Application of Biomimetic Superhydrophobic/Hydrophilic Stripe Surfaces in Electrostatic Fog Collection Study

Hydrophobic/hydrophilic hybrid surfaces are important biomimetic surfaces for fog collection. In this study, superhydrophobic/hydrophilic alternating stripe patterns were fabricated on an electrically conductive ITO glass and used in electrostatic fog collection as the charged water particle receiving surface. When negative or positive high voltage was applied, the air breakdown current showed a direct correlation with the amount of collected water: the higher the current, the larger the amount of water collected. The width of the hydrophilic stripes showed negligible impact on the merging of condensed water drops and shedding of water drops. For 50% superhydrophobic coating coverage, ITO surfaces with 1, 2, 3, and 5 mm wide hydrophilic stripes had similar collected water amounts compared to fully covered superhydrophobic coatings and the ITO surface. Therefore, electrostatic current is the dominant factor that governs electrostatic fog collection efficiency, regardless of surface wettability differences and surface stripe pattern differences. The orientation of the striped pattern affects the shedding path of condensed water. However, the overall fog collection efficiency is not affected by the stripe orientation.