One‐Step Assembly of Versatile Multifunctional Coatings Based on Host‐Guest and Polyphenol Chemistry

Abstract Developing a facile, efficient, and versatile polyphenol coating strategy and exploring its novel applications are of great significance in the fields of material surfaces and interfaces. Herein, a one‐step assembly strategy for constructing novel tannic acid (TA) coatings via a solvent evaporation method is reported using TA and polycyclodextrin (PCD) particles (TPP). TPP with a high phenolic group activity of 88% integrates the advantages of host‐guest and polyphenol chemistry. The former can drive TPP dynamically assemble into a large and collective aggregation activated by high temperature or density, and the latter provides excellent adhesion properties to substrates (0.9 mg cm⁻²). TPP can assemble into a coating (TPC) rapidly on various substrates within 1 h at 37 °C while with a high availability of feed TPP (≈90%). The resulting TPC is not only high‐temperature steam‐sensitive for use as an anti‐fake mask but also pH‐sensitive for transforming into a free‐standing film under physiological conditions. Moreover, various metal ions and functional particles can incorporate into TPC to extend its versatile properties including antibacterial activity, enhanced stability, and conductivity. This work expands the polyphenol coating strategy and builds up a one‐step and efficient preparation platform of polyphenol coating for multiapplication prospects in various fields.