不同参数多壁碳纳米管的拉曼光谱研究

拉曼光谱是进行碳材料结构与性质研究的有力手段，为了研究多壁碳纳米管(MWCNT)的管径和长度对其拉曼光学性质的影响，本研究对一系列不同管径和长度的多壁碳纳米管进行拉曼光谱的测试和分析。研究发现: 与高取向的石墨相比，多壁碳纳米管一阶拉曼光谱的G峰中心和D峰中心都会向低波数发生不同程度的红移;MWCNT两个主要特征峰(G峰和D峰)峰强在其他条件相同的情况下，与MWCNT的管径成正比，与长度成反比;G峰的频移与MWCNT的管径和长度两个因素密切相关，与管径成反比关系(这与单壁碳纳米管的径向呼吸模有着一致的结果)，与管长成正比关系，而D 峰的频移受MWCNT的管径和长度的影响很弱，并对此现象进行了初步分析。在此基础上，我们以MWCNT的长径比为横坐标，G峰频移为纵坐标作图，进行线性拟合，得到了G峰频移与长径比成一定的线性递增关系。采用同样的分析方法，我们将G峰和D峰强度分别对MWCNT的长径比作图，进行线性拟合，得到了G峰和D峰强度分别与MWCNT的长径比成一定的线性递减关系。

Study on Raman Spectra of Multi-Walled Carbon Nanotubes with Different Parameters

In order to study the influencing factors on Raman spectroscopy, we research a series of comparative Raman spectroscopy of multi-walled carbon nanotubes (MWCNT) with different tube diameter and length. The results suggest that the G peak and D peak of MWCNT are all red-shifted as compared to that of polycrystalline graphite; In the same conditions, the peak intensity (G peak and D peak) is directly proportional to the diameter of the MWCNT, and inversely proportional to the length of the MWCNT; G peak frequency shift is closely related to the MWCNT diameter and length, which are inversely proportional to the diameter (with identical results of the single-walled carbon nanotube radial breathing modes) and direct proportional to the length. While, the influences of the diameter and length on D peak frequency shift are weak, and future analysis for the reason of this kind of phenomenon is as follows. Subsequently, we investigated the relation between D peak frequency shift and MWCNT aspect ratio, the relationship between G peak frequency shift and aspect ratio is nearly linear increase. Using the same analysis method, we plotted the different graphs of G peak and D peak intensity vs the aspect ratio of MWCNT, respectively. As the expected, the linear degression relation are existent in the two relationships.