氟和碳酸根復(fù)合替代磷灰石的制備及性能研究
發(fā)布時(shí)間：2018-09-14 15:53
【摘要】：羥基磷灰石(簡(jiǎn)稱HA)具有良好的生物活性和生物相容性,作為骨植入材料廣泛應(yīng)用醫(yī)學(xué)領(lǐng)域。然而由于人體自然骨中的羥基磷灰石是非化學(xué)計(jì)量的,其中碳酸根(CO_3~(2-))是含量最多的替代離子。由于復(fù)合替代在優(yōu)化磷灰石結(jié)構(gòu)和性能方面能夠取長(zhǎng)補(bǔ)短,因此在單一替代的基礎(chǔ)上,不少學(xué)者將目光放在了復(fù)合替代的研究上。碳酸根和氟離子替代對(duì)磷灰石的結(jié)構(gòu)和性能均有不同程度的影響,因此可以通過控制碳酸根和氟離子的替代調(diào)控磷灰石的綜合性能。本文通過化學(xué)沉淀法制備碳氟共替代羥基磷灰石粉體(CFHA),探討了制備工藝參數(shù)對(duì)碳酸根和氟離子共替代的影響,并對(duì)CFHA粉體和塊體進(jìn)行熱處理研究,利用XRD、SEM、TEM、FTIR、DTA/TG等一系列表征手段研究了碳酸根和氟共替代對(duì)HA結(jié)構(gòu)和性能的影響。通過化學(xué)沉淀法合成CFHA粉體,研究了反應(yīng)溫度和pH值、CO_3~(2-)/F-原料的初始濃度和添加順序、堿液添加時(shí)機(jī)、原料中Na~+的共替代、n(Ca)/n(P)摩爾比等工藝參數(shù)對(duì)磷灰石中碳酸根和氟的替代、結(jié)構(gòu)和形貌的影響。研究結(jié)果表明:(1)隨著反應(yīng)溫度升高,晶粒尺寸和長(zhǎng)徑比增加;隨著pH值的增大,納米HA晶粒尺寸和長(zhǎng)徑比都隨之減少,并且堿性的反應(yīng)環(huán)境更有利于HA結(jié)晶和替代的發(fā)生。(2)碳酸根和氟離子共替代時(shí),氟離子濃度對(duì)于HA形貌影響不大,而隨著碳酸根濃度增加,HA晶粒尺寸和長(zhǎng)徑比相應(yīng)減少,且在高F-和CO_3~(2-)濃度下,更利于碳酸根的B型替代。合成粉體中氟和碳酸根含量隨初始氟、碳酸根離子濃度的增加而非線性增加,但碳酸根含量測(cè)量值高于理論值,而氟離子含量測(cè)量值遠(yuǎn)低于理論值。(3)先加堿液的方式使晶核形成速率過快出現(xiàn)大量晶體團(tuán)聚的現(xiàn)象;后加堿液方式制備得到的晶體呈片狀。(4)Na~+的存在促進(jìn)磷灰石晶體的生長(zhǎng),且含Na~+體系中會(huì)發(fā)生Na~+/CO_3~(2-)共替代,更有利于碳酸根B型替代的發(fā)生。(5)原料的鈣磷配比會(huì)影響CFHA的碳酸根替代和最終的物相組成。將CFHA粉體和塊體在濕CO_2保護(hù)氣氛下進(jìn)行熱處理,研究了碳氟共替代對(duì)CFHA粉體的熱穩(wěn)定性、CFHA的塊體燒結(jié)性能、熱膨脹系數(shù)和抗折強(qiáng)度的影響。研究結(jié)果表明:(1)濕CO_2保護(hù)氣氛有利于CFHA的熱穩(wěn)定性;而碳氟替代對(duì)于樣品的熱分解影響不明顯。(2)在濕CO_2保護(hù)氣氛進(jìn)行熱處理,當(dāng)處理溫度為850℃時(shí),隨著初始碳含量增加,CFHA燒結(jié)試樣的吸水率降低,當(dāng)處理溫度為950℃時(shí),碳氟替代對(duì)于樣品的燒結(jié)致密度影響不大。(3)CFHA試樣的膨脹系數(shù)隨著溫度升高而增大,隨著初始碳氟替代含量的增加而減小。(4)CFHA試樣的抗折強(qiáng)度隨著初始碳氟替代含量的增加而增大。
[Abstract]:Hydroxyapatite (HA) has good bioactivity and biocompatibility. However, hydroxyapatite in human natural bone is nonstoichiometric, in which CO_3~ (2-) is the most abundant substitute ion. Because compound substitution can complement each other in optimizing apatite structure and performance, many scholars have focused on the study of composite substitution on the basis of single substitution. The substitution of carbonate and fluorine ions has different effects on the structure and properties of apatite, so the comprehensive properties of apatite can be controlled by controlling the substitution of carbonate and fluorine ions. In this paper, the influence of preparation parameters on the co-substitution of carbonate and fluorine ions in (CFHA), powder prepared by chemical precipitation method was investigated, and the heat treatment of CFHA powder and bulk was studied. The effects of carbonate and fluorine co-substitution on the structure and properties of HA were studied by means of XRD,SEM,TEM,FTIR,DTA/TG and other characterization methods. CFHA powder was synthesized by chemical precipitation method. The initial concentration and addition order of reaction temperature and pH value were studied. The substitution of carbonate and fluorine in apatite was studied, such as the initial concentration and addition order, the addition time of alkali solution, the molar ratio of co-substitution of Na~ to n (Ca) / n (P) in the raw material, and so on. The influence of structure and morphology. The results show that: (1) with the increase of reaction temperature, the grain size and aspect ratio increase, and with the increase of pH value, the grain size and aspect ratio of nanometer HA decrease. And the alkaline reaction environment is more favorable to the crystallization and substitution of HA. (2) the concentration of fluorine ion has little effect on the morphology of HA, but with the increase of carbonate concentration, the grain size and the ratio of length to diameter of HA decrease correspondingly, (2) when the carbonate and fluorine ions are co-substituted, the concentration of fluorine ion has little effect on the morphology of HA. At high concentration of F-and CO_3~ (2 -), type B substitution of carbonates is more favorable. The content of fluorine and carbonate in the synthesized powder increases linearly with the increase of the initial fluoride and the concentration of carbonate ion, but the measured value of the content of carbonate is higher than the theoretical value. However, the measured value of fluorine ion content is far lower than the theoretical value. (3) the nucleation rate of crystal is too fast by adding alkali solution, and then the crystal prepared by adding alkali solution is flake. (4) the