Fracture-based interfacial breakage has shown promise in efficiently removing ice accretion. Here, intrigued by the response of human skin to stress-induced deformation, we present a strategy to design tough-skin de-icing surfaces (TSDSs) that actively manipulate crack-induced ice-substrate interfacial breakage during ice removal. This design leverages the surface instability of thin films to generate extensive wrinkling at the ice-substrate interface, which serves as crack initiation sites. We demonstrate efficient ice shedding by creating wrinkles at two length scales, macro wrinkles for actively initiate the cracks at the rim of ice and micro wrinkles for further promoting stress concentration at the ice-substrate interface. The TSDS (τ < 10 kPa) displays excellent durability and weather resistance, achieving a large-area ice self-shedding effect solely through gravity. The universality of the proposed mechanism is verified on multiple materials and potential applications. This design concept offers valuable insights into creating durable de-icing materials with enhanced ice-shedding properties.
Shizhong Zhang,Chuanbiao Zhang,Yang Fu,Linhai Li,Chuanbing Huang,Yang Lin,Chongqin Zhu,Joseph S. Francisco,Zhiyuan He,Xin Zhou,Jianjun Wang
Ice affects many chemical reactions in nature, which greatly influences the atmosphere, climate, and life. However, the exact mechanism of ice in these chemical reactions remains elusive. For example, it is still an open question as to whether ice can act as a catalyst to greatly enhance the reactivity and selectivity, which is essential for the production of some natural compounds in our planet. Here, we discover that ice can lead to high efficiency and stereoselectivity of the [2 + 2] photodimerization of coumarin and its derivatives. The conversion of the [2 + 2] photodimerization of coumarins enhanced by ice is dozens of times higher than that in the unfrozen saturated solution, and the reaction displays a high syn-head-head stereoselectivity (>95%) in comparison with those in the absence of the ice. Note that almost no reaction occurs in the crystal powder and melt of the coumarins, indicating that the role of ice in the photodimerization reaction is not simply due to the usual mechanisms found in the freezing concentration. We further reveal that the reaction rate is found to be proportional to the total area of the ice surface and follows Michaelis–Menten-like kinetics, indicating that the ice surface catalyzes the reaction. Molecular dynamics simulations demonstrate that ice surfaces can induce reactants to form a two-dimensional liquid-crystal-ordered layer with a suitable intermolecular distance and unique side-by-side packing, facilitating stereoselective photodimerization for syn-head-head dimers. These findings give evidence that ice-surface-induced molecular assembly may play an important role in atmospheric heterogeneous photoreaction processes.
Lei Feng,Yilang Shi,Bei Huang,Tong Wu,Chuanxi Wang,Xuefeng Lin,Weirong Lin,Zhe Meng,Tingwei Wang,Shanglin Xiang,Dongyu Cai
A hierarchical coating was fabricated via a roller painting method with a layer of fluorine-modified boron nitride (fBN) nanoparticles buried in a porous network of Al 2 O 3 microparticles bridged by a fluorocarbon (FC) resin. The sticky FC resin made the fBN nanoparticles firmly locked in the cavities and this enhanced structural stability of the Al 2 O 3 -based porous network. This enabled the formation of a superhydrophobic coating with excellent resistance to environmental erosion and high thermal conductivity. The de-icing temperature of this coating was lowered by 22.2 °C in comparison with a conventional superhydrophobic coating. A case study showed a potential of applying this coating onto large-sized uneven surface like turbine blades.
危险品化学品经营许可证（带存储）