Synthesis of α-Al_2O_3 Nanopowder

[中文文摘]以AlCl_3·6H_2O为原料,用溶胶—凝胶法制备出Al(OH))3凝胶,反复多次冷冻离心脱水,1180℃煅烧得到纳米级α-Al_2O_3,用x射线粉末衍射(XRD)、透射电镜(TEM)、比表面测定(BET)对产品进行表征,证明产品直径为93nm,并讨论了其原理。[英文文摘]α-Al_2O_3 nanopowder was synthesized by baking the colloid of A1(OH)_3 at 1180℃ after it dehydrated by means of multi-freeze and centrifugal. Using A1_2O_3·6H_2O as raw materials, colloid of Al (OH)_3 was prepared by colloidal chemistry method. The structure and characteristic of the powder were studied by means of XRD, BET and TEM, it was revealed that the average size of α-Al_2O_3 is about 90nm. The formation mechanism of colloid was discussed

Preparation and Characterization of MgO Nanopowder

[中文文摘]以六水合硝酸镁为原料 ,以尿素分解产物为沉淀剂 ,以乙醇为反应介质 ,制备出氢氧化镁凝胶 ,反复冷冻 -离心干燥 ,在 773K下焙烧 ,制得氧化镁粉体 .经 XRD、BET、TEM表征 ,所获的氢氧化镁团聚程度小 ,平均粒度为 2 6nm,属于立方晶系 .对结果进行了讨论.[英文文摘]Magnesium oxide nanopowder was prepared by firing the gel of Mg(OH)_2 at 773 K after being dehydrated by means of multi-freeze and centrifugal, using Mg(NO_3)_2·6H_2O as a raw material, a product of carbamide decomposition as a precipitating agent and alcohol as a reaction media. The crystal structure and characteristics of the powder were studied employing XRD, BET and TEM. The results revealed that the crystalline was belong to cubic system and the meanparticle size was 26 nm. The formation mechanism of the nanopowder is discussed