Magnetic superhydrophobic sponge with 3D interpenetrating network structure coating for multimodal driven oil/water separation

In this paper, a simple dipping technique was employed to construct a 3D interpenetrating network structure coating, which was used to prepare a robust, superhydrophobic and magnetic sponge. The modified sponge exhibits rapid adsorption behavior, high adsorption capacity (up to 60–159 times its own dry weight or above 119 %–186 % of its own volume for various oils/organic solvents), stable superhydrophobicity and reusability. After 100 times extrusion adsorption test, it retains 70 % adsorption capacity and the WCA is still over 140°. More importantly, the modified sponge presents excellent robustness and chemical stability after a long time of chemical reagent treatment (HCl, KOH, NaCl) and mechanical friction test 1000 cycles. Notably, the magnet, pump, self-adsorption, gravity and solar-driven oil/water separation devices based on the modified sponge also were applied, particularly the separation of crude oil mixtures via the solar-driven mode, demonstrating the broad prospects of such modified sponges in actual applications. As such, this study not only provides an environmentally friendly, efficient, robust and low-cost design strategy for multi-state oil spill cleaning, but also focuses on solving the problem of material recovery and the use of materials in harsh environment.