【摘要】： 摘要：Al2O3材料具有高強(qiáng)度、高硬度、抗腐蝕、耐高溫、抗氧化性等特性,A1203粉體是制備催化劑及其載體、牙科材料、特種陶瓷的重要原料。多孔A1203球形顆粒不僅可以作為優(yōu)良的催化劑及其載體,應(yīng)用于藥物緩釋／控釋制劑,又因?yàn)轭w粒為多孔結(jié)構(gòu),可以節(jié)省原材料,降低生產(chǎn)成本；此外,由于A1203顆粒為球形,其流動性和成型性好,這樣制出的塊體具有良好的致密性。本論文首次采用一種新穎的準(zhǔn)氣相反應(yīng)法,制備出新穎的具有多孔結(jié)構(gòu)的氧化鋁球形顆粒。 首先,以氯化鋁溶液和高純氨氣為原料,合成多孔氧化鋁前驅(qū)物球形顆粒,研究了AlC13溶液濃度、系統(tǒng)真空度、NH3氣流量等因素對前驅(qū)物顆粒形貌、大小和顯微結(jié)構(gòu)的影響,獲得了較佳的合成工藝條件：AICl3溶液濃度為25wt%、系統(tǒng)真空度為-0.01MPa、NH3氣流量為50L／H。在較佳的合成工藝下,合成出的多孔氧化鋁前驅(qū)物顆粒的平均粒徑為6.705μm,標(biāo)準(zhǔn)偏差3.224μm,球形度良好,顯微結(jié)構(gòu)為實(shí)心結(jié)構(gòu)和空心結(jié)構(gòu)兩種。 其次,探討了多孔氧化鋁前驅(qū)物球的干燥制度和煅燒制度。研究了烘箱干燥、室溫干燥和微波干燥三種干燥方式對前驅(qū)物球性能的影響，，并研究了500℃、800℃、1000℃和1200℃煅燒溫度下對氧化鋁球性能的影響。研究表明：在較佳的合成條件下合成出的氧化鋁前驅(qū)物球,經(jīng)過微波“低火”干燥12min,1200℃煅燒2h后,得到的多孔氧化鋁球的平均粒徑為2.68μm,形貌為球形,晶型為單斜結(jié)構(gòu)的α-Al2O3。 最后,研究了在準(zhǔn)氣相反應(yīng)合成過程中的收集瓶內(nèi)和干燥過程中對團(tuán)聚狀態(tài)的控制,分別加入不同分子量、不同含量的聚乙二醇對顆粒團(tuán)聚狀態(tài)的影響。結(jié)果表明：在收集瓶中和干燥過程中,分別加入質(zhì)量分?jǐn)?shù)為1.0%的聚乙二醇6000可以有效地控制團(tuán)聚的發(fā)生。 因此,通過本課題的研究,采用準(zhǔn)氣相反應(yīng)法能夠制備出多孔氧化鋁球形顆粒,其較佳工藝條件為：AICl3溶液濃度為25wt%、系統(tǒng)真空度為-0.01MPa、NH3氣流量為50L／H,微波“低火”干燥12min,1200℃煅燒2h。制備出的多孔氧化鋁顆粒的平均粒徑為2.68μm,形貌為球形,分散性好,其晶型為單斜結(jié)構(gòu)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

本文編號：2235958