隔膜电沉积法制备片状氢氧化镁及其影响因素

Preparation of Flake-Like Magnesium Hydroxide by Diaphragm Electrodeposition Method and Its Influence Factors

以氯化镁为原料,采用隔膜电沉积法制备了片状氢氧化镁.考察了氯化镁浓度、反应温度、电流密度对氢氧化镁形貌及颗粒粒径的影响.采用SEM和激光粒度分布仪对产物氢氧化镁的形貌和颗粒粒径大小进行了表征.结果表明,该法获得的产物沉降快且易分离;电解质浓度增加,片状形貌更大且更厚,颗粒粒径变大;反应温度升高,导致片状形貌缺陷增大,团聚更严重,颗粒粒径先减小后增大;电流密度增强,造成片状特性变差,最终出现枝状形貌,颗粒粒径减小.对样品进行BET检测,发现合成样品中比表面积最大可达82.36 m2/g,对甲基紫的吸附量可达1 256 mg/g.

Flake-like magnesium hydroxide was prepared by the diaphragm electrodeposition method using magnesium chloride hexahydrate （MgC^ - 6H20） as raw material. The effects of processing parameters, such as the concentration of Mg2＋, reaction temperature and the electric current density,on the morphology and particle size of magnesium hydroxide were investigated. The morphology and particle size of the produced magnesium hydroxide （ Mg （OH） 2） particles were characterized by scanning electron microscopy （ SEM） and laser particles distribution instrument, respectively. The results indicate that the products from this method have higher rate of settlement and easily segregates. When the initial concentration of Mg2＋ increases,the particle size increases and the flaky morphology is bigger and thicker. With the increasing reaction temperature,the flaky morphology defects become greater and particle agglomeration is more serious, while the particle size decreases firstly and then increases. As the current density increases,the particle size decreases. Meanwhile,the flake features are degraded and eventually dendritic morphology appears. The specific surface area of these samples can be detected by the brunauer emmett teller （BET） method with a maximum value of 82. 36 m2/g and its adsorption capacity of methyl violet （MV） can reach 1 256 mg/g.