Interaction Mechanism of Graphene Oxide and Polyacrylonitrile During Pre‐Oxidation: Insights Into Structural Evolution and Thermal Behavior

ABSTRACT Polyacrylonitrile (PAN)‐based carbon fibers suffer from defects and skin‐core heterogeneity due to thermal runaway and uneven oxygen diffusion during pre‐oxidation. Graphene oxide (GO) shows promise as a modifier, yet its interaction mechanism with PAN, particularly the distinct roles of oxygen‐containing groups and sp 2 ‐conjugated skeleton remains unclear. Herein, GO/PAN composite fibers (0.1–7.5 wt% GO) were prepared via wet spinning and characterized by DSC, TG, FTIR, XPS, and Raman spectroscopy. Results reveal a dual, atmosphere and content‐dependent regulation. It is inferred that ˙OH radicals generated from GO deoxygenation may scavenge cyclization intermediates to suppress disorder, while the restored sp 2 skeleton templates ordered structures via π–π interactions. Under nitrogen, radical scavenging and templating enhance reaction uniformity; under air, GO promotes oxidative crosslinking and moderates oxygen diffusion, mitigating skin‐core formation. Notably, GO1.0‐PAN exhibits the lowest I D /I G (0.88), and GO7.5‐PAN achieves 74.82% carbonization yield. This work establishes quantitative structure–property correlations for optimizing high‐performance CFs.