Eco-friendly antifouling membranes via green coordination chemistry: Bioinspired CuII-Juglone@PDA modification membranes

An ecofriendly modification mitigates membrane flux decline and extends operation lifespan. • Cu 2+ –juglone coating imparts efficient antibacterial activity to commercial membrane. • PDA layer enhances membrane hydrophilicity and prolongs antibacterial activity. • The optimal modified membrane exhibits significantly enhanced antifouling performance. Fouling remains a critical challenge limiting the widespread application of membrane technologies in water treatment. This study introduces a synergistic interface engineering strategy for polyvinylidene fluoride (PVDF) membranes by integrating Cu II –juglone coordination chemistry with polydopamine (PDA) coating. Conducted under ambient conditions (25 °C, pH 7.4), this green assembly process constructs a robust Cu II -Juglone network that facilitates dual-mode antibacterial activity while minimizing copper dependency. Subsequent PDA deposition further enhances surface hydrophilicity and ensures sustained antibacterial durability, concurrently mitigating organic foulant adhesion. Comprehensive characterization revealed that the optimized PVDF/Cu II -Juglone@PDA membrane exhibited an ∼8° decrease in water contact angle and a marked increase in surface electronegativity compared with PVDF membrane. These modifications collectively improved resistance to organic foulant adhesion, as evidenced by a 63.4% lower total organic carbon (TOC) accumulation than the pristine membrane. The optimized membrane achieved 95% antibacterial efficiency against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), together with a 39.1% reduction in flux decline under dynamic filtration. This performance arose from synergistic antifouling effects: the PDA layer enhanced hydrophilicity and electrostatic repulsion via a hydration barrier, while the Cu II -juglone layer provided sustained antibacterial activity through metabolic disruption induced by Cu II /juglone release. These combined effects highlight an effective strategy for the eco-friendly fabrication of multifunctional antifouling membranes for sustainable water purification. Download: Download high-res image (221KB) Download: Download full-size image