State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
Nanoscale. 2017 Sep 14;9(35):12969-12975. doi: 10.1039/c7nr05087a.
Responsive photonic crystals (PCs) would exhibit reversible changes in reflectance wavelength under external stimuli. Generally, external stimuli are applied, which would result in the variation of the photonic band gap. Internal stimuli would be more attractive for not destroying the hierarchical structures. Herein, we report a straightforward way to fabricate an optically induced thermo-responsive PC for the first time by coating butterfly wing scales with thermo-sensitive poly(N-isopropylacrylamide) (PNIPAm) with Ag nanoparticles formed in situ. As optic-thermo converters, Ag nanoparticles can convert light into thermal energy because of their surface plasmon resonance properties. The increase in temperature resulted in the phase transition of the PNIPAm coating on the wing scales, leading to the change of the bioinspired PC structure. Correspondingly, a blue shift in reflectance wavelength was detected for the obtained PC. Interestingly, a reversible optical thermo-responsive performance was observed through controlling the light source. This strategy is believed to be applied in other internal stimuli-responsive PCs with attractive properties, with the combination of various noble particles and a wide range of hierarchical photonic structures in nature.
响应型光子晶体 (PC) 在外部刺激下会表现出反射波长的可逆变化。通常，施加外部刺激会导致光子带隙发生变化。内部刺激更具吸引力，因为它们不会破坏分层结构。在此，我们首次报道了一种通过用原位形成的银纳米粒子涂覆对热敏感的聚 N-异丙基丙烯酰胺 (PNIPAm) 来制备光致热响应型 PC 的简单方法。作为光热转换器，由于其表面等离子体共振特性，Ag 纳米粒子可以将光转化为热能。温度的升高导致鳞片上的 PNIPAm 涂层发生相转变，从而改变了仿生 PC 的结构。相应地，检测到反射波长的蓝移。有趣的是，通过控制光源观察到了可逆的光学热敏响应性能。相信这种策略将应用于具有吸引力的特性的其他内部刺激响应型 PC 中，结合各种贵金属颗粒和自然界中广泛的分层光子结构。
