Cellulose nanofibril-loaded filter paper for highly efficient removal of microplastics via multiscale capture mechanisms.

Microplastics (MPs) have emerged as a critical environmental issue, given their pervasive distribution across the global biosphere and emerging risks to ecosystems and human well-being. Herein, cellulose nanofibrils-loaded filter paper (C/FP) composite was constructed by facile vacuum filtration technique to achieve MPs remediation from aqueous environment. The C/FP composite showcased filtration efficiency of >93 % for polystyrene (PS), polypropylene (PP) and polyethylene terephthalate (PET). Mechanistic investigation revealed that this excellent capture performance was driven by multiscale interactions involving physical interception, electrostatic interaction and hydrogen bonding. Molecular dynamics simulation further demonstrated that both van der Waals (vdW) and coulomb interactions between C/FP and PS facilitated the efficient capture of MPs. Meanwhile, the C/FP composite exhibited impressive reusability with stable filtration efficiency of 96 % after ten cycles. Moreover, higher filtration efficiency (99 %) was maintained even in real rivers and lakes, which exemplified good adaptability to various water bodies. Overall, this work establishes a cellulose-based filter framework for understanding colloidal interactions in microplastic remediation, showcasing promising applications in drinking water purification and microplastic separation from complex aquatic systems.