Efficient recovery of highly viscous crude oil spill by superhydrophobic ocean biomass-based aerogel assisted with solar energy

The crude oil spills is one of the crucial ocean environmental disaster. The low fluidity of high-viscosity crude oil poses significant challenges for its penetration into conventional porous adsorption materials. Fortunatelly, the viscosity of crude oil is especially temperature-sensitive, leading to the extensive research on porous materials that utilize solar heat for heat generation. In this work, we propose a biodegradable marine bio-based aerogel (PDMS-Ink@CS) with aligned channel structure via directional freeze casting technique, primarily composed of chitosan and cuttlefish ink. The PDMS-Ink@CS demonstrates excellent photothermal conversion and oil adsorption performance. We systematically investigated the effects of sunlight intensity and pore structure on the viscosity-reduction and adsorption rate of crude oil. Under simulated sunlight intensity of 1 kW m−2, the surface temperature of PDMS-Ink@CS aerogel reaches approximately 70 ℃ within 60 s, allowing to absorb crude oil 18 times its weight and recover via extrusion. When combined with a vacuum pump device, the PDMS-Ink@CS aerogel realizes the continuous recovery of crude oil from the seawater surface. Moreover, the separation efficiency of PDMS-Ink@CS aerogel for W/O emulsions can reach 99 %, which greatly broadens its range of applications. Particularly noteworthy is the fact that the PDMS-Ink@CS aerogel biodegrades within 30 days without causing environmental pollution. Thus, this super-hydrophobic ocean biomass-based chitosan aerogel exhibits vast potential for oil spill recovery applications.