Extreme water repellency of nanostructured low-surface-energy non-woven fabrics

We report the extreme water repellent nature of non-woven fabrics of PET (polyethyleneterephthalate) whose fiber surfaces are nanotextured with oxygen plasma and coated with a low-surface-energy nanofilm. The surface effectively suppresses vapor condensation and repels condensed water droplets in addition to exhibiting a high contact angle and a low contact angle hysteresis with a millimetre-sized water drop. We also show that the surface maintains its superhydrophobicity after water-vapor condensation and after oil-wetting due to high-aspect-ratio nanohairs on the fibers. The superior water-repellent ability of the plasma treated non-woven fabric can be exploited in a variety of industrial applications including water harvesting and fuel cell water management even under oily contaminations.