Multiscale Simulation and Experimental Study on the Edge-Catalyzed Carbonization of PAN-Based Carbon Fibers with...

Carbon nanomaterials (CNMs) are frequently incorporated into polyacrylonitrile (PAN) precursors as structural templates or reinforcements to enhance the microstructure and the macroscopic performance of carbon fibers. However, the interfacial characteristics and mechanisms governing the dynamic evolution of PAN during heat treatment remain elusive. Herein, we investigated PAN composites reinforced with CNMs, including zero-dimensional fullerenes, one-dimensional carbon nanotubes, and two-dimensional RGOs. First-principles calculations and noncovalent interaction analyses were employed to elucidate interfacial properties between CNMs and PAN chains. Subsequently, large-scale molecular dynamics (MD) simulations revealed the structural evolution of these systems under both room temperature and high-temperature carbonization conditions. The results confirmed an edge-guided interfacial alignment and demonstrated that CNMs of varying dimensions exhibit distinct edge-catalytic effects. These theoretical findings were validated experimentally via X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), etc., characterizations of composite carbonized at various temperatures, which corroborated the differential catalytic impacts of CNMs. The results show that carbon nanotubes present higher catalytic activity, whereas RGO contributes to a more-thermally stable graphitic architecture. This research provides a comprehensive atomic-level understanding of PAN/CNM composites, offering significant theoretical guidance for the development of carbon fiber-based functional materials.