Preparation of superhydrophobic nanowires on polypropylene surface via injection compression molding for efficient fog collection†

In this work, a superhydrophobic polypropylene (PP) replica with nanowires is fabricated using an injection compression molding (ICM) process. The morphology, superhydrophobicity and fog water harvesting efficiency of the as-prepared PP replica surface are investigated. Morphological characterization indicates that the PP replica surface exhibits nanowires with intertwined tips. Compared to the untreated PP surface (referred to as the PP counterpart), the PP replica surface shows a higher contact angle (CA) and lower rolling angle (RA). Furthermore, the complete transfer of a water droplet with no volume loss from the PP replica surface to the filter paper shows that nanowires on the PP replica surface are responsible for the superhydrophobic and low-adhesive properties of the surface. The Cassie–Baxter state with a CA of ∼153°, low ice adhesion strength (13.3 kPa at −20 °C) and good fog water harvesting efficiency (∼7.26 g m⁻² s⁻¹) demonstrate that the prepared PP replica has economic potential for fog water harvesting applications.