碳／碳复合材料表面声电沉积磷灰石动力学研究

Deposition Kinetics of Apatite Coating on CVI Carbon/Carbon Composite by Sonoelectrodeposition Technique

摘要:

采用声电沉积技术，在碳／碳复合材料表面制备了生物活性磷酸钙涂层。扫描电镜、X射线衍射、红外反射以及X射线能谱分析表明所制涂层呈现网状结构，其由钙磷比为1．64、含碳酸根的羟基磷灰石组成。根据扫描电镜观察，描述了磷灰石的形成过程。羟基磷灰石的沉积过程可简化为两步——钙磷离子向碳／碳阴极表面运动和羟基磷灰石在碳／碳表面生长。基于此描述，导出了羟基磷灰石沉积动力学公式，并且发现，沉积过程受扩散控制，扩散活化能是30．3kJ／mol．

Abstract:

Bioactive calcium phosphate coating was prepared on C/C composites by sonoelectrodeposition technique. The analyses by SEM, XRD, FRIR and EDS show that as-received coating exhibiting subtle net-like morphology is composed of carbonate hydroxyapatite with the Ca/P ratio of 1.64. On the base of SEM observation, the procedure of the formation of apatite on C/C composite is described. We suggest that the procedure of HA deposition could be simplified to two steps, e.g. the movement of ions including Ca and P species toward C/C cathode and the growth of HA on the surface of C/C composite. In virtue of this description, the kinetics formulas of HA deposition is derived and it is found that the deposition procedure is controlled by ion diffusion in the electrolyte and the diffusion activation energy is 30.3 kJ/mol.