The structure and solubility of carbonated hydroxyl and chloro lead apatites
The structure and solubility of carbonated hydroxyl and chloro lead apatites
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DOI：
10.1016/j.poly.2010.05.001
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发表时间：
2010-07-28
期刊：
影响因子：
2.6
通讯作者：
Yoder, Claude H.
中科院分区：
文献类型：
--
作者：
Sternlieb, Mitchell P.;Pasteris, Jill D.;Yoder, Claude H.
碳酸化羟基和氯化铅磷灰石的性质，即Pb10(PO4)(6)(OH)(2)和Pb10(PO4)(6)Cl2，可以作为碳酸盐与其医学上重要的钙类似物结合的模型，在铅修复过程中，碳酸盐可能会结合到不溶的磷酸铅相中。我们在60-80℃合成了一系列碳化的羟基和氯化铅磷灰石。X-射线粉末衍射、红外光谱和拉曼光谱、固体核磁共振谱和元素分析证明了碳酸盐进入了磷灰石结构。通过燃烧分析确定了碳酸盐的含量，并用拉曼光谱分析进行了确认。随着羟基磷灰石中碳酸盐含量的增加，拉曼光谱显示925和950 cm(-1)处的磷酸盐拉伸模式发生变化，1050 cm(-1)处的新峰强度增加和下移，3560 cm(-1)处的O-H拉伸的光谱特征发生变化。氯铅磷灰石的晶胞参数随碳酸盐含量的变化与钙磷灰石中B型取代的记录相似。铅-207核磁共振谱证实了B型取代。对于羟基铅磷灰石，晶胞参数的变化表明是A型和B型取代的组合。用电感耦合等离子体质谱(ICP-MS)测定碳化铅磷灰石的溶解度，在低至中等碳酸盐含量时略有增加，但在碳酸盐含量约为5.0wt%时，增加幅度较大。外推至碳酸盐含量为零的K-sp值表明，氯铅磷灰石的溶解度确实低于羟基类似物。(C)2010爱思唯尔有限公司。保留所有权利。
The properties of carbonated hydroxyl and chloro lead apatites, Pb-10(PO4)(6)(OH)(2) and Pb-10(PO4)(6)Cl-2, serve as models for the incorporation of carbonate into their medically important calcium analogs, and there is likely incorporation of carbonate in an insoluble lead phosphate phase during lead remediation. We have synthesized a series of carbonated lead hydroxyl- and lead chloro-apatites at 60-80 degrees C. The incorporation of carbonate into the apatite structure was documented by X-ray powder diffraction, IR and Raman spectroscopy, Pb-207 solid state NMR spectroscopy, and elemental analysis. The carbonate content was determined by combustion analysis and confirmed by Raman spectroscopic analysis. As carbonate content increases in hydroxyl lead apatite, Raman spectra show changes in the phosphate stretching modes at 925 and 950 cm(-1), an increase in intensity and downshift of a new peak at 1050 cm(-1), and changes in the spectral features of the O-H stretch at about 3560 cm(-1). The variation in unit cell parameters for the chloro lead apatite as a function of carbonate content is similar to that documented for B-type substitution in calcium apatites. The Pb-207 NMR spectra corroborate B-type substitution. For the hydroxyl lead apatite, the changes in cell parameters suggest a combination of A- and B-type substitution. Solubilities of the carbonated lead apatites, determined by ICP-MS, increase slightly at low to moderate carbonate content, but more strongly at ca. 5.0 wt.% carbonate content. K-sp values extrapolated to zero carbonate content reveal that the chloro lead apatite is indeed less soluble than the hydroxyl analog. (C) 2010 Elsevier Ltd. All rights reserved.