Magnetic hydrophobic cellulose-modified polyurethane filter for efficient oil-water separation in a complex water environment

Magnetic porous materials have been of interest for oil-water separation due to their efficient ease of separation. This work presented a facile approach for preparing a magnetic polyurethane foam (PUF) modified with pretreated cellulose-decafluorobiphenyl (MCF). The prepared materials were characterized using several techniques. They showed high oil-water separation for a variety of oils and chemical solvents. More significantly, the absorbed oil was easily retrieved by squeezing. After several absorbing-squeezing cycles, the modified PUF maintained a high magnetic responsivity, due to the addition of Fe3O4 magnetic nanoparticles, and still exhibited a significant oil absorption capacity. MCF's oil absorption capacity, separation efficiency, oil flux, and reusability were evaluated. The results reveal that the prepared material has a high absorption capacity which varies between 9 and 32 times its own weight, excellent separation efficiency (>97.68 %), and high flux which reaches 48,750 Lm−2h−1 for n-hexane, and high reusability (>50 times) in oil-water separation. The magnetic MCF foam could be reused through a simple squeeze treatment. The oil-water separation performance of MCF is excellent in complex environments including acidic solutions (pH = 2), basic solutions (pH = 12), and simulated seawater. This makes it a very promising material for the aforementioned purposes.