权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Real-space and Real-time Study of Two-dimensional Colloidal Quasicrystals

二维胶体准晶的实空间和实时研究

基本信息

批准号：
2030480
负责人：
Ning Wu
金额：
$ 35.73万
依托单位：
Colorado School of Mines
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-10-01 至 2024-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2030480&HistoricalAwards=false
关键词：
Real space time Study Two

项目摘要

Quasicrystals are structures that lie between crystalline and disordered phases. They exhibit some properties similar to those of crystals, but they do not have the periodic structure of crystals. Quasicrystals can interact with light in unique ways and exhibit rich optical properties that are not manifested in crystals or in completely disordered materials. Although atomic quasicrystals are predominantly metallic alloys, synthetic quasicrystals have also been found in soft materials made from nanoparticles, micelles, and polymers. However, both natural and synthetic quasicrystals are built from units that are too small to be directly observed by optical microscopy. As a result, it has proven challenging to fully understand the formation and stability of quasicrystals. The goal of this project is to build two-dimensional quasicrystals from single-component microparticles that are large enough to observe with optical microscopy. The assembly of the microparticles into quasicrystals will be driven using applied alternating current electric fields. The formation of the Microparticles will be observed in detail and the experiments will be compared with numerical simulations to understand the dynamics of quasicrystal formation. Results of the project will address fundamental questions about quasicrystal formation, such as how the long-range but non-periodic order emerges and evolves and what stabilizes low and high temperature quasicrystals. The research will be integrated with a variety of educational and outreach efforts, including an activity to encourage participation of children with dyslexia in science and engineering. The objective of this project is to assemble two-dimensional dodecagonal quasicrystals from particles whose sizes are comparable to the wavelengths of visible light. Owing to the size of the particles, the dynamic formation of quasicrystals can be observed directly with optical microscopy. This provides a tool to address fundamental issues related to quasicrystal formation from soft matter. Large high-quality two-dimensional quasicrystals will be assembled from colloidal microspheres of different materials by combining externally applied fields with geometric confinement. The coordinates of all particles will be visualized as a function of time, the underlying driving forces that stabilize colloidal quasicrystals will be determined, and nucleation and growth mechanisms will be identified. Complementary Monte Carlo and Brownian Dynamics simulations will be performed in parallel to interpret experimental observations. Finally, the photonic properties of the assembled quasicrystals in both visible and near-infrared light spectra will be measured. This project will offer an opportunity to search for physical principles that unify the formation of soft-matter quasicrystals over a broad range of length scales.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.

准晶是介于结晶相和无序相之间的结构。它们表现出一些类似于晶体的性质，但它们不具有晶体的周期结构。准晶体可以以独特的方式与光相互作用，并表现出丰富的光学性质，这些性质在晶体或完全无序的材料中没有表现出来。虽然原子准晶主要是金属合金，但在由纳米颗粒、胶束和聚合物制成的软材料中也发现了合成准晶。然而，天然和合成的准晶都是由太小而不能通过光学显微镜直接观察到的单元构成的。因此，充分理解准晶的形成和稳定性已被证明具有挑战性。该项目的目标是从单组分微粒中构建二维准晶体，这些微粒大到足以用光学显微镜观察。将使用所施加的交流电场来驱动微粒组装成准晶体。将详细观察微粒的形成，并将实验与数值模拟进行比较，以了解准晶形成的动力学。该项目的结果将解决有关准晶形成的基本问题，例如长程但非周期性的秩序如何出现和演变，以及什么使低温和高温准晶稳定。这项研究将与各种教育和推广工作相结合，包括鼓励有阅读障碍的儿童参与科学和工程的活动。这个项目的目标是组装二维十二方准晶的颗粒，其大小与可见光的波长相当。由于颗粒的尺寸，准晶的动态形成可以直接用光学显微镜观察。这提供了一个工具，以解决有关软物质的准晶体形成的基本问题。将外加场与几何约束相结合，可以从不同材料的胶体微球中组装出大尺寸的高质量二维准晶。所有粒子的坐标将被可视化为时间的函数，将确定稳定胶体准晶的潜在驱动力，并确定成核和生长机制。将并行进行补充蒙特卡罗和布朗动力学模拟，以解释实验观察结果。最后，在可见光和近红外光谱中测量组装的准晶的光子学性质。该项目将提供一个机会，以寻找统一的软物质准晶体的形成在一个广泛的长度尺度的物理原理。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。