Microwave Hydrothermal Controllable Synthesis And Modification Of Nano-hydroxyapatite Powder

Nano-HAP has excellent biocompatibility,biological activity and inducing bone growth in a state without rejection.In recent years,nano-HAP has become widely recognized as a good bone substitute material.At present,there are still limitations in the methods for synthesizing nano-HAP.For example,nano-HAP crystals are easy to agglomerate and have a long reaction time.These problems limit the wider application of nano-HAP.In order to avoid the above problems,this paper based on microwave hydrothermal method to study the effects of time,temperature,reactant concentration and surfactant concentration on nano-hydroxyapatite crystals,which can synthesize small particle size,high purity and particle size distribution in a short time.(1)Based on the microwave hydrothermal method,the effects of time,temperature and reactant concentration were studied.The results show that within the experimental temperature,as the reaction temperature increases,the crystallinity of the crystal increases and the grain grows,but the crystallinity does not increase significantly after 160?.During the experimental time,as the reaction time prolonged,the crystallinity of the crystal increased,but the crystallinity did not increase significantly after 40 minutes.The nano-HAP with higher crystallinity can be synthesized in 1 minute,and the reaction condition at 160~oC for 40 minutes is a preferable reaction condition.The nanocrystal is rod-shaped,the particle diameter is64.7±13.6 nm,and the diameter is 29.1±3.9 nm.(2)Different sodium polyacrylate concentrations have an effect on the grain size and dispersibility of hydroxyapatite.It can be seen from the TEM image that when the concentration of sodium polyacrylate is too low or too high,the agglomeration of nano-hydroxyapatite powder is serious.It can be seen from the sedimentation experiment that as the concentration of sodium polyacrylate increases the dispersibility of the dispersion,when the concentration of polyacrylic acid is too large,agglomeration is caused.The good dispersibility of the nano-HAP suspension is attributed to the interaction of the material with the steric effect of sodium polyacrylate.(3)Hemolysis experiments and cytotoxicity experiments were carried out on microwave hydrothermal method combined with nano-hydroxyapatite synthesized by ultrasonic spray method and hydroxyapatite stabilized with different concentrations of sodium polyacrylate.The experimental results show that the hemolysis rate of the two materials is far lower than the national standard for biomedical materials and medical devices requiring a hemolysis rate of less than 5%.The results of cytotoxicity experiments showed that the cell survival rate decreased with the increase of material concentration.When the concentration of sodium polyacrylate increased,the cell survival rate decreased.The cell survival rate decreased significantly.However,the survival rate of cells with different concentrations of the two materials is higher than80%,and the cytotoxicity is also very low.Both can be applied to bone repair materials.