钛表面含硅羟基磷灰石涂层的电化学合成和表征

Synthesis and Charaterization of Silicon-Substituted Hydroxyapatite Coating by Electrochemical Deposition on Ti Substrate

在含有Ca2+,PO43-以及SiO32-的电解液中,通过电化学恒电位方法,在工作电压为3 V温度为85℃的条件下沉积1 h,于钛表面上制得含硅羟基磷灰石涂层。通过电感耦合等离子体原子发射光谱(ICP)、扫描电镜(SEM)、X-射线衍射(XRD)、探针式轮廓仪(SP)、红外光谱(FTIR)对涂层进行分析。结果表明:电化学恒电位方法可制得Si饱和含量为0.55wt%左右的Si-HA涂层,Si以SiO44-形式取代PO43-进入HA晶格,造成羟基磷灰石中OH-减小以维持电荷平衡。另外,电解液中Si元素的存在抑制涂层中HA晶体的生长,使涂层变薄,且当电解液中nSi/(nSi+nP)达到20%时Si-HA晶体形貌由单独的棒状转变为根部相连的树枝状。

Silicon-substituted hydroxyapaptite coatings were prepared on titanium substrate with electrochemical deposition technique in electrolytes containing Ca2＋,PO43-and SiO32-ions.The deposition was all conducted at a constant voltage of 3.0 V for 1 h at 85 ℃.The as-prepared coatings were examined by inductively coupled plasma（ICP）,X-ray diffraction（XRD）,stylus profiler（SP）,Fourier transform infrared spectroscopy（FTIR）,field-emission-type scanning electron microscope（SEM）.The results show that the silicon amount in Si-HA coatings deposited by electrochemical method can reach to a saturation level of around 0.55wt%,and the substitution of silicate for phosphate in the form of SiO44-results in loss of some OH-to maintain the charge balance.Additionally,the presence of silicon ions in electrolytes inhibits HA crystals growth in coatings,leading to decrease of coating thickness and transformation of rod-like crystals into dendritic crystals in the electrolyte of 20% molar ratio silicon.