Supramolecular co-assembly of cellulose acetate networks via interfacial hydrogen-bonding engineering for super-strong, high-barrier and multi-emissive intelligent packaging.

Developing eco-friendly and sustainable structural bioplastics from natural resources is a paramount trajectory to mitigate the environmental crises posed by petroleum-derived plastic waste. However, the inherent brittleness and poor gas-barrier properties of raw polysaccharides severely impede their practical applications in advanced packaging scenarios. Herein, an interfacial supramolecular co-assembly strategy is established to fabricate smart, biodegradable, and super-strong cellulose acetate structural films by introducing an ultra-low loading <2% of a tailored rigid chromophore, 1-aminoanthraquinone (AAQ). Benefiting from the precise match of the donor-acceptor domains, a highly dense and intertwined intermolecular hydrogen-bonding network was successfully constructed across the CA-AAQ interfaces. The tight restriction of intramolecular motion and alteration of the excited-state intramolecular proton transfer pathways endow the films with noteworthy wavelength-dependent fluorescence, enabling vivid transition from day-light wheat color to deep yellow (254 nm), peach (300 nm), and purple (365 nm) under UV excitations. Further, the CA-AAQ film revealed much improved water vapor penetrability of 4.480 × 10-15 g·mm/m2·day·kPa and O2 transmission rate of 0.2095 cm3·μm/m2·day·kPa, respectively, compared to CA film having water vapor penetrability of 1.088 × 10-14 g·mm/m2·day·kPa O2 and transmission rate of 0.6635 cm3·μm/m2·day·kPa. This work provides a promising strategy for designing high-performance bioplastic materials targeted at next-generation intelligent packaging applications.