Drop impact on a heated liquid bath: Formation of antibubbles

Abstract

As a ubiquitous phenomenon, drop impact on a liquid bath has been widely studied. This paper demonstrates a systematical study on the collision between the volatile drops and a heated liquid bath. In the experiments, water, alcohol, and hydrogen fluoride ether (HFE-7100) were used to generate drops. The experimental results vary with the impact parameters and liquid properties. Despite the common phenomena, like bouncing and coalescence, antibubble was observed at an intermediate impact velocity with the HFE-7100 drops. A regime map is built based on the experimental results. A qualitative model is proposed to elucidate the stability of the air film separating the impinging droplet and the surrounding liquid during collision. This study should stimulate further investigation on the surfactant-free antibubbles and the control of antibubble lifetime.