Hybrid microfibrillar green fluff for efficient capture of realistic micro/nanoplastics and post-use valorization

Micro/nanoplastics (MNPs) represent an emerging environmental challenge due to their widespread occurrence, persistence, and potential impacts on ecosystems. Despite increasing efforts toward their mitigation, the development of advanced materials capable of efficiently capturing environmentally relevant MNPs while enabling sustainable end-of-life management remains a major challenge. In this study, a circular approach for MNPs mitigation was developed by designing polymer-based hierarchical filters capable of both efficient particle removal and post-treatment valorization. Polypropylene (PP) and polyethylene terephthalate (PET), selected as representative polymers of common plastic waste streams, were melt blended to achieve a poor self-compatibilization and subsequently processed via melt spinning to produce spheroidal porous fluff (P = 98.4%) filters through a vortex-assisted assembly process in water. The resulting balance between polymer miscibility and immiscibility enabled the formation of a hybrid, hierarchical, microfibrillar structure while preserving fiber integrity. Environmentally relevant MNPs mix were produced from post-consumer plastic products, by environmental aging. The developed fluffs demonstrated effective removal of MNPs mix over multiple cycles (RE = 96.5%), attributed to their hierarchical morphology and favourable physico-chemical interactions between the polymeric matrix and plastic particles. Furthermore, the possibility of valorizing post-consumer filters was demonstrated by exploiting captured MNPs as active sorbents for the removal of organic contaminants, using paracetamol (PCM) as a model pollutant, achieving PCM removal of 50.6% in recirculation strategy. This possibility offers new perspectives for the synergistic removal of complex pollutant mixtures from aquatic environments.