promising aerogels with potential application in the construction, automotive, and aeronautics sectors, among others. This thesis, supervised by Prof. Dr. Miguel Ángel Rodríguez-Pérez and Prof. Dr. Fernando Villafañe González, constitutes the opening of a new research line at CellMat Laboratory, Department of Condensed Matter Physics of the University of Valladolid, allowing the development of numerous lines of future work. |
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