Supramolecular Assembly of Multifunctional Collagen Nanocomposite Film via Polyphenol-Coordinated Clay Nanoplatelets

Functional bionanocomposites have evoked immense research interests in many fields including biomedicine, food packaging, and environmental applications. Supramolecular self-assembled bionanocomposite materials fabricated by biopolymers and two-dimensional (2D) nanomaterials have particularly emerged as a compelling material due to their biodegradable nature, hierarchical structures, and designable multifunctions. However, construction of these materials with tunable properties has been still challenging. Here, we report a self-assembled, flexible, and antioxidative collagen nanocomposite film (CNF) via regulating supramolecular interactions of type I collagen and tannic acid (TA)-functionalized 2D synthetic clay nanoplatelets Laponite (LAP). Specifically, TA-coordinated LAP (LAP-TA) complexes were obtained via chelation and hydrogen bonding between TA and LAP clay nanoplatelets and further used to stabilize the triple-helical confirmation and fibrillar structure of the collagen via hydrogen bonding and electrostatic interactions, forming a hierarchical microstructure. The obtained transparent CNF not only exhibited the reinforced thermal stability, enzymatic resistance, tensile strength, and hydrophobicity but also good water vapor permeability and antioxidation. For example, the tensile strength was improved by over 2000%, and the antioxidant property was improved by 71%. Together with the simple fabrication process, we envision that the resulting CNF provides greater opportunities for versatile bionanocomposites design and fabrication serving as a promising candidate for emerging applications, especially food packaging and smart wearable devices.