Photoactive Lignin-Derived Nanolayers for Camouflaged Bioaromatic Interfaces

Bioaromatic polymers derived from lignin have largely been confined to bulk materials or dispersed (nano)particles, limiting their ability to control interfacial phenomena at the nanoscale. Here, we establish lignin as a platform for programmable photoactive bioaromatic nanolayers that form transferable interfaces across solid, liquid, and soft matter substrates. Depolymerized lignin is chemically functionalized and hybridized with a glycerol-derived triglycidyl ether to yield homogeneous bioresins that can be directly UV-cured into conformal nanoconfined networks. These coatings form nanometer- to micrometer-thick interfaces combining mechanical robustness, water repellency, and conformal integration across rigid substrates, elastomers, and hydrogels. The hybrid aromatic-aliphatic architecture enables both stiffness and conformability, supporting stable performance under deformation and in aqueous environments. Ultrathin confinement renders the inherently colored lignin network visually imperceptible under ambient light while preserving its interfacial functionality. The bioaromatic network exhibits intrinsic fluorescence without external dyes, enabling wavelength-dependent optical logic, invisible patterning, and light-addressable surface functions. This work establishes a general strategy to transform lignin into multifunctional interfacial nanomaterials, opening new opportunities for sustainable coatings, photonic surfaces, and multifunctional hydrated interfaces.