Local stress-assisted fabrication of supramolecular structural color materials for anti-counterfeiting applications

Supramolecular colloidal photonic crystals possess the advantages of both photonic crystals and supramolecular materials to prepare dynamically reversible structural color materials with high flexibility, functionality and recyclability. However, the driving force for the ordered arrangement of colloidal nanoparticles is limited since the significant increase of the viscosity in the system, consequently the shear-induced technique with complicated equipment needs to be applied to achieve the assembly of colloidal nanoparticles. Herein, we report a local stress-assisted assembly strategy for fabricating high-performance supramolecular colloidal photonic crystal films without the need of complex shearing equipment. The introduced local stress promotes the rapid dissociation of disordered colloidal aggregates, enabling the formation of highly ordered colloidal arrays through electrostatic interactions and solvation layers. Based on this strategy, a series of functional supramolecular structural color materials have been fabricated, demonstrating unique applications in display, anti-counterfeiting, and information encryption with the excellent recyclability and reusability.