【摘要】 采用H2 O2 沉淀铝酸钠溶液和乙醇分散并洗涤沉淀相结合的方式成功地制备出了大孔容纳米γ Al2 O3 纤维 .运用XRD、FT IR、TG DSC、TEM、BET和压汞法对比研究了水洗和乙醇分散并洗涤两种沉淀处理方式对产物结构、形貌和织构性质的影响 结果表明 ,乙醇洗涤产物γ Al2 O3 纤维的直径约为 10nm ,长度约在 10 0nm以上 ,孔容和比表面分别为 2 2 3ml·g-1和 2 2 2 0m2 ·g-1,而水洗γ Al2 O3 的二次粒子无固定形状 ,孔容和比表面仅为 0 37ml·g-1和 16 2 3m2 ·g-1.乙醇洗涤时形成的CH3 CH2 O—基不仅使γ Al2 O3 前驱物拟薄水铝石晶粒定向生长成纤维 ,还阻止了相邻颗粒表面之间因Al—O—Al键形成而产生的硬团聚 .更多还原

【Abstract】 Nanofibrous γ-Al 2O 3 with very large pore volume was successfully prepared by precipitation from H 2O 2 and sodium aluminate solutions combined with dispersing and washing the precipitate with ethanol.The effects of ethanol washing and water washing on structure, morphology and texture properties of pseudoboehmite-calcined γ-Al 2O 3 were comparatively studied with XRD, FT-IR,TG-DSC,TEM,BET and mercury porosimeter.The ethanol-processed γ-Al 2O 3 presented fibrous-like texture about 10 nm thick and over 100 nm long whose pore volume and BET surface area could reach about 2.23 ml·g -1 and 222.0 m2·g -1, respectively.However,the secondary particles of the water-processed γ-Al 2O 3 had no regular shape and its as-mentioned texture properties of pore volume and BET surface were only 0.37 ml·g -1 and 162.3 m2·g -1,respectively. CH 3CH 2O—groups on the surface of ethanol-processed pseudoboehmite particles could not only induce fiber formation through hydrogen bonding between the oxide groups and the surface OH—groups, but also inhibit chemical Al—O—Al bonds formation among the adjacent particles and thus hard agglomerate could be prevented.更多还原