Surface tension of very small liquid drops

There has been much debate in the literature on the surface tension of very small liquid drops. It would be useful to have a simple analytical model to better understand and predict any changes that occur at the nanoscopic scale. In this work, it is hypothesized that density variation at the interface of liquids due to curvature causes surface tension to deviate from bulk values. Equations were derived to predict that variation in terms of the diameters of the drop and its constituent atoms and molecules. Surface tension is expected to decrease exponentially for drops that have diameters less than a few nanometers and/or that contain less than several thousand atoms or molecules. These findings agree with those from earlier simulation and experimental studies.

Automated summary

This study discusses the surface tension of very small liquid drops and proposes a simple analytical model to predict the changes at the nanoscopic scale. The study finds that the surface tension decreases exponentially for drops with diameters less than a few nanometers and/or containing less than several thousand atoms or molecules. These findings align with earlier simulation and experimental studies.