Recent progress in responsive photonic crystals of block copolymers.

Responsive block copolymer photonic crystals (BCP PCs) have a tunable photonic band gap (PBG) and structural colour under external stimuli, enabling their wide applications in bionics, sensing, display, and others. In this review, we summarize the recent progress in the preparation and applications of responsive BCP PCs. The effect of molecular weight, molecular architecture, and additives on the optical performance of BCP PCs is discussed. Then, we review the responsiveness of BCP PCs to mechanical, electric, thermal, solvent, humidity, and ionic stimuli. Moreover, we highlight the responsive PC microparticles prepared by the three-dimensional confined assembly of BCPs. Finally, we discuss the current challenges and perspectives in this field. [ABSTRACT FROM AUTHOR]