Zhou Can, Zhang Shoubin, Hui Taoran, Cui Qiuhong, Hu Yuandu
Department of Materials Science and Engineering, School of Physical Sciences and Engineering, Beijing Jiaotong University, Beijing 100044, China.
TDK Headway Technologies, Inc., Milpitas, CA 95035, USA.
Polymers (Basel). 2022 Sep 22;14(19):3954. doi: 10.3390/polym14193954.
The assembly of two different kinds of colloidal particle-based photonic structures into an individual micro-object can achieve multifunctionality. In this study, core-shell photonic microcapsules with dual structural colors and photonic stop bands were prepared through a standard microfluidic technique. Photocurable resin suspension of silica nanoparticles and an aqueous suspension of nanogels were used as shell and core parts of microcapsules, respectively. The structural colors of shells and cores can be tuned by adjusting the concentrations of silica nanoparticles and soft nanogels in their corresponding suspensions. The individual microcapsules possess two distinct stop bands when the two suspensions are combined appropriately. Remarkably, the color information of the core part cannot be directly viewed at a macroscopic level (such as visual inspection) but can be detected at a microscopic scale (such as optical microscopy observation). The color information hidden enables the capability for information encryption and has potentially critical applications in anti-counterfeiting, display, and other fields.
将两种不同类型的基于胶体粒子的光子结构组装成单个微物体可以实现多功能性。在本研究中，通过标准微流控技术制备了具有双结构颜色和光子禁带的核壳光子微胶囊。二氧化硅纳米粒子的光固化树脂悬浮液和纳米凝胶的水悬浮液分别用作微胶囊的壳层和核层部分。通过调节相应悬浮液中二氧化硅纳米粒子和软纳米凝胶的浓度，可以调整壳层和核层的结构颜色。当两种悬浮液适当组合时，单个微胶囊具有两个不同的禁带。值得注意的是，核层部分的颜色信息在宏观层面（如目视检查）无法直接观察到，但可以在微观尺度（如光学显微镜观察）下检测到。隐藏的颜色信息实现了信息加密能力，在防伪、显示和其他领域具有潜在的关键应用。
