Dynamics of droplet impact on hydrophobic/icephobic concrete with the potential for superhydrophobicity.

The ability of superhydrophobic surfaces to resist wetting and repel impinging water droplets is not less important for practical applications than the contact angle and contact angle hysteresis. Here we study novel hydrophobic concrete (with the potential for superhydrophobicity) and its ability to repel incoming droplets (e.g., rain). It is found that the onset of the pinning mode can be delayed by changing the surface topography. Also, the pinning or breakup of droplets of higher velocities depends on the incoming angle. Hydrophobic concrete with better pinning resistance showed less tendency for ice accretion.