Polydimethylsiloxane Brush Coating Strategy for Scalable Superhydrophobic Filter Paper with Oil–Water Separation, Self-Cleaning, and Anti-icing Properties

Considerable effort has been made to design low-cost and eco-friendly materials for effective oil-water separation. In this work, an efficient strategy for fabricating superhydrophobic filter paper (PDMS-Paper-x) via dip coating in a methoxy-terminated polydimethylsiloxane (PDMS macromolecule coupling agent) solution was reported. The chemical constitution and surface morphology of PDMS-Paper-x were characterized by using scanning electron microscopy, X-ray photoelectron spectroscopy, and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. PDMS-Paper-0.5 shows a water contact angle of 151.1°, exhibiting superhydrophobicity. Owing to its interfibrous pore structure and superhydrophobicity, PDMS-Paper-0.5 demonstrated high-efficiency separation properties for immiscible oil-water mixtures. Under the gravity-driven condition, the separation flux value of hexane-water mixtures was 603.9 L·m^-2·h^-1, and the separation flux value of continuous octane-water mixture separation was higher, reaching up to 14187.6 L·m^-2·h^-1. Additionally, PDMS-Paper-0.5 has anti-icing properties with an ice adhesion strength of 10.0 kPa. This work demonstrates a simple coating strategy to fabricate superhydrophobic filter paper with potential applications in oil purification and anti-icing.