Novel fibrous/nano-Al2O3 insulation composites produced using sol-gel impregnation for energy-saving

The sol-gel method is a technique used to create a controlled porous structure by building up colloidal particles during the gelation process. In this study, a sol-gel method was utilized to prepare fibrous/nano-Al2O3 insulation composites using glass fiber, nano-Al2O3, and silica sol as primary materials for performance characterization. The samples exhibited high porosities (78.35–81.30%) and low thermal conductivities (0.084–0.159 W m−1 k−1 at 200–600 °C). The introduction of nano-Al2O3 resulted in a well-distributed aperture hierarchy and promoted multidirectional heat transfer paths. The fibers were arranged in a three-dimensional structure, overlapping each other, while the nano-powders were dispersed in a liquid phase and cross-linked to form a spatial mesh structure. The findings of this research have potential applications in heat preservation and energy-saving.