Responsive photonic gels based on block copolymers

Abstract

Self-assembly of block copolymers has been widely employed in the fabrication of various 1D, 2D and 3D photonic crystals by utilizing the abundant morphologies of block copolymers. When one or both domains of block copolymers were swollen with a significant amount of diluents, they form photonic gels. Comparing with conventional dry polymer or inorganic photonic crystals, photonic gels are very flexible and responsive to the various external stimuli. Especially, polyelectrolyte block copolymer 1D photonic gels swollen with solvents exhibited extremely large tunability of optical properties by chemical, mechanical, thermal, and electrical stimuli. These unique features have been proved to be useful for applications in sensors and displays. In this chapter, we will reviewthe recent works on block copolymer photonic gels. The scope of this review will cover (1) theoretical background of photonic stopbands, (2) fabrication and characterization of photonic gels by self-assembly, and (3) various applications of photonic gels in sensors and displays.