准气相反应法制备多孔氧化铝球形颗粒

发布时间：2018-09-11 07:04

【摘要】： 摘要：Al2O3材料具有高强度、高硬度、抗腐蚀、耐高温、抗氧化性等特性,A1203粉体是制备催化剂及其载体、牙科材料、特种陶瓷的重要原料。多孔A1203球形颗粒不仅可以作为优良的催化剂及其载体,应用于药物缓释／控释制剂,又因为颗粒为多孔结构,可以节省原材料,降低生产成本；此外,由于A1203颗粒为球形,其流动性和成型性好,这样制出的块体具有良好的致密性。本论文首次采用一种新颖的准气相反应法,制备出新颖的具有多孔结构的氧化铝球形颗粒。 首先,以氯化铝溶液和高纯氨气为原料,合成多孔氧化铝前驱物球形颗粒,研究了AlC13溶液浓度、系统真空度、NH3气流量等因素对前驱物颗粒形貌、大小和显微结构的影响,获得了较佳的合成工艺条件：AICl3溶液浓度为25wt%、系统真空度为-0.01MPa、NH3气流量为50L／H。在较佳的合成工艺下,合成出的多孔氧化铝前驱物颗粒的平均粒径为6.705μm,标准偏差3.224μm,球形度良好,显微结构为实心结构和空心结构两种。 其次,探讨了多孔氧化铝前驱物球的干燥制度和煅烧制度。研究了烘箱干燥、室温干燥和微波干燥三种干燥方式对前驱物球性能的影响，，并研究了500℃、800℃、1000℃和1200℃煅烧温度下对氧化铝球性能的影响。研究表明：在较佳的合成条件下合成出的氧化铝前驱物球,经过微波“低火”干燥12min,1200℃煅烧2h后,得到的多孔氧化铝球的平均粒径为2.68μm,形貌为球形,晶型为单斜结构的α-Al2O3。 最后,研究了在准气相反应合成过程中的收集瓶内和干燥过程中对团聚状态的控制,分别加入不同分子量、不同含量的聚乙二醇对颗粒团聚状态的影响。结果表明：在收集瓶中和干燥过程中,分别加入质量分数为1.0%的聚乙二醇6000可以有效地控制团聚的发生。 因此,通过本课题的研究,采用准气相反应法能够制备出多孔氧化铝球形颗粒,其较佳工艺条件为：AICl3溶液浓度为25wt%、系统真空度为-0.01MPa、NH3气流量为50L／H,微波“低火”干燥12min,1200℃煅烧2h。制备出的多孔氧化铝颗粒的平均粒径为2.68μm,形貌为球形,分散性好,其晶型为单斜结构的α-Al2O3。
[Abstract]:A1203 powder with high strength, high hardness, corrosion resistance, high temperature resistance and oxidation resistance is an important raw material for the preparation of catalyst and its carrier, dental materials and special ceramics. Porous A1203 spherical particles can be used not only as a good catalyst and their support for drug delivery / controlled release preparations, but also because the particles are porous, which can save raw materials and reduce production costs, in addition, because A1203 particles are spherical, Its fluidity and formability are good, so the produced block has good compactness. In this paper, a novel quasi-gaseous phase reaction method was used to prepare new spherical alumina particles with porous structure for the first time. Firstly, the spherical particles of porous alumina precursor were synthesized from aluminum chloride solution and high purity ammonia gas. The effects of concentration of AlC13 solution, vacuum degree of system and flow rate of NH _ 3 gas on the morphology, size and microstructure of the precursor were studied. The optimum synthetic conditions were obtained: the concentration of the solution of: AICl3 was 25 wt.The vacuum degree of the system was -0.01 MPA (NH3) and the flow rate of NH3 was 50 L / H. Under the better synthesis technology, the average particle size of porous alumina precursor is 6.705 渭 m, the standard deviation is 3.224 渭 m, the sphericity is good, and the microstructure is solid structure and hollow structure. Secondly, the drying system and calcination system of porous alumina precursor ball were discussed. The effects of oven drying, room temperature drying and microwave drying on the properties of the precursor spheres were studied. The effects of the calcination temperature of 500 鈩

本文编号：2235958