Strong and Sustainable Supramolecular Nanofiber Assembling in Acoustic Flow Field

Hierarchical assembly of polysaccharides into nanofiber is at the core of generating advanced biomimetic nanomaterials. However, the artificial synthesis of supramolecular nanofiber from polysaccharides remains an open challenge due to their complicated structure, irregular, and strong interaction. Herein, by mimicking the assembly of natural macromolecules in an out-of-equilibrium state, supramolecular nanofiber is successfully fabricated from natural polysaccharides through regular and strong interaction, and a high-energy and oriented flow field. The high energy of ultrasound can surmount the energy landscape of dynamically stable electrostatic interaction among polysaccharides, while the acoustic-oriented streaming overcomes the disordered arrangement of macromolecules, thus inducing the orderly arrangement of polysaccharide chains to form kinetically stable nanofibers. The kinetically trapped assembly and the resulting structural evolution can be monitored by scattering and imaging experiments, while the microscopic mechanism can be confirmed by theoretical simulation. Mechanically strong, water-resistant, and humidity stimulus-responsive bioplastic film can be fabricated from the supramolecular nanofibers. The discoveries provide critical insights into the assembly of polysaccharides into supramolecular nanofibers and open up many possibilities to prepare advanced nanomaterials from natural polysaccharides.