El Briak-Benabdeslam H, Ginebra M P, Vert M, Boudeville P
Institut des Biomolécules Max Mousseron, Dpt Biopolymères Artificiels, IBMM UMR-CNRS 5247, Faculté de Pharmacie, 15 Avenue Charles Flahault, BP 14 491, 34093 Montpellier Cedex 5, France.
Acta Biomater. 2008 Mar;4(2):378-86. doi: 10.1016/j.actbio.2007.07.003. Epub 2007 Jul 21.
Mechanosynthesis of calcium phosphates can be performed under wet or dry conditions. In most papers and patents, grinding under wet conditions was selected. So far, only a few papers were devoted to dry mechanosynthesis of calcium phosphates. To understand why wet mechanosynthesis was preferred, the influence of water addition on the kinetics of the mechanochemical reaction of dicalcium phosphate dihydrate with calcium oxide was investigated. The DCPD disappearance rate constant k and the final reaction time t(f) were determined in each case and correlated with the water content present in the slurry. Results showed that the addition water (i) slowed down the reaction rate and (ii) increased the powder contamination by mill material (hard porcelain) due to ball and vial erosion; and that (iii) wet milling did not generate the expected products, in contrast to dry grinding, because porcelain induced hydroxyapatite decomposition with the formation of beta-tricalcium phosphate and silicon-stabilized tricalcium phosphate. Consequently, dry mechanosynthesis appears preferable to wet milling in the preparation of calcium phosphates of biological interest.
磷酸钙的机械合成可以在湿法或干法条件下进行。在大多数论文和专利中，选择的是湿法研磨。到目前为止，只有少数论文致力于磷酸钙的干法机械合成。为了理解为何湿法机械合成更受青睐，研究了加水对二水磷酸二钙与氧化钙机械化学反应动力学的影响。在每种情况下都测定了磷酸二钙消失速率常数k和最终反应时间t(f)，并将其与浆料中的含水量相关联。结果表明，加水(i)减缓了反应速率，(ii)由于球和小瓶的磨损增加了磨料（硬瓷）对粉末的污染；并且(iii)与干磨相比，湿磨没有生成预期产物，因为瓷会导致羟基磷灰石分解形成β-磷酸三钙和硅稳定的磷酸三钙。因此，在制备具有生物学意义的磷酸钙时，干法机械合成似乎比湿磨更可取。
