Two modes of contact‐time reduction in the impact of particle‐coated droplets on superhydrophobic surfaces

Abstract

Abstract Reducing the contact time during droplet impact is essential for many scientific and industrial applications, such as self‐cleaning, anti‐icing, heat transfer, and condensation. This paper reports contact‐time reduction by coating droplets with micro–nano hydrophobic particles. Such particle‐coated droplets are known as liquid marbles (LM). LM impact on superhydrophobic surfaces reveals two different modes of contact‐time reduction. For lower impact energies, the reduced adhesion of LM with the surface is responsible for a reduction of up to 21%. Contact‐time reduction in this regime is found to be independent of particle size but dependent on the solid fraction of LM. However, a fragmentation‐based contact‐time reduction is observed for larger particle sizes and higher impact energies. Here, the reduction is as high as 65%. Such fragmentation occurs because the spreading LM lamella breaks when its thickness becomes similar to particle dimensions. Our findings reveal the potential of LM as a novel approach to reduce contact time during droplet impact, with implications for various scientific and industrial applications.