Improving the Fracture Toughness and Strength of Epoxy Resin Using NH2-silica-C8H17 Janus Nanosheets

Graphical NH 2 -silica-C 8 H 17 nanosheets containing short n-octyl chains and aminopropyl groups were investigated as a novel toughening agent for enhancing the toughness and strength of epoxy resin. The incorporation of 0.5 wt.% Janus nanosheets led to remarkable enhancements in the mechanical, dynamic mechanical, and thermal properties of the epoxy resin, as evidenced by the characterization results. In this work, a NH 2 -silica-C 8 H 17 Janus nanosheet with short n -octyl chains on one side and aminopropyl groups on the opposite side was prepared by the sol-gel method. This nanosheet was used to improve the toughness and strength of epoxy resin. The morphologies and structures of Janus nanosheets and the properties of NH 2 -silica-C 8 H 17 /epoxy nanocomposites were characterized. Results show that the addition of Janus nanosheets not only increases the storage modulus and glass transition temperature of nanocomposites, but also improves their mechanical performance and thermal stability. The tensile strength, elongation at break, fracture toughness and impact strength of nanocomposites are increased by ca. 57, 80, 74 and 63 %, respectively, at the 0.5 wt.% loading of Janus nanosheets. These findings suggest that NH 2 -silica-C 8 H 17 Janus nanosheets exert an effective influence on the toughness and strength of ultimate nanocomposites, which is attributed to the fact that NH 2 -silica-C 8 H 17 Janus nanosheet simultaneously contains n -octyl and aminopropyl groups on both sides, thus improving the nanosheet/matrix interface adhesion.