All biomass-based superhydrophobic aqueous coatings enabled by lignin-containing nanocellulose

Achieving sustainable superhydrophobic surfaces remains a major challenge due to the pervasive use of fluorinated, silane, or nanoparticle-based modifiers that rely on toxic or non-degradable components and organic solvents. Here, we report an all-biomass, aqueous strategy for constructing multifunctional superhydrophobic coatings based on lignin-containing dissolution-regenerated nanocellulose (LDNC). LDNC, prepared via the co-dissolution and co-regeneration of cellulose and lignin, exhibits excellent water dispersibility and amphiphilicity. This unique structure enables stable emulsification of beeswax and facile spray fabrication of an all-biobased superhydrophobic coating. The resulting coated paper exhibits excellent water resistance and moisture barrier properties, effectively preventing food deterioration under high humidity and extending shelf life. Additional functionalities such as photothermal de-icing and antibacterial activity are imparted, making the coating highly suitable for food packaging. Together, this work introduces a solvent-free, fully bio-based pathway to superhydrophobic coatings, bridging functionality with sustainability and offering a scalable route toward next-generation green surface protection and packaging materials.