Magnetic, superelastic and superhydrophobic porous thermoplastic polyurethane monolith with nano-Fe3O4 coating for highly selective and easy-recycling oil/water separation

Magnetic, superelastic and superhydrophobic porous thermoplastic polyurethane (TPU)-based monolith was fabricated by immobilizing Fe3O4 nanoparticles (NPs) onto its skeleton and dip-coating with low-surface-energy trimethoxy (1H, 1H, 2H, 2H -heptadecafluorodecyl) silane (FAS). Due to unique hierarchical porous structure and hydrophobic surface chemistry, the as-prepared TPU/Fe3O4 @FAS monolith possessed superhydrophobicity (153 degrees) and high saturated absorption capacities of 6.0-41.1 g g(-1) for oils/organic solvents. Besides, the absorbency and hydrophobicity of magnetic monolith exhibited excellent chemical/thermal stability in harsh environments. The compressive elasticity and fatigue resistance of porous monolith were prominently improved because of the rigid Fe3O4 NPs coated onto its skeleton. Coupling with the magnetically driven attraction endowed by Fe3O4 NPs, the TPU/Fe3O4 @FAS monolith revealed convenient recyclability via magnetic collecting and mechanical squeezing. Moreover, the absorbed monolith revealed high oil/water separation efficiency of over 99.1% after 50 cycles. On the basis of these outstanding properties, TPU/Fe3O4 @FAS monolith has huge potential in oily wastewater treatment application.

Automated summary

A magnetic, superelastic, and superhydrophobic porous thermoplastic polyurethane monolith was successfully fabricated, demonstrating excellent performance in adsorbing oils/organic solvents, chemical/thermal stability, and high recyclability. This monolith also displayed high oil/water separation efficiency and has great potential for oily wastewater treatment applications.