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.