滴体积法测液-液界面张力

采用一套简易的界面张力测试装置，研究了用滴体积法测液一液界面张力时，对毛细管滴头内径和外径选取的原则。实验表明，当毛细管内液相不能润湿滴头端面时，在Tate公式中应采用毛细管内径进行计算，实际悬滴半径等于滴头内半径。当毛细管内液相能润湿滴头端面时，对任何待测体系均存在一个适用的滴头外径范围，应采用毛细管外径进行计算。只有所选滴头外径在此范围内，才能保证水、有机液体与玻璃间三相线稳定在滴头的外周线上。否则会使滴头外半径与实际悬滴半径不等，给测量结果造成严重偏差。

Drop Volume Technique Measuring Interfacial Tension Between Two Liquids

By using a simple set of drop volume apparatus, the authors systematically studied the selection principle for the inner and external radius of the capillary tubes in measurement of the interfacial tension between two liquids. When the dropping tip is not be wetted by the liquid in the capillary tube,the capillary inner radius should be used in the Tate equation;Otherwise the external radius of the capillary tube should be applied in the equation. The difference between the capillary external radius and the spreading radius of drop is the basic reason why the liquid-liquid interfacial tension could not be exactly measured by the drop volume method.