Symmetry Making and Breaking in the Synthesis and Assembly of Stellated and Bimetallic Nanocrystals

星状和双金属纳米晶体的合成和组装中对称性的形成和破坏

基本信息

批准号：
1602476
负责人：
Sara Skrabalak
金额：
$ 43.5万
依托单位：
Indiana University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-15 至 2019-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602476&HistoricalAwards=false
关键词：
Symmetry Making Breaking Synthesis Assembly

项目摘要

Nature demonstrates symmetry in the beauty of a flower, the precision of a honeycomb, and the elaborate patterns of snowflakes. Beyond the appeal of symmetric forms, symmetry can also impart function. For example, orb spiders weave in a spiral pattern to maximize the strength of their webs and bees construct honeycombs with close packed hexagons to maximize honey storage. This correlation between structure and function is also captured in modern nanomaterial design, where changing the symmetry of a nanocrystal or the internal order of a superstructure built from nanocrystals can give novel function. However, the synthesis and assembly of nanomaterials have been limited to simple compositions and structures until recently. In this research, the principal investigator, Sara Skrabalak, is developing new synthetic methods to make metal nanostructures with multiple metals and defined shapes. These nanostructures are also being used as building blocks to form larger structures, where the symmetries of the building blocks direct the shapes of the larger superstructures. The principal investigator and her students also study how the compositions and structures impart functionality. In particular, studies into the new light-matter interactions that arise as a function of symmetry are underway in an effort to achieve multi-functional platforms for chemical sensing applications. Ultimately, this research has broader impacts in the field by forging links between multiple disciplines, including nano/inorganic/solid-state chemistry, condensed matter physics, surface science, and material science. This project also incorporates outreach and educational efforts that introduce nanoscale concepts to non-scientists. The project also involves undergraduates in research activities in ways that emphasize their connection to the surrounding community.The Skrabalak group at Indiana University is developing seed-mediated co-reduction as a new synthetic strategy to multimetallic nanostructures, where multiple metals are simultaneously deposited onto shape-controlled nanocrystals. The symmetry of the nanocrystal seeds is transferred to the final nanostructures. This research includes studying how lattice mismatch and deposition kinetics contribute to bimetallic distribution. This work is coupled with a study of how symmetry can be reduced along specific crystallographic directions during seed-mediated co-reduction in order to achieve new stellated nanocrystal symmetries and in turn functional diversification. Finally, the Skrabalak group is using the stellated metal nanocrystals to assemble close-packed and low-density lattices to expand crystallization capabilities to new structural classes. They also characterize the collective optical properties that emerge. These three aims are coupled with outreach and educational efforts in which undergraduate researchers are Science Ambassadors to their former high schools, introducing nanoscale concepts to students and serving as role models to those interested in science, technology, engineering and mathematics fields. Advancement in the research expands the classes of nanocrystals and superstructures possible and identifies the roles of seed and building block symmetry in the synthesis and assembly of metal nanocrystals for broader impact in the science.

大自然在花的美丽，蜂窝的精度和精致的雪花模式中展示了对称性。除了对称形式的吸引力之外，对称性还可以赋予功能。例如，Orb蜘蛛以螺旋模式编织，以最大程度地发挥其网的强度，而蜜蜂则用紧密的六边形构造蜂窝状，以最大程度地储存蜂蜜。在现代纳米材料设计中也捕获了结构和功能之间的这种相关性，在这种设计中，改变纳米晶体的对称性或由纳米晶体构建的上部结构的内部顺序可以提供新的功能。然而，直到最近，纳米材料的合成和组装才限于简单的组成和结构。在这项研究中，主要研究者Sara Skrabalak正在开发新的合成方法，以制造具有多种金属和定义形状的金属纳米结构。这些纳米结构也被用作形成较大结构的构件，其中构件的对称性指导较大的上层建筑的形状。首席研究人员和她的学生还研究了组成和结构如何赋予功能。特别是，正在进行对随着对称性的函数而产生的新光结合相互作用的研究，以实现用于化学传感应用的多功能平台。最终，这项研究通过在包括纳米/无机/固态化学，凝结物理物理学，表面科学和材料科学在内的多个学科之间建立联系，从而对该领域产生了更大的影响。该项目还结合了外展和教育工作，将纳米级概念引入非科学家。该项目还以强调其与周围社区的联系的方式涉及研究活动的大学生。印第安纳大学的Skrabalak集团正在开发种子介导的共同还原，作为多金属纳米结构的一种新的合成策略，在该策略中，多种金属同时沉积在形状受控的纳米机构上。纳米晶种子的对称性转移到最终的纳米结构中。这项研究包括研究晶格不匹配和沉积动力学如何有助于双金属分布。这项工作与研究在种子介导的共还原过程中如何沿特定的晶体学方向减少对称性的研究相结合，以实现新的恒星纳米晶体对称性和又有功能多样性。最后，Skrabalak群使用恒星的金属纳米晶体组装封闭式和低密度晶格，以将结晶能力扩展到新的结构类别。它们还表征了出现的集体光学特性。这三个目标与外展和教育工作相结合，本科研究人员是其以前高中的科学大使，向学生介绍了纳米级概念，并将其作为对科学，技术，工程，工程和数学领域感兴趣的人的榜样。研究的进步扩大了可能的纳米晶体和上层建筑的类别，并确定了种子和构建基础对称性在金属纳米晶体的合成和组装中的作用，从而在科学中更广泛影响。