纳米氢氧化铜的均匀沉淀法制备及低温热容

Preparation of Cu(OH)_2 nanometric powders by homogeneous precipitation and their low temperature heat capacity

使用氨水溶解硫酸铜 ,加入氢氧化钡沉淀分离硫酸根 ,所得铜氨清液加热蒸氨得氢氧化铜超细沉淀 .沉淀分别用氨水和无水乙醇洗涤 ,6 0℃干燥 ,放置干燥器中至恒重 .XRD、TEM、ICP测定表明 ,其平均粒径尺寸为 45nm ,粒度分布范围窄 ,纯度高 .用高精密全自动量热仪在 78～ 370K温区测定了热容 ,拟合出热容随温度变化的多项式方程 。

The Cu(OH) 2 nanometric powders were prepared by a new method of homogeneous precipitation. The CuSO 4 was dissolved in ammonia and the SO 2- 4 was removed by adding Ba(OH) 2. The filtrate was heated to remove ammonia and the Cu(OH) 2 was homogeneously deposited. The deposition was washed by ammonia and ethanol, and the product was dried at 60 ℃, and then put in a desiccator to keep constant weight. The gained powders were examined by XRD, TEM and ICP techniques and the results show that the grain size of Cu(OH) 2 nanometric powders is 45 nm in average within a narrow distribution range, and the powders are highly purified. The heat capacity of the powders was measured in the temperature range of 78～370 K, and the polynomial equations expressing the change of heat capacity with temperature was fitted. The ammonia leach techniques and thermodynamic properties were discussed.