Scalable-Manufactured Superhydrophobic Multilayer Nanocomposite Coating with Mechanochemical Robustness and High-Temperature Endurance

Artificial
superhydrophobic coatings with mechanical stability,
chemical stability, and strong adhesion have been achieved separately.
However, a simultaneous demonstration of these features along with
stability to high-temperature exposure is challenging. Herein, inspired
by the micro/nanoscale hierarchical superhydrophobic surfaces of solid
cactus plants, we propose a novel plasma-enhanced high temperature
liquid-phase-assisted oxidation and crosslinking (PHLOC) in-situ co-growth
strategy to design superhydrophobic nanocomposite coatings on metals
based on organic–inorganic multilayer structures in which PTFE
nanoparticles cross-linked to form a compact top layer with hierarchical
surface textures on a ceramic skeleton with a papilla array, integrating
multiple robust wettability characteristics with mechanochemical strength
to isolate the underlying materials from the external environment.
Remarkably, the superhydrophobic coating exhibits strong mechanical
robustness undergoing the 120th linear abrasion or 40th rotary abrasion
cycle and can be applied on large area and arbitrary shapes of metal
substrates. Moreover, the samples sustain exposure to highly corrosive
media, namely, aqua regia, sodium hydroxide solutions, and simulated
seawater solution, to reflect long-term chemical robustness. More
importantly, the multilayer coating demonstrates excellent high-temperature
endurance, thermal cycling stability of 500 °C, and thermal repairability
of superhydrophobicity. With multifaceted robustness and scalability,
the superhydrophobic multilayer coating should find potential usage
in the field of high-tech equipment with severe alternating or impact
loads, high-temperature service, and chemical corrosion.