Microplastics produced from the environmental weathering of plastic waste are currently considered as environmental contaminants of emerging concern. Laboratory-based plastic weathering studies under simulated environmental conditions provided evidence for the formation of nanosized plastic particles. Therefore, nanoplastics might be as widespread in the environment as microplastics, although they remain largely undetectable, limiting our capacity to generate knowledge regarding nanoplastics exposure. Nanoplastics are currently beyond the capacity of available filtration materials, and their size is too small to be detected by the spectroscopic techniques used in the analysis of microplastics.
Magnetic Zeolitic Imidazolate Frameworks nanocomposites (Fe@ZIFs) allowed the highly efficient aggregation and subsequent magnetic removal of microplastics from water. On depending on the metal used to build the desired Fe@ZIF additional features can be integrated into the nanocomposite material. One example is the ability of Fe@ZIF-8 to magnetically remove polyethylene terephthalate (PET) nanoplastics from water and subsequently catalyse their depolymerization through a glycolysis reaction, enabling their quantification using liquid chromatography at parts-per-million concentration levels. Another relevant example is the capacity of Fe@ZIF-67 to integrate an advanced oxidation process, degrading the organic pollutants present in the sample, with the subsequent magnetic removal of micro/nanoplastics for further sample processing. The overall aim of this contribution is to showcase recent research examples developed in our group towards micro/nanoplastics separations using advanced porous magnetic nanomaterials.