The influence of oxygen on the skin-core structure of polyacrylonitrile-based precursor fibers has been systemically studied using attenuated total reflection infrared spectroscopy (ATR-IR), atomic force microscopy (AFM), nanoscale infrared spectroscopy (nano-IR), X-ray, scanning electron microscopy (SEM), optical microscopy (OM) and nanoscale Lorentz contact resonance (nano-LCR). ATR-IR, AFM and nano-IR reveal the radial distribution of specific functional groups. It was found that under oxygen-sufficient conditions, many ladder aromatic rings are formed in the skin. Intermolecular crosslinking presumably occurs through oxygen-induced dehydrogenation reactions. Under oxygen-deprived conditions, large numbers of isolated aromatic rings are generated in the core. Intermolecular crosslinking is dependent on comonomer concentration. In addition, different fractured and polished morphologies of skin and core may be identified using SEM and OM, providing evidence for radial transformations of crystal structure. Moreover, the modulus distribution in the fiber as reflected by nano-LCR further supports the proposed intermolecular crosslinking and crystal rearrangement processes.

已经使用衰减全反射红外光谱（ATR-IR），原子力显微镜（AFM），纳米级红外光谱（nano-IR），X-射线对氧对聚丙烯腈基前体纤维的皮芯结构的影响进行了系统研究。射线，扫描电子显微镜（SEM），光学显微镜（OM）和纳米级洛伦兹接触共振（nano-LCR）。ATR-IR，AFM和nano-IR揭示了特定官能团的径向分布。发现在氧气充足的条件下，在皮肤中形成许多梯形芳环。分子间交联大概是通过氧诱导的脱氢反应发生的。在缺氧条件下，核心中会生成大量孤立的芳环。分子间交联取决于共聚单体的浓度。此外，可以使用SEM和OM鉴定出表皮和核心的不同破裂和抛光形态，从而为晶体结构的径向转变提供了证据。而且，由纳米LCR反映的纤维中的模量分布进一步支持了所提出的分子间交联和晶体重排过程。