Hybrid Hairy Janus Particles for Anti-Icing and De-Icing Surfaces: Synergism of Properties and Effects

A novel route for the design of functional surfaces with effective anti-icing and de-icing capability based on hybrid Janus particles is presented. The heterogeneous surfaces formed by Janus particles exhibit special surface “edge” morphologies. Water first condenses on the hydrophilic portion of the surfaces, occupying relatively large hydrophilic clusters. It is pinned at the boundary between the hydrophilic and the hydrophobic regions and thus cannot penetrate in the cavities between the particles. Further condensation leads to the fast coalescence of the water clusters, which after freezing yields a fast appearance of large ice crystals, dendrites, in the shape of the agglomeration of sector plates. The mechanism of the dendrite formation is proved experimentally and by Monte Carlo simulations. Moreover, a dry band is formed around the large crystals due to the evaporation of small drops in the vicinity of the large water clusters and the subsequent ice crystals. The synergism of both effects, the area free of ice and the large unstable dendrites at the edges of heterogeneities, leads to an extremely low ice adhesion of ca. 56 kPa. The presented approach opens a new avenue for the rational design of ice-free coatings using Janus particles as building blocks.