Improving the anti-icing/frosting property of a nanostructured superhydrophobic surface by the optimum selection of a surface modifier

Recent advances of slippery liquid-infused porous surfaces with anti-corrosion

Metal materials are susceptible to the influence of environmental media, and chemical or electrochemical multiphase reactions occur on the metal surface, resulting in the corrosion of metal materials, which can directly damage the geometry and reduce the physical properties of metal materials. This corrosion damage can seriously affect the long-term use of metal materials in marine equipment and the aerospace industry, and other fields. Inspired by the special microstructure and slippery properties of natural nepenthes intine, researchers have prepared slippery liquid-infused porous surfaces (SLIPS) with a stable continuous lubricant layer by injecting low-surface-energy lubricants into a substrate with a micro/nano-porous structure. This surface has excellent hydrophobicity, low friction, non-adhesiveness, and self-healing properties. The broad application prospects of SLIPS in the fields of anti-corrosion, anti-icing, anti-bacteria, and anti-fouling have made it a hot research topic directing the study of biomimetic materials at present. However, SLIPS are susceptible to environmental shear forces, such as ocean flow or extraneous fluids, resulting in destruction of the porous structure and loss of surface lubricant, thereby depriving SLIPS of the ability to protect metals from corrosion. Therefore, it is important for metal corrosion protection to find ways to improve the stability and extend the service life of SLIPS. Over the last several years, research into and development of SLIPS have come a long way. Herein, a summary of available reports on SLIPS is given in terms of design principles and their performance characteristics, the construction of rough/porous substrate structures, the choice of low-surface-energy modifiers and lubricants, and lubricant infusion methods. Ways of constructing different substrate structures and the characteristics, advantages, and disadvantages of choosing various modifiers and lubricants to prepare the surface are compared. Finally, a comprehensive summary and outlook of SLIPS with anti-corrosion properties are provided. We are convinced that a comprehensive review of SLIPS will provide important guidance and strong reference for the design and preparation of green and economical SLIPS with anti-corrosion capabilities in the future.

Recent advances in bioinspired superhydrophobic ice-proof surfaces: challenges and prospects

Bionic superhydrophobic ice-proof surfaces inspired by natural biology show great potential in daily life. They have attracted wide research interest due to their promising and wide applications in offshore equipment, transportation, power transmission, communication, energy, etc. The flourishing development of superhydrophobic ice-proof surfaces has been witnessed due to the availability of various fabrication methods. These surfaces can effectively inhibit the accumulation of ice, thereby ensuring the safety of human life and property. This review highlights the latest advances in bio-inspired superhydrophobic ice-proof materials. Firstly, several familiar cold-resistant creatures with well-organized texture structures are listed briefly, which provide an excellent template for the design of bioinspired ice-proof surfaces. Next, the advantages and disadvantages of the current techniques for the preparation of superhydrophobic ice-proof surfaces are also analyzed in depth. Subsequently, the theoretical knowledge on icing formation and three passive ice-proof strategies are introduced in detail. Afterward, the recent progress in improving the durability of ice-proof surfaces is emphasized. Finally, the remaining challenges and promising breakthroughs in this field are briefly discussed.

Condensation Frosting on Micropillar Surfaces - Effect of Microscale Roughness on Ice Propagation

Microscale surface structures have been widely explored as a promising tool for antifreezing or frost avoidance on heat transfer surfaces. Despite studies of many surface feature designs, the mechanisms associated with condensation freezing and ice propagation on microstructured surfaces have yet to be thoroughly elucidated, espectially when it comes to quantitative understanding. In this work, condensation freezing on circular micropillar surfaces is investigated, with varying pillar spacing and height (layout/microscale roughness) but a constant pillar diameter. The pillar layout is found to have significant effects on both liquid nucleation and neighboring droplet interactions, as reflected by the condensation droplet distribution prior to soilidification and eventually the freezing front propagation area velocity. In general, nucleation is preferred on the pillar top rather than the bottom of the pillared surface unless there is a large distance between the pillars. Interactions between neighboring droplets solely on pillar tops (or bottom surfaces) can induce heterogeneity in the droplet distribution and slow freezing front propagation. Based on the roles the pillars play in nucleation, droplet coalescence, and ice bridging, four different condensation states are identified and related to the layout of the pillars, and the freezing front area propagation velocity is found to be different in each state. The findings provide a quantitative basis for designing antifreezing surfaces, applicable to a wide range of thermal systems.