CAREER: Solid-State and Materials Chemistry applicable to Titanean Model Planetary Ices

第一部分： 非技术性总结通过这个NSF职业奖，由材料研究部的固态和材料化学计划支持，首席研究员和他的研究小组对一些最小的有机分子的结晶和固相进行实验研究。这些化学物质，如苯和乙腈，经常被用作工业和日常生活中的液体溶剂和/或燃料，但它们也在土星冰冷的卫星泰坦的大气中产生。随着降雨，它们降落在土卫六的表面，在那里它们结晶为行星冰。令人惊讶的是，关于这些最小的有机化合物的固态和材料化学存在许多悬而未决的问题，这些有机化合物与地球上的材料和泰坦上的矿物有关。这个NSF CAREER项目包括固态结构的详细实验表征和这些材料系统的组成，这些材料系统由两个或多个单独的分子组分组成，这些分子组分结晶为一种具有新特性的材料。在这方面，特别令人感兴趣的是发现和设计新型低温热膨胀材料（在加热和冷却时物理尺寸急剧变化的固体），以及可用于合成其他功能性固态材料的材料。关于将小分子和益生元分子自组装成有机矿物和（行星）冰的研究也与NSF的10大想法中的两个相关：宇宙窗口和了解生命规则;通过低温功能材料的设计，该研究与10大想法中的另一个相关：导航新北极。沿着实验研究，这个NSF职业奖教育新一代材料科学家，并为他们提供知识和技能，以解决材料表征中具有挑战性和长期存在的问题。高中生参与STEM活动，并可能有动力追求STEM职业生涯，在期刊封面艺术和图形内容设计表的帮助下。 该NSF职业奖由材料研究部的固态和材料化学项目支持，重点在于阐明基本相关的多组分有机体系的结构和组成，这些体系由最小的有机分子组成，如苯、吡啶、乙腈、丙腈、丁腈等。这项研究的部分动机是最近结束的卡西尼-惠更斯使命，它揭示了土星的卫星泰坦的表面藏有大量的小有机分子，固化和结晶为行星冰。该项目解决了结构和组成知识以及对最小有机系统的理解方面的主要差距。最值得注意的是，这些系统的二元和三元相图还没有被充分研究，其中一些系统的晶体结构在发现几个世纪后仍然未知。本研究建立在这些多组分系统的相平衡，并提供了一个详细的结构帐户上的晶体，本地和动态结构的固态采用X射线和中子衍射和光谱，拉曼，红外和中子光谱，和量热技术。这些系统的结构和组成方面的知识为新功能材料的设计和开发提供了大量的可能性，例如巨大的热膨胀性能。这种膨胀性可用于低温应用的模块化热膨胀材料的设计。这些分子在晶格中的独特排列还允许前所未有的固态反应性和具有改性或官能化的石墨烯或金刚石样结构的多组分扩展固体的合成。这些扩展的固体材料在环境条件下具有无数潜在的应用。这个NSF CAREER奖的教育部分有助于培养新一代材料研究人员，他们具备从粉末衍射数据中解决晶体结构的知识。此外，首席研究员从事高中学生的帮助下，封面艺术和图表的内容设计。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

PART 1: NON-TECHNICAL SUMMARYWith this NSF CAREER award, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, the principal investigator and his research group carry out experimental research on the crystallization and solid phases of some of the smallest organic molecules. Such chemicals, like benzene and acetonitrile, are frequently used as liquid solvents and/or fuels in industry and everyday life, but they are also produced in the atmosphere of Titan, Saturn’s icy moon. Carried by rainfall, they descend on the surface of Titan, where they crystalize as planetary ices. Surprisingly, there are many open questions about the solid-state and materials chemistry of these smallest organic compounds which are relevant as materials on Earth, and minerals on Titan. This NSF CAREER project includes detailed experimental characterization of the solid-state structure and the composition of these materials systems that consist of two or more individual molecular components that crystallize as one material with new properties. Of particular interest, in this regard, is the discovery and design of novel low-temperature thermal expansion materials (solids for which the physical size drastically changes upon heating and cooling), and of materials that can be used for the synthesis of other functional solid-state materials. The studies on the self-assembly of small and prebiotic molecules into organic minerals and (planetary) ices, are also relevant to two of the NSF’s 10 Big Ideas: Windows on the Universe, and Understanding the Rules of Life; and with the design of low-temperature functional materials, the research connects to another of the 10 Big Ideas: Navigating the New Arctic. Along with the experimental research, this NSF CAREER award educates a new generation of materials scientists and equips them with the knowledge and skillset to address challenging and long-standing questions in materials characterization. High-school students become engaged in STEM activities, and possibly motivated to pursue STEM careers, with the help of journal cover art and table of graphical content design.PART 2: TECHNICAL SUMMARYThis NSF CAREER award, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, focuses on elucidating the structure and composition of fundamentally relevant multicomponent organic systems, comprised of the smallest organic molecules, such as benzene, pyridine, acetonitrile, propionitrile, butanenitrile, etc.. This research is in part motivated by the recently concluded Cassini-Huygens mission, which revealed that the surface of Saturn’s moon Titan harbors large inventories of small organic molecules, solidified and crystalized as planetary ices. The project addresses major gaps in the structural and compositional knowledge and understanding of the smallest organic systems. Most notably, the binary and ternary phase diagrams of these systems are vastly underexplored, and the crystal structures of some of them remain unknown, centuries after their discovery. This research establishes the phase equilibria in these multicomponent systems, and provides a detailed structural account on the crystal, local and dynamic structure of their solid-state by employing X-ray and neutron diffraction and spectroscopy, Raman, infrared and neutron spectroscopy, and calorimetric techniques. The obtained knowledge on the structure and composition of these systems opens a plethora of possibilities for the design and development of new functional materials, for example colossal thermal expansion properties. This expansivity can be leveraged in the design of modular thermal expansion materials for low-temperature applications. The unique arrangement of these molecules in the crystal lattice also allows for unprecedented solid-state reactivity and synthesis of multicomponent extended solids with modified or functionalized graphene- or diamond-like structures. These extended solid materials have myriad of potential applications at ambient conditions. The educational segment of this NSF CAREER award contributes to training of the new generation of materials researchers, equipped with the knowledge to solve crystal structures from powder diffraction data. Additionally, the principal investigator engages high-school students with the help of cover art and table of graphical content design.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.