【作者】 邱杨；

【导师】 夏海平；

【作者基本信息】 宁波大学 ， 通信与信息系统， 2009， 硕士

【摘要】 本文用超声喷雾技术进行了常温常压下制备HAP（羟基磷灰石）纳米粉体和稀土离子掺杂的YAG（钇铝石榴石）纳米荧光粉的研究和探索,研究了化学反应时间与烧结温度对HAP的结晶度和颗粒均匀性的影响规律,并探讨了在制备工艺过程中添加不同表面活性剂对制备的HAP纳米粉体的分散性能、颗粒大小、均匀性及形貌等的影响情况;详细地研究了稀土离子掺杂的YAG纳米荧光粉的结构、物相组成、颗粒形貌以及不同掺杂浓度纳米荧光粉的发射光谱和激发光谱。主要成果和进展如下:（1）在常温常压下,以Ca（NO₃）₂·4H₂O和（NH₄）₂HPO₄为原料制备了HAP纳米粉体,获得了颗粒度为30⁴0 nm的均匀HAP粉体。研究了化学反应时间与烧结温度对HAP的结晶度和颗粒均匀性的影响规律。与传统的超声化学法和化学沉淀法制得的HAP粉体样品比较,发现此法可以在较短的反应时间内制备出纳米HAP,显著提高HAP的合成效率、结晶度,且获得的颗粒度相对均匀。（2）探讨了在超声喷雾法制备工艺过程中添加柠檬酸、甘氨酸、葡萄糖和TX-10四种表面活性剂对制备的HAP纳米粉体的分散性能、颗粒大小、均匀性及形貌等的影响情况。表面活性剂的加入对粉体的产物相没有影响,但对制备出的纳米HAP粉体的分散效果均有一定的影响。从SEM照片看出,在本反应体系中当甘氨酸适量加入时,对纳米HAP粉体能起到很好的分散作用,有利于颗粒的细化与均匀;而等量柠檬酸的加入反而加剧了纳米HAP颗粒的团聚;葡萄糖与TX-10的加入则使颗粒度变大,并易造成局部团聚。（3）将Al（NO₃）₃、Y（NO₃）₃和Ce（NO₃）₃的混合溶液作为母盐溶液,以NH₄HCO₃与NH₃·H₂O的混合溶液为复合沉淀剂,应用新型的超声喷雾技术,把母盐溶液加入到复合沉淀剂中,获得的前驱体沉淀物经过一定温度煅烧,制得YAG:Ce纳米荧光粉。详细地研究了粉体的结构、物相组成、颗粒形貌以及不同掺杂浓度纳米荧光粉体的发射光谱和激发光谱。此法制得的YAG:Ce荧光粉体呈现均匀的、分散的、尺寸为50⁷0 nm的纳米颗粒,与共沉淀法法相比,明显地改善了粉体的颗粒度与分散性。当Ce掺杂浓度达6⁷ mol%时,荧光强度达到最大,其浓度猝灭效应明显高于共沉淀法所报道的4.8 mol%,可望实现YAG基荧光材料的高浓度掺杂与高发光效率。（4）以NH₄HCO₃与NH₃·H₂O的混合溶液为沉淀剂,用超声喷雾共沉淀法结合后续不同温度煅烧制备了纳米YAG:Eu荧光粉。对粉体的结构、物相组成、颗粒形貌以及不同铕掺杂浓度的发射光谱和激发光谱进行了研究。此法与溶胶-凝胶法和共沉淀法等技术制备的颗粒大小和均匀性相比,显示出一定的优势。同时研究还表明,烧结温度对YAG:Eu荧光粉的析晶有重要影响,随着烧结温度的升高,衍射峰逐渐变窄,衍射强度增大,有利于促进YAG相的生成。更多还原

