本文以CaCl2与KH2PO4为原料, Na2EDTA·2H2O为螯合剂, 通过NH3·H2O调节溶液pH值, 系统研究了水热釜填充度(16%~64%)与溶液pH值(3.5~6.0)对水热法制备钛表面钙磷涂层形貌和物相的影响。结果表明: 当pH值为3.5和4.0时, 涂层在所研究填充度的范围内主要为三斜结构(P1)的板块状磷酸氢钙(DCPA); 当pH值为4.5和5.0时, 低填充度有利于形成六方结构(P63/m)的蒲公英状羟基磷灰石(HAP), 并随填充度的提高, 涂层由蒲公英状HAP逐渐转变为板块状DCPA; 当pH值为5.5和6.0时, 涂层在所研究填充度的范围内主要为蒲公英状HAP, HAP的结晶度随填充度的提高逐渐增加, 而随pH值的升高蒲公英状HAP的直径逐渐减小。另外, 本文获得的单相HAP涂层、单相DCPA涂层和(HAP+DCPA)两相混合涂层的润湿性均显著优于钛表面, 这将有助于植体的骨整合。同时, 本文也探究了不同钙磷涂层的反应机理。

In this paper, CaCl2 and KH2PO4 were used as raw materials, Na2EDTA·2H2O as chelating agent, and NH3·H2O was used to adjust pH value of the solution, the calcium-phosphate coatings on titanium substrate were prepared via hydrothermal method, and the effects of filling condition (FC) (16%~64%) and pH value (3.5~6.0) on morphology and phase constitutions of the coatings were systematically investigated. The results show that: when the pH value is 3.5 and 4.0, the coatings are mainly platelet-like calcium hydrogen phosphate (DCPA) (P1) at different FC, and FC has no remarkable effect on phase constitution of the coatings; when the pH value is 4.5 and 5.0, dandelion-like hydroxyapatite (HAP) (P63/m) are easily found at lower FC, and with the increase of FC, the coating changes from dandelion-like HAP to platelet-like DCPA; when the pH value is of 5.5 and 6.0, the coatings are mainly dandelion-like HAP at different FC, and with the increase of FC, the crystallinity of HAP increases, while with the increase of pH value, the diameter of dandelion-like HAP decreases. Otherwise, the wettability of the three typical coatings (i.e., the dandelion-like HAP, the platelet-like DCPA, and the mix of (HAP+DCPA)) show much better wettability than the titanium substrate, this indicates that the calcium-phosphate coatings would benefit the future osseointegration. Meanwhile, the formation mechanisms of different kinds of coatings were discussed.