Super-Hydrophobic Macroporous TPU Gels for Oil–Water Separation and Organic Pollutant Adsorption

Abstract

Marine oil spills and plastic waste accumulation represent two critical environmental threats that urgently require integrated remediation strategies. In this work, we address both issues simultaneously by developing a facile, template-free, water-assisted thermally induced phase separation approach to fabricate superhydrophobic macroporous thermoplastic polyurethane (TPU) gels from recycled TPU pellets. Under optimal conditions (8% TPU, 9:1 1,4-dioxane/water, 0 °C, 30 min), the gel exhibits an interconnected macroporous network with ~84% porosity and a BET surface area of 7.67 m2/g. Notably, it achieves intrinsic superhydrophobicity (150.3°) without any additives or surface modifications. The gel shows high absorption capacities (5.39–55.64 g/g), rapid kinetics (equilibrium within 15 s), and excellent recovery efficiency (>97%) in pump-assisted separation. Beyond oil/water mixtures, we systematically investigate trace organic pollutant adsorption from oil-in-water emulsions, achieving up to 97% removal efficiency. This work establishes a closed-loop “waste-to-resource” strategy, positioning recycled-TPU-derived macroporous gels as cost-effective candidates for oil spill remediation and wastewater treatment.