A toughening indole‐based epoxy film with efficient anti‐counterfeiting properties driven by cation–π interaction

A strong and tough indole‐based epoxy film driven by cation–π interaction is designed, evading the trade‐off between stiffness and extensibility in epoxy resins. The film with high strength, toughness and effective anti‐counterfeiting properties induced by cation–π interaction is promising in the development of the fields of aerospace and electronic devices. © 2023 Society of Industrial Chemistry. A strong and tough indole‐based epoxy film driven by cation–π interaction is designed and prepared, endowing epoxy resins with effective anti‐counterfeiting properties.