Department of Materials Science and Engineering (MSE) and Research Institute of Advanced Materials (RIAM), Seoul National University , 599 Gwanangno, Gwanak-gu, Seoul 151-742, Republic of Korea.
Department of Nanoengineering, University of California , San Diego, California 92093, United States.
Langmuir. 2017 Sep 12;33(36):9057-9065. doi: 10.1021/acs.langmuir.7b01919. Epub 2017 Aug 24.
Electrically tunable colloidal photonic crystals (ETPCs) have been investigated because of several merits such as easy color tunability, no discoloration, and clear color. The coloration mechanism of ETPCs has been explained in terms of only the electric field. Herein, we report on a new mechanism: electric field plus redox reaction. Specifically, the coloration behavior of ETPCs was investigated under electrically conductive or insulated conditions using current-voltage, cyclic voltammetry, and zeta potential measurements, as well as scanning electron microscopy. Electrophoretic movement of ETPC particles toward the positive electrode was caused by the electric field due to the particles' negative surface charge. At the positive electrode, ETPC particles lost their electrons and formed a colloidal crystal structure. Finally, an ETPC transparent tube device was constructed to demonstrate the coloration mechanism.
电可调胶体光子晶体（ETPC）因其易于调节颜色、不褪色和颜色清晰等优点而受到研究。ETPC 的着色机制仅从电场方面进行了解释。在此，我们报告了一种新的机制：电场加氧化还原反应。具体而言，通过电流-电压、循环伏安法和 zeta 电位测量以及扫描电子显微镜研究了在导电或绝缘条件下 ETPC 的着色行为。由于颗粒带负电荷，电场导致 ETPC 颗粒向正极电泳运动。在正极，ETPC 颗粒失去电子并形成胶体晶体结构。最后，构建了一个 ETPC 透明管器件来演示着色机制。
