Synthesis Of Ultralong Hydroxyapatite Nanowires By Solvothermal Treatment And Fabrication Of Antimicrobial Bioceramics

Hydroxyapatite(Ca₁₀?OH?₂?PO₄?₆,HAP)is the main inorganic constituent of bone in vertebrates,possessing excellent properties such as high biocompatibility and bone conductibility,is widely used in bone substitute materials and metal implant coatings.However,because there was no antibacterial properties,the existing implants cannot prevent bacterial infections in the process of operation.In order to overcome this deficiency of the implants,the antimicrobial bioceramics was successfully fabricated by in-situ synthesis of nano ZnO in a HAP porous ceramic structure.Firstly,an ultra-long hydroxyapatite?HAP?nanowire with a diameter of approximately14 nm and a length of up to 72?m was successfully prepared by a simple solvothermal method.The results showed when the NaOH concentration was 1.5 mol/L,the aspect ratio of HAP nanowires reached the maximum value?5143?,and the hydrophilicity was the best.Then,HAP ceramics were successfully prepared using HAP nanowires as raw materials.As the sintering temperature increases,the ceramic's relative density gradually increases,and the porosity decreases gradually.When the sintering temperature reached 800oC,HAP gradually changed to?-TCP.When the sintering temperature reached 900oC,the porosity was minimized?2.2%?.And then,ZnO@HAP bioceramics was successfully prepared by in-situ synthesis of nano ZnO in porous HAP ceramics structure.ZnO@HAP bioceramics have obvious antibacterial performance to E.coli and S.aureus,and with the increase of the sintering temperature of HAP ceramics,its antibacterial performance has shown decreasing trend.The antibacterial performance of ZnO@HAP bioceramics is mainly affected by the content of ZnO grown in ceramic structure.At the same time,in order to reduce the synthesis cost of HAP nanowires,the process of reusing the reaction residue to synthesize HAP is studied.Two methods are adopted.After four cycles,the samples obtained were all HAP nanowires.Although the length was slightly reduced,the aspect ratio was still large.Therefore,some reference data is provided for reducing the cost of synthetic HAP nanowires.