Abstract:

MgO nanoparticles were prepared by using a direct deposition method, in which, the precursor, alkaline magnesium carbonate/paraffin, was firstly obtained by direct precipitation of the mixture of MgCl₂·6H₂O and Na₂CO₃ in paraffin emulsion, and then calcined at 600℃. The nanoparticles were characterized by using TG-DTA, FTIR, XRD, BET and FESEM. Under the optimum conditions, the as-prepared MgO nanoparticles were hexagonal crystals with a uniform size of around 60 nm and a specific surface area of 132.54 m²·g^-1. The optimum preparation conditions were: MgCl₂·6H₂O concentration, 0.6 mol·L^-1; Na₂CO₃ concentration, 0.6 mol·L^-1; reaction time, 0.5 h; calcination temperature, 600℃, and calcination time, 3 h.

Key words: MgO, emulsion system, nanoparticles, precipitation, paraffin

摘要：

MgCl₂·6H₂O和Na₂CO₃在石蜡乳液中直接沉淀出碱式碳酸镁/石蜡前驱体,该前驱体在600℃条件下焙烧后获得MgO纳米粉体。采用TG-DTA、FTIR、XRD、BET和FESEM等手段对MgO粉体进行表征分析,并研究焙烧温度和物料比对纳米MgO的粒径及形貌的影响。结果表明,在最佳工艺条件下,石蜡乳液体系中能够得到分散性好、晶粒呈六边形、颗粒均匀、平均粒径约60 nm和比表面积132.54 m²·g^-1的纳米MgO。其最佳工艺条件为:MgCl₂·6H₂O溶液浓度0.6 mol·L^-1、Na₂CO₃溶液浓度0.6 mol·L^-1、反应时间0.5 h、焙烧温度600℃和焙烧时间3 h。

关键词: MgO, 乳液体系, 纳米粒子, 沉淀法, 石蜡