Self-cleaning of superhydrophobic nanostructured surfaces at low humidity enhanced by vertical electric field

Self-cleaning is the key factor that makes superhydrophobic nanostructured materials have wide applications. The self-cleaning effect, however, strongly depends on formations and movement of water droplets on superhydrophobic nanostructured surfaces, which is greatly restricted at low humidity (< 7.6 g center dot kg(-1)). Therefore, we propose a self-cleaning method at low humidity in which the pollution is electro-aggregated and driven in the electric field to achieve the aggregation and cleaning large areas. The cleaning efficiency of this method is much higher than that of water droplet roll-off, and will not produce pollution bands. A simplified numerical model describing pollution movements is presented. Simulation results are consistent with experimental results. The proposed method realizes the self-cleaning of superhydrophobic nanostructured surfaces above dew point curve for the first time, which extends applications of superhydrophobic nanostructured materials in low humidity, and is expected to solve self-cleaning problems of outdoor objects in low humidity areas (< 5.0 g center dot kg(-1)).

Automated summary

This study proposes a method to achieve self-cleaning at low humidity. By electro-aggregating and electric field driving, pollutants are aggregated and cleaned on a large scale. The cleaning efficiency of this method is higher than water droplet roll-off and does not produce pollution bands. Simulation results match experimental results, and this method realizes the self-cleaning of superhydrophobic nanostructured surfaces in low humidity for the first time.