Earth-Abundant Kaolin Derived Antiviral Coating via Triple Synergistic Capture–Inactivate–Block Mechanism

Abstract

Antiviral coating translation is constrained by additive aggregation and resin incompatibility. We upgrade natural kaolin into an efficient antiviral additive via thermal activation and one-pot ball milling with copper precursors, yielding amorphous metakaolin uniformly decorated with copper particles (Cu Ps). This solvent-free protocol suppresses Cu Ps agglomeration and ensures homogeneous dispersion within silicone–acrylic binders, essential for coating integrity. The metakaolin scaffold serves as a high-affinity viral capture platform, while anchored Cu Ps synergistically generate superoxide radicals (•O2–) and sustain localized Cu+/Cu2+ release, enabling dual-modal oxidative inactivation. Combined with the resin’s physical barrier, this capture–oxidize–block mechanism delivers >99.9% inactivation of influenza A H3N2 and enterovirus EV-71 under ambient conditions. The composite supports kilogram-scale production (2.22 kg batch), maintains full activity after >6000 washing cycles, and passes dermal safety tests. This work transforms a low-cost clay mineral into a structurally engineered antiviral material and provides a scalable route that overcomes persistent manufacturability and durability limitations in surface protection.