existence of Na~ promotes the growth of apatite crystal. The co-substitution of Na~ / CO3- ~ (2-) in the system containing Na~ is more favorable to the occurrence of substitution of B type of carbonate. (5) the ratio of calcium to phosphorus of raw material will influence the substitution of carbonates and the final phase composition of CFHA. The effects of carbon-fluorine co-substitution on the bulk sintering properties, thermal expansion coefficient and flexural strength of CFHA powders were studied. The results show that: (1) the wet CO_2 protective atmosphere is favorable to the thermal stability of CFHA, while the substitution of fluorocarbon has no obvious effect on the thermal decomposition of the samples. (2) when the temperature is 850 鈩，
本文編號(hào)：2243162
[Abstract]:Hydroxyapatite (HA) has good bioactivity and biocompatibility. However, hydroxyapatite in human natural bone is nonstoichiometric, in which CO_3~ (2-) is the most abundant substitute ion. Because compound substitution can complement each other in optimizing apatite structure and performance, many scholars have focused on the study of composite substitution on the basis of single substitution. The substitution of carbonate and fluorine ions has different effects on the structure and properties of apatite, so the comprehensive properties of apatite can be controlled by controlling the substitution of carbonate and fluorine ions. In this paper, the influence of preparation parameters on the co-substitution of carbonate and fluorine ions in (CFHA), powder prepared by chemical precipitation method was investigated, and the heat treatment of CFHA powder and bulk was studied. The effects of carbonate and fluorine co-substitution on the structure and properties of HA were studied by means of XRD,SEM,TEM,FTIR,DTA/TG and other characterization methods. CFHA powder was synthesized by chemical precipitation method. The initial concentration and addition order of reaction temperature and pH value were studied. The substitution of carbonate and fluorine in apatite was studied, such as the initial concentration and addition order, the addition time of alkali solution, the molar ratio of co-substitution of Na~ to n (Ca) / n (P) in the raw material, and so on. The influence of structure and morphology. The results show that: (1) with the increase of reaction temperature, the grain size and aspect ratio increase, and with the increase of pH value, the grain size and aspect ratio of nanometer HA decrease. And the alkaline reaction environment is more favorable to the crystallization and substitution of HA. (2) the concentration of fluorine ion has little effect on the morphology of HA, but with the increase of carbonate concentration, the grain size and the ratio of length to diameter of HA decrease correspondingly, (2) when the carbonate and fluorine ions are co-substituted, the concentration of fluorine ion has little effect on the morphology of HA. At high concentration of F-and CO_3~ (2 -), type B substitution of carbonates is more favorable. The content of fluorine and carbonate in the synthesized powder increases linearly with the increase of the initial fluoride and the concentration of carbonate ion, but the measured value of the content of carbonate is higher than the theoretical value. However, the measured value of fluorine ion content is far lower than the theoretical value. (3) the nucleation rate of crystal is too fast by adding alkali solution, and then the crystal prepared by adding alkali solution is flake. (4) the existence of Na~ promotes the growth of apatite crystal. The co-substitution of Na~ / CO3- ~ (2-) in the system containing Na~ is more favorable to the occurrence of substitution of B type of carbonate. (5) the ratio of calcium to phosphorus of raw material will influence the substitution of carbonates and the final phase composition of CFHA. The effects of carbon-fluorine co-substitution on the bulk sintering properties, thermal expansion coefficient and flexural strength of CFHA powders were studied. The results show that: (1) the wet CO_2 protective atmosphere is favorable to the thermal stability of CFHA, while the substitution of fluorocarbon has no obvious effect on the thermal decomposition of the samples. (2) when the temperature is 850 鈩，
本文編號(hào)：2243162
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