3D-printed flexible thermoplastic polyurethane membrane for ultrafast oil/water separation

The purification of oily wastewater from diverse industries emerges as a critical solution to alleviate the existing freshwater crisis. Advanced oil–water separation techniques, including membrane separation, have garnered significant attention for their high efficiency, low energy consumption, and ease of maintenance. Notably, the integration of superhydrophobic surfaces in membrane fabrication has shown promise in enhancing separation performance. However, conventional methods often fail to ensure long-term wear resistance and scalability, necessitating innovative strategies for membrane preparation. In this context, 3D printing technology, particularly selective laser sintering (SLS), presents a novel approach for the tailored production of hydrophobic membranes. By leveraging the inherent properties of thermoplastic polyurethane (TPU) and thermoplastic elastomers (TPE), untreated polymer powders can be directly sintered into intricate porous structures with micro-nano rough surfaces, exhibiting superior oil–water separation capabilities. The fabricated 3D-printed membranes demonstrate exceptional hydrophobicity and oleophilicity, coupled with robust chemical, environmental, and mechanical properties and high separation efficiency (>99.3 %) at an impressive separation flux of 3.23 × 10 5 L·m −2 ·h −1 under gravity-driven conditions. Furthermore, the eco-friendly nature and scalability of this approach hold promise for large-scale implementation, signaling a significant step towards sustainable environmental development.