▎ 摘　　要

The interfacial performance is one of the most important factors that determine the mechanical properties of carbon fiber reinforced polymers (CFRPs). Recently, improving the interfacial properties of CFRPs using graphene oxide (GO) has received intensive attention from researchers. Using GO can effectively improve the interfacial properties of CFRPs, however, the effect of the size of GO on the properties of CFRPs remains unclear. In this study, GO sheets with different lateral dimensions are selected to elucidate the aforementioned issue. Results showed that GO sheets with smaller lateral dimensions are more advantageous to enhance the interfacial properties of CFRPs. The presence of a larger number of functional groups and higher roughness on the surface of CFs that modified by smaller GO sheets is believed to be contributing factor, as evidenced by oS and AFM. Furthermore, higher surface energy is detected on the surface of smaller GO sheets modified CFs which is likely related to the size effect of nano-scale GO. The above suggests that nano-scale GO can significantly enhance the chemical bonding and mechanical interlocking of matrix-fiber interface. The proposed approach can be easily implemented which does not deteriorate the strength of CFs. This work provides an effective way to improve the interface properties of CFRPs using GO sheets with smaller lateral dimensions.