The effects of different receiver surfaces and emitter tips on electrostatic fog water collection

High-efficiency, low-energy-consumption electrostatic fog water-harvesting technology can alleviate drinking water shortages in high-fog and water-scarce regions. Through systematic investigation of key factors, including material properties and structural arrangements of collection surfaces and emission terminals, various materials were selected to construct uniform planar collection surfaces. A multi-parameter analysis was conducted to examine their impact on electrostatic water collection efficiency. The results reveal that the hydrophilicity/hydrophobicity, resistance, and conductivity of collection surfaces are not the dominant factors. Instead, collection efficiency primarily depends on the magnitude of corona-induced air currents, exhibiting an exponential relationship. Within the initial current range, efficiency increases rapidly with increasing current, but shows slower growth beyond a threshold value. The type of tip of electrostatic emitters affect collection efficiency by influencing electric field uniformity, with carbon fiber emitters demonstrating superior performance compared to copper needle emitters. Collection distance modifies efficiency through its dual effects on air current magnitude and electric field uniformity, while maintaining consistent exponential correlation with current for the same emitter material. Hydrophilic insulating surfaces exhibit high collection efficiency, whereas hydrophobic insulating plastic surfaces perform poorly. Notably, hydrophobic polytetrafluoroethylene (PTFE) microporous membranes achieve efficient fog collection by creating conductive pathways. Clarification of these fundamental factors provides valuable guidance for the future design of safer, more energy-efficient, and more portable electrostatic fog water-harvesting devices.