Shape and Dimensional Precision in Polymeric Nanostructures

技术概述：精确的尺寸和形状控制仍然是共价和超分子聚合物设计中的一个巨大挑战。提出的工作重点是通过仔细设计其单体亚基来控制超分子聚合物的大小和形状。该提案的智力价值在于其目标是开发自组装模式，该模式集成了机械和键合力、聚集动力学和模板策略，以模拟生物结构的方式定义超分子聚合物的大小和形状。这些受自然启发的合成结构可以实现高水平的结构控制，这对新功能至关重要。这个程序研究了三种不同的代码来精确控制超分子的大小和形状。在一种方法中，使用带相反电荷的两亲分子产生弯曲（非球形）囊泡。这些流体膜将用于将薄金属层或半导体矿物模板化为非球形三维结构。第二种方法是使用卷曲的肽，将其组装成蘑菇形状的极性聚集体。然后，精确长度的带电聚合物（例如DNA）将通过精确的尺寸控制模板形成高阶组件。在第三种方法中，使用小分子来组装一维结构，其中形态由分子结构和生长动力学控制。从初步研究中学到的原理将应用于形成更复杂的结构和超分子嵌段共聚物。这三个项目都需要化学合成、电子显微镜和衍射技术，以及粗粒度建模。非技术总结：从自然界中看到的复杂结构中学习已经成为现代材料研究的主要目标之一。其动机是设计新的、复杂的材料，如用于电子、能源或传感设备的人工分子马达，以及用于修复组织和器官的生物医学材料。这项工作涉及物理科学、生命科学和工程学科，因此是培养未来科学家和国际合作的绝佳平台。作为迈向复杂功能材料目标的一步，提出的研究涉及精确控制几个自组装系统的形状和大小。一种方法是使用精确长度的DNA分子作为外部模板来决定合成材料中成分的尺寸。另一种方法是让分子形成类似于许多病毒的非球形纳米结构。提议的工作将对材料研究研究生的跨学科教育产生广泛的影响，因为每个提议的项目都在合成化学、物理和材料科学的界面上运作。一些来自弱势群体的学生正在PI的实验室接受这种培训，拟议的项目可以极大地扩展这一努力。

TECHNICAL SUMMARY: Precise dimension and shape control remains a great challenge in the design of covalent and supramolecular polymers. The proposed work focuses on controlling the size and shape of supramolecular polymers by carefully designing their monomeric subunits. The intellectual merit of the proposal is its goal to develop self-assembly modes that integrate mechanical and bonding forces, aggregation kinetics, and templating strategies to define the size and shape of supramolecular polymers in ways that emulate biological structures. These synthetic structures inspired by nature could enable a high level of structural control that is essential for novel functions. This program studies three different codes to precisely control supramolecular size and shape. In the one approach, buckled (non-spherical) vesicles are created using oppositely charged amphiphilic molecules. These fluid membranes will be used to template a thin metal layer or a semiconducting mineral into non-spherical three-dimensional structures. The second approach uses coiled-coil peptides that assemble into mushroom-shaped, polar aggregates. A charged polymer of precise length (e.g., DNA) will then template the formation of higher order assemblies with precise dimensional control. In a third approach, small molecules are used to assemble one-dimensional structures, in which morphology is controlled by the molecular structure and the growth kinetics. The principles learned from preliminary studies will be applied to form more complex architectures and supramolecular block copolymers. All three projects require chemical synthesis, electron microscopy and diffraction techniques, as well as coarse-grained modeling.NON-TECHNICAL SUMMARY: Learning from the complex structures seen in nature has been one of the major goals of modern materials research. The motivation is to design new, sophisticated materials such as artificial molecular motors for electronics, energy, or sensing devices and also biomedical materials to repair tissues and organs. The work cuts across physical sciences, life sciences, and engineering disciplines, and it is therefore an excellent platform for education of future scientists and for international collaborations. As a step toward the goal of complex functional materials, the proposed research involves precisely controlling the shape and size of several self-assembling systems. One approach involves the use of DNA molecules of precise length as external templates to dictate the dimension of components in synthetic materials. The other approach programs molecules to form nanostructures with non-spherical shapes similar to many viruses. The proposed work will have broad impact on the interdisciplinary education of graduate students in materials research, since each of the proposed projects operates at the interface of synthetic chemistry, physics, and materials science. Several students from underrepresented groups are receiving this training in the PI's laboratory and the proposed program could greatly extend this effort.