Mucin-Inspired Thermogels for Programmable Nanoplastic Removal in Water Purification

Plastic pollution represents a critical threat to global ecosystems, as fragmentation generates micro- and nanoplastics (NPs) that pose unique ecological and toxicological risks. The detection and removal of NPs from aquatic systems remain a major challenge due to their nanoscale dimensions and extreme dilution. To address this, we developed – inspired by the performance of jellyfish mucus – multifunctional mucin-inspired, amphiphilic bottlebrush copolymers based on oligo(ethylene glycol) acrylate (OEGA) that self-assemble into micelles in aqueous solution. These copolymers exhibit a reversible, temperature-triggered sol-gel-syneresis transition, driven by the terminal OEGA methoxy groups, that enables hydrophobic enrichment of NPs in the collapsing hydrogel matrix. Using fluorophore-labeled polystyrene NPs (PS-NPs; 20, 100, and 1 000nm) as a model system, removal efficiencies of 68 -100% were achieved, dependent on NP size and copolymer composition, and were further enhanced by activated carbon. The scalability of the approach for treating large water volumes was demonstrated by employing pre-collapsed hydrogels under passive filtration conditions, achieving capture efficiencies >70% within 24 h. Furthermore, NP enrichment is essential for water analysis. Upon cooling, dissolution of the collapsed hydrogel matrix enables on-demand release of the captured NP, achieving recovery efficiencies up to 61% via ultracentrifugation (UC) for subsequent trace analysis. Finally, chemical functionalization with charged groups enabled selective dye capture, demonstrating the system’s versatility as a modular, programmable platform for next-generation water purification technologies.