【Abstract】 In this paper, a novel metod named ultrasonic atomization precipitation method was employed to synthesize the HAP nanopowders and YAG phosphor powders at room temperature and normal atmospheric pressure. The effects of the reaction time, the sintering temperature on the crystal morphology of HAP and homogeneity were investigated and the effect of the different surfactants on the synthesis and characteristic of HAP was discussed. Moreover, the influence of the rare earth doping concentration on the luminescence and excitation spectra of the as-prepared powders was studied. The results and development are as follows:1. At room temperature and normal atmospheric pressure, the hydroxyapatite nano-powders were prepared by ultrasonic atomization precipitation method and with Ca（NO₃）₂·4H₂O and （NH₄）₂HPO₄ as raw materials. The obtained powders were homogenous and in size of 30⁴0 nm. The effects of the reaction time, the sintering temperature on the crystal morphology of HAP and homogeneity were investigated. The obtained HAP powders were compared with those synthesized by the conventional ultrasonic method and traditional chemical precipitation method under the same conditions. The results revealed that the method taken in the experiment can shorten reaction time to make HAP nano-powders, enhance the synthetic efficiency effectively and crystallinity of HAP nanopowders in a relatively short reaction period, moreover, the obtained nano-particles were more homogenous.2. In the normal temperature and pressure, nano-hydroxyapatite was synthesized by ultrasonic atomization process with Ca（NO₃）₂·4H₂O and （NH₄）₂HPO₄ as the calcium and phosphorus precursors respectively. The effect of four different surfactants on the synthesis and characteristic of hydroxyapatite （HAP） was discussed. The phase of the samples with addition of the same quantity surfactant have no significant change showed in the XRD patterns, therefore, we can consider that the surfactant presence or absence did not to have an affect on crystallization. Scanning electron microphotographs shows that the different additives affect the size and morphology of HAP nanoparticles. The glycine had a positive effect on promoting homogeneity and separation of HAP nanoparticle, and the D-Glucose and TX-10 shows little effect on HAP morphology, whereas Citric acid induced into heavy degree of particle agglomeration. The Author was explored and explained the effect of four different surfactants on the synthesis and characteristic of hydroxyapatite （HAP） from the basic principles of physical chemistry. These results will be provided an effective means of technology to synthesized nano-hydroxyapatite and other ultrafine powders.3. The Y（NO₃）₃, Al（NO₃）₃ and Ce（NO₃）₃ mixed solution was transferred into the NH₄HCO₃ and NH₃·H₂O mixed solution via the ultrasonic atomizer,then the powder was calcined at different temperature. Finally, the homogenous and separate YAG:Ce powders in size of 50-70 nm were obtained. X-ray diffraction, Scanning electron microscopy were used to characterize the phase and morphology of the obtained phosphor powders. The influence of Ce concentration on the luminescence and excitation spectra of the as-prepared powders was studied. The results showed that the ultrasonic atomization and co-precipitation method for preparation of YAG:Ce nano-phosphor have advantages of traditional one in homogeneity and separation of nano-powders. The emission intensity of YAG:Ce reached to the maximum as the Ce-doping concentration to 6-7 mol%. The concentration quenching was obviously higher than that prepared by co-precipitation method, which was only 4.8 mol%. The present studies show that ultrasonic atomization and co-precipitation precipitation method is a promising approach to obtain homogenous YAG:Ce phosphor powders. This method can be employed as a new route for synthesizing analogous phosphor materials.4. Eu-doped Y3Al5O12 （YAG:Eu） phosphor ultrafine powders were synthesized by the Ultrasonic atomization and Co-precipitationmethod using the mixture solution of ammonium hydroxide（NH₃·H₂O） and ammonium hydrogen carbonate（NH₄HCO₃） as precipitant.Fluorescence spectrometer、X-ray diffraction、Scanning electron microscopy were used to characterize the phosphor powders and the influence of Eu concentration on the luminescence of the as-prepared powders was studied.The obtained powders were homogenous and in size of 50⁷0 nm, and were compared with those synthesized by the sol-gel method and other method shows some advantages.When the calcination temperature was increased, the width of the diffraction peaks decreased and the intensity increased.更多还原