On‐Site Surface Coordination Complexation via Mechanochemistry for Versatile Metal–Phenolic Networks Films

The development of functional metal–phenolic networks (MPNs) films by a simple and green strategy on metallic plane substrates for surface modification is a big challenge. Herein, tribochemistry, as an effective and robust method to prepare MPNs films with versatile applications and controllable thickness (≈1.5 nm to 2.2 µm) by surface coordination complexation derived from tannic acid (TA) and metal oxides or ions (M) on plane substrates, is reported. The mechanism of the formation of TA‐M films is investigated in detail, showing that films are constructed by two‐layer structures. At the bottom of films, the chelation of TA active moieties and M is triggered by friction, facilitating the coating growth and reducing the friction coefficient. There is a downward trend in the concentration of M with the thickness of films increasing, which is attributed to the diffusion of metal ions. As a result, the dominant structure of films changes into the hydrogen bonding or π–π stacking interaction among oligomers derived from coupling of the TA active moieties. Such facile surface modification strategy can broaden in situ mechanochemical synthesis of functional layers and open a promising route for the design of patterning, antifouling, and controlled release coatings. A new finding is that metal–phenolic networks films are constructed by two‐layer structures, with cooperation of mechanical and chemical effects on various metal surfaces via tribochemistry. The polyphenolic films prepared with green and clean approach can provide a versatile platform for their versatile applications and meet industrial demands without environmental pollution.