Hydrophilic oil-absorbent with macroscopic pores for recovery of high-viscosity oil*

Oleophilic absorbents are widely utilized in most oil spills for cleaning up, small pore size of these oleophilic absorbents presents challenges in recovering high-viscosity oil from the ocean. Additionally, the difficulty in taking back the recovered oil from the absorbent causes a secondary pollution that they are supposed to be burnt. In this talk, we present a hydrophilic absorbent that can recover high-viscosity oils by its millimeter-scaled pore. To determine the optimal pore size, we systematically tuned the pore size in a millimeter scale by 3d printing technology. Polydopamine coating was then applied to provide a hydrophilic surface. To present, hydrophilic oil-absorbent have a better oil-recovery capability than conventional oleophilic absorbents. They also show unique reusability by virtue of the water film which helps to detach oil from the absorbent when an impulsive vibration is applied. Moreover, it is observed that the hydrophilic oil-absorbent can recover more oil as the absorbent thickness increases, which is hard to be realized by using the oleophilic absorbent. Hydrophilic oil-absorbents have an additional advantage in oil-recovery compared to oleophilic absorbents as the thickness of the absorbent increases.