Study On The Preparation And Properties Of Nano-BaTiO₃/Hydroxyapatite Composite

Human bone has significant piezoelectric effect,which can produce potential under stress.Barium titanate?BaTiO₃?is a representative ferroelectric crystal with an oxygen octahedral structure,BaTiO₃ based ceramics are one of the most important electronic ceramic due to their high dielectric constant,excellent ferroelectric,piezoelectric and dielectric properties.Then Hydroxyapatite?Ca10?PO4?6?OH?2,HA?nanoparticles,as one of the major components of natural bone,are considered to be one of the most potential human hard tissue replacement materials because of their good biological compatibility and biological activity.On the one hand,as a piezoelectric material,BaTiO₃ can meet the piezoelectric effect of biological bone,stimulate the proliferation and differentiation of bone cells,help the formation and matrix mineralization;On the other hand,HA can make the bionic materials have biological activity and bone binding capacity,which is in accordance with the biological requirements of bone tissue engineering.Research hopes the best of both worlds in one set,then to prepare BaTiO₃/HA biological composite materials.The preparation of BaTiO₃/HA nano-composites can be divided into two parts,?1?Using barium chloride?BaCl2·2H2O?and butyl titanate?C16H36O4Ti?as raw materials,Nano BaTiO₃ particles were prepared by hydrothermal method.On this basis,disperse the commercial HA nano-powder in aqueous solution or other different solvents?DMF,ethanol,ethylene glycol?,then mixing the solution with BaTiO₃ precursor solution to prepare BaTiO₃/HA nanocomposites via primary hydrothermal reaction.?2?Using anhydrous calcium chloride?CaCl2?and ammonium phosphate??NH4?2HPO4?as raw materials,HA nanorods were prepared by hydrothermal method combined with template.Then a second hydrothermal reaction by mixing HA rod and BaTiO₃ precursor solution to obtain BaTiO₃/HA nanocomposites.During the experiment,the phase composition and microstructure of the synthesized BaTiO₃,HA and BaTiO₃/HA compositeproduct were analyzed,and the electrical and biological properties of the composite ceramics were studied.The following conclusions are obtained:?1?BaTiO₃ nanoparticles can be prepared with good crystallinity,uniform particle size by the hydrothermal method.The size of BaTiO₃ can be macro-controlled by changing the hydrothermal temperature and hydrothermal time;?2?Compared to the other solvent systems,hydrothermal synthesis in distilled water system will increase the degree of crystallinity of the composite under the same conditions?160 ?,12 h?,which makes it have better electrical properties;?3?We can prepare the HA nanorods with good crystallinity,single phase,and uniform particle size by adjusting the hydrothermal temperature and time;?4?Compared to BaTiO₃/HA composite by the primary hydrothermal synthesis,the new composite products achieve the BaTiO₃ particles were synthesized in situ on HA nanorods under the second hydrothermal synthesis conditions,The composite in the morphology and particle size have been very good control.The resulting composite ceramics have good electrical properties,and no cytotoxicity.