零维胶体粒子基元构筑三维多功能形状记忆高分子材料

Both amphiphilic block copolymer self-assembly and smart shape-memory polymer (SMP) have gained extensive attention in the past decades, but developed separately in their own field. While how to bridge the both of them in order to complement each other's advantages is not only of the fundamental interest but also practical application potential. In this proposal, we are planning to develop a brand-new approach, from 0D to 3D, to build shape-memory polymer materials by making use of amphiphilic block copolymer self-assemblies (micelles, vesicles et al) in aqueous solution and unveil the effects of macromolecular architecture, assembly morphology, crosslink density, phase structure, et al on the specific shape-momory behavior. Furthermore, the multifunctionality of shape-memoy polymer, specifically photothermal，photochromic and luminescent shape-momery polymer films constructed by crosslinking amphiphilic block copolymer self-assemblies encapsulated functional organic small molecules (such as porphyrin, azobenzene, spiropyrane, BODIPY, perylene etc) into their hydrophobic core domain, is as well addressed. The great efforts would also be made to understand the interplay of photothermal, photochromic and luminescent property of the bulk polymeric solid materials and the used amphiphilic block copolymer self-assemblies which serve as the buliding blocks and further demonstrate it is a simple and general way to fabricate multifunctional shape-memory polymers by virtue of the amphiphilic block copolymer self-assemblies and film-forming method.

两亲性大分子自组装和形状记忆高分子在过去二十年间虽得到高度关注，但一直分属于两个独立的研究领域。如何将二者有机联系起来，实现优势互补将具有重要的理论意义与潜在的应用价值。本项目将通过以两亲性嵌段共聚物在水溶液中自组装形成的零维胶体粒子（胶束、囊泡等）为基元，建立构筑三维多功能形状记忆高分子材料的方法与途径，阐明构筑基元的链结构、组装结构、交联行为、成膜方式以及微相分离形态等与材料形状记忆行为之间的内在联系；利用两亲性嵌段聚合物对疏水分子的增溶作用，借助共组装法将有机功能小分子（如卟啉、偶氮苯、螺吡喃、BODIPY、苝等）选择性地包覆在胶体粒子（胶束、囊泡）特定的疏水微区中，通过化学交联和溶液成膜简便地制备光热响应型、光致变色型和发光型等多功能形状记忆高分子材料，揭示光热响应、光致变色和发光等功能效应与大分子链结构、凝聚态结构以及构筑基元（胶体粒子）之间的构效关系。

在本项目的支持下，研究团队通过将荧光基元-碳量子点引入化学与物理双重交联的聚乙烯醇水凝胶中，制备了发光形状记忆聚乙烯醇水凝胶，揭示了碳量子点的发光行为与形状记忆行为之间的关系；将生物基卟啉单元通过物理胶束增溶或化学键接的方式引入可交联的聚丙烯酸酯材料中，制备了光热响应的多功能形状记忆高分子材料，系统研究了生物基元卟啉的光热转换性质与红光响应的形状记忆行为；进一步地，借助层层叠合手段将石墨烯与液晶聚合物复合制备了近红外光响应的可逆形状记忆高分子材料（聚合物致动器），研究其光驱动的“蠕动”行为等。总之，本项目通过引入低维功能性构筑基元（如卟啉分子、复合胶束粒子、碳量子点、石墨烯等），制备了系列三维多功能形状记忆高分子材料，阐明了构筑基元的功能性与形状记忆行为之间的依存关系，拓展了多功能形状记忆高分子材料的构筑手段，为其在智能高分子材料方面的应用奠定了基础。