Controllably constructing organic-inorganic multilevel network structures by regulating the ratio of APES/OCNTs on the basalt fiber surface to enhance the interfacial properties of fiber/polyethersulfone composites

Basalt fiber-reinforced polyethersulfone (BF/PES) composites exhibit high strength, heat resistance, chemical resistance, excellent mechanical properties, and environmental sustainability. However, the smooth and chemically inert surface of BF results in weak interfacial bonding with PES, limiting its broader applications. In this study, an organic-inorganic multilevel network structure was constructed on the fiber surface by optimizing the ratio of APES and OCNTs, significantly improving the interfacial properties of BF/PES composites and enhancing their overall performance. After treatment with APES2/OCNTs3, the interlaminar shear strength (ILSS), flexural strength, flexural modulus, and interfacial shear strength (IFSS) reached 71.9 MPa, 379.1 MPa, 12.8 GPa, and 55.1 MPa, representing increases of 94.8%, 64.1%, 140.5%, and 161.1%, respectively. Furthermore, the enhancement mechanism and influence pattern of the APES/OCNTs hybrid sizing agent on the composite interface were thoroughly investigated. This simple, effective, and controllable method offers considerable potential for improving the interfacial bonding of BF/PES composites. • The ratio of APES/OCNTs hybrid sizing agent on BF surface was regulated. • The ILSS, flexural strength of BF/PES composites were increased by 94.8 %, 64.1 %. • The interfacial enhancement mechanism of BF/PES composites were studied. • The BF/PES composites have good high and low temperature usability.