Attraction of sessile pure droplets evaporating into air

Two pure droplets of the same perfectly wetting volatile liquid are seen to attract when deposited nearby on a flat horizontal substrate in the ambient atmosphere. The phenomenon is studied in detail using interferometry for a number of liquids. Possible driving factors behind the interaction, acting through the gas phase and the substrate are being investigated both experimentally and theoretically. To predict the velocity of attraction, a model will be presented and verified against the experimental data obtained in this work. The influence of the initial distance between the drops, and the physical properties of vapor, liquid, and solid will be investigated.