Synthesis of Ceramic Powders for Biomedical Applications

The HT powders were synthesized by the sol-gel method, as previously described [34 (link)]. Briefly, TEOS, ethanol, and HNO₃ were mixed in a certain ratio and stirred to hydrolyze for 0.5 h. Then Zn(NO₃)₂·6H₂O and Ca(NO₃)₂·4H₂O were added to the clarified solution after complete hydrolysis and stirred thoroughly for 4 h. The mixed solution was sealed at 60 °C for 36 h to form a gel, which was then dried at 120 °C for 72 h. The dried gel obtained was calcined at 1250 °C for 4 h. The SrCSi powders were synthesized by wet chemical precipitation [35 (link)]. All powders were milled for 8 h in a planetary ball mill (Chishun Sci&Tech Co., China) with a certain percentage of ethanol solution as a medium to obtain ultrafine particle-size powders (<5 μm). X-ray diffraction (XRD, Rigaku, Tokyo, Japan) and inductively coupled plasma-optical emission spectroscopy (ICP-OES; Thermo, UK) were used to verify the phase and elemental composition (calcium, strontium, silicon) of the synthesized powders.