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.

准晶体是晶体和无序相之间的结构。它们表现出与晶体相似的某些特性，但没有晶体的周期性结构。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特性，这些特性未在晶体或完全无序的材料中表现出来。尽管原子准晶体主要是金属合金，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的准晶体。但是，天然和合成的准晶体都是由太小的单位建造的，无法通过光学显微镜直接观察到。结果，完全理解准晶体的形成和稳定性已被证明具有挑战性。该项目的目的是从单一组分微粒构建二维准晶体，它们足够大，可以使用光学显微镜观察。将使用施加的交替电流电场驱动微粒将微粒组装到准晶体中。将详细观察微颗粒的形成，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体形成的基本问题，例如如何出现远距离但非周期性的秩序以及如何稳定低温和高温准晶体。这项研究将与各种教育和外展工作相结合，包括一项活动，以鼓励患有阅读障碍的儿童参与科学和工程学。该项目的目的是组装来自颗粒的二维十二型准晶体，其大小与可见光的波长相当。由于颗粒的尺寸，可以直接观察到光学显微镜直接观察到准晶体的动态形成。这提供了一种工具，可以解决与软物质与准晶形成有关的基本问题。通过将外部施加的田地与几何限制相结合，将从不同材料的胶体微球中组装出大型高质量的二维准晶体。所有颗粒的坐标将被视为时间的函数，将确定稳定胶体准晶体的基础驱动力，并确定成核和生长机制。互补的蒙特卡洛和布朗动力学模拟将同时进行解释实验观测。最后，将测量组装的准晶体的光子性能。该项目将提供一个机会来搜索物理原理，这些物理原则在广泛的长度范围内统一了软性型准晶体的形成。该奖项反映了NSF的法定任务，并通过基金会的智力优点和更广泛的影响来评估NSF的法定任务，并被认为值得支持。