Circular, Reconfigurable DNA-Surfactant Materials for Coatings with Tunable Oil and Water Barrier Properties

Abstract Commercial coatings for paper often rely on nonrenewable, nonbiodegradable polymers, thereby restricting the end-of-life options of the composite to noncircular pathways. The application of biopolymer–surfactant complexes composed of DNA (deoxyribonucleic acids) and cationic lipids as barrier coatings resolves these issues. The coatings are recoverable and closed-loop recyclable via multiple methods (e.g., dissolution or salt-triggered dissociation) by leveraging the solubility of the complexes and the reversibility of their noncovalent interactions, enabling the reuse of the base material (i.e., paper), coating (i.e., complex), and components (i.e., DNA and cationic lipids). The performance of the coating is tunable by selecting the cationic lipid structure and self-assembly behavior, yielding a range of hydrophobic/hydrophilic and oleophobic/oleophilic properties that can exceed industry requirements (e.g., Kit rating >6). Moreover, the circular, reconfigurable design of the coating during reassembly (i.e., by swapping the original cationic lipid component for another) yields fit-for-purpose coatings. The synthesis and purification of this material system follow numerous principles of green chemistry (e.g., atom economy, less hazardous chemical syntheses, safer solvents and auxiliaries, design for energy efficiency, use of renewable feedstocks, and inherently safer chemistry for accident prevention). Ultimately, the mix-and-match selection of components and their reversible noncovalent interactions enable assembly, disassembly, and reconfigurability, presenting a framework for constructing functional, sustainable, and circular platform materials.