EFFECT OF NANO-RENFORCEMENT SHAPES ON THE PROPERTES OF ]EPOXY]BASED) NANOCOMIPOSITES: FRACTURE TOUGHINESS

The carbonic mano-reinforcements have revolutionized the nanocomposites research society. Several researchers have studied the effects of these nano-particles on different physical properties of nanocomposites. However, the geometry effects of these nano-particles on their efficiency as reinforcements have not been investigated. In the present study, the effects of three different shapes of carbonic nano-reinforcement, including the spherical (nano-diamond (ND)), cylindrical (carbon nano fiber (CNF)) and platelet (graphene oxide (GO), on the fracture toughness of epoxy-based nanocomposites were investigated. While addition of the ND particles to pure epoxy led to inferior properties, GO was found as a promising candidate to improve the fracture toughness of epoxy. The experimental results showed that addition of 0.5 wt.% of GO and CNF could enhance the fracture toughness up to 23% and 19%, respectively. However, the ND particles with the spherical shape did not show any beneficial effects on the fracture toughness of epoxy and even reduced it about 9%. To justify the obtained trend of results, the effect of nano-filler shapes on the fracture toughness mechanisms of nanocomposites was investigated. Moreover, the effects of presence of mentioned nano-reinforcement on the observed features of fracture surface of specimens was analyzed using the scanning electron microscopy imaging.