| 초록 |
Materials with hysteresis, showing bistability to the external stimuli, have been widely investigated due to their potential applications. Herein we report tunable block copolymer photonic gels exhibiting optical hysteresis in response to the change of the external stimuli such as pH and electric field. As a model system, we used PS-b-P2VP block copolymers forming lamellar structures. The photonic gel films prepared from PS-b-P2VP show a strong reflectance in aqueous solution and the band position was varied with chemically or electrically induced pH gradient. Interestingly, a very strong optical hysteresis was observed while the stop bands were tuned by pH. Taking advantage of the hysteric responses of photonic gels, we demonstrated photonic pixels which exhibit stable nonvolatile photonic colors. We anticipate that tunable photonic gels with hysteresis can be applicable to novel applications such as a component of memory devices, photonic switches, e-papers or drug delivery vehicles. |
