电导法研究过饱和铝酸钠溶液均相成核过程

采用自行研制电导在线跟踪仪, 配套特制的传感器式电导电极, 研究铝酸钠溶液均相成核过程中溶液电导变化规律, 及溶液过饱和度对反应诱导期作用; 通过测定铝酸钠溶液均相成核过程诱导期, 结合溶液均相成核理论, 测得323 K下, 饱和度S>3.8的铝酸钠溶液均相成核过程中的表观反应级数n=4±1, 固-液界面能γ=(40.6±2.0) mJ·m-2, 并据此估算临界成核粒径rc=(1.1±0.2) nm. 研究结果与文献值吻合, 证明该套仪器具有较高的灵敏度和可靠性.

Investigation of the Homogeneous Nucleation of Al(OH)3 Crystals from Supersaturated Sodium Aluminate Solution by Conductance Probe

This paper presents the application of a novel conductance detector together with a self-made conductance probe, for studying the homogeneous nucleation of Al(OH)3 from supersaturated sodium aluminate solution under isothermal, batch crystallization conditions. The effects of supersaturation on indication period were examined. The nucleation kinetics showed a (4±1)-order dependence upon Al2O3 relative supersaturation and an interfacial energy of (40.6±2.0) mJ·m-2, which were used to predict the critical nucleus size of (1.1±0.2) nm at 323 K, S>3.8. These results were consistent with those in literatures, indicating the satisfactory reliability and sensitivity of the apparatus.