摘要
本研究通过集成同步辐射微聚焦广角X射线散射、原位显微红外光谱及广角X射线散射等多尺度表征技术,首次系统揭示了电子束辐照对聚丙烯腈(PAN)前驱体纤维径向异质结构的皮层选择性作用机制。研究证实,辐照与未辐照PAN纤维均呈现显著的皮芯结构,皮层中(100)晶面的结晶度、晶体尺寸及取向度均高于芯层;随着吸收剂量的增加,皮层结晶度下降,晶粒尺寸缩小,取向度略微降低,而晶面间距几乎保持不变,芯层结构参数则变化甚微。这种皮芯结构之间的差异化演变可在一定程度上提升氧气扩散效率,为改善PAN纤维预氧化进程的均匀性奠定基础。进一步研究发现,辐照与热处理存在协同效应,200 kGy为最佳环化率吸收剂量,温度250℃下反应程度可达62%;而500 kGy为最佳碳收率辐照吸收剂量,1000℃下碳产率可达50.5%(相比于未辐照样品增幅12.25%)。通过合理调控辐照条件可优化PAN纤维的预氧化与碳化过程,为制备高性能PAN基碳纤维提供了新的实验依据。
In this study,the skin-core selective mechanism of electron beam irradiation on the radially heterogeneous structure of polyacrylonitrile(PAN)precursor fibers is systematically revealed for the first time.This is achieved by integrating multi-scale characterization techniques,including synchrotron radiation microfocused wide-angle X-ray scattering,in-situ microfilm infrared spectroscopy,and wide-angle X-ray scattering.The study confirms that irradiated and non-irradiated PAN fibers exhibit distinct cortex-core structures,with the(100)crystal planes in the cortex showing higher crystallinity,crystal size,and degree of orientation compared to the core layer.As the irradiation dose increases,the cortex's crystallinity decreases,grain size reduces,and degree of orientation slightly diminishes,while crystal face spacing remains nearly unchanged,and core structure parameters show minimal variation.This differential evolution between cortex and core structures enhances oxygen diffusion efficiency to some extent,laying the foundation for improving the uniformity of PAN fiber pre-oxidation processes.Further studies reveal a synergistic effect between irradiation and heat treatment:200 kGy is the optimal irradiation dose for achieving a 62%cyclization rate at 250℃,while 500 kGy provides the best carbon yield at 1000℃,reaching 50.5%(a 12.25%increase over non-irradiated samples).Through rational adjustment of irradiation conditions,PAN fibers'pre-oxidation and carbonization processes can be optimized,providing new experimental evidence for developing high-performance PAN-based carbon fibers.
作者
盛炯森
邵瑞琪
田丰
荣慧
石海婷
徐志伟
张昊
SHENG Jiongsen;SHAO Ruiqi;TIAN Feng;RONG Hui;SHI Haiting;XU Zhiwei;ZHANG Hao(State Key Laboratory of Separation Membranes and Membrane Processes,School of Textile Science and Engineering,Tiangong University,Tianjin 300387,China;Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China;Bros Eastern Co.,Ltd.,Ningbo 315206,China)
出处
《辐射研究与辐射工艺学报》
2026年第1期33-45,共13页
Journal of Radiation Research and Radiation Processing
基金
国家自然科学基金(12205218、52275190)
“纺织之光应用基础研究计划”(J202402)资助。
关键词
同步辐射
电子束辐照
聚丙烯腈纤维
皮芯结构
碳纤维
Synchrotron radiation
Electron beam irradiation
Polyacrylonitrile fibers
Skin-core structure
Carbon fibers
