Superhydrophobic fluorinated nanoparticle-modified surfaces for fast, efficient, and selective elimination of oil from water

An effective, low-cost method for fabricating superhydrophobic surfaces was investigated. A mixed solution of tetrahydrofuran, 2,3,4,5,6-pentafluorostyrene, and Al₂O₃ nanoparticles was introduced to the original materials to obtain superhydrophobic modified polypropylene (M-PP), cotton fiber (M-CTF), and polyurethane foam (M-PUF). The novelty of this work includes the development of cost-effective, stable materials with superhydrophobic surfaces for extreme water-repellency. The prepared materials were evaluated for hydrophobicity, oil absorption capacity, separation efficiency, oil flux, and reusability using several techniques. They all showed superhydrophobicity with water contact angles higher than 151 ± 0.5°. The results also reveal that the materials exhibited significant oil absorption capacities between 9.8 and 40.3 times their own weights, high separation efficiency (>97.2%), oil flux (>41,110 Lm⁻²h⁻¹), and reusability (>100 times) in the separation of oil-water. Moreover, all the treated materials demonstrated excellent oil selectivity in different salty waters. The samples could still retain outstanding separation even after 10 abrasion cycles with sandpapers. The excellent anti-intrusion and anti-abrasion behavior make the prepared materials promising for oil/water separation in harsh environments.