Strengthening of basalt fibers with nano-SiO2–epoxy composite coating

Coatings, which were made from pure epoxy and SiO2 nanoparticle modified epoxy composite, respectively, were applied onto the basalt fiber rovings. The SiO2 nanoparticles were synthesized using a sol–gel method and modified using coupling agent. Fourier transform infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC) analyses indicated the formation of modified SiO2 nanoparticles. The SiO2 nanoparticle–epoxy composite coating gave rise to a significant increase in the tensile strength of the basalt fibers as compared with the pure epoxy coating, and also the coating endowed the basalt fiber with a promising interfacial property in the basalt fiber reinforced resin matrix composite. The coating modification was an effective way in improving the mechanical properties of basalt fibers and the properties of basalt fiber/epoxy resin composites.

► Nano-SiO2 particles were synthesized using a sol–gel method.
► The synthesis of modified SiO2 particles was confirmed by IR and DSC analysis.
► The dispersion state of nano-SiO2 particles in the composite coatings is good.
► The specific coating gave a rise of 30% in the basalt fibers’ tensile strength.
► The ILSS of the basalt fiber reinforced composite was enhanced by 15%.