Energy-effective frost-free coatings based on superhydrophobic aligned nanocones.

We demonstrate the feasibility of superhydrophobic aligned nanocones as energy-effective frost-free coatings. Exemplified by Co(OH)2 nanocone films with condensed microdrop self-removal ability, their edge and whole-surface frosting time can be delayed to about 10 and 150 min, respectively. By using a Teflon gasket to shield edges, the samples can keep frost-free state over 90 min. Further, the lasting frost-free state can be realized by intermittent weak airflow heating, which is energy-effective in contrast to usual high-power heating for defrosting flat surfaces. These findings are significant to develop antifrosting nanotechnologies for energy-effective heat exchangers such as heat pumps and refrigerators.