A Passive Anti-icing Strategy Based on a Superhydrophobic Mesh with Extremely Low Ice Adhesion Strength

Although superhydrophobic materials have attracted much research interest in anti-icing,some controversy still exists.In this research,we report a cost-effective method used to verify the contribution of area fraction to ice adhesion strength.We tried to partially-embed siliea nanopnarticles into microscale fabrics of a commercial polyamide mesh.Then,the area fraction could be determined by altering the mesh size.Generally,the ice adhesion strength decreases as the area fraction decreases.An ice adhesion strength of~1.9 kPa and a delayed freezing time of~1048 s can be obtained.We attribute the low ice adhesion strength to the combination of superhydro-phobicity and stress concentration.The superhydrophobicity prohibits the water from penetrating into the voids of the meshes,and the small actual contact area leads to stress concentration which promotes interfacial crack propagation.Moreover,our superhydrophobic mesh simultaneously exhibis a micro-nano hierarchical structure and a partally-cmbedded structure.Therefore,the as-prepared superhydrophobic mesh retained the ieephobicity after 20 icingldeicing cycles,and maintained its superhydrophobicity even afier 60 sandpaper-abrasion cycles and a 220"C thermal treatment.

A Superhydrophobic Hydrogel for Self-Healing and Robust Strain Sensor with Liquid Impalement Resistance

The superhydrophobic strain sensor is a fantastic direction,which could protect the strain sensor in harsh environment.Nevertheless,the self-healing superhydrophobic strain sensor has not been reported.In this research,we developed a superhydrophobic strain sensor,which demonstrated excellent self-healing,mechanical robustness,and liquid impalement resistance simultaneously.The key innovation is to partially embed hydrophobic graphene and carbon nanotubes into the hydrogel matrix.The hodrogel substrate endows the sample with self-healing property.The graphene,carbon nanotubes and hydrogel together lead to an accurate and real-time monitoring of human motion.Furthermore,the prepared sample demonstrated super-robust superhydrophobicity,which retained superhydrophobicity after many kinds of damage(such as 1000%stretch,10000 stretching-releasing cycles,hand-rub,tape-peeling,and high-speed drop/jet impact).

A Superhydrophobic/Electrothermal/Photothermal Synergistically Anti-icing Strategy with Excellent Self-healable and Anti-abrasion Property

Unexpected ice accumulation tends to cause many problems or even disasters in our daily life.Based on the superior electrothermal and photothermal function of the carbon nanotubes,we introduced a superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy.When a voltage of 15 V was applied to the superhydrophobic sample,the surface could rapidly melt the ice layer(~3 mm thickness)within 530 s at the environmental temperature of-25℃.When the near-infrared light(808 nm)irradiates on the superhydrophobic sample,the ice could be rapidly removed after 460 s.It was found that the superhydrophobicity helps the melted water to roll off immediately,and then solves the re-freeze problem the traditional surfaces facing.Moreover,the ice can be completely melted with 120 s when the superhydrophobic/electrothermal/photothermal synergistically anti-icing strategy was utilized.To improve the mechanical robustness for practical application,both nanoscale carbon nanotubes and microscale carbon powders were utilized to construct hierarchical structure.Then these dual-scale fillers were sprinkled onto the semi-cured elastomer substrate to prepare partially embedded structure.Both hierarchical structure and partially embedded structure were obtained after completely curing the substrate,which imparts excellent abrasion resistance(12.50 kPa,16.00 m)to the prepared sample.Moreover,self-healable poly(urea–urethane)elastomer was introduced as the substrate.Thus,the cutted superhydrophobic sample can be mended by simply contacting at room temperature.

A Robust Superhydrophobic Smart Coating with Reversible Thermochromic and Photochromic Property

Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big obstacle.Inspired by the lotus leaf,to endow the chromic coating with superhydrophobicity is a possible solution.In this research,a dual response coating was prepared by adding photochromic and thermochromic particles simultaneously.The prepared sample demonstrated at least four-state color switching,which can be successfully used in tactile imaging,multi-color fabric,erasable record,and security labels.The superhydrophobicity was achieved by introducing vinyl-terminated polydimethylsiloxane,which not only offers low surface energy but also can cross-link with the particles to increase the adhesion.Thus,the prepared sample maintained superhydrophobicity after various kinds of destruction(such as sandpaper abrasion,corrosive liquid attack,ultrasonic treatment,UV irradiation,and high-speed drops/turbulent jets impact).Even though the superhydrophobicity can be destroyed by plasma etching,it can be recovered after 12 h at room temperature.