Coupling Carbon-Based Composite Phase Change Materials with a Polyurethane Sponge for Sustained and Efficient Solar-Driven Cleanup of Viscous Crude Oil Spill

The efficient cleanup of crude oil spills is a worldwideproblemdue to their high viscosity and low fluidity. Under the assistanceof solar radiation, adsorbents with in situ heatingfunction are becoming the ideal candidates to solve this problem.In this study, a new strategy coupling a polyurethane (PU) spongewith phase change materials (PCMs) is proposed to realize the efficientutilization of solar energy and crude oil cleanup. Wormlike carbonnanotubes/mesoporous carbon (CNTs/MC) with a core-shell structurewas used to encapsulate polyethylene glycol (PEG), which was thenintroduced into the PU sponge for photothermal conversion and thermalstorage. After coating with a polydimethylsiloxane (PDMS) layer, thesponge was further endowed with hydrophobic characteristics. Additionally,PDMS can function as a binder between PEG@CNTs/MC and sponge skeleton.The resulting PEG@CNTs/MC/PU/PDMS (named as PEG@CMPP) exhibited excellentphotothermal conversion and high absorption capacity for high-viscositycrude oil. Most importantly, thanks to the heat storage propertiesof PEG, the stored heat can be sustainably transferred to the surroundingcrude oil to promote its continuous absorption even under insufficientlight intensity conditions. The crude oil absorption capacity of PEG@CMPP-3reached approximately 0.96 g/cm(3) even after the light sourcewas removed, which manifested the distinctive advantages comparedto the conventional photothermal adsorbent. The proposed approachintegrates the high efficiency of solar-assisted heating and energy-conservingadvantage, thereby providing a feasible strategy for highly efficientremediation of viscous crude oil spills.