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.

在这个由化学系大分子、超分子和纳米化学项目资助的项目中，理查德·G·乔治城大学的韦斯正在开发具有特殊性质的“分子胶凝剂”（聚合成三维网络的小分子，这些网络可以包裹大量液体），例如能够可逆地转化为自由流动的液体。 本研究的一个主要目标是发展的基本关系的形状和功能的结构简单的分子凝胶因子和它们的凝胶的性质。要做到这一点，两个基本的科学问题正在解决：“是什么构成了一个有效的分子胶凝剂？如何设计胶凝因子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差距，这些差距导致除了凝胶之外的各种自组织材料。 几种凝胶可用于包括艺术保护、石油回收和食品化学的应用。 另一个非常重要的影响是培训青年科学家，包括代表性不足的群体和发展中国家的青年科学家。所有级别的学生--从博士后到高中--都有机会通过参加会议并在会议上展示他们的研究成果，以及通过与世界各地其他合作实验室的学生直接互动，融入科学界。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、葡糖胺和12-羟基硬脂酸）分子。 或者，胶凝剂容易由相关分子合成。使用汉森或剖析液体性质的其他参数集来预先选择作为胶凝剂的最适当补充的溶剂。 该凝胶被设计为提供“特殊”的性能，例如在破坏性剪切后具有可变恢复率的高触变性，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，以及通过添加或去除中性三原子气体（例如CO2）诱导的等温溶胶-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。