Nonporous water-proof coatings with resistance to harsh water environments and spontaneous dewetting

The superhydrophobic surfaces in harsh water environments (such as deep sea or extreme rainstorms) often suffer from irreversible air layer collapse or structural damage. However, the rough micro/nano-structures dominating superhydrophobicity are usually loose and fragile, which generate insufficient anti-wetting capillary pressure to deal with harsh water environments. Here, an electrostatic-field-assisted aerosolization deposition (EFAAD) method was proposed to fabricate a densified superhydrophobic surface featuring nonporous microlevel protrusion with nanoscale secondary modification. The mechanism of controllable deposition was investigated and spraying parameter configuration was optimized. The EFAAD coating showed exciting tolerance of high-speed jet impact (85.4 m/s, Weber number of 202588), ultrasonic micro jet impact (25 min), and hydrostatic pressure (5 MPa) for the coordinated structural robustness and air layer stability. Even though the superhydrophobicity of EFAAD coating was compromised under extreme conditions, the water film could dewet spontaneously induced by any bubble with radium than 130 μm. Moreover, the EFAAD coating has also proved comprehensive tolerance to tape peeling (more than 400 cycles), UV irradiation, and severe solution corrosion, exhibiting particularly promising for various high-water-pressure applications.