Magnetic, self–heating and superhydrophobic sponge for solar–driven high–viscosity oil–water separation

In this work, a novel oil–adsorption sponge with superhydrophobicity was fabricated using polymer–assisted electroless deposition and dip–coating techniques for depositing a rough polydopamine layer, magnetic particles, and low surface energy polydimethylsiloxane onto the surface of a sponge skeleton. The as–prepared superhydrophobic sponge (WCA > 150° and SA < 5°) exhibited rapid adsorption behavior, large adsorption capacity (up to 50.6 times its own dry weight or above 90% of its own volume), excellent durability (above 80% of the adsorption capacity after 80 recycles), and a self–cleaning property owing to sufficient open–cell pores and superelasticity provided by the melamine–formaldehyde host as well as the hierarchical roughness and convenient magnetic recovery enabled by the polymer–assisted electroless deposition approach. The pump–, gravity–, and solar–driven oil–water separation devices based on the fabricated cubic composites were also demonstrated, particularly the separation of high–viscosity oil–water mixtures via the solar–driven mode, demonstrating the broad prospects of such modified sponges in actual applications. This study provides a new avenue for rationally designing novel oil adsorption and separation materials.