Optimization of Interfacial Strengthening and Sound Absorption Properties of Acid–Alkali Nano-SiO2 Infiltrant Synergistically Modified Basalt Fiber Fabric/Epoxy Composites

BF is a promising reinforcing material for resin matrix composites. Still, it fails to fully utilize its excellent mechanical and functional properties due to the weak interfacial bonding between BF and the resin matrix. In this work, the fibers were treated by acid and alkali synergistically with nano-infiltrant (containing nano-SiO 2 ) to improve the inertness of the fiber surface and enhance the interfacial bonding. Then, BFFC was prepared by hand-coating bisphenol F epoxy resin on the surface of BFF. The microstructure, mechanical properties, durability, thermal stability, and sound absorption properties of the composites were investigated. The results showed that the acid and alkali synergistic nano-infiltrant-modified BF surfaces showed excellent interfacial bonding with increased roughness and reactive groups, which effectively revised the bonding strength between BF and the resin matrix. In particular, the tensile strength, durability, and thermal stability of the composites with alkali synergistic nano-infiltrant were revised by 59.8%, 45.9%, and 48.1%, respectively, compared with the untreated samples, and the structure of the composites was also optimized to enhance the sound-absorbing performance, reaching an average sound absorption coefficient of 0.49. In future, it can promote the development of BF composites toward multi-functionalization.