Supramacromolecules: Structure/Property Control via Self-Assombly with Well Defined Macromolecules

超大分子：通过明确大分子的自组装进行结构/性能控制

• 批准号: 0097126
• 负责人: Harry Gibson
• 金额: $ 48.4万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0097126&HistoricalAwards=false
• 关键词: Supramacromolecules; Structure; Property; Control; via

Macroscopic properties of solids, e.g., polymeric materials, result from the combination of molecular structure and macroscopic organization or order. Polymer chemists have become adept at covalent synthesis of macromolecules that can be designed to be amophous, crystalline, bi- or tri-phasic, etc. On the other hand the central aim of supramolecular science is to design building blocks with the proper structure that allows them to self-assemble by noncovalent boding at the molecular level. Synergistic combination of the principles of these two fields should enable more precise design and control of macroscopic structure and properties by utilizing properly designed macromolecular building blocks, i.e., more macroscopic control should result from the use of such precisely defined structural units. %%%The primary goals of this project are to apply self-assembly, to form pseudorotaxane structures, to well defined macromolecular host and guest species and study the structures and properties of the resultant supramacromolecular materials. Using living polymerization protocols constructed and then allowed to self-assemble into a variety of noncovalent analogs of various types of block and graft copolymers, which will be studied and compared to the corresponding covalent analogs when these are available. Pseudorotaxane formation is reversible and this feature can be exploited to enable facile melt processing of mechanically linked (vs. Covalently linked) polymeric systems, which disassemble upon heating to lower molecular weight and lower viscosity building blocks; upon cooling self-assembly is expected to produce solid state features of phase separation, blend compatibilzation and enhanced mechanical properties associate with classical covalent block and graft copolymers. Additionally a great advantage of this modular approach is that from a few precisely defined macromolecular building blocks a large library of two and three dimensional structures can be self-assembled without further synthetic effort. Furthermore, the pseudorotaxane linkage is selective in terms of the cyclic/linear components (in a complementary lock and key fashion) and this gives rise to the possibility of control over the orientation and connectivity of building blocks, allowing construction of novel ensembles, including noncovalent analogs of ABC triblock copolymers.

固体的宏观性质，例如，聚合物材料是由分子结构和宏观组织或秩序的组合产生的。 聚合物化学家已经成为善于共价合成的大分子，可以设计成无定形，结晶，双或三相等另一方面，超分子科学的中心目标是设计具有适当结构的积木，使它们能够通过非共价键合在分子水平上自组装。 这两个领域的原理的协同组合应该能够通过利用适当设计的大分子结构单元，即，使用这种精确定义的结构单元将产生更宏观的控制。 本项目的主要目标是应用自组装，形成准轮烷结构，明确定义的大分子主体和客体物种，并研究所得超大分子材料的结构和性能。 使用活性聚合方案构建，然后允许自组装成各种类型的嵌段和接枝共聚物的各种非共价类似物，当这些可用时，将对其进行研究并与相应的共价类似物进行比较。 假轮烷形成是可逆的，并且该特征可用于使得能够容易地熔融加工机械连接的聚合物。（相对于共价连接的）聚合物体系，其在加热时分解成较低分子量和较低粘度的结构单元;在冷却时，预期自组装产生相分离、共混物相容性和与经典共价嵌段和接枝共聚物相关的增强的机械性能的固态特征。 此外，这种模块化方法的一个很大的优点是，从几个精确定义的大分子结构单元中，可以自组装一个大型的二维和三维结构库，而无需进一步的合成工作。 此外，伪轮烷键在环状/线性组分方面是选择性的（以互补的锁和键的方式），这产生了控制结构单元的取向和连接性的可能性，允许构建新的集合体，包括ABC三嵌段共聚物的非共价类似物。