Up-Cycling Plastic Waste into Reusable Super-Sorbents

Abstract

Pollution caused by plastic waste and oil spills has been a primary environmental concern. One of the remedies to address this issue is to upcycle plastic waste into super oil sorbents. Herein we report a reusable super oleophilic oil sorbent that was prepared using a simplified two-steps technique: (a) isolating and quantifying polyolefins from the plastic waste stream and (b) preparing oil sorbent by dissolving polyolefins and dispersing inorganic filler followed by spin coating and annealing. The super-sorbent comprises macropores and cavities ranging from 0.5-5 µm and 150-200 µm, respectively, with an average of 600 cavities per cm2. Each cavity can swell twenty times the thickness of the sorbent, thus, acting like a sponge. The sorbent exhibited an oil uptake capacity of 70 to 140 g/g, depending upon the type of sorbate and dripping time, which is superior to commercially available sorbents. Additionally, the sorbent can be squeezed mechanically or manually to recover the sorbed oil, allowing maximum reusability with at least 97% efficiency. Using the integrated technique demonstrated in this work may lead to greater utilization of plastic waste as an abundant source of value-added materials.

Keywords: Plastic Waste, Polyolefins, polyethylene, oil sorbent, polymers