Department of Analytical Chemistry, University of Córdoba, E-14071 Córdoba, Spain.
Analyst. 2014 Jan 7;139(1):290-8. doi: 10.1039/c3an00642e.
Raman spectroscopy has been employed in analytical sciences for purity determination of carbon nanotube samples based on the consideration of G-/D-band intensity ratios. This work demonstrates the role of aggregation in these feature bands, which, in the case of single walled carbon nanotubes (SWNTs), has proved to be crucial for G-/D-band intensity ratio measurements. We have found variation in the relative intensities of G- and D-bands across a sample of SWNTs without any other treatment, discarding the possible influence of the laser beam or sample focusing. In the case of multiwalled carbon nanotubes (MWNTs), this effect is less notorious. Thus, to achieve a good representativeness of Raman measurements, it is important to consider the sample preparation procedure in order to avoid aggregation, which has an effect over the signals, making difficult the subsequent interpretation of results.
拉曼光谱已被应用于分析科学中，用于基于 G-/D- 带强度比的碳纳米管样品的纯度测定。这项工作证明了聚集在这些特征带中的作用，对于单壁碳纳米管（SWNTs），已经证明聚集对于 G-/D- 带强度比的测量至关重要。我们发现，在未经任何其他处理的情况下，SWNTs 样品中 G- 和 D- 带的相对强度会发生变化，从而排除了激光束或样品聚焦的可能影响。对于多壁碳纳米管（MWNTs），这种效应则不那么明显。因此，为了实现拉曼测量的良好代表性，重要的是要考虑样品制备过程，以避免聚集，因为聚集会对信号产生影响，从而使结果的后续解释变得困难。
