Sandu Ion, Antohe Iulia, Fleaca Claudiu Teodor, Dumitrache Florian, Urzica Iuliana, Dumitru Marius
Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, 077125 Magurele, Romania.
Romanian Academy of Scientists (AOSR), 54 Splaiul Independentei, 050094 Bucharest, Romania.
Polymers (Basel). 2024 Jul 6;16(13):1931. doi: 10.3390/polym16131931.
High-quality, 3D-shaped, SiO colloidal photonic crystals (ellipsoids, hyperboloids, and others) were fabricated by self-assembly. They possess a quadratic surface and are wide-angle-independent, direction-dependent, diffractive reflection crystals. Their size varies between 1 and 5 mm and can be achieved as mechanical-resistant, free-standing, thick (hundreds of ordered layers) objects. High-quality, 3D-shaped, polystyrene inverse-opal photonic superstructures (highly similar to diatom frustules) were synthesized by using an inside infiltration method as wide-angle-independent, reflective diffraction objects. They possess multiple reflection bands given by their special architecture (a torus on the top of an ellipsoid) and by their different sized holes (384 nm and 264 nm). Our hanging-drop self-assembly approach uses setups which deform the shape of an ordinary spherical drop; thus, the colloidal self-assembly takes place on a non-axisymmetric liquid/air interface. The deformed drop surface is a kind of topological interface which changes its shape in time, remaining as a quality template for the self-assembly process. Three-dimensional-shaped colloidal photonic crystals might be used as devices for future spectrophotometers, aspheric or freeform diffracting mirrors, or metasurfaces for experiments regarding space-time curvature analogy.
通过自组装制备了高质量的三维形状的SiO胶体光子晶体（椭球体、双曲面体等）。它们具有二次曲面，是与广角无关、与方向有关的衍射反射晶体。其尺寸在1至5毫米之间变化，并且可以制成机械抗性强、独立、厚（数百个有序层）的物体。通过内部渗透法合成了高质量的三维形状的聚苯乙烯反蛋白石光子超结构（与硅藻壳高度相似），作为与广角无关的反射衍射物体。它们具有由其特殊结构（椭球体顶部的圆环）和不同尺寸的孔（384纳米和264纳米）给出的多个反射带。我们的悬滴自组装方法使用使普通球形液滴形状变形的装置；因此，胶体自组装在非轴对称的液/气界面上发生。变形的液滴表面是一种拓扑界面，其形状随时间变化，作为自组装过程的优质模板保留下来。三维形状的胶体光子晶体可作为未来分光光度计的器件、非球面或自由曲面衍射镜，或用于时空曲率类比实验的超表面。
