CAREER: Understanding Quasicrystalline Superstructures Formed from Pyramidal Nanocrystals

职业：了解由金字塔形纳米晶体形成的准晶超结构

• 批准号: 1943930
• 负责人: Ou Chen
• 金额: $ 67.79万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1943930&HistoricalAwards=false
• 关键词: CAREER; Understanding; Quasicrystalline; Superstructures; Formed

Non-Technical Summary:Crystalline materials are characterized by a structure with a regular, repeating pattern of atoms, while amorphous materials such as glass are disordered. Quasicrystalline (QC) materials are unusual in that they are ordered but not periodic, making them a fundamentally different category of materials which is neither a crystal nor a glass. The unique structure gives QC materials intriguing thermal, electrical, magnetic, optical and mechanical properties, making them useful for applications such as non-stick and thermally insulating coatings or corrosive-resistant and extremely strong materials for medical devices and surgical instruments. This CAREER award, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, enables study of QC materials self-assembled from pyramid-shaped nano-sized particles (nanocrystals). The project includes detailed characterization of new QC materials’ structures and formation processes and also develops new characterization and growth methods that may be applicable to studying other soft matter assembly systems. The research offers ample fundamental and visual interest, as well as technological relevance, all of which are integrated into the PI’s education and outreach activities. YouTube movies with a jargon-free, storytelling style are created and promoted through various social media platforms. These videos take unique advantage of the connection between the beautiful and eye-catching QC patterns created by this fundamental study and real-world art, decoration and architectural design. Additionally, the project supports outreach to local high school students through an annual STEM Day. Technical Summary:This CAREER project, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, integrates education and research on quasicrystalline (QC) superstructures assembled from pyramid-shaped nanocrystals (NCs). Self-assembly of NCs into novel superstructures is a promising approach for transporting nanoscopic properties into macroscopic materials to eventually enable highly efficient solar cells, low-energy-consumption lighting and displays, and more sensitive biological sensors. To realize these opportunities requires rational control over the formation of NC superstructures. Quasicrystals are ordered but not periodic and as such defy classification as either a crystal or a glass. The study of NC QC superlattices (QC-SLs) is in its infancy compared to efforts on conventional NC crystalline superstructures. It remains an outstanding question how NCs organize into these long-range ordered yet aperiodic lattices; methods to produce and characterize these unique materials are limited. To address these issues, the PI's group first synthesizes anisotropic pyramidal NCs and assembles them into QC superstructures. These materials are then characterized using combinations of in situ and ex situ real space methods (electron microscopies and tomography) complemented by reciprocal space measurements (electron diffraction and X-ray scattering). In addition to 2D superlattices, 3D QC supercrystals grown via microfluidics will be structurally characterized using a new super-crystallography technique. Together, these tools provide exquisite detail concerning the packing of these structures and specify the relative orientation of individual NCs. Such information clarifies how NC synthesis, superstructure formation and transformation work together to create QC superstructures. Results generated in this research are integrated into a series of outreach activities that target younger students and adults alike with compelling, visual stories designed to provoke interest in science and technology.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.

