Cao Liangliang, Jones Andrew K, Sikka Vinod K, Wu Jianzhong, Gao Di
Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
Langmuir. 2009 Nov 3;25(21):12444-8. doi: 10.1021/la902882b.
We use nanoparticle-polymer composites to demonstrate the anti-icing capability of superhydrophobic surfaces and report direct experimental evidence that such surfaces are able to prevent ice formation upon impact of supercooled water both in laboratory conditions and in natural environments. We find that the anti-icing capability of these composites depends not only on their superhydrophobicity but also on the size of the particles exposed on the surface. The critical particle sizes that determine the superhydrophobicity and the anti-icing property are in two different length scales. The effect of particle size on ice formation is explained by using a classical heterogeneous nucleation theory. This result implies that the anti-icing property of a surface is not directly correlated with the superhydrophobicity, and thus, it is uncertain whether a superhydrophobic surface is anti-icing without detailed knowledge of the surface morphology. The result also opens up possibilities for rational design of anti-icing superhydrophobic surfaces by tuning surface textures in multiple length scales.
我们使用纳米颗粒-聚合物复合材料来展示超疏水表面的防冰能力，并报告直接的实验证据，证明此类表面在实验室条件和自然环境中均能在过冷水撞击时防止结冰。我们发现，这些复合材料的防冰能力不仅取决于其超疏水性，还取决于表面暴露颗粒的大小。决定超疏水性和防冰性能的临界颗粒尺寸处于两个不同的长度尺度。通过使用经典的非均相成核理论来解释颗粒尺寸对结冰的影响。这一结果意味着表面的防冰性能与超疏水性并非直接相关，因此，在不详细了解表面形态的情况下，超疏水表面是否具有防冰性能并不确定。该结果还为通过在多个长度尺度上调整表面纹理来合理设计防冰超疏水表面开辟了可能性。
