Process optimization of continuous preparation of carbon nanotubes/carbon fiber multi-scale reinforcement

This article provides a method for growing carbon nanotubes (CNTs) on carbon fibers (CFs) using a one-step method at low temperatures using Fe-Ni bimetallic catalysts in a chemical vapor deposition (CVD) furnace. It was found that the best surface morphology, and tensile strength of 4.55 GPa, could be obtained by controlling the CVD process at 550 degrees C, 3.5 cm/min, and 0.45:0.30 L/min hydrogen to acetylene gas ratio, which is 6.56 % higher compared to Desized CFs. This proves that enhancement effect of CNTs on CFs. Subsequently, wettability tests and microstructure analysis were performed for quasi-vacuum CNTs/CF and continuous CNTs/CF under the optimal process, demonstrating that the bond strength of CF and resin was also significantly improved. The catalyst under this optimal process has a low etching effect on CFs, and the grown CNTs have a clear structure with good coaxiality and wall uniformity, which can effectively improve the performance of CNTs/CFs.