溶剂性质对合成纳米层状双金属氢氧化物的影响研究

Effects of properties of solvents on the synthesis of nano-layered double-metal hydroxides

采用恒定pH一步反应液相法,制备纳米层状双金属氢氧化物(简称LDH)粉体。以水、10%(质量分数)乙醇溶液为溶剂,在不同pH条件下制备样品,2%(质量分数)聚乙烯醇作分散剂制备纳米层状双金属氢氧化物。用XRD,TEM,DTA分别对样品的物相、形貌、粒径和热行为进行分析与表征。结果表明,以10%乙醇溶液为溶剂,在pH>12.5条件下,可制备纯度>98%的单晶纳米粉体,采用聚乙烯醇作分散剂可以制备类球形的纳米层状双金属氢氧化物,且分散性好,尺寸约20nm。

Powder of nano-layered double-metal hydroxide （ LDH ） was prepeared by one step liquid phase reaction under constant pH. Under different pH, adapting 2% （mass fraction） polyvinyl ethanol as dispersant, using water and 10% （ mass fraction ） alcohol solution as solvents to prepare different nano - LDH samples respectively. Using XRD, TEM, and DTA to characterize and analyze the samples＇phase, morphology, grain size, and thermal action. Results showed, under the conditions of 10% alcohol as solvent and pH higher than 12.5 ,nano-sized monocrystals with purity more than 98% can be obtained. Using polyvinyl alcohol as dispersant, spherical nano - LDH with good dispersibility and with the size of about 20 nm can be preoared.