Facile preparation of durably magnetic superhydrophobic sponge and its application in oil-water separation

Herein, a stable three-dimensional composite sponge with magnetic and superhydrophobic was prepared via a two-step process including self-polymerization of dopamine (DA) and anchoring of Fe 3 O 4 particles assisted by polydopamine (PDA) and polydimethylsiloxane (PDMS). The modified sponge exhibited high adsorption capacity (52.39–91.52 g/g) for diverse oils and organic solvents , which can be easily recovered in oil-water mixture under magnetism . The excellent properties were attributed to the synergistic effect of micro-nano structures and low surface energy, which were derived from the coatings of PDA and Fe 3 O 4 and hydrophobic methyl groups of PDMS, respectively. When the temperature of PDA coating was 40 °C, the water contact angle (WCA) of the prepared superhydrophobic sponge reached 152.74 ± 0.2°. More importantly, the present adsorbents possessed robust chemical, mechanical, and temperature stability at a harsh environmental and good reusability for oil-water separation after 12 cycles of repeated adsorption, which enable to deal with oil leakage under harsh conditions still maintaining the excellent performance.