Two Dimensional Polymerizations in Supramolecular Assemblies

超分子组装中的二维聚合

• 批准号: 9619887
• 负责人: Neal Armstrong
• 金额: $ 28.5万
• 依托单位: University of Arizona
• 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: 1997-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9619887&HistoricalAwards=false
• 关键词: Two; Dimensional; Polymerizations; Supramolecular; Assemblies

9619887 O'Brien Several methods to polymerize supramolecular assemblies have been introduced in recent years. These new and evolving chemistries open opportunities to prepare novel biomolecular materials with particular properties of interest to both biological and material sciences. Success in the design and reproducible preparation of new materials requires a clear understanding of the polymerization processes used to modify the assemblies. %%% The objective of this proposal is to advance our understanding of polymerizations in organized media in a manner that permits the utilization of the emerging information to control the properties of polymerized supramolecular materials and to prepare novel macromolecular architectures. The reasonably well-developed understanding of linear polymerizations in bilayers is complemented by the emerging picture of crosslinking polymerizations in bilayers. Polymerization of monomeric lipids in an assembly proceeds in a linear or crosslinking manner depending on the number of polymerizable groups per monomeric lipid. Lipids that contain a single reactive moiety in either of the hydrophobic tails or associated with the hydrophilic head group yield linear polymers. Polymerization of lipids with reactive groups in each hydrophobic tail yields crosslinked polymers. In contrast the polymerization of lipids that have different reactive groups (bifunctional amphiphiles) in the same hydrophobic tail does not necessarily yield crosslinked polymers, because if the groups are insufficiently separated the correlation of the polymerization paths could produce ladder polymers rather than crosslinked polymers. The preferred reaction path will depend on several factors including the nature of the spacer group, the extent of conformational and diffusional freedom within the molecular assembly, and the reactivity of the polymerizable groups. In order to obtain a clearer understanding of the effect of these factors on the preferred p olymerization process in organized media this research will examine each in turn with a family of newly designed bifunctional amphiphiles. The findings from these studies will be used to select bifunctional monomers for the preparation of ladder-like copolymers composed of dissimilar polymers, e.g. poly(diene) and poly(acrylate). The objective is to utilize our understanding of the polymerization process in organized media to create novel soluble copolymers that are not readily available through solution polymerizations. In addition these polymerization studies will aid in the design of bifunctional fatty acids for the crosslinking polymerization of monolayers or multilayers in a manner that does not modify the hydrophilic head group of the amphiphile. Finally the research will utilize the understanding of crosslinking processes in organized assemblies to prepare novel phthalocyanines for the stabilization of discotic liquid crystals. ***

9619887 O‘Brien近年来介绍了几种聚合超分子组装体的方法。这些新的和不断发展的化学为制备具有生物和材料科学都感兴趣的特殊性质的新型生物分子材料提供了机会。新材料的设计和可重复制备的成功需要对用于修改组件的聚合工艺有清楚的了解。这项建议的目的是以一种允许利用新出现的信息来控制聚合超分子材料的性质和制备新的大分子结构的方式来促进我们对有组织介质中的聚合反应的理解。对双层中线性聚合的合理发展的理解被双层中交联化聚合的新图景所补充。根据每个单体脂中可聚合基团的数量，单体脂在组件中的聚合以线性或交联性方式进行。在任一疏水尾部或与亲水头部基团相关的脂类中含有单一反应部分的脂类产生线性聚合物。脂类在每个疏水尾部具有反应性基团的聚合可产生交联型聚合物。相反，在同一疏水尾部具有不同活性基团(双官能团两亲)的脂类的聚合不一定产生交联聚合物，因为如果基团没有充分分离，聚合路径的关联可能产生梯形聚合物而不是交联聚合物。优选的反应路径将取决于几个因素，包括间隔基的性质，分子组装中构象和扩散自由的程度，以及可聚合基团的反应性。为了更清楚地了解这些因素对有组织介质中首选聚合过程的影响，本研究将用一系列新设计的双官能两亲分子依次考察每一个因素。这些研究结果将被用于选择双功能单体来制备由不同聚合物组成的梯形共聚物，例如聚二烯和聚丙烯酸酯。其目的是利用我们对有组织介质中聚合过程的了解来创造通过溶液聚合不容易获得的新型可溶共聚物。此外，这些聚合研究将有助于设计用于单层或多层的交联化聚合的双功能脂肪酸，而不改变两亲分子的亲水头基。最后，这项研究将利用对有组织组装中的交联过程的了解来制备用于盘状液晶稳定的新型酞菁。***