블록공중합체 포토닉젤의 전기적 히스테리시스를 통한 비휘발성 디스플레이 픽셀의 제조 와 마이셀 효과에 의한 각 자유도를 가지는 블록공중합체

Abstract

Responsive photonic crystals have been of great interest due to their potential applications in sensors, displays and optoelectronics. Recently our group developed photonic gels which are responsive to various chemical stimuli. Extending the work, we report electrically tunable photonic gels which exhibit bistability against applied electric signals. Electrically tunable photonic gels were prepared from self-assembly of polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymers. The position of photonic band gap (PBG) was tuned by controlling swelling/deswelling of P2VP layers via modulating the extent of ionic crosslinking with electrical signal. The extent of crosslinking within the photonic gels can be controlled by redox control of anions. In this presentation, we demonstrate that electrochemical control of ionic crosslinking is effective for tuning of photonic stop bands in the photonic gel films and developing optical bistability Photonic crystals have been of great interest not only because of their unique optical properties but also because of their broad engineering applications. Although various photonic crystals with different geometry from simple 1D to complicate 3D have been demonstrated so far, most practical applications are still limited to the 1D photonic crystals due to their facile fabrication. Despite such merit, a significant drawback of 1D photonic materials hinders their applications in sensors and displays. 1D photonic crystals intrinsically show strong angle dependent optical behaviors. For example, the photonic stop bands gradually shift to the shorter wavelength regime as decreasing incident angle of light. Herein, we report 1D block copolymer photonic gels exhibiting strong angle independent photonic colors.