Alternative approach for determining interfacial tension at the low values

Cooling the electronic processors or extracting the shale fuels requires the low surface tension substances. Non-traditional approach to modelling the surface tension phenomena applies the closed-form expressions for the drop or bubble shapes, which oversimplifies determining the interfacial tension; this determination is done when the investigated interface is at rest, which satisfies the model assumptions. Isobutanol was chosen for validating the new method at the low interfacial tensions, which was done at the range of 0.3–98.2 °C; the results overlap with the Grabar & Nikitine (1936) outcomes; the regression curve was modelled between the freezing and boiling points of water. The closed-form expression for drop volume is derived from the non-traditional approach. Temperature rise decreases the drop volume; the greater surface tension increases this volume.