Solar-heating superhydrophobic sponge based on size-controllable polydopamine nanoparticles for fast crude oil recovery and photothermal deicing

In the wake of recurring oil spills causing devastating environmental and ecological damage, there is an urgent need for efficient oil spill remediation strategies. Conventional absorbents are often ineffective in harsh environments and struggle with the recovery of high-viscosity crude oil at room temperature. Although photothermal absorbents can greatly improve the fluidity of crude oil, their practical applications are still limited due to complicated preparation processes, hazardous fluorinated reagents, and secondary pollution. This study introduces a facile, one-step dip-coating method to develop a photothermal superhydrophobic melamine sponge (MS), incorporating a fluorine-free suspension of polydimethylsiloxane (PDMS), siloxane-containing acrylate copolymers (SAC), and polydopamine nanoparticles (PDA NPs). The resulting PDMS/SAC-PDA@MS shows an exceptional water contact angle (WCA) and significant self-cleaning abilities due to its superhydrophobicity. With superior mechanical and chemical durability, the sponge achieves remarkable oil absorption (up to 102.6 times its weight) and efficient oil/water separation. Crucially, under solar irradiation, the sponge's surface temperature reaches 87.6 °C, effectively reducing oil viscosity and enabling rapid cleanup of oil spills and active deicing. This study presents a green, economical approach to synthesizing photothermal superhydrophobic adsorbents with potential applications in environmental cleanup and active deicing.