Superhydrophobic/superoleophilic magnetic polyurethane sponge for oil/water separation

Abstract

Oil/water separation is a worldwide challenge and addressing this challenge calls for the development of efficient absorbent materials. Here a superhydrophobic/superoleophilic magnetic polyurethane (PU) sponge was fabricated via the facile dopamine self-polymerization to anchor Fe₃O₄ nanoparticles onto the skeleton of the PU sponge, followed by the introduction of low-surface-energy hydrophobic molecules heptadecafluoro-1,1,2,2-tetrahydrodecyltrimethoxysilane (FAS-17) on the sponge surface to induce the superhydrophobic transformation. The magnetic PU sponge displays excellent superhydrophobicity and superoleophilicity, and more favorably possesses magnetic responsiveness and superior stability against corrosive solutions; it gave outstanding separation performance under magnetic actuation not only for floating oils on the water surface and heavy organic pollutants under water, but also in the more complex environments such as an acidic solution (pH = 1) and simulated seawater, suggesting great potential in practical oily wastewater treatment. The presented approach provides a facile and easily scalable solution for the design and construction of multifunctional magnetic absorbent materials with low costs for practical applications in the petro-chemical field.