Co-Polymerized P(AN-co-IA)-Derived Electrospun Nanofibers with Improved Graphitization via Dual-Metallocene Integration at Low Temperature

In this study, COOH-functionalized co-polymer of acrylonitrile and itaconic acid (P(AN-co-IA)) is synthesized via free radical copolymerization using DMSO as solvent. The continuous non-aligned carbon nanofibers (CNFs) with different amounts of metallocene (zirconocene and ferrocene) are fabricated through electrospinning, followed by a series of heat treatments under an inert atmosphere. The influence of metallocenes on electrospun carbon nanofiber diameter, alignment, and structural ordering was systematically investigated using FESEM, XRD, Raman spectroscopy, and TEM. Incorporation of dual metallocenes significantly alters the fiber diameter, improves orientation, and promotes graphitic domain formation at 1100 °C, a much lower temperature than conventional graphitization. The optimized sample (Zr-Fe)₁-P(AN-co-IA)-eGNF) exhibited the lowest I_D/I_G ratio compared to pristine and all prepared samples, indicating an improved degree of graphitization due to the uniform distribution of metallocene nanofiber matrix. Furthermore, the electrical conductivity of optimized (Zr-Fe)₁-P(AN-co-IA)-eGNF reached the highest value (1654.5 S/m) due to the high degree of graphitization of carbon nanofibers. These results show that integrating dual metallocene is an efficient pathway for tailoring nanofiber morphology and achieving conductive, structurally ordered electrospun eGNFs at reduced temperatures, with potential applications in various fields.