Development of a Precision Tensiometer with Differential Capillary Instability Method

Abstract

無中文摘要

We created a new method, the Differential Capillary Instability Method, to measure the interfacial tension of fluid interfaces by creating two separated interfaces using capillary tubes. The differential nature from separated interfaces of this original design eliminates the need to explicitly define the pressure value at any of the interfaces, which sets a lower demand for the experimental condition. The capillary nature eliminates the need to numerically determine the geometrical profile of the interface. The instability nature of the measuring process allows us to pinpoint the value of interfacial tension with high precision. We’ve measured the surface tension of a few common samples with our Differential Capillary Instability Tensiometer and we compared the results with some published values. The measurement result shows a general consistency with the reported values acquired by other methods in several other researches. Various kinds of conditions have been carried out to test the method with different samples, surface property of capillary tubes, and formation speed of the interface. Some operation principles was concluded to optimize the measurement when applying the Differential Capillary Instability Method.