表征PAN纤维和炭纤维微细结构的HRTEM样品制备方法

SAMPLE PREPARATION METHODS FOR CHARACTERIZING HRTEM MICROSTRUCTURES OF PAN AND CARBON FIBERS

为用高分辨透射电子显微术(HRTEM)表征聚丙烯腈(PAN)纤维和炭纤维的微细结构,从纤维性能出发,探讨研碎、离子束减薄和超薄生物切片三种制备方法及其工艺步骤,结合实验结果,对比了三种制备方法的原理、优缺点,提出了制备方法的适用范围和选择原则,并推断适于表征预氧化纤维微细结构的样品制备方法。与生物样品的制备方法类似,把超薄生物切片法引入到纤维材料HRTEM样品制备领域,为系统研究炭纤维微细结构的演变提供了线索。

To characterize the microstructures of PAN and carbon fibers by high-resolution transmission electron microscopy (HRTEM), considering the strict demand of the measurement for the prepared samples and originating from fiber properties, three preparation methods (including grinding, ion beam modulating and biological ultra-thin sectioning methods) and their technical processes are studied. Their principles and relative merits are compared combining with our experimental results. The application range and selection principles are proposed for the preparation methods of those fibers, some preparation methods are inferred to characterize microstructures of pre-oxidized fibers. Similar to the biological fields, the ultramicrotomy method, providing a clue to investigate systemically the microstructural evolution of carbon fibers, is introduced into HRTEM sample preparation of fiber materials.