Preparation of CF-CNTs multi-scale reinforcement and mechanical properties of CF-CNTs/epoxy composites

The carbon nanotubes (CNTs) were grown on to the surface of carbon fibers (CF) by chemical vapor deposition (CVD) method, the CF-CNTs and CF-CNTs/epoxy (EP) composites were obtained. Effects of different CVD technological parameters on the CF-CNTs multi-scale reinforcement were researched by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscope (HRTEM) methods and so on. Mechanical properties of CF-CNTs/EP composites with different CVD time were also studied. The results show that the CF-CNTs multi-scale reinforcement with the best performance can be obtained when the deposition temperature is 500℃, the deposition time is 10 min, and the corresponding reaction pressure is controlled about 0.02 MPa. The wettability of the CF-CNTs multi-scale reinforcement to EP is significantly higher than that of CF without CNTs. The interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) can be improved by 90.6% and 24.4%, respectively. At the same time, compared to the twisted CF in preparation process of EP composites, the ILSS of non-twisted CF composites can be increased by 11.3%.