How Micro-/Nanostructure Evolution Influences Dynamic Wetting and Natural Deicing Abilities of Bionic Lotus Surfaces

Abstract

Anti-icing materials have become increasingly urgent for many fields such as power transmission, aviation, energy, telecommunications, and so on. Bionic lotus hydrophobic surfaces with hierarchical micro-/nanostructures show good potential of delaying ice formation; however, their icephobicity (deicing ability) has been controversial. It is mainly attributed to lack of deep understanding of the correlation between micro-/nanoscale structures, wettability, and icephobicity, as well as effective methods for evaluating the deicing ability close to natural environments. In this article, the natural deicing ability is innovatively proposed on the basis of ice adhesion and the influence of microscale structure evolution on dynamic wetting and deicing ability (both ice adhesion strength and natural deicing time) was systematically investigated. Interestingly, different modes (sticky or slippery) were found in natural deicing of hierarchical hydrophobic surfaces, although their ice adhesion strength was higher than that of smooth surfaces. The mechanism was analyzed from three aspects: mechanics, heat transfer, and dynamic wetting. It is highlighted that the sliding of melted interface is not equal to water droplet sliding (dynamic wetting) before freezing or after deicing but significantly depends on the microscale structure. The fundamental understanding on natural deicing of bionic hydrophobic surfaces will open up a new window for developing new anti-icing materials and technology.

Reduction of Ice Adhesion Using Surface Acoustic Waves: Nanoscale Vibration and Interface Heating Effects

“…Reduction of ice accumulation is highly crucial, and ice adhesion force is one of the critical parameters. If ice adhesion is weak enough and the externally applied shear forces can separate the ice from the interface, deicing or anti-icing can be easily achieved. , Over the past several decades, sustainable solutions for anti/deicing has been extensively investigated, − which can be grouped into two categories, that is, active and passive. Active anti/deicing methods disrupt the ice–structure interface in order to achieve deicing effects, using methods such as resistance heating, hot air, radiation, deicing fluids, electro-impulsive/expulsive, and ultrasonic techniques. − These methods often require significant energy or chemical consumption, along with complex systems with low efficiencies.…”

Carbon-Based Photothermal Superhydrophobic Materials with Hierarchical Structure Enhances the Anti-Icing and Photothermal Deicing Properties

“…To further explain the roll off behavior of the freezing droplet on the ST@CA/CC surface, we perform a force analysis, as shown in Figure b. Based on an existing study, we assume that the freezing droplet on inclined surfaces is only affected by gravity and adhesion. The adhesion force is expressed as follows: where F water is the adhesion force of the water–solid interface and F ice is the adhesion force of the ice–solid interface.…”

Metal surface wettability modification by nanosecond laser surface texturing: A review

“…Microscale and nanoscale textures can form a hierarchically rough structure, a substantial contributor to the hydrophobicity of a surface. The wettability can be changed by the microscale or nanoscale texture [37,38]. The innate defects of a surface and the textures influence the surface roughness.…”