Bio-Inspired Structural Colors Based on Linear Ultrahigh Molecular Weight Block Copolymers

Ultrahigh molecular weight (UHMW) block copolymers (BCPs) are promising candidates for the fabrication of photonic materials. Here, we demonstrate the synthesis and self-assembly capability of well-defined amphiphilic UHMW BCPs with overall molar masses up to 4432 kg mol –1 obtained via living anionic polymerization. BCP micelles featuring hydrodynamic diameters in the range of the wavelength of the visible light to the near-infrared region (300–1143 nm) are used for colloidal crystal formation. By varying the BCP composition, brilliant structural colors can be observed. Microphase separation of the UHMW BCPs in the bulk state reveals uniform domains and showing blue to green structural color transitions. Finally, we provide examples of how BCP structural control can be used to generate reversibly switchable solvatochromatic optical sensors.