Up-cycling plastic waste into swellable super-sorbents

Environmental pollution caused by plastic waste and oil spills has emerged as a major concern in recent years. Consequently, there has been a growing interest in exploring innovative solutions to address these challenges. Herein, we report a method to upcycle polyolefins-based plastic waste by converting it into a bimodal super-oleophilic sorbent using dissolution, spin-coating, and annealing techniques. The resulting sorbent possesses an extensive network of pores and cavities with a size range from 0.5 to 5 µm and 150–200 µm, respectively, with an average of 600 cavities per cm². Each cavity can swell up to twenty times the thickness of the sorbent, exhibiting sponge-like behavior. The sorbent had an oil uptake capacity of 70–140 g/g, depending on the type of sorbate and dripping time. Moreover, the sorbent can be mechanically or manually squeezed to recover the sorbed oil. Our integrated methodology provides a promising approach to upcycling plastic waste as an abundant source of value-added materials.