Crystals and Their Defects on Flat and Curved Surfaces

平面和曲面上的晶体及其缺陷

• 批准号: 1105417
• 负责人: Paul Chaikin
• 金额: $ 43.5万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1105417&HistoricalAwards=false
• 关键词: Crystals; Their; Defects; Flat; Curved

Non-Technical AbstractIt is easy to perfectly tile a flat surface with hexagons, as in parks and playgrounds and bathroom floors. But when you try to tile a curved surface, the hexagonal tiling is frustrated and the defects, for example pentagons, are essential for relieving the stresses and strains. Witness the 12 pentagons required to close an otherwise hexagonally tiled geodesic dome, or a soccer ball or a C60 molecule. The present study introduces a unique system whereby particles bound to a surface of arbitrary curvature solve the geometric problem and create a relaxed structure with defects arranged optimally. The study involves colloidal particles, thirty times smaller than a human hair, which arrange themselves on different shaped water droplets a tenth of a millimeter in diameter. The particles are imaged microscopically and added or moved with focused light, optical tweezers. Students working on this project are trained in the latest optical techniques. The video imaging of defects and their dynamics in crystals is a great pedagogical tool for instructing students and researchers at all levels as to the basic properties of liquids and solids. Since geometry is important for structures at all length scales these results will be important for designing new molecules, for assembling nano and colloidal particles and for engineering new architectural structures.Technical AbstractTopology plays a crucial role in the geometry and order of materials and topological defects, disclinations and dislocations, determine many of the mechanical properties of crystals. Curvature tends to frustrate periodic order, and here topological defects play an important role in relieving the resulting stresses and strains. Witness the 12 pentagons required to close an otherwise hexagonally tiled geodesic dome, or a soccer ball or a C60 molecule, curvature requires the introduction of topological defects, pentagons - disclinations, which force reorientation. But within the past several years it has been realized that although topology constrains the net number of defects it is energetics that dictates the actual arrangements. The present study introduces a system and a number of techniques to experimentally observe and manipulate mobile colloidal particles which are bound to an arbitrarily curved surface oil-water interface. Students involved will be trained in the latest soft matter and optical techniques. The video images are great pedagogically for students and researchers at all levels. These topological results will be important for designing new molecules, for assembling nano and colloidal particles and for engineering new architectural structures.

非技术抽象很容易与六角形完美地铺一个平坦的表面，例如在公园，游乐场和浴室地板中。但是，当您尝试铺一个弯曲的表面时，六边形的平铺就会感到沮丧，并且缺陷，例如五角大州，对于缓解压力和菌株至关重要。见证要关闭否则六角形的大地测量圆顶，足球或C60分子所需的12个五角大龙。本研究引入了一个独特的系统，从而使粒子结合到任意曲率的表面解决了几何问题，并创建了一个放松的结构，并具有最佳排列的缺陷。该研究涉及胶体颗粒，比人毛小三十倍，它们将自己放在直径十分之一毫米的不同形水滴上。这些颗粒是通过显微镜成像的，并以聚焦的光晶镊子添加或移动。从事该项目的学生接受了最新的光学技术培训。缺陷的视频成像及其在晶体中的动态是一个很好的教学工具，可指导各个级别的学生和研究人员有关液体和固体的基本特性。由于几何形状对于在所有长度尺度的结构都很重要，因此这些结果对于设计新分子，组装纳米和胶体颗粒以及工程新的建筑结构至关重要。技术抽象学在材料的几何形状和材料和拓扑缺陷，束缚和错位，确定许多机械的属性中，在材料和拓扑缺陷的几何形状和顺序中起着至关重要的作用。曲率倾向于挫败周期性的顺序，在这里拓扑缺陷在减轻所得的压力和压力方面起着重要作用。目睹否则要关闭六角形瓷砖的大地圆顶或足球或C60分子所需的12个五角大人，曲率需要引入拓扑缺陷，五角大族 - 脱节，这会迫使重新定位。但是在过去的几年中，人们已经意识到，尽管拓扑限制了净数量的净数量，但它决定了实际安排。本研究介绍了一种系统和许多技术来实验观察和操纵与任意弯曲的表面油水界面结合的移动胶体颗粒。参与的学生将接受最新软件和光学技术的培训。对于各个级别的学生和研究人员来说，视频图像在教学上很棒。这些拓扑结果对于设计新分子，组装纳米和胶体颗粒以及工程新的建筑结构至关重要。