纳米氧化镁合成过程中颗粒粒度及形状控制研究

摘要

采用化学沉淀-热分解法,合成粒度在20～120 nm的氧化镁粉体.采用透射电镜及X射线衍射分析,研究纳米氧化镁的粒度和形状的控制因素对纳米氧化镁颗粒形成过程的影响.结果表明:镁源及分散荆的种类、沉淀反应温度、样品干燥方式都是影响氧化镁粒度和形状的重要因素.在以Mg(NO3)2为镁源、n(Mg2+):n(OH-)=2:1、沉淀温度为30℃、体积分数为8%的乙二醇为分散剂、微波低火干燥2 min条件下,得到平均粒径为40 nm的氧化镁产品.前驱物的形状与产物纳米氧化镁的形状存在对应关系.%A chemical precipitation- heat decomposition method was developed for synthesis of MgO nano-particles with diameter of 20～120 nm. XRD and TEM techniques were used to study the composition,morphology and size of the as-prepared MgO nano-particles. The results indicated that the species of magnesia compounds and organic reagents,precipitation temperature way played the key roles on the size and shape of MgO nano-particles. At the condition of adding Mg(NO3)2 into the solution of NaOH with 8％ (volume fraction) ethanediol which the molar ratio of Mg2+ and OH- was 1: 2, the precipitation temperature was 30 ℃, the time of microwave lowfire dehydration was 2 min, the average size 40 nm of MgO particles with sphere shape was prepared. There was a corresponding relation between the shape of the precursor Mg(OH)2 and the shape of MgO nano-particles.