Study On The Preparation And Application Of Hydroxyapatite Nanoparticles With Spherical Morphology

Hydroxyapatite?HA?is a biomaterials,which has strong bioactivity and biocompatibility.Therefore,it is widely used in the fields of bone repairing,drug carrier and functional material adsorption.Spherical HA nano-particles not only have strong bioactivity and biocompatibility,but also have the advantages of large surface area,strong ion exchange and large adsorption capacity.Therefore,it has become a hot topic for researchers in the preparation of HA with spherical morphology,particle size and in the nanometer range.In this thesis,carbon quantum dots?CDs?are used as spherical hard templates.Under hydrothermal conditions,cetyltrimethylammonium bromide?CTAB?is used to encapsulate CDs and induce HA to deposit on the surface of CDs.This thesis also discuessed the effects of CDs concentration,crystallization time,crystallization temperature,CTAB concentration and pH value on HA morphology and particle size,so as to obtain the best spherical HA nanoparticles.And under the best reaction conditions,the author changed the type of surfactant,such as Tween 80?TW-80?,Sodium Dodecyl Sulfate?SDS?to observe changes in HA morphology and particle size.At the same time,the products were characterized and analyzed by means of sem,tem,infrared spectrometer,UV-Vis spectrophotometer,X-ray diffractometer,nanoparticle size analyzer and other detection methods.The results show that CTAB can induce the uniform deposition of HA on the surface of CDs,while the HA prepared by TW-80 and SDS has irregular morphology and serious agglomeration.In this thesis,CDs are used as the spherical hard template,the surfactant of CTAB is used as the nucleation site of HA,the buffer solution prepared by sodium phosphate and sodium dihydrogen phosphate is used as the phosphorus source and anhydrous calcium chloride is used as the calcium source for the best experimental conditions.Under the conditions of 1.57 calcium/phosphorus molar ratio,0.50mmol/L CDs concentration,5 h reaction time,1.00 mmol/L CTAB concentration,80?temperature and 10 pH,the authors obtained spherical HA nanoparticles with good dispersion,high crystallinity,regular morphology,and a particle size of about200 nm.Under the best experimental conditions,this thesis selected the HA prepared by adsorption experiments on Cu²⁺and Pb²⁺.The results show that spherical HA canCompared with other shapes of HA adsorption,spherical HA nanoparticles have good adsorption performance,strong adsorption capacity,no pollution,and can be reused.Its application value is very considerable.