Department of Chemistry and Chemical Biology, Gunma University, Japan.
Appl Spectrosc. 2012 Jul;66(7):798-802. doi: 10.1366/11-06389.
We present a sandwich liquid-core waveguide for the study of the dynamic extraction of dye molecules by ionic liquid (IL). The incident light was introduced into the core of the IL phase directly via a fused silica prism to form total reflection at the IL/cladding interface. The changes in light intensity and absorbance spectra over time were monitored during the extraction process by maintaining an optical focus on the IL/water interface. The dynamic extraction of the dye Eriochrome Black-T (EBT) by the IL 1-n-butyl-3-methylimidazolium hexafluorophosphate (BmimPF(6)) at different concentrations and various pH conditions was investigated. The results indicated that the accumulation of the dye at the IL/water interface and the dynamic extraction of the dye into the IL phase both contributed to the increase in absorbance. The increased signal along with the increase in pH suggests that electrostatic interaction might be the main driving force for the extraction of EBT by BmimPF(6), and the micro-circumstance provided by IL also has a decisive effect on the characteristics of the spectra recorded by the waveguide system.
我们提出了一种夹层液芯波导，用于研究离子液体（IL）对染料分子的动态萃取。入射光通过熔融石英棱镜直接引入 IL 相的芯部，在 IL/包层界面处形成全反射。通过保持在 IL/水界面上的光学焦点，在萃取过程中监测光强和吸光度光谱随时间的变化。在不同浓度和不同 pH 值条件下，研究了 IL 1-丁基-3-甲基咪唑六氟磷酸盐（BmimPF(6))对染料 Eriochrome Black-T（EBT）的动态萃取。结果表明，染料在 IL/水界面的积累和染料向 IL 相的动态萃取都导致吸光度增加。随着 pH 值的增加信号增强表明，静电相互作用可能是 BmimPF(6)萃取 EBT 的主要驱动力，而 IL 提供的微环境对波导系统记录的光谱特征也有决定性影响。
