ANALYSIS OF WATER DROPLET FLOATING BEHAVIOR AT THE OIL-WATER INTERFACE

This paper investigates the anomalous phenomenon of water droplets floating at the water-oil interface. Control experiments confirmed the droplet composition as water rather than air. A static equilibrium model was established by combining the three-interface tension balance and the Young-Laplace equation. Dimensionless analysis was performed using characteristic parameters such as capillary length, equivalent radius, and Bond number. The contact angle was solved through a multi-stage optimization strategy, yielding a theoretical value. Experimental measurements were conducted using a Dataphysics OCA 25 video optical contact angle measuring instrument. The average measured contact angle deviated from the theoretical value within the allowable experimental error range, thereby validating the accuracy and reliability of the established model. The study reveals that this phenomenon is dominated by surface tension, with droplet stability influenced by size (smaller droplets exhibit higher stability). This finding challenges classical energy analysis and offers new insights for interfacial tension research and industrial applications (e.g., oil-water separation).