Nazifi Sina, Huang Zixu, Hakimian Alireza, Ghasemi Hadi
Department of Mechanical Engineering, University of Houston, 4726 Calhoun Rd, Houston, Texas 77204, USA.
Department of Chemical and Biomolecular Engineering, University of Houston, 4726 Calhoun Rd, Houston, Texas 77204, USA.
Mater Horiz. 2022 Oct 3;9(10):2524-2532. doi: 10.1039/d2mh00619g.
Icing imposes a significant burden on those living in cold climates, with negative impacts on infrastructure, transportation, and energy systems. Over the past few decades, a wide range of materials with ice-shedding characteristics have been developed, including surfaces that are non-wetting/hydrophobic, liquid-infused, stress-localized, and those with low interfacial toughness. Although many of these materials have demonstrated low ice adhesion in a laboratory setting, none have achieved widespread practical adoption. This is primarily a result of the fact that they tend to have very low durability, limiting their applicability. Thus, the primary challenge in developing ice-shedding materials is finding materials with both low ice adhesion AND good durability. Here, we introduce the concept of a so-called "fracture-controlled surface." Through coordinated mechanical and chemical heterogeneity in the material structure, we affect the interfacial crack nucleation and growth on these surfaces. Through this controlled process, fracture-controlled surfaces exhibit both low ice adhesion and very high mechanical durability. Measurements of the durability of these surfaces indicate performance that is three orders of magnitude greater than other state-of-the-art ice-shedding materials. Physically, mechanical heterogeneity of the material, we pre-specified the crack nucleation coordinates at the interface and guided the crack growth in an interfacial plane, with no kinking in other directions. This helps to maximize the energy that goes towards crack nucleation and growth. A detailed mathematical model is developed to predict adhesion of external solid objects on these materials. The model suggests that an elastic matching criterion is required to achieve minimal adhesion of solid objects on these materials. Fracture-controlled surfaces provide a rich material platform to guide future innovation of materials with minimal adhesion while having very high durability.
结冰给生活在寒冷气候地区的人们带来了巨大负担，对基础设施、交通和能源系统产生负面影响。在过去几十年里，人们开发了多种具有防冰特性的材料，包括非湿润/疏水表面、注入液体的表面、应力局部化表面以及界面韧性低的表面。尽管其中许多材料在实验室环境中表现出低冰附着力，但没有一种材料得到广泛的实际应用。这主要是因为它们的耐久性往往很低，限制了其适用性。因此，开发防冰材料的主要挑战在于找到兼具低冰附着力和良好耐久性的材料。在此，我们引入了所谓“断裂控制表面”的概念。通过材料结构中机械和化学的协同非均匀性，我们影响这些表面上的界面裂纹成核和扩展。通过这个可控过程，断裂控制表面既表现出低冰附着力又具有非常高的机械耐久性。对这些表面耐久性的测量表明，其性能比其他现有防冰材料高出三个数量级。从物理角度来看，通过材料的机械非均匀性，我们预先指定了界面处的裂纹成核坐标，并引导裂纹在界面平面内扩展，而不会向其他方向弯折。这有助于使用于裂纹成核和扩展的能量最大化。我们开发了一个详细的数学模型来预测外部固体物体在这些材料上的附着力。该模型表明，需要一个弹性匹配标准来实现固体物体在这些材料上的最小附着力。断裂控制表面提供了一个丰富的材料平台，以指导未来具有最小附着力且耐久性极高的材料创新。
