| Hydroxyapatite (HAp) possesses a certain bioactivity, it can release the ions to help the tooth mineralization and also can be used to plug the tooth surface damage which is eroded by the acid to reduce the sensitivity of the teeth. The addition of fluoride and potassium in HAp can not only improve the mechanical properties and biological activity, but also improve the health of the oral cavity. Therefore, how to control the process parameters to prepare the fluorine and potassium doped HAp materials with good biological activity is the outstanding problem that needs to be solved.In this paper, calcium nitrate and phosphoric acid were used as rawmaterials, and ammonia was applied as the pH adjusting agent. First, the calcium phosphate was prepared by precipitation method,then the powder of calcium phosphatewas sintered in a muffle furnace at different temperatures,thus α-Ca3(PO4)2andpower were obtained.At last, the a-TCP powder was hydrated and the hydration product of deficient calcium hydroxyapatite was added to the solution of KOH, thus was potassium(KHAp) prepared.The atomic absorption spectrophotometry,theX-ray diffraction scanning electron microscope, the fourier infrared spectrometer and the X-ray energy spectrum were used toanalysis the characterize of the prepared material. Then KHAp powder was added into the solution that contain the ions fluoride, the fluorine ion concentration in solution was determined by selective electrode method.By fitting the the adsorption kinetics equation and adsorption isotherm equation, the influences of the solution pH and amount of powder on the adsorption fluorine ion property of the powder was researched,at last, the prepared fluoride, potassium hydroxyapatite powder was tested in simulated body fluid to study its biological activity.The conclusions were drawn as following:(1) The Ca3(PO4)2presence at other temperatures, found throughexperiments at 1250℃ conditions, the sample is pure phase of α-Ca3(PO4)2.(2) By orthogonal experiment, temperature, time, pH value as experimental factor, after incorporation spectrum test results as an indicator, optimum experimental conditions, through poor size analysis, the corresponding factors: temperature> pH> Time. Through experiments to explore, found that the reaction temperature is above 100℃, in favor of potassium incorporation. In this paper, the experiment is the use of hydration at 120℃ conditions prepared by the reaction of potassium-doped HAp powder, as a result of lattice distortion, HAp grain size decreases after doping potassium.(3) When the solution pH=6, KHAp has the best adsorption effect. Within the first four hours, the powder of F- the adsorption rate increased rapidly, the removal rate can reach 90%, the reaction time, the removal rate of up to about 92%, indicating that the adsorption equilibrium time was 6 hours. KHAP adsorption of F for monolayer adsorption, absorption rate constant calculated secondary k2=7.526 × 10-3 g·(mg·min)-1, maximum adsorption capacity of 31.55 mg·g-1.(4) FKHAp materials in SBF can induce new apatite deposits. FKHAp have a certain biological activity, this study found that the incorporation of F in HAp, K may enhance the biological activity of HAp. |
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