Electrohydrodynamic behavior of water droplets on a horizontal super hydrophobic surface and its self-cleaning application

Abstract

Moisture is a significant factor that affects the insulation performance of outdoor high-voltage insulators in power systems. Accumulation of water droplets on insulators causes severe problems such as flashover of insulators and power outage. In this study, we develop a method to fabricate a micro/nano hierarchical super hydrophobic surface. The as-prepared super hydrophobic surface exhibits a water contact angle (WCA) of 160.4±2°, slide angle (SA) less than 1° and surface free energy (SFE) of 5.99 mJ/m 2. We investigated the electrohydropdynamic behavior of water droplet on a horizontal super hydrophobic surface compared with hydrophobic RTV silicone rubber surface which was widely used as anti-pollution coating or shed material of composite insulator. Results show that water droplet tended to a self-propelled motion on the super hydrophobic surface while it tended to elongate and break up on the RTV surface. The micro/nano hierarchical surface structure and chemical components with low surface free energy of the super hydrophobic surface jointly contributed to the reduction of skin fraction drag and subsequently made it possible for the motion of water droplet driven by electric field. Furthermore, the self-propelled motion of water droplets could also sweep away contaminations along its moving trace, which provides super hydrophobic surface a promising anti-pollution prospect in power systems.

High-voltage applications of the triboelectric nanogenerator—Opportunities brought by the unique energy technology

“…Microfluidics targets at the precise control and manipulation of fluids with small volumes, [59][60][61][62] while the high-voltage source and the control circuits increase the complexity of the microfluidic system. [63][64][65][66][67] To achieve the effective control of position and velocity of fluids in the microchannels, Nie et al 68 developed a fully self-powered microfluidic system that eliminates the need for the power source and the control circuits. By integrating a TENG and a simple circuit board, the motion of water droplets can be controlled by the output of the TENG.…”

Effect of superhydrophobicity on surface damage of silicone rubber under AC voltage

“…19 Droplets can easily slide and leave the superhydrophobic surface under the effects of an electric field. 20,21 Apparently, if we could introduce superhydrophobic surface into electrical engineering, the idea mentioned above could be realized. However, few researchers focus on this way to deter surface damages.…”

Mobility of A Water Droplet on Liquid Phase of N-Octadecane Coated Hydrophobic Surface

“…Although droplet mobility on oil impregnated surface was studied previously 7 , the main focus was to introduce a scaling model incorporating the viscosity of lubricant and elucidating the dependence of drag reduction on the ratio of viscosity of working fluid to that of the lubricant. In addition, the water droplet mobility on a hydrophobic surface under a thermal radiative heating was investigated 20 ; however, the influence of gravitational potential energy on the droplet motion on the inclined impregnated surface was left for the future study. The exchange of the surface wetting state is demonstrated to be possible when the surface is coated by a thin layer of a phase change material 10 , 21 ; however, the droplet mobility on the liquid phase of the thin film of the phase change material needs to be examined further.…”