新型分子刷嵌段共聚物的合成、受限组装及光学性能研究

Up to now, research on bottlebrush block copolymers (BCPs) has generally focused on self-assembly in bulk. The obtained microstructures have limited tunability, and the optical properties need to be enhanced for practical use. In the research proposal, we investigate the self-assembly behaviors of bottlebrushes within confined three-dimensional (3D) spaces such as emulsion micro-droplets, characterize the resulting microstructures formed in obtained micro-balls after drying, and disclose the correlations between structures and optical properties. Different from the confined self-assembly of linear BCPs, more structural tunability and diversity are available arising from liquid-liquid interfacial effects due to more tunable molecular parameters of bottlebrushes including molecular flexibility and symmetry. In addition, the periodicity of the bottlebrush structure greatly increased compared to that of the linear BCP, which enables the interactions between structure and visible light providing a novel route to the design and fabrication of well-ordered functional polymer materials. With the proposed project, we aim to create bottlebrush micro-balls with unique structures and attractive optical properties, offering an ideal model for a systematic study of the relationship between structure and optical property. Subsequently, we are expecting a precise control over the optical properties via tailoring microstructure, and create red, green and blue photonic balls with reflection over 95% for practical uses.

目前，关于分子刷嵌段聚合物的研究大都侧重于本体自组装，形成微结构的可调控性有限，材料的光学性能亟待提高。本项目将分子刷的研究拓展到受限组装领域，拟探明分子刷在三维空间受限条件下的自组装行为和聚集态结构。区别于线性嵌段聚合物的受限组装，分子刷结构独特且拥有更多的可调控性如分子柔性、对称性等，在受限自组装界面效应的影响下易形成更为丰富多样的微结构。分子刷组装形成的结构尺寸远大于传统嵌段聚合物，赋予了微结构物理性能，有望为高分子功能结构材料的设计制备开辟一条新的道路。本研究课题的实施能产出结构新颖和光学性能独特的聚合物微粒（光子微球），为系统研究组装结构与光学性能之间的关系提供理想的模型。通过以上研究，我们拟实现对材料结构和光学性能的精准调控，并能制备反射率高于95%的红绿蓝三基色光子微球，为此类材料的实际应用打下坚实基础。

在本项目的资助支持下，系统深入的研究了嵌段共聚物刷乳液受限自组装行为、聚集态结构以及光学性能之间的关系，显著增强了材料的光学性能，实现了预期研究目标。提出了嵌段共聚物刷限域自组装制备光子颜料的新策略，成功制备了全可见光区可调的嵌段共聚物刷光子微球，反射率最高可达100%，并在纳米尺度上构建“软-硬”交替排列的“洋葱”结构，成功制备了力致变色的高分子微球材料。发现并阐释了两亲性嵌段共聚物刷引发的有序自发乳化科学机制(OSE)，证明了聚合物刷的棒状构象是OSE机制的关键因素，建立了基于双乳液的嵌段高分子界面自组装新体系。基于OSE提出了一种通过调控聚合物链构象调节结构色的全新理念，只需单一原料即可制备出颜色连续可调的光子颜料，制备过程简便、快捷、易于规模化生产。建立了利用剪切力控制光学结构生长的有效方法，成功制备了低角度依赖性的光子颜料。开发了一种嵌段共聚物限域共组装策略，巧妙的将传统的微相分离与有序自发乳化机制相结合，简单高效的制备了具有复杂结构的光子微球材料，获得了丰富多样的光学功能。