一个巨大的超分子液晶晶格子
Goran Ungar1, Yongsong Liu, Xiangbing Zeng
1Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD, UK. g.ungar@shef.ac.uk
概括
研究人员发现了一种复杂的液晶阶段,由自组装的超分子树状体形成. 这一发现推动了用于电子和催化剂的先进有机纳米结构的设计.
科学领域:
- 超分子化学 超分子化学
- 材料科学是一种材料科学.
- 液晶是一种液体晶体.
背景情况:
- 自组织的超分子有机纳米结构对于分子电子,光子学和纳米孔状催化剂至关重要.
- 通过分子架构控制自我组装是设计复杂纳米结构的关键.
研究的目的:
- 报告一个新的和复杂的液晶相.
- 为了研究超分子树状体的自我组装.
- 提出一个树突聚合物排列的模型.
主要方法:
- 超分子树枝状体的合成和表征.
- 液晶相位分析.液晶相位分析.
- 结构建模. 结构建模.
主要成果:
- 发现了一种具有四角形三维单元细胞的液晶相.
- 每个单元细胞的30个球状上分子树枝体的观察.
- 每个树突分子从12个树突分子中自组装.
结论:
- 报告的液晶阶段是迄今为止发现的最复杂的阶段之一.
- 提出了一个模型来解释基于分子结构和温度的树突聚合物的空间布局.
- 这项工作使得设计更复杂的超分子纳米结构成为可能.
相关概念视频
Structures of Solids
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
Molecular and Ionic Solids
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
Unit Cells
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...
Crystal Density
The crystal lattice structure of a material allows us to determine how many molecules exist in its unit cell. With this information, alongside the unit-cell parameters - three distance parameters (a, b, c) and three angular parameters (α, β, γ).Density (ρ) = (Z × M) / (a × b × c × NA)where:Z is the number of formula units per unit cellM is the molar mass of the substancea, b, and c are the edge lengths of the unit cellNA is Avogadro’s numberFor a simple cubic lattice, atoms are located only at...


