水热釜填充度与溶液 pH 值对水热法制备钙磷涂层的影响

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.