The wettability of the solid surface is often characterized by the contact angle of the liquid on the solid surface. However, it has long been found that the contact angle of liquid on a solid surface can take a range...The wettability of the solid surface is often characterized by the contact angle of the liquid on the solid surface. However, it has long been found that the contact angle of liquid on a solid surface can take a range of values between two extremes: the advancing and the receding contact angles. The difference between the advancing and the receding contact angles is conventionally called contact angle hysteresis. Knowledge of contact angle hysteresis is essential to understand surface wettability and control surface wetting behavior. The wettability can be affected, for example, by the roughness of the solid surface. In our work, textile is used as macroscopic roughness surfaces, and smooth plate surface is used as well to determine contact angle hysteresis. The advancing and receding contact angles are measured on polyamide materials.展开更多
Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically studied.Experimental data shows that the critical impact veloci...Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically studied.Experimental data shows that the critical impact velocity induced wetting transition of droplet on the superhydrophobic surfaces is strongly determined by the perimeter of single micropillar,the space between the repeat pillars and the advancing contact angle of the sidewall of the micropillars.The proposed model agrees well with the experimental results,and clarifies that the underlying mechanism which is responsible for the superhydrophobic surface with hierarchical roughness could sustain a higher liquid pressure than the surfaces with microstructures.展开更多
文摘The wettability of the solid surface is often characterized by the contact angle of the liquid on the solid surface. However, it has long been found that the contact angle of liquid on a solid surface can take a range of values between two extremes: the advancing and the receding contact angles. The difference between the advancing and the receding contact angles is conventionally called contact angle hysteresis. Knowledge of contact angle hysteresis is essential to understand surface wettability and control surface wetting behavior. The wettability can be affected, for example, by the roughness of the solid surface. In our work, textile is used as macroscopic roughness surfaces, and smooth plate surface is used as well to determine contact angle hysteresis. The advancing and receding contact angles are measured on polyamide materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.11072126,91326108 and 51206042)
文摘Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically studied.Experimental data shows that the critical impact velocity induced wetting transition of droplet on the superhydrophobic surfaces is strongly determined by the perimeter of single micropillar,the space between the repeat pillars and the advancing contact angle of the sidewall of the micropillars.The proposed model agrees well with the experimental results,and clarifies that the underlying mechanism which is responsible for the superhydrophobic surface with hierarchical roughness could sustain a higher liquid pressure than the surfaces with microstructures.