基于芘共轭体系V型刚棒-线团分子的合成、自组装及性能研究

The rod-coil molecules with excellent self-assembly ability and varieties of shapes have been extensively studied. Recently the V-shaped rod-coil molecules were found to have unique self-assembly properties, but the self-assembly mechanism is not clear. In this project, three types of rod-coil molecules with V-conjugated block will be designed and synthesized, and their self-assembling behaviors and physical properties will be studied in bulk and solution. Different self-assembly aggregates will be built adopting pyrene as a rigid core, the hydrophilic and hydrophobic chains as flexible segments by changing the length of the rigid block and the category, volume fraction, cross-sectional area, chirality of the flexible block. The self-assembly structure of V-shaped rod-coil molecules will be tuned through clarifying internal relationship between the molecular structure and self-assembling behavior. The stimuli-responsive micelles or supramolecular hydrogels will be built by changing the external environment to provide a theoretical basis for its application in the field of controlled release of drug. The nano-reactors of Suzuki or Heck coupling reaction will be constructed by adjusting the molecular hydrophilic and hydrophobic. The relationship between molecular structure, the morphology of aggregates and physical properties will be clarified to provide new ideas for its application in the field of catalysis. This project can enrich topological structure of the copolymer and improve the theory of self-assembly, furthermore, it has important theoretical significance in design and preparations of novel nano-materials.

刚棒-线团分子被证明具有很好的自组装能力，目前多种形状体系已被广泛研究，近期V型分子被发现具有独特的自组装性能，但其组装机理尚不清晰。鉴于此，本申请拟设计、合成三类具有V型共轭嵌段的刚棒-线团分子，对其在本体和溶液中的自组装行为及物理性能进行研究。拟采用芘作为刚性核，选取亲水、疏水两类柔性链，通过改变刚棒嵌段的长度、组成，柔性嵌段的类型、体积比、横截面积、手性等因素来构筑不同的自组装聚集体，明确分子结构与自组装行为之间的关系，实现对此类分子自组装结构的有效调控。通过改变外场来构筑刺激响应性胶束或超分子水凝胶，为其在药物控释领域的应用提供理论依据。通过调节分子两亲性来构筑Suzuki、Heck等偶联反应的纳米反应器，明确分子结构、聚集体形态与物理性能之间的关系，为此体系在催化领域的应用提供新思路。本课题可以丰富共聚物拓扑结构、完善自组装理论，对新颖纳米材料的设计与制备具有重要的理论指导意义。

V型刚棒-线团分子因其具有独特的自组装性能越来越受到人们的广泛关注。本研究利用1,8-二取代芘，二苯并[a, c]吩嗪为刚性核，以聚乙二醇单甲醚为柔性链，构建了多种类型的两亲性V型刚棒-线团分子。系统研究了这些分子在本体和溶液中的自组装行为，通过改变柔性嵌段的长度、形状、横截面积、手性等因素，构筑了不同结构的自组装聚集体。明确了分子结构与自组装聚集体之间的关系，实现了对此类分子自组装结构的有效调控，为其实际应用奠定了基础。.具体结果如下：1）单分支的V型刚棒-线团分子，柔性链的体积分数在0.58以内，固态可形成矩形柱状结构。在水中，通过调控柔性链长度可得到纺锤形、方形、圆柱形胶束以及线性纤维。此结果丰富了共聚物的拓扑结构、完善了自组装理论。2）二分支和三分支的V型刚棒-线团分子，柔性链的体积分数分别控制在0.52和0.48以内，固态可分别形成双连续立方体和六方柱状结构。3）以二苯并[a, c]吩嗪为刚性核的V型刚棒-线团分子，调控柔性链长度可得到球形、圆柱形胶束或短纤维，引入手性可构筑螺旋纤维等聚集体，这对开发具有药物运输能力的刚棒-线团分子具有一定的启发意义。4）改变刚性核的形状构建具有相同柔性链的不同刚棒-线团分子，其自组装结构大不相同，说明刚棒嵌段形状是调控分子自组装的重要因素，此结果对新型自组装分子的设计具有指导意义。5) 通过结构上的分子设计，可构筑在水介质中识别金属离子的荧光探针，这为V型分子的应用开辟了新途径。此外，在研究中发现以聚乙二醇单甲醚为柔性链合成的双链型V型刚棒-线团分子，在本体组装时不易形成液晶相，有序结构少；在水溶液中形成的胶束很难构建超分子水凝胶或纳米反应器。尽管这方面未取得预期想要的结果，但是已有结果对继续开展相关研究具有一定的借鉴意义。本工作可加深理解刚棒-线团分子自组装的影响因素，为新型光电功能自组装材料的设计与开发打下初步的理论与实践基础。