Iodine species uptake by cement and CSH studied by I K-edge X-ray absorption spectroscopy
Iodine species uptake by cement and CSH studied by I K-edge X-ray absorption spectroscopy
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DOI：
10.1524/ract.2002.90.9-11_2002.647
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发表时间：
2002
影响因子：
1.8
通讯作者：
I. Bonhoure;A. Scheidegger;E. Wieland;R. Dähn
中科院分区：
文献类型：
--
作者：
I. Bonhoure;A. Scheidegger;E. Wieland;R. Dähn
总结使用X射线吸收光谱（XAS）研究了HCP（硬化水泥浆）和CSH（硅酸钙水合物）相在高碱性条件下对碘物质（I−/IO 3 −）的吸收。该研究在IK边缘（33.169 keV）而不是IL 3边缘（4.557 keV）进行，以避免干扰Ca（K边缘=4.038 keV），Ca是HCP和CSH相中的主要元素。XANES（X射线吸收近边结构）光谱显示，在HCP和CSH吸收后，碘化物（I（-I）−）和碘酸盐（I（V）O3−）的形式氧化态没有变化。从I−处理过的HCP和CSH样品中得到的EXAFS（扩展X射线吸收精细结构）振荡被发现非常微弱，限制了对EXAFS数据的解释。IO 3 − EXAFS光谱表明，由三个氧原子组成的IO 3 −实体具有特征I-O距离（<$1.78 <$），在被HCP和CSH吸收后保持不变。XANES进一步表明，CSH不是HCP的摄取控制相。
Summary The uptake of iodine species (I−/IO3−) by HCP (hardened cement paste) and a CSH (calcium silicate hydrate) phase under highly alkaline conditions has been investigated using X-ray absorption spectroscopy (XAS). The study was performed at the I K-edge (33.169 keV) instead of the I L3-edge (4.557 keV) to avoid interference with Ca (K-edge=4.038 keV), a major element in HCP and CSH phases. The XANES (X-rays absorption near-edge structure) spectra revealed no changes in the formal oxidation state of iodide (I(-I)−) and iodate (I(V)O3−) upon uptake by HCP and CSH. The EXAFS (extended X-ray absorption fine structure) oscillations from I− treated HCP and CSH samples were found to be extremely weak, limiting interpretation of the EXAFS data. The IO3− EXAFS spectra showed that the IO3− entity consisting of three oxygen atoms with a characteristic I-O distance (∼1.78 Å) is maintained upon uptake by HCP and CSH. XANES further indicated that CSH is not the uptake-controlling phase in HCP.