Laboratory for Waste Management, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
Environ Sci Technol. 2010 Feb 1;44(3):921-7. doi: 10.1021/es902175w.
The influence of dissolved CO(2) on the sorption of trivalent curium (Cm) on alumina (gamma-Al(2)O(3)) and kaolinite was investigated by time resolved laser fluorescence spectroscopy (TRLFS) using the optical properties of Cm as a local luminescent probe. Measurements were performed at T < 20 K on Cm loaded gamma-Al(2)O(3) and kaolinite wet pastes prepared in the absence and presence of carbonate in order to pictorially illustrate any changes through a direct comparison of spectra from both systems. The red-shift of excitation and emission spectra, as well as the increase of fluorescence lifetimes observed in the samples with carbonate, clearly showed the influence of carbonate and was fully consistent with the formation of Cm(III) surface species involving carbonate complexes. In addition, the biexponential decay behavior of the fluorescence lifetime indicated that at least two different Cm(III)-carbonate species exist at the mineral-water interface. These results provide the first spectroscopic evidence for the formation of ternary Cm(III)-carbonate surface complexes.
运用时间分辨激光荧光光谱（TRLFS）技术，通过三价锔（Cm）的光学性质作为局部发光探针，研究了溶解二氧化碳对氧化铝（γ-Al（2）O（3））和高岭石上 Cm 吸附的影响。在 T < 20 K 下，对负载在 γ-Al（2）O（3）和高岭石上的 Cm 进行了测量，这些湿糊剂是在不存在和存在碳酸盐的情况下制备的，以便通过直接比较两个系统的光谱来直观地说明任何变化。在含有碳酸盐的样品中观察到激发和发射光谱的红移以及荧光寿命的增加，这清楚地表明了碳酸盐的影响，并且与涉及碳酸盐配合物的 Cm（III）表面物种的形成完全一致。此外，荧光寿命的双指数衰减行为表明，在矿物-水界面处至少存在两种不同的 Cm（III）-碳酸盐物种。这些结果为形成三元 Cm（III）-碳酸盐表面配合物提供了第一个光谱证据。
