Directed Assembly and Microstructural Control of Carbon Nanotube Fibers via Carbon Source Manipulation

Floating catalyst chemical vapor deposition (FCCVD) is recognized as a pivotal technique for fabricating high-performance carbon nanotube fibers (CNTFs). However, the role of carbon-source-directed growth and assembly in regulating the alignment and densification of CNTFs has received limited attention. Herein, we systematically investigated the assembly and microstructural regulation mechanisms of CNTFs via adjusting carbon sources (e.g., ethanol and acetone) in the FCCVD process. Analysis results demonstrate that compared with tangled few-wall carbon nanotubes (CNTs) derived from ethanol, the rigid multiwall CNTs with acetone as the carbon source tend to be aligned and densely arranged during gas-phase assembly, thus improving the strength of CNTFs. As a result, the acetone-derived CNTF with low entangled morphology showcases superior alignment and mechanical properties compared to those of ethanol-derived CNTF. This work offers critical insights and guidance for the direct floating-spinning of high-performance CNTFs.