Enhancing the interfacial adhesion between continuous basalt fibers and epoxy resin by depositing silicon dioxide nanonparticles

Herein, inorganic silicon dioxide (SiO ₂ ) nanoparticles are deposited on the surface of continuous basalt fibers (CBFs) to enhance the interfacial interactions between CBFs and epoxy matrix (EP) and the tensile strength of composites. According to results from scanning electron microscopy and atomic force microscopy, the surface morphology of CBFs changes from smooth to rough with the increase of SiO ₂ deposition content. The rough surface plays a role of chock to make CBFs implant into the EP better, offering strong mechanical engagement effect to the interface between CBFs and EP. Therefore, the interfacial shear strength (IFSS) between CBFs and EP and the tensile strength of composites both increase. However, depositing excessive SiO ₂ nanoparticles also brings some porous structures on CBFs surface, becoming defects and stress concentration points to weaken the IFSS and the tensile strength of composites. Finally, a comparison between grafting organic aliphatic chains and depositing inorganic rigid nanoparticles about their effects on the surface roughness of modified CBFs and the interfacial interactions between modified fibers and matrix is carried out to clarify the reinforcing mechanisms of interfacial adhesion and the tensile strength of composites.