Preparation And Properties Of Fluorine-doped Nano Hydroxyapatitie

Hydroxyapatite?HAP?is the main inorganic component of human and animal bones.Due to its excellent biocompatibility and biological activity,it has no stimulating and repelling effects on tissue after implantation in the human body,and can form strong with bone The chemical combination is an ideal substitute for human bones.However,due to its poor thermal stability,poor corrosion resistance,and poor mechanical properties,it is difficult to meet medical requirements,which limits its wide application.Fluorine hydroxyapatite?FHAP?prepared by fluorine ion doping has a lower solubility than HAP,which improves the problem of poor thermal stability of HAP.At the same time,the added fluoride ion also has a bacteriostatic effect,which can effectively prevent dental caries.Therefore,FHAP is expected to be widely used in bone tissue repair,stomatology and other fields.We uses fluoride?NH₄F/Na F?,sodium phosphate,calcium nitrate tetrahydrate,sodium citrate and other drugs as raw materials,using hydrothermal method to prepare fluorohydroxyapatite samples with different fluorine doping levels,and studied the different raw materials.The order of addition and the effect of different fluorine doping rates on the crystallinity,morphology size and stability of fluorohydroxyapatite,to find the best process for the preparation of FHAP with crystallinity and stability coexistence and regular shape and order condition.Characterize the crystal structure and physicochemical properties of the synthesized fluorohydroxyapatite nanoparticles.Observe the crystal parameters such as phase purity and crystallinity by XRD;observe the crystal structure and particle size by SEM;by Zeta potential Results The particle size analysis and colloidal stability were studied.In this thesis,sodium fluoride is first used as the source of fluorine.Under the conditions of hydrothermal temperature of 180oC and hydrothermal time of 6 h,fluoride ion doping is controlled to increase by 20%,and the sodium fluoride solution and sodium phosphate are adjusted at the same time.The FHAP was prepared by the order of solution addition.The research results show that the FHAP sample synthesized according to the sequential addition order of sodium fluoride solution and sodium phosphate solution has higher crystallinity,and when the fluorine doping rate is 80%,the morphology is The particles gradually changed into short rod-like structures;the colloidal stability of FHAP samples synthesized in the order of sodium fluoride and sodium phosphate mixed dropwise addition was better and the particles were concentrated.In this thesis,under the same experimental conditions as above,ammonium fluoride is used as the source of fluoride,and the fluoride ion is controlled to increase by 20%.Two experimental schemes for different dropping orders of ammonium fluoride solution and sodium phosphate solution are designed.The results of the study found that the samples synthesized in the order of dropwise addition of ammonium fluoride solution and sodium phosphate solution had higher crystallinity,and when the fluorine doping rate was 40%,a rod-like structure with a more uniform morphology was exhibited,and the average particle size The increase in fluorine doping rate increases and the colloidal stability is improved within a certain range;however,the samples synthesized in the order of mixed dropwise addition of ammonium fluoride and sodium phosphate only appear more regular when the fluorine doping rate is 80%The average particle size of the grains increases first and then decreases with the increase of the fluorine doping rate,while the stability of the synthesized sample gradually decreases.