Zyman Zoltan, Epple Matthias, Goncharenko Anton, Rokhmistrov Dmytro, Prymak Oleg, Loza Kateryna
Physics of Solids Department, V.N. Karazin Kharkiv National University, 4 Svoboda Sq., Kharkiv, 61022, Ukraine.
Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg- Essen, Essen, Germany.
J Mater Sci Mater Med. 2017 Mar;28(3):52. doi: 10.1007/s10856-016-5820-4. Epub 2017 Feb 14.
Thermal evolution of amorphous calcium phosphate (ACP) powder from a fast nitrate synthesis with a Ca/P ratio of 1:1 were studied in the range of 20-980 °C. The powder consisted of amorphous dicalcium phosphate anhydrate (CaHPO) after heating to 200 °C. CaHPO gradually condensed to amorphous calcium pyrophosphate CaPO (CPP) between 200 to 620 °C. Amorphous CPP crystallized at 620-740 °C to a metastable polymorph α'-CPP of the high-temperature phase α-CPP and β-CPP. The α'-CPP/ β-CPP phase ratio reached a maximum at 800 °C (60 wt% α'-CPP/40 wt% β-CPP), and α'-CPP gradually transformed to β-CPP at a higher temperature. Some β-TCP occurred at 900 °C, so that a three-phasic mixture was obtained in the powder heated to 980 °C. The occurrence of metastable α'-CPP is attributed to Ostwald's step rule, and a mechanism for β-TCP formation is proposed. The advantages of prospective biomaterials from these powders are discussed.
研究了通过快速硝酸盐合成法制备的钙磷比为1:1的无定形磷酸钙（ACP）粉末在20-980°C范围内的热演化过程。加热至200°C后，该粉末由无定形无水磷酸二钙（CaHPO）组成。在200至620°C之间，CaHPO逐渐缩合为无定形焦磷酸钙CaPO（CPP）。无定形CPP在620-740°C结晶为高温相α-CPP和β-CPP的亚稳多晶型α'-CPP。α'-CPP/β-CPP相比例在800°C时达到最大值（60 wt%α'-CPP/40 wt%β-CPP），且在更高温度下α'-CPP逐渐转变为β-CPP。在900°C时出现了一些β-TCP，因此在加热至980°C的粉末中获得了三相混合物。亚稳α'-CPP的出现归因于奥斯特瓦尔德步阶规则，并提出了β-TCP形成的机制。讨论了由这些粉末制备的潜在生物材料的优点。