非技术概述：晶态材料的特征是具有规则的、重复的原子图案，而玻璃等非晶态材料则是无序的。准晶(QC)材料的不同寻常之处在于它们是有序的，但不是周期性的，这使它们成为一种根本不同的材料类别，既不是晶体，也不是玻璃。独特的结构使QC材料具有耐人寻味的热、电、磁、光和机械性能，使其适用于不粘和隔热涂层或医疗器械和外科器械的极强耐腐蚀材料等应用。这项职业奖由材料研究部内的固态和材料化学项目支持，能够研究由金字塔形纳米颗粒(纳米晶体)自组装的质量控制材料。该项目包括对新的QC材料的结构和形成过程的详细表征，并开发了新的表征和生长方法，这些方法可能适用于研究其他软物质组装系统。这项研究提供了充分的基本兴趣和视觉兴趣，以及技术相关性，所有这些都纳入了国际和平协会的教育和外联活动。YouTube上的电影没有术语，讲故事的风格是通过各种社交媒体平台创作和推广的。这些视频利用了这一基础研究创造的美丽而引人注目的QC图案与现实世界的艺术、装饰和建筑设计之间的独特联系。此外，该项目还支持通过一年一度的STEM日向当地高中生提供服务。技术总结：这个职业项目由材料研究部的固态和材料化学项目支持，整合了关于由金字塔状纳米晶体(NC)组装的准晶(QC)超结构的教育和研究。将纳米结构自组装成新型超结构是一种很有前途的方法，可以将纳米特性转移到宏观材料中，最终实现高效太阳能电池、低能耗照明和显示器以及更灵敏的生物传感器。要实现这些机遇，需要对NC上层建筑的形成进行合理的控制。准晶是有序的，但不是周期性的，因此不能归类为晶体或玻璃。与传统的纳米晶体超结构相比，纳米QC超晶格(QC-SLS)的研究处于起步阶段。NCs如何组织成这些长程有序的非周期晶格仍然是一个悬而未决的问题；制备和表征这些独特材料的方法有限。为了解决这些问题，Pi的团队首先合成了各向异性的锥形NC，并将它们组装成QC超结构。然后，使用现场和非现场真实空间方法(电子显微镜和断层摄影术)的组合，辅之以相互空间测量(电子衍射和X射线散射)，对这些材料进行表征。除了2D超晶格外，通过微流控生长的3D QC超晶将使用一种新的超结晶学技术进行结构表征。总之，这些工具提供了有关这些结构的包装的精细细节，并指定了各个NC的相对方向。这些信息阐明了NC合成、超结构形成和转变如何共同作用来创建QC超结构。这项研究产生的结果被整合到一系列针对年轻学生和成年人的外展活动中，通过引人入胜的视觉故事来激发人们对科学和技术的兴趣。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Fast Lifetime Blinking in Compact CdSe/CdS Core/Shell Quantum Dots

紧凑型 CdSe/CdS 核/壳量子点的快速寿命闪烁

• DOI: 10.1021/acs.jpcc.1c03949
• 发表时间: 2021
• 期刊: The Journal of Physical Chemistry C
• 作者: Sun, Yonglei;Zhu, Hua;Jin, Na;Chen, Ou;Zhao, Jing
• 通讯作者: Zhao, Jing

Bulk Grain-Boundary Materials from Nanocrystals

• DOI: 10.1016/j.chempr.2020.12.026
• 发表时间: 2021-02
• 期刊: Chem
• 影响因子: 23.5
• 作者: Yasutaka Nagaoka;M. Suda;Insun Yoon;N. Chen;Hanjun Yang;Yuzi Liu;B. Anzures;S. Parman;Zhongwu Wan

Influence of local structures on the energy transfer efficiencies of quantum-dot films

• DOI: 10.1103/physrevb.102.035437
• 发表时间: 2020-07
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Lintao Peng;Xuedan Ma;Hua Zhu;Ou Chen;Wei Wang

Quasicrystalline materials from non-atom building blocks

• DOI: 10.1016/j.matt.2022.09.027
• 发表时间: 2023-01
• 期刊: Matter
• 影响因子: 18.9
• 作者: Yasutaka Nagaoka;J. Schneider;Hua Zhu;Ou Chen

Synthesis of Ultrathin Perovskite Nanowires via a Postsynthetic Transformation Reaction of Zero-Dimensional Perovskite Nanocrystals

• DOI: 10.1021/acs.cgd.1c00118
• 发表时间: 2021-03
• 期刊: Crystal Growth & Design
• 影响因子: 3.8
• 作者: Hanjun Yang;Tong Cai;Lacie Dube;Katie Hills‐Kimball;Ou Chen