Robust mussel-inspired LBL carbon nanotube-based superhydrophobic polyurethane sponge for efficient oil–water separation utilizing photothermal effect

Abstract

Superhydrophobic materials possessing efficient and rapid oil–water separation capabilities, as well as robustness, have emerged as the epicenter of global attention. Conventional three-dimensional adsorbent materials often succumb to impaired performance under extreme environmental conditions, rendering it arduous to ensure the efficacy of oil–water separation, and confining the application scenarios. In this study, polyurethane sponges (PUs) co-modified with stearic acid (SA), polydimethylsiloxane (PDMS), and multi-walled carbon nanotubes (MWCNTs), designated as SA-PDMS/MWCNTs@PU (SPMPU), were successfully synthesized via layer-by-layer (LBL) self-assembly and liquid-phase deposition. The SPMPU sponge exhibits an overall separation efficiency of not less than 90 %. It boasts a stable adsorption capacity, formidable mechanical properties, and commendable reusability. SPMPU sponges maintain unparalleled stability in extreme environments, such as strong acids and alkalis, and in the photothermal effect experiment, the SPMPU sponge can attain a temperature of 101.5 °C within 2 min, with rapid reaction kinetics, high efficiency, and unwavering stability. Through the photothermal effect-assisted oil–water separation, a reliable solution is furnished for the current oil–water separation endeavors. The SPMPU sponge preparation is uncomplicated, economical, and yields stable performance, holding significant potential for application in marine oil spills and industrial oil–water separation scenarios.