Abstract Nanostructures in the PAN-based carbon fibres were investigated by means of the Raman spectroscopy which was performed using a series of different excitation wavelengths. UV-Raman measurements showed the predominance of sp2 carbon for the carbon fibres with Young's moduli ranging from 55 to 440 GPa. The excitation wavelength dependence of the spectral line shape implied the presence of the graphitic (sp2 carbon layers) as well as the amorphous carbon-like component (sp2 carbon clusters) in these fibres. An analytical model based upon the Tuinstra-Koenig relation and the rule-of-mixtures concept was proposed to account for the observed behaviour of the peak intensity ratio ID/IG. It was suggested that the carbonisation heat treatment led to the sp2 carbon layers extending rapidly throughout the nanostructure, resulting in the complete loss of the sp2 carbon clusters for the higher-modulus carbon fibres. These new findings together with the proposed analytical model are believed to be essential keys towards the development of new generation carbon fibres.

中文翻译：

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使用拉曼光谱研究碳纤维中的纳米结构

摘要 利用一系列不同激发波长的拉曼光谱研究了 PAN 基碳纤维中的纳米结构。UV-拉曼测量表明，对于杨氏模量范围为 55 至 440 GPa 的碳纤维，sp2 碳占优势。谱线形状的激发波长依赖性暗示这些纤维中存在石墨（sp2 碳层）以及无定形碳样成分（sp2 碳簇）。提出了基于 Tuinstra-Koenig 关系和混合规则概念的分析模型来解释峰值强度比 ID/IG 的观察行为。有人提出碳化热处理导致 sp2 碳层在整个纳米结构中迅速延伸，导致高模量碳纤维的 sp2 碳簇完全丢失。这些新发现与提议的分析模型一起被认为是开发新一代碳纤维的关键。