Kinetic Molecular Modulation of Highly-Aligned Self-Locking Nanofibers for Strong, Tough, and Transparent Bioplastic Films

Cellulose-based bioplastic films have long been considered a promising alternative to unrecyclable plastics. However, the failure to harness their full potential of hydroxyl-rich nature causes weakness and brittleness, restricting their successful applications. Inspired by natural bamboo, a supramolecular engineering strategy is proposed to modulate the self-assembly kinetics of cellulose chains for simultaneously reinforcing and toughening cellulose films. A loosely-structured amorphous molecular network is first constructed to enable dynamic rearrangement, and then the stretching field induce the formation of highly-aligned nanofibers, resembling a natural snap-fit self-locking system. As a result, the highly-aligned and tightly-stacked nanofiber imparts transparent cellulose films with an increase of exceeding 300% in fracture toughness to 6.82 MJ·m −3 and an impressive tensile strength of 176 MPa, surpassing the most previously reported fully regenerated cellulose films. This pioneering approach of kinetic molecular modulation opens up a new perspective for high-performance, transparent, and truly sustainable bioplastic films and beyond.