快速响应小分子平板结构水凝胶光子材料的制备研究

Photonic materials (PMs) are composed of periodic arrays of contrasting refractive index materials. Of these, polymeric hydrogel based responsive PMs have been extensively studied, since they are capable of showing tunable optical properties, e.g., color, in response to external stimuli. However, they suffer a slow response behavior, due to the multiple interactions in the hydrogel matrix, such as polymer entanglements, polymer-analyte and polymer-environment interactions. As a consequence, of importance to this research is the fabrication of fast response PMs.. This proposal describes novel polymer-free, or small molecular, hydrogel based PMs that exhibit fast response to temperature, humidity, solution pH, ions and others. At the core of the material are bimolecular membranes self-assembled by small molecules, which give a lamellar hydrogel structure in solution, and thus produce colors. We will study the effect of different self-assemblied molecules, co-stabilizers, cations/anions and charged macromolecules on the stability of PMs. To achieve fast-responsive goal outlined above, we will systematically investigate the optical properties of PMs under different stimuli, combined with characterization of the micro-structures as well as theoretical simulations. The knowledge gained here sheds light on the fabrication of a novel polymer-free lamellar hydrogel based PMs with fast response and will make them well suited to make contributions in such environmental and biological sensing industries..

光子材料是由介电常数不同的材料在空间周期性排列而成的一种特殊结构。其中，聚合物水凝胶基响应性光子材料能够对外界物理/化学刺激产生光学信号变化，因而受到广泛关注。然而聚合物水凝胶三维网络结构中聚合物链段之间化学交联缠绕、聚合物与检测物、环境之间的物理摩擦，导致材料响应速率慢。因此，制备能够对外界刺激进行快速响应的光子材料是目前需要解决的问题之一。. 本项目将通过制备小分子平板结构水凝胶光子材料解决上述问题。以小分子在水中自组装形成的双分子膜与水相之间交替形成的平板结构水凝胶为基础，研究不同种类的组装小分子、助稳定剂、荷电离子以及大分子荷电物质对光子材料稳定性的影响。结合其在外界环境下的光学信息，并与微区结构和理论模型分析相结合，验证该方法的可靠性，实现快速响应光子材料的构筑。该研究为设计快速响应光子材料提供可行的方法和途径，并探索其在环境、生物检测等方面的应用价值。

光子材料是由介电常数不同的材料在空间周期性排列构筑的特殊结构，能够产生独特的光学性质（例如：颜色）。本项目首先提出一种新颖的凝胶光子材料：巧妙设计多种两亲性有机小分子，使其在不同溶剂中，自组装形成平板结构光子晶体。实验结果表明，三乙醇胺基双十六烷基磷酸酯能够在水/乙醇混合溶剂中自组装得到平板结构光子材料。该凝胶体系在不同外界条件下能产生各种颜色的衍射光，更重要的是通过平板结构中的溶剂层，能够利用限域空间，制备得到聚吡咯超薄膜。此外，我们还拓展有机小分子凝胶光子材料体系到高分子凝胶光子材料和分离材料。一方面研究金属-响应性聚合物凝胶平板结构复合光子材料相行为及其在传感器方面应用。通过紫外光谱法和石英微天平（QCM-D）两种手段，研究水凝胶颗粒在组装条件下的响应性行为。研究结果表明，组装形态并不影响其温度/pH双重响应性行为。该光子材料赋予QCM-D上极高的灵敏度（0.8◊10-3oC Hz-1），这是目前报道的QCM-D基温度传感器最大灵敏度。接着，该体系拓展到pH，离子强度传感器等应用，解决了这类传感器灵敏度较低的缺点。另一方面，我们将响应性聚合物凝胶与超薄分离膜的概念合并，成功制备光热/压力响应性分离膜，他们能够高选择性，快速分离油水微乳液。