Mechanically Robust MXene‐Metal Polyphenol Network Hybrid Interfaces for Multifunctional Protection of Keratin Fibers

ABSTRACT Keratin is a fibrous protein for stabilizing epithelial cell structures and consisted of nail and hair for protecting tissues and organs. Hair keratin fibers protect the scalp, regulate the temperature, and absorb UV. Their surface morphology, gloss, color, and shape also represent an identical outlook of individuals and a healthy state. However, their physicochemical properties are easily damaged by harmful extrinsic factors such as UV exposure, dryness, high‐temperature styling, bleaching, dyeing, and permanent waving. Despite extensive research for hair keratin protection, conventional haircare products can only promote temporal increase of surface gloss, moisture level, and smoothness by weak adsorption of most ingredients on the keratin surface. In this study, we developed a facile and robust coating layer on hair keratin surface with delaminated Ti 3 C 2 MXene nano‐sheets via bio‐compatible metal‐polyphenol networks (MPN) composed of multivalent metal cations and tea catechin, epigallocatechin gallate (EGCG). Owing to the inherent properties of MXene and polyphenol, this composite coating showed versatile functionalities, including UV screening, rapid thermal dissipation, enhanced mechanical strength, reducing charge accumulation, and sustained antioxidation activity. It could also restore the wettability of human keratin fibers. This coating method can be applicable to other 2D nanomaterials for covering bio‐interfaces.