Biomimetic mineralization of silicon dioxide onto carbon fiber for elevated interfacial properties and hydrothermal aging resistance of carbon fiber/epoxy composites

Abstract A carbon fiber‐tannic acid‐silicon dioxide (CF‐TA‐SiO 2 ) reinforcement with a “diatom frustule‐like” structure was built via biomimetic mineralization to boost the performance of carbon fiber/epoxy resin (CF/EP) composites. As a bio‐based polyphenolic compound, TA was used to modulate the mineralization of SiO 2 , and the easy agglomeration of SiO 2 was effectively avoided. The interfacial adhesion of the CF/EP composites was considerably heightened by improving the roughness and wettability of CF as well as by increasing the interfacial interactions between CF and the EP. Compared with the pristine composites, the flexural strength, interlaminar shear strength and interfacial shear strength of the CF‐TA‐SiO 2 /EP composites increased by 41.2%, 56.6%, and 50.4%, respectively. Moreover, the introduction of Si‐O‐Si and C‐O‐Si bonds at the interface led to a remarkable improvement in the hydrothermal aging resistance. This research provides a novel interfacial design for advanced composites with excellent interfacial properties, which broadens the application of these composites in hygrothermal environments. Highlights A “diatom frustules‐like” structure was successfully constructed on the CF surface. This biomimetic mineralization was simple and environmentally friendly. This method solved the problem of easy agglomeration of SiO 2 . The interfacial properties of composites were obviously improved. The hydrothermal aging resistance of composites was enhanced.