Design of Molecular Gels with Exceptional Structural, Dynamic and Mechanical Properties

具有优异结构、动态和机械性能的分子凝胶的设计

• 批准号: 1502856
• 负责人: Richard Weiss
• 金额: $ 54万
• 依托单位: Georgetown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2022-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1502856&HistoricalAwards=false
• 关键词: Design; Molecular; Gels; Exceptional; Structural

In this project funded by the Macromolecular, Supramolecular and Nanochemistry program of the Chemistry Division, Professor Richard G. Weiss of Georgetown University is developing 'molecular gelators' (small molecules that aggregate into 3-dimensional networks which immobilize large amounts of a liquid) with special properties, such as the ability to transform reversibly into free-flowing liquids. A primary objective of this research is to develop fundamental relationships between the shapes and functionalities of structurally simple molecular gelators and the properties of their gels. To do so, two fundamental scientific questions are being addressed: "What constitutes an efficient molecular gelator?" and "How can the gelator structures be designed to provide materials with rather unique structural and mechanical properties?" The results from this research are expected to contribute information that is important to both basic and applied science and to fill current large gaps of understanding between molecular structure and self-assembly that lead to a wide range of self-organized materials in addition to gels. Several of the gels may be useful in applications that include art conservation, oil recovery, and food chemistry. Another very important impact is the training of young scientists, including thosein under-represented groups and from developing countries. Students at all levels--postdoctoral to high school- are given opportunities to become integrated within the scientific community by attending and presenting their research results at conferences and by interacting directly with students in other collaborating labs throughout the world.The gelators selected are commercially available (e.g., ethylenediaminetetraacetic acid, Ethomeen surfactants, and polyethylenimines) or naturally occurring (e.g., sphingosine, glucamine, and 12-hydroxystearic acid) molecules. Alternatively, the gelators are easily synthesized from related molecules. Solvents that are most appropriate complements to the gelators are pre-selected using Hansen or other parameter sets that dissect liquid properties. The gels are designed to provide 'exceptional' properties, such as high degrees of thixotropy with variable recovery rates after destructive shear, gel-to-gel transitions initiated by thermally and photochemically induced changes of the molecular packing within gel fibers, and isothermal sol-gel transitions induced by adding or removing a neutral triatomic gas (such as CO2). Several spectroscopic, thermodynamic and kinetic techniques are available for characterizing the structural/functionality relationships for this study.

在这个由化学系高分子、超分子和纳米化学项目资助的项目中，乔治城大学的 Richard G. Weiss 教授正在开发“分子凝胶剂”（聚集成 3 维网络的小分子，可固定大量液体）特殊性质，例如可逆地转化为自由流动液体的能力。 这项研究的主要目的是开发结构简单的分子胶凝剂的形状和功能与其凝胶特性之间的基本关系。为此，需要解决两个基本的科学问题：“高效分子胶凝剂的构成是什么？”以及“如何设计胶凝剂结构以提供具有相当独特的结构和机械性能的材料？”这项研究的结果预计将为基础科学和应用科学提供重要的信息，并填补目前分子结构和自组装之间的巨大理解空白，从而产生除凝胶之外的各种自组织材料。 其中几种凝胶可用于艺术品保护、石油回收和食品化学等应用。 另一个非常重要的影响是对年轻科学家的培训，包括来自代表性不足群体和发展中国家的年轻科学家。各个级别的学生（博士后到高中）都有机会融入科学界，参加会议并展示他们的研究成果，并与世界各地其他合作实验室的学生直接互动。所选的胶凝剂可在市场上购买（例如，乙二胺四乙酸、Ethomeen 表面活性剂和聚乙烯亚胺）或天然存在的（例如，鞘氨醇、葡萄糖胺和 12-羟基硬脂酸）分子。 或者，凝胶剂很容易由相关分子合成。使用汉森或其他剖析液体特性的参数集预先选择最适合胶凝剂补充的溶剂。 这些凝胶旨在提供“特殊”性能，例如破坏性剪切后具有可变恢复率的高度触变性、由热和光化学诱导的凝胶纤维内分子堆积变化引发的凝胶到凝胶转变，以及等温溶胶通过添加或去除中性三原子气体（例如 CO2）引起的凝胶转变。几种光谱、热力学和动力学技术可用于表征本研究的结构/功能关系。