Al2O3-SiO2 aerogel reinforced with aluminum silicate nanofibers: a strategy to preserve the properties of Al2O3-SiO2 aerogel

• Published in: Journal of sol-gel science and technology 2024-02, Vol.109 (2), p.523-533
• Main Authors: Hao, Mingyuan, Chen, Huanle, Xia, Chenkang, Su, Teng, Ma, Chao, Miao, Yang
• Format: Article
• Language: English
• Subjects: Aerogels; Aluminum; Aluminum oxide; Aluminum silicates; Ceramics; Chemistry and Materials Science; Composite materials; Composites; Compressive strength; Glass; Heat conductivity; Heat transfer; High temperature; Inorganic Chemistry; Materials Science; Mechanical properties; Nanofibers; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper; Silicon dioxide; Sol-gel processes; Structural integrity; Thermal conductivity; Thermal stability
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-023-06286-5

Aluminum silicate nanofibers (ASNFs) have attracted significant attention due to their excellent stability and high-temperature properties. Al 2 O 3 -SiO 2 aerogel (ASAs) has high porosity and low thermal conductivity, but its mechanical properties need to be improved. Reinforcing aerogels with fibers can lead to remarkable enhancements in their properties. Reducing the fiber diameter has proven to be an effective means of improving the structural integrity and mechanical stability of aerogel composites. In the context of this study, we prepared aluminum silicate nanofibers (ASNFs) with a diameter of 170 nm through the utilization of electrostatic spinning. These ASNFs were then successfully integrated with aluminum silicate aerogels (ASAs) to create a novel composite material known as aluminum silicate nanofiber-reinforced Al 2 O 3 -SiO 2 aerogel (AS/ASNFAs). Its microstructure, mechanical properties and heat insulation properties have been researched. The results show that the compressive strength of AS/ASNFAs (0.44 MPa) is significantly higher than that of Al 2 O 3 -SiO 2 aerogel (0.16 MPa). Meanwhile, the AS/ASNFAs has high specific surface area (600 m 2 /g), low density (0.15 g/cm 3 ), and low thermal conductivity (0.026 W/(m·K)). This work provides a useful solution to improve the comprehensive properties of Al 2 O 3 –SiO 2 aerogel composites. Graphical Abstract Highlight An aluminum silicate nanofiber-reinforced Al 2 O 3 -SiO 2 aerogel (AS/ASNFAs) has been prepared by sol-gel method. Addition of aluminum silicate nanofibers (ASNFs) improves mechanical properties of Al 2 O 3 -SiO 2 aerogel (ASAs), and compressive strength of AS/ASNFAs-0.2 (0.44 MPa) is more than twice that of ASAs (0.16 MPa). Low thermal conductivity (0.026 W/(m·K)) is achieved for AS/ASNFAs-0.1. Due to the good dispersion of ASNFs in ASAs, the interaction of them not only improves mechanical properties of AS/ASNFAs but also increases thermal stability at high temperature.