Desublimation Frosting on Nanoengineered Surfaces

Ice nucleation from vapor presents a variety of challenges across a wide range of industries and applications including refrigeration, transportation, and energy generation. However, a rational comprehensive approach to fabricating intrinsically icephobic surfaces for frost formation—both from water condensation (followed by freezing) and in particular from desublimation (direct growth of ice crystals from vapor)—remains elusive. Here, guided by nucleation physics, we investigate the effect of material composition and surface texturing (atomically smooth to nanorough) on the nucleation and growth mechanism of frost for a range of conditions within the sublimation domain (0 °C to −55 °C; partial water vapor pressures 6 to 0.02 mbar). Surprisingly, we observe that on silicon at very cold temperatures—below the homogeneous ice solidification nucleation limit (<−46 °C)—desublimation does not become the favorable pathway to frosting. Furthermore, we show that surface nanoroughness makes frost formation on sili...