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以异丙醇铝为原料,用聚乙二醇(PEG1000)络合溶胶-凝胶法合成了Al2O3纳米晶,并采用差热-热重分析、X射线衍射、透射电子显微镜等对络合前驱体及粉体进行表征;探讨了PEG1000及煅烧温度对纳米Al2O3相结构、粒子尺寸、形貌及分散性的影响规律。结果表明:PEG1000增强了纳米Al2O3粒子的分散性。干凝胶在600～900℃煅烧后得到γ-Al2O3相;在600℃煅烧条件下,得到γ-Al2O3粒子形貌为针状结构,长度约为50～60nm;随着煅烧温度的升高,γ-Al2O3针状粒子长度逐渐减小,在750℃煅烧后,得到γ-Al2O3粒子长度为20～30nm;在900℃煅烧条件下,γ-Al2O3粒子形貌为颗粒状,平均粒径尺寸为10nm;当干凝胶在1000℃煅烧后得到θ-Al2O3和α-Al2O3的混合相,所得粒子平均粒径尺寸为20nm;当干凝胶在1200℃煅烧后,得到的Al2O3全部转化α-Al2O3相,制得的纳米Al2O3粒子尺寸均一且分散性良好。
Al 2 O 3 nanocrystals were synthesized by PEG1000 complex sol-gel method using aluminum isopropoxide as raw material. The effects of complex precursors The effects of PEG1000 and calcination temperature on the phase structure, particle size, morphology and dispersion of nano-Al2O3 were discussed. The results showed that PEG1000 enhanced the dispersibility of nano-Al2O3 particles. After calcined at 600-900 ℃, the γ-Al2O3 phase was obtained. The morphology of γ-Al2O3 particles was acicular structure with a length of about 50-60 nm when calcined at 600 ℃. With the calcination temperature increasing, The length of γ-Al2O3 needle-shaped particles decreases gradually. After calcination at 750 ℃, the length of γ-Al2O3 particles is 20-30nm. The morphology of γ-Al2O3 particles is granular with the average particle size of 10nm. When the xerogel was calcined at 1000 ℃, the mixed phase of θ-Al2O3 and α-Al2O3 was obtained. The average particle size of the obtained particles was 20nm. When the xerogel was calcined at 1200 ℃, Phase, the prepared nano-Al2O3 particles are uniform in size and good dispersibility.