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 °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.