Precisely Tunable Photonic Pigments via Interfacial Self-Assembly of Bottlebrush Block Copolymer Binary Blends
Xi Chen, Dong‐Po Song, Yue‐Sheng Li
Abstract
Binary blends of two different amphiphilic bottlebrush block copolymers (BBCPs) with relatively high- and low-molecular weights (MWs) are demonstrated to stabilize ordered water-in-oil-in-water (w/o/w) multiple emulsions, templating ordered porous microparticles upon solidification. Despite the shape-persistent nature of BBCPs, uniform internal w/o droplets are obtained through co-assembly of the high-MW BBCP and the low-MW one at the highly curved w/o interface. The spherical curvature of internal droplets is well manipulated simply by variation of the relative ratio of the two different BBCPs, resulting in photonic microparticles with reflected colors precisely tunable in the whole visible spectrum. The efficiency of color tuning can be greatly enhanced with a slightly increased difference in MW when the ratio of MWs is no larger than two. This work provides a highly efficient strategy for obtaining precisely tunable photonic pigments, which eliminates the requirement of multiple time-consuming polymer synthesis and lowers the cost of photonic pigments.