羟基磷灰石的制备与吸附水中氟离子性能研究

发布时间：2018-06-15 23:50

本文选题：羟基磷灰石 + 化学沉淀法　；参考：《安徽大学》2015年硕士论文

【摘要】：作为生物体不可缺少的构成成分,羟基磷灰石大概在骨骼的无机成分中占百分之六十,并且其显示出较好的生物相容性和生物活性。过去十年间,研究者对羟基磷灰石的合成有了越来越浓的兴趣,大量的羟基磷灰石合成路线被开发,不同合成方法制备出的羟基磷灰石颗粒特性各异。比如,干法合成、湿法合成、热分解法均可产生结晶性良好的颗粒。本课题利用传统的化学沉淀法和溶胶-凝胶法合成纳米结构羟基磷灰石,用来去除水溶液中的氟离子,报告了不同的合成方法制备出不同形貌结构的羟基磷灰石,且对去氟效果有显著不同,这表明羟基磷灰石的不同合成方法对氟离子的吸附产生了影响。结果显示,在25℃时,化学合成法制备的羟基磷灰石的吸附量为1.99mg/g,进行透射电子显微镜分析可知化学沉淀法得出的羟基磷灰石主要呈圆片状,且尺寸分布较为均,于溶液中稳定存在,直径平均为五十纳米；X射线衍射分析显示该图谱与标准羟基磷灰石图潜较为一致；相比较,如果用溶胶凝胶法所制备的羟基磷灰石的吸附量为1.75mg/g,进行透射电子显微镜分析得知溶胶凝胶法得出的羟基磷灰石主要呈现出杆状,尺寸分布较为均一,杆的长度在2μm-20μm,宽在50nm左右,此外,X射线衍射分析显示其图谱也与标准羟基磷灰石图谱保持一致。综上分析,从透射电子显微镜可见两种合成方法所得的样品图像有所区别,化学沉淀法合成出圆片状,溶胶凝胶则是棒状,从透射电镜图可见溶胶凝胶法得出的样品更为精细。此外,X射线衍射分析也显示出溶胶凝胶法所合成样品更为精细,相对强度也较大,说明晶体结构更为整齐有序,结晶度更好。此外,本文也进一步研究了不同合成方法制备出的羟基磷灰石在氟离子溶液中的吸附与时间的关系。结果显示：两种合成方法的吸附动力学曲线虽符合Langmuir一级方程,但计算得出的氟离子吸附量与实际不合,因此其不符合Langmuir一级动力学方程。但后发现两种合成方法符合Langmuir准二级反应模型,相关系数R2大于0.9990。动力学实验还表明两种羟基磷灰石吸附氟离子的模型也符合韦伯和莫里斯模型。表明吸附过程可表述为吸附剂表面吸附和孔道缓慢扩散两个吸附过程。吸附剂表面吸附在第一阶段显示出较快的吸附速率,这可能归因于此过程为氟离子从溶液里扩散到羟基磷灰石表面引起羟基磷灰石的表面吸附,且其拟合直线均不经过原点,说明内扩散不是控制吸附过程的唯一步骤。而在孔道缓慢扩散吸附过程中,吸附速率有所下降,这可能归因于氟离子进入羟基磷灰石表面后在羟基磷灰石内部孔道的缓慢扩散。可见传统化学合成法制备得到的羟基磷灰石在第一阶段的速率要高于溶胶-凝胶法制备的羟基磷灰石,这与化学合成法得到的羟基磷灰石颗粒比表面积比较大,吸附效率较高有关；而在第二阶段,溶胶凝胶法制备的羟基磷灰石的速率要略高于传统化学合成法制备得到的羟基磷灰石,这可能是由于溶胶-凝胶法制备的棒状羟基磷灰石,其空隙大小要大于传统化学合成法制备得到的片状的羟基磷灰石。
[Abstract]:As an indispensable component of the organism, hydroxyapatite is about sixty percent of the inorganic components of the bone, and it shows better biocompatibility and bioactivity. In the past ten years, researchers have become more and more interested in the synthesis of hydroxyapatite, and a large number of hydroxyapatite synthetic routes have been developed. The properties of hydroxyapatite particles prepared by the same method are different. For example, dry synthesis, wet synthesis, and thermal decomposition can produce fine crystalline particles. This subject uses the traditional chemical precipitation method and sol-gel method to synthesize hydroxyapatite, which is used to remove fluorine ions in water solution, and reports different synthetic sides. The hydroxyapatite with different morphologies was prepared by the method, and the effect on Defluoridation was significantly different. It showed that the different synthesis methods of hydroxyapatite had an influence on the adsorption of fluorine ions. The results showed that the adsorption amount of hydroxyapatite prepared by chemical synthesis method was 1.99mg/g at 25. The hydroxyapatite obtained from the precipitation method is mainly round, and the size distribution is more uniform, and the average diameter is fifty nanometers in the solution. The X ray diffraction analysis shows that the atlas is more consistent with the standard hydroxyapatite map, and the adsorption amount of hydroxyapatite prepared by the sol-gel method is 1.75mg/g. Transmission electron microscope analysis showed that the hydroxyapatite obtained by the sol-gel method mainly showed pole shape, the size distribution was more uniform, the length of the rod was 2 m-20 mu m, and the width was about 50nm. In addition, the X ray diffraction analysis showed that its atlas was consistent with the standard hydroxyapatite atlas. Comprehensive analysis, from transmission electron microscopy, two The sample images obtained by the method of synthesis are different, the chemical precipitation method is made of round flakes, the sol-gel is rod like, and the sample obtained by the transmission electron microscope is more fine. In addition, the X ray diffraction analysis also shows that the sol-gel method is more fine and relatively strong, indicating the structure of the crystal is more. In addition, the relationship between adsorption and time of hydroxyapatite in fluoride ion solution prepared by different synthetic methods was further studied. The results showed that the adsorption kinetic curves of the two synthetic methods were in accordance with the first order equation of Langmuir, but the calculated adsorption amount of fluorine ions was not compatible with the actual conditions. Therefore, it does not conform to the Langmuir first order kinetic equation. However, it is found that the two synthetic methods conform to the Langmuir quasi two stage reaction model, the correlation coefficient R2 is greater than the 0.9990. kinetic experiment, and the model of the two hydroxyapatite adsorbing fluorine ions also conforms to the Webb and the Maurice model. The two adsorption processes of the channel are slowly diffused. The adsorbent surface is adsorbed in the first stage and shows a faster adsorption rate, which may be attributed to the surface adsorption of hydroxyapatite from the diffusion of fluorine ions from the solution to the hydroxyapatite surface, and the fitting lines are all without the origin, indicating that the internal diffusion is not the control of the adsorption process. In the process of slow diffusion adsorption, the adsorption rate decreased, which may be attributed to the slow diffusion of fluorine ions in the hydroxyapatite inner pore after entering the hydroxyapatite surface. It is obvious that the rate of hydroxyapatite prepared by the traditional chemical synthesis method is higher than that prepared by the sol-gel method. Hydroxyapatite, the hydroxyapatite particles obtained from the chemical synthesis method are larger than the surface area of the hydroxyapatite, and the adsorption efficiency is higher. In the second stage, the rate of hydroxyapatite prepared by the sol-gel method is slightly higher than that of the hydroxyapatite prepared by the traditional chemical synthesis method, which may be due to the sol-gel method of the rod like hydroxyapatite prepared by the sol-gel method. The porosity of apatite is larger than that of traditional hydroxyapatite prepared by chemical synthesis.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ132.32

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