Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA.
ACS Nano. 2012 Aug 28;6(8):6569-77. doi: 10.1021/nn302310q. Epub 2012 Jun 15.
Ice-repellent coatings can have significant impact on global energy savings and improving safety in many infrastructures, transportation, and cooling systems. Recent efforts for developing ice-phobic surfaces have been mostly devoted to utilizing lotus-leaf-inspired superhydrophobic surfaces, yet these surfaces fail in high-humidity conditions due to water condensation and frost formation and even lead to increased ice adhesion due to a large surface area. We report a radically different type of ice-repellent material based on slippery, liquid-infused porous surfaces (SLIPS), where a stable, ultrasmooth, low-hysteresis lubricant overlayer is maintained by infusing a water-immiscible liquid into a nanostructured surface chemically functionalized to have a high affinity to the infiltrated liquid and lock it in place. We develop a direct fabrication method of SLIPS on industrially relevant metals, particularly aluminum, one of the most widely used lightweight structural materials. We demonstrate that SLIPS-coated Al surfaces not only suppress ice/frost accretion by effectively removing condensed moisture but also exhibit at least an order of magnitude lower ice adhesion than state-of-the-art materials. On the basis of a theoretical analysis followed by extensive icing/deicing experiments, we discuss special advantages of SLIPS as ice-repellent surfaces: highly reduced sliding droplet sizes resulting from the extremely low contact angle hysteresis. We show that our surfaces remain essentially frost-free in which any conventional materials accumulate ice. These results indicate that SLIPS is a promising candidate for developing robust anti-icing materials for broad applications, such as refrigeration, aviation, roofs, wires, outdoor signs, railings, and wind turbines.
疏冰涂层在许多基础设施、交通运输和冷却系统中具有显著的节能和提高安全性的作用。最近，人们致力于开发疏冰表面，主要是利用荷叶启发的超疏水表面，但这些表面在高湿度条件下会失效，因为会发生水凝结和结霜，甚至由于表面积增大而导致冰附着力增加。我们报告了一种基于光滑、液体注入多孔表面（SLIPS）的疏冰材料，在这种材料中，通过将不混水的液体注入化学功能化的纳米结构表面，使稳定的、超光滑、滞后低的润滑剂覆盖层得以维持，这种表面具有高亲液性，并将液体锁定在原位。我们开发了一种在工业相关金属（特别是铝）上直接制备 SLIPS 的方法，铝是应用最广泛的轻质结构材料之一。我们证明，SLIPS 涂层的铝表面不仅通过有效去除凝结的水分来抑制冰/霜的积聚，而且其冰附着力比现有材料至少低一个数量级。基于理论分析和广泛的结冰/除冰实验，我们讨论了 SLIPS 作为疏冰表面的特殊优势：由于极低的接触角滞后，滑动液滴的尺寸大大减小。我们表明，我们的表面在任何常规材料都会结冰的情况下，仍基本无霜。这些结果表明，SLIPS 是开发广泛应用的抗冰材料的有前途的候选材料，例如制冷、航空、屋顶、电线、户外标志、栏杆和风轮机。
