Cylindrical and Spherical Supermolecules from Polymer Backbones Jacketed with Dendritic Coats

来自聚合物主链的圆柱形和球形超分子，覆盖有树枝状涂层

• 批准号: 9708581
• 负责人: Virgil Percec
• 金额: $ 25万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1999-06-04
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708581&HistoricalAwards=false
• 关键词: Cylindrical; Spherical; Supermolecules; Polymer; Backbones

9708581 Percec This research will design libraries of monodendritic building blocks with well defined flat tapered and conical shapes which self-assemble into cylindrical and respectively spherical shapes. These supermolecules will generate columnar hexagonal and spherical thermotropic and lyotropic liquid crystalline (LC) phases. These LC phases will warrant a thermodynamic control of their assembly and will allow the determination of their shape by X-ray diffraction. Libraries of flat tapered and conical monodendritic building blocks functionalized with polymerizable groups will be polymerized via living methods to generate the first examples of giant polymers with cylindrical and spherical shapes with diameter and length and respectively diameter controlled at the nanoscale level. The organization of these giant dendritic monomers in a LC assembly will also be used to aggregate their polymerizable groups in a reactor of artificially enhanced concentration and restricted geometry during the polymerization process and therefore, will generate a new approach to the control of polymerization. This research will provide an entry into the design of polymeric materials with predictable and dramatically different properties which are determined by their shape. Cylindrical and spherical giant polymers obtained from flexible backbones jacketed with dendritic coats will access new mechanisms to control the conformation and rigidity of their flexible chain regardless of their tacticity. Mechanisms to change in a reversible and controlled way the shape of the polymer from rod-like to spherical will be elaborated. It is expected that these cylindrical 3-D polymers will produce more rigid structures than the currently known 1-D linear rigid-rods. %%% This research will transplant concepts from Nature into the field of complex synthetic polymeric materials. Natural systems provide the most efficient mechanisms for the storage and transfer of energy and information and for the production of structural materials. The polymeric systems developed by this program will provide new technologic concepts which will allow for the first time the development of new materials such as functional fibers, films, membranes, viscosity controllers, electronic, photonic and controlled release systems with externally regulated physical properties via principles elaborated by Nature during the long process of evolution. ***

小行星9708581 本研究将设计具有明确定义的扁平、锥形和圆锥形形状的单枝晶构建块库，其自组装成圆柱形和球形。 这些超分子将产生柱状、六方和球形的热致和溶致液晶（LC）相。 这些LC相将保证其组装的热力学控制，并允许通过X射线衍射确定其形状。 用可聚合基团官能化的扁平锥形和圆锥形单树枝状结构单元的库将通过活性方法聚合，以产生具有圆柱形和球形形状的巨型聚合物的第一个例子，其直径和长度分别控制在纳米级水平。 这些巨大的树枝状单体在LC组件中的组织也将用于在聚合过程期间在人工增强浓度和限制几何形状的反应器中聚集它们的可聚合基团，因此，将产生控制聚合的新方法。 这项研究将提供一个进入聚合物材料的设计与可预测的和显着不同的性质，这是由他们的形状决定。 由柔性主链包覆树枝状涂层得到的圆柱形和球形巨型聚合物将获得新的机制来控制其柔性链的构象和刚性，而不管它们的立构规整度。 将阐述以可逆和可控的方式将聚合物的形状从棒状改变为球形的机制。 预期这些圆柱形3-D聚合物将产生比目前已知的1-D线性刚性杆更刚性的结构。 这项研究将把自然界的概念移植到 复杂的合成聚合物材料。 自然系统为能量和信息的储存和传递以及结构材料的生产提供了最有效的机制。 该计划开发的聚合物系统将提供新的技术概念，这将首次允许开发新材料，如功能材料。 纤维、薄膜、隔膜、粘度控制器，电子， 光子控释 系统 具有外部 调节 物理 性能 经由 这是大自然在漫长的进化过程中精心制定的原则。 ***