Orthophosphates. Part II. The transformations brushite → fluoroapatite and monetite → fluoroapatite in aqueous potassium fluoride solution
Orthophosphates. Part II. The transformations brushite → fluoroapatite and monetite → fluoroapatite in aqueous potassium fluoride solution
复制标题
第二部分：氟化钾水溶液中透钙磷石→氟磷灰石和三磷灰石→氟磷灰石的转变。
DOI：
10.1039/j19710000033
复制
发表时间：
1971
期刊：
影响因子：
--
通讯作者：
E. J. Duff
中科院分区：
文献类型：
--
作者：
E. J. Duff
在25 °C的酸性KF水溶液中研究了透钙磷石→氟磷灰石和三斜磷钙石→氟磷灰石的转化。10-1M，F-。的转换涉及一级吸收的F-由二级正磷酸盐，然后由固态重排为氟磷灰石与二级释放的H2 PO 4-。根据透钙磷石→磷灰石的转变计算出氟磷灰石的ΔGf°为-1524 statist 1 kcal mol-1，并通过计算三斜磷钙石的ΔGf°值为-401 statist 1 kcal mol-1得到证实。根据这些结果，羟基磷灰石、Ca 5 OH（PO 4）2、Ca 3（PO 4）2和Ca（H2 PO 4）2以及Ca（H2 PO 4）2、H2O的ΔGf°值计算为-1494 statists 2、-925 statists 1、-677 statists 8和-729 statists 5 kcal mol-1。讨论了氟磷灰石中钾取代钙的可能性。
The transformations brushite → fluoroapatite and monetite → fluoroapatite have been investigated at 25 °C in aqueous acidic KF solutions, ca. 10–1M in F–. The transformations involve a first-order uptake of F– by the secondary orthophosphates, followed by a solid-state rearrangement to fluoroapatite with the second-order release of H2PO4–. The ΔGf° for fluoroapatite has been calculated from the brushite → apatite transformation as –1524·1 kcal mol–1, and confirmed by calculation of the ΔGf° value for monetite as –401·1 kcal mol–1. From these results, the ΔGf° values of hydroxyapatite, Ca5OH(PO4)2, Ca3(PO4)2, and Ca(H2PO4)2, and Ca(H2PO4)2,H2O were calculated as –1494·2, –925·1, –677·8, and –729·5 kcal mol–1. The possibility of K substitution for Ca in fluoroapatite is discussed.