Effect of CNTs deposition on carbon fiber followed by amination on the interfacial properties of epoxy composites

To enhance the interfacial properties of carbon fiber/epoxy composites, a layer of carbon nanotubes (CNTs) about 25–30 nm thickness was deposited on carbon fiber surface at low temperature by chemical vapor deposition (CVD), and then the CNTs were aminated to increase the surface wettability . Microbond test was conducted to characterize the interfacial shear strength (IFSS) of carbon fiber reinforced epoxy resin composites and the interlaminar shear strength (ILSS) and modeⅠfracture toughness (G IC ) of carbon fiber composite laminates were also measured to characterize the interlaminar properties. The results showed that this surface treatment method significantly increased the fiber surface energy, effectively improving the interfacial bonding of the composites. The IFSS, ILSS and G IC of composites reinforced by the final treated carbon fiber were 39.42%, 32.21% and 95.33% higher than that of composites reinforced by the raw carbon fiber. The fracture surfaces also indicated a great interphase appeared in the composites, which was formed by the mechanical interlocking of CNTs and the chemical reaction between surface functional groups and resin.