Preparation Of Hydroxyapatite Powder And Biomimetic Synthesis Of Calcium Carbonate

Hydroxyapatite(HAP) and calcium carbonate are all one of thebiomaterials. For example, HAP is the main inorganic constituent ofhuman hard tissures, such as bones and teeth. The main constituent ofpearl and shell is calcium. At first, HAP powders were synthesized bythree methods. Secondly, calcium carbonate was obtained bybiomimetic method and the corresponding formation mechanism isbiomineralization. The resultant products were collected for thecharacterization of SEM, TEM, XRD and FTIR. The effect ofdifferent methods, synthesis parameters on the formation and themorphology of HAP were studied. We also analyzed the differencemorphology of HAP obtained of three systems. Firstly, the HAP powders were synthesized by the followedmethods. Ca(NO₃)₂·4H₂O and Na₃PO₄·12H₂O were used as reagents,the effect of different Ca/P ratio, heating mode and heating time ofmicrowave on the formation of HAP were stuided. The results showedthe HAP powders were not obtained without microwave heating.When heating time and mode of microwave were different, themorphology of HAP powder was different. In the second system, CaHPO₄·2H₂O was used as main reagent, theeffect of hydrothermal temperature, time, surfactant and PH value onthe synthesis of HAP powder were investigated. The SEM resultsshow the product obtained were whiskers and nanorods with differentaspect ratio. As to the solvothermal method in this thesis, Na₃PO₄·12H₂O andCaCl₂ were used as precursors, and alcohol was used as solvent. XRDand FTIR results show HAP were obtained when solvothermalreaction time is 48h. . At last, a combination of Double-Hydrophilic block Copolymer(DHBC) method and In-Situ Polymerization method was performed asa new strategy. And the effects on the crystallization of CaCO3 isdiscussed with a combination of PH value. Based on the observationsand results, the influence on the nucleation and crystal growth ofdifferent experiment conditions and polymers were discussed.