Robust superhydrophobic resin sponges modified by polydimethylsiloxanes/epoxy-based copolymer for high-efficiency oil/water separation

The development of recyclable, durable and widely adaptable porous hydrophobic materials is of vital importance for the effective separation of leaking oil–water mixtures. Herein, we functionally modified melamine formaldehyde resin sponge (MFRS) with PMMA, PDMS-PMMA and PDMS-PGMA via a facile solution-immersion process. Compared with PMMA-coated MFRS, the improvement of the water contact angle (WCA) and oil–water mixture separation efficiency of PDMS-PMMA/MFRS was sufficient enough to verify that the introduction of PDMS block enhanced the hydrophobic performances. Moreover, the importance of the GMA block in PDMS-PGMA/MFRS was confirmed by the excellent performance of the material in oil–water separation recycling experiments, with 91.5% separation efficiency after 8 runs. The fabricated PDMS-PMMA/MFRS with improved WCA (155°) and oil–water mixture separation efficiency (99.1%) demonstrated superhydrophobic property, which was attributed to the introduction of hydrophobic block PDMS and coating-induced surface geometric folds. Besides, the acid resistance and widely adaptable (efficient separation of various oil–water mixtures) performances of PDMS-PGMA/MFRS were experimentally confirmed. The freely available manufacturing raw materials and facile functionalization process of PDMS-PMMA/MFRS offer possibilities for its adoption in the efficient cleanup of oil spills.