Sorting Commodity Plastics by MOF-based Molecular Sieving
Year: 2026
Type: preprint
Abstract: Efficient sorting of waste plastics according to their chemical structure is desirable for plastics recycling. Here, we present a novel methodology based on a molecular sieving mechanism to realize molecular-level sorting of polymer chains. Using nanopores in metal–organic frameworks (MOFs) as the sieve, polymer chains are differentiated by their thickness and branching structure through selective infiltration into the nanopores in the molten state. The infiltration process is evaluated in situ and semi-quantitatively via continuous monitoring of relative diffraction intensity from the MOF using variable-temperature X-ray diffraction. Three MOFs with varying effective pore window diameters are identified as promising candidates that enable sequential sorting of four highly important commodity plastics: low-density polyethylene, polystyrene, polypropylene, and high-density polyethylene. This work would open up a new paradigm in the field by providing a versatile method capable of sorting the waste plastics mixture with molecular-level precision.
Source: ChemRxiv
Institution: The University of Tokyo
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7216476349