文献类型：期刊文献

英文题名：Kinetics of hydroxyapatite precipitation at pH 10 to 11

作者：Liu, Changsheng[1]; Huang, Yue[1]; Shen, Wei[1]; Cui, Jinghua[1]

机构：[1]E China Univ Sci & Technol, Inst Tech Chem & Phys, Shanghai 200237, Peoples R China

年份：2001

卷号：22

期号：4

起止页码：301

外文期刊名：BIOMATERIALS

收录：;EI(收录号：2001385462955);WOS:【SCI-EXPANDED(收录号:WOS:000166428300001)】；

语种：英文

外文关键词：hydroxyapatite; kinetics; precipitation; activation energy; conversion

摘要：The mechanism and kinetics of hydroxyapatite (HAP) precipitation from aqueous solution at the conditions of pH 10-11 and at calcium ion concentrations of more than 0.5 mol/I were investigated. The results show that the reaction undergoes the following process: transferring from octacalcium phosphate (OCP) to amorphous calcium phosphate (ACP) rapidly, and then from ACP to calcium-deficient hydroxyapatite (DAP) and HAP. DAP was the non-stoichiometric material that ACP converts to HAP. Reaction temperature greatly affects the reaction rate of the conversion from ACP to HAP. It takes about 24 h to form pure-phase HAP at 25 degreesC while it takes only 5 min at 60 degreesC. The temperature also has a great deal of influence on the particle size and morphology of precipitated hydroxyapatite. The reaction of transformation from ACP to DAP was second order and the activation energy was 95 kJ/mol (22.7 kCal/mol) and therefore it was inferred that the conversion reaction was a surface control process. (C) 2001 Elsevier Science Ltd. Ail rights reserved.