A novel electrostatic precipitator with superhydrophobic coating for enhanced particulate removal efficiency restoration

Electrostatic precipitators (ESPs) are widely used for particulate matter control in buildings due to their cost-effectiveness and low maintenance requirements. However, existing ESPs exhibit low removal efficiency for submicron particles and inefficient dust cleaning after accumulation. To address these limitations, a collection module in ESP, featuring electrodes coated with a PVDF/H-SiO₂ superhydrophobic coating, is proposed. The applied voltage, electrode gap, and coating material are evaluated in this study. Results showed that the water contact angle on the coated surface was 152.4°, attributed to the combination of low-surface-energy groups and rough structures. When superhydrophobic electrodes with a 2-mm gap were used and air velocity of 1.5 m/s, the removal efficiency for 0.3–0.5 μm particles was 92.5%. Additionally, the removal efficiency of the collection module with superhydrophobic coating could be restored to 99.7% of its initial efficiency, compared to 83.1% for the collection module without the coating. Moreover, the removal efficiency of the ESP remained consistently high over 21 days with an average of 91.3%. The proposed novel ESP demonstrates significant potential for air removal in ventilation systems for clean and sustainable building environments.