Mucin-Inspired Thermogels for Programmable Nanoplastic Removal in Water Purification

Plastic pollution represents a threat to global ecosystems, as fragmentation generates nanoplastics (NPs) that pose ecotoxicological risks. Their nanoscale size and low concentrations make detection and removal from water challenging. Inspired by jellyfish mucus, we develop amphiphilic bottlebrush copolymers based on oligo(ethylene glycol) methyl ether acrylate (OEGA). These polymers self-assemble into micelles and exhibit a reversible, temperature-induced sol-gel-syneresis transition, capturing NP from solution in situ. Heating triggers hydrogel collapse via terminal OEGA-methoxy groups, enriching hydrophobic NPs within the matrix. Using fluorophore-labeled polystyrene NPs (20-1 000 nm), we achieve removal efficiencies of 68-100%; activated carbon further improves performance. Pre-collapsed hydrogels enable passive filtration, capturing >70% within 24 h. Cooling dissolves the matrix and releases captured NPs, achieving recovery efficiencies of up to 61% after ultracentrifugation for trace analysis. Ionic groups enable selective dye capture, underscoring the system’s versatility as a modular, programmable platform for next-generation water purification technologies.