Monomer-biased manufacture of industrial-scale colloidal photonic films

Complex functions in nature arise from the ordered assembly of simple building blocks. Transformation of colloidal aggregates into industrial-scale photonic crystals under rapid ambient conditions remains challenging owing to high energy barriers and limited assembly control. In this study, common monomers act as mediators that lower these barriers and bias ambient shear-induced ordering within seconds. This enables in situ processing compatible with roll-to-roll manufacturing of colloidal photonic crystal films with tunable mechanical properties. Robust 15-micrometer-thick films, incorporating a supramolecular matrix, can be produced up to 4000 meters long and 1.3 meters wide at a rate of 25 meters per minute. These combine vivid structural color and high transparency (>90%) with mechanical robustness and rapid self-healing, demonstrating a scalable route to high-quality colloidal photonic materials.