Frost-free zone on macrotextured surfaces

Abstract

Numerous studies have focused on designing functional surfaces that delay frost formation or reduce ice adhesion. However, solutions to the scientific challenges of developing antiicing surfaces remain elusive because of degradation such as mechanical wearing. Inspired by the discontinuous frost pattern on natural leaves, here we report findings on the condensation frosting process on surfaces with serrated structures on the millimeter scale, which is distinct from that on a conventional planar surface with microscale/nanoscale textures. Dropwise condensation, during the first stage of frosting, is enhanced on the peaks and suppressed in the valleys, causing frost to initiate from the peaks, regardless of surface chemistry. The condensed droplets in the valley are then evaporated due to the lower vapor pressure of ice compared with water, resulting in a frost-free zone in the valley, which resists frost propagation even on superhydrophilic surfaces. The dependence of the frost-free areal fraction on the geometric parameters and the ambient conditions is elucidated by both numerical simulations based on steady-state diffusion and an analytical method with an understanding of boundary conditions independent of surface chemistry. We envision that this study would provide a unified framework to design surfaces that can spatially control frost formation, crystal growth, diffusion-controlled growth of biominerals, and material deposition over a broad range of applications.

A One‐Pot Universal Approach to Fabricate Lubricant‐Infused Slippery Surfaces on Solid Substrates

“…[ 19 ] However, only a few approaches have been adopted to reduce the surface energy of these substrates, utilizing mostly hydrocarbon‐ or fluorinated chains with silane‐ [ 10h,18a,20 ] or phosphate‐based functional binding groups. [ 10g,11,13c,d,19,21 ] However, silane‐based molecules are expensive and the process is complicated, thus making the functionalization processes barely scalable. On the contrary, short‐chain perfluoroalkyl chemicals, which are unpretentious in use with low surface tension values matching well the SLIPS requirements, are subjected to the global regulation due to their environmental and human toxicity issues.…”

Ice Coverage Induced by Depositing a Water Drop onto the Supercooled Substrate at Extreme Low Vapor Pressure

“…Despite being a complex and unorthodox phase change problem, an appreciable portion of the physics underlying condensation frosting has been revealed recently as an in situ observation of frosting dynamics and is accessible in most experiments [10][11][12]. Abundant anti-/de-frosting technologies [13][14][15][16][17][18], both passive and active, have been developed to mitigate frosting problems.…”

Anti-gas hydrate surfaces: perspectives, progress and prospects

“…220 Repressing ice growth is another effective approach for tackling the icing problem, which can be achieved through engineering ice-free zones on surfaces. 221–224 Recently, surfaces with patterned polyelectrolytes were reported to realize large scale ice-free zones (taking up ∼96% of the entire surface area). 222 Overall, surfaces using the above three anti-icing strategies can make parts of and even the whole surfaces ice free for a certain period of time.…”