Silica nanoparticle-decorated alumina rough platelets for effective reinforcement of epoxy and hierarchical carbon fiber/epoxy composites

Alumina platelets, ∼200 nm in thickness, have been previously used as the filler of polymers, especially for bio-inspired nacre-like composites. However, to the best of our knowledge, they have not been applied to hierarchical carbon fiber/epoxy composites. Herein, the effect of smooth alumina platelets and silica nanoparticle-decorated platelets with nanoasperities on the mechanical properties of epoxy resin and hierarchical composites were investigated. The rough platelets are much more effective than the smooth ones for the reinforcement, because of the greatly improved matrix-filler interactions. The increases of mechanically properties by the submicrometer-thick rough platelets are comparative with or even better than those by carbon nanotubes, nanofibers and graphene derivatives previously reported. The increase of the total energy dissipated during flexural fracture of the hierarchical composites and Mode II interlaminar fracture toughness are also more significant than the smooth platelets. This study provides a new approach for the reinforcement of hierarchical composites.