Super-hydrophobic film retards frost formation

Hydrophobic and super-hydrophobic isotactic polypropylene (i-PP) films were prepared and the process of frost formation was investigated. It was found that frost formation is greatly retarded on the super-hydrophobic i-PP surface. During the frost formation, the wettability on the super-hydrophobic film oscillates, while the wettability on the hydrophobic film increases steadily. This special oscillation is due to the micro-and nanometre structures, which leads to the delay of the solidification of liquid water at the three-phase line (TPL) region. This result gives a new explanation for the retardation of frost formation on the super-hydrophobic film surface and will be of great significance for the effective design of anti-frost materials.