Optimized and Refined Apparatus for Measuring Surface Tension with the Bubble-Pressure Method

摘要

A modified apparatus for measuring surface tension with the bubble-pressure method is proposed. Compared with a traditional instrument, this apparatus improved the accuracy of maximum pressure difference measurement and achieved the hydrostatic pressure correction. The apparatus was employed to determine the surface tension values of distilled water and ethanol, respectively, at different temperatures. Additionally, the cross-sectional area of the ethanol molecule was obtained from the surface tension of ethanol solutions with different concentrations and Gibbs adsorption. It was found that all measured values were in accordance with literature data. Thus, the improved device exhibited excellent accuracy and reliability. Furthermore, all of the instrumental components were assembled into one body, making it easy for undergraduate students to operate.