冷冻干燥法——水溶液合成无机物新法之一

One of the new processes for inorganic synthesis in aqueous solution——freezing-drying process

冷冻干燥法是以可溶性盐为原料,配制成水溶液,经喷雾,冷冻,在减压条件下加热使冰升华,形成无水盐,再加热分解得氧化物或复合氧化物微粉末的方法。用该法制备的上述粉末具有粒径小、粒度和组成均匀、纯度高、比表面积大等优点。本文主要介绍冷冻干燥法的原理、实验条件、特点及其在无机合成中的应用。

Freezing-drying process is a method for preparation of micropowder of oxides or co-oXides. The process uses soluble salt as raw material to prepare aqueous solution according to set formulation. The solution then goes through steps of spraying and freezing. Under depressurization heat is provided to make ice sublimate and a dehydrated salt is formed subsequently. Heat is again provided to obtain the micropowder of oxides or co-oxides through decomposition roaction. The powder thus obtained is characterized by small particle size, uniformity of particle size and particle formation, bigh purity and large surface area. This article describes mainly the principles of freezing-drying process, experiment conditions, characteristics and its application in inorganic synthesis.