Experimental Evaluation of Inter facial Segregation between Liquid Alloys and Molten Salt by using Electro-chemical Capillarity

虽然从热力学的角度认识到液态合金与熔盐之间存在界面偏析，但用任何实验方法都不能直接观察到这种现象。这种分离发生在几个原子层内。由于电化学毛细现象对上述很小的原子区域内的物理化学性质的变化非常敏感，因此可以通过电化学毛细现象检测界面偏析。在本工作中，电化学毛细现象的实验装置的制作，然后在液态合金和熔盐之间的界面过量电荷的测量，以确认这两个液相之间的界面偏析。首先，测量了LiCl-KCl熔融体系和Ga-Bi液态合金的电化学毛细管曲线，其中Bi的成分发生了变化。得到了液态Ga-Bi合金中Bi的体成分与界面过剩电荷之间的关系，该关系对应于液态Ga-Bi合金中Bi的体成分与表面偏析之间的关系。因此，从上述实验中发现，液态合金和熔盐之间的界面偏析可以通过电化学毛细作用的测量来评估。

Although the interfacial segregation between liquid alloys and molten salt is recognized from a thermodynamic view point, the phenomenon can not be seen directly by using any experimental method. This segregation occurs within a few atomic layers. Since the electro-chemical capillarity is quite sensitive to the change of the physico-chemical properties in the above very small atomic region, the interfacial segregation might be detected by using the electro-chemical capillarity. In the present work, the experimental apparatus for the electro-chemical capillarity was made, and then the interfacial excess electric charge between liquid alloys and molten salt was measured to confirm the above interfacial segregation between these two liquid phases. First of all, the electro-chemical capillary curves were measured for molten LiCl-KCl systems and liquid Ga-Bi alloys, of which compositions of Bi were changed. Then, the relationship between the interfacial excess electric charge and the bulk composition of Bi in liquid Ga-Bi alloys was obtained, which corresponded to the relation between the surface segregation and the bulk composition of Bi in liquid Ga-Bi alloys. Thus, it was found from the above experiments that the interfacial segregation between liquid alloys and molten salt can be evaluated from the measurement of the electro-chemical capillarity.