Monodisperse and size-regulable nanoparticles by polymerization-induced self-assembly for printable colloidal photonic crystals†

Colloidal photonic crystals (CPCs) have attracted much attention due to their distinctive and vibrant structural colors. Precise control over the size and dispersity of nanoparticles is vital for high quality CPC patterns by bottom-up colloidal self-assembly. The polymerization-induced self-assembly (PISA) method has emerged as a promising strategy for preparing nanoparticles of specific morphology and size with good adaptability to a wide range of monomers and solvents. Nevertheless, achieving monodisperse particles with a specific particle size to fabricate structural color patterns by PISA remains a challenge. In this study, we present a novel aqueous PISA approach that enables the large-scale preparation of monodisperse nanospheres (diameter polydispersity <1.001) and the fabrication of printable CPCs. The method allows for the large-scale preparation of uniform polymeric nanoparticles with precise size control, thus enabling accurate manipulation of structural colors. The aqueous dispersions were used as inks to print structural color patterns on paper substrates, achieving photonic patterns with characteristic angle-dependent and water-responsive color variations. This study highlights the significant potential of the PISA method in advancing the fabrication of functional colloidal materials and expanding the application of CPCs.