School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Analyst. 2013 Nov 7;138(21):6671-6. doi: 10.1039/c3an01129a.
Current and future applications of single-wall carbon nanotubes (SWCNTs) depend on the dispersion of the SWCNTs in aqueous solution and their quantitation. The concentration of SWCNTs is an important indicator to evaluate the dispersibility of the surfactant-dispersed SWCNTs suspension. Due to the complexity of the SWCNTs suspension, it is necessary to determine both the total concentration of the dispersed SWCNTs and the concentration of individually dispersed SWCNTs in aqueous suspensions, and these were evaluated through the absorbance and the resonance ratios of UV-Vis-NIR absorption spectra, respectively. However, there is no specific and reliable position assigned for either calculation of the absorbance or the resonance ratio of the UV-Vis-NIR absorption spectrum. In this paper, different ranges of wavelengths for these two parameters were studied. From this, we concluded that the wavelength range between 300 nm and 600 nm should be the most suitable for evaluation of the total concentration of dispersed SWCNTs in the suspension; also, wavelengths below 800 nm should be most suitable for evaluation of the concentration of individually dispersed SWCNTs in the suspension. Moreover, these wavelength ranges are verified by accurate dilution experiments.
当前和未来的单壁碳纳米管（SWCNTs）应用取决于 SWCNTs 在水溶液中的分散性及其定量分析。SWCNTs 的浓度是评估表面活性剂分散的 SWCNTs 悬浮液分散性的重要指标。由于 SWCNTs 悬浮液的复杂性，有必要确定分散的 SWCNTs 的总浓度以及在水溶液悬浮液中单独分散的 SWCNTs 的浓度，分别通过吸光度和 UV-Vis-NIR 吸收光谱的共振比来评估。然而，对于吸光度或 UV-Vis-NIR 吸收光谱的共振比的计算，没有指定特定且可靠的位置。在本文中，研究了这两个参数的不同波长范围。由此得出结论，300nm 至 600nm 之间的波长范围最适合评估悬浮液中分散的 SWCNTs 的总浓度；此外，800nm 以下的波长最适合评估悬浮液中单独分散的 SWCNTs 的浓度。此外，这些波长范围通过准确的稀释实验得到验证。
