相关实验视频
Updated: Jul 4, 2025

12:35
Atomically Traceable Nanostructure Fabrication
Published on: July 17, 2015
8.8K
半导体魔力大小集群中的离子交换
Xinke Kong1, Yalei Deng1, Yihao Zou1
1State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
Journal of the American Chemical Society
|February 2, 2024
概括
在魔法大小集群 (MSC) 中实现了阴离子交换,揭示了涉及共价无机复合体 (CIC) 的阶段性途径. 这项研究加深了对量子点 (QD) 合成和纳米材料设计的理解.
科学领域:
- 材料科学
- 纳米技术
- 化学学
背景情况:
- 离子交换是设计体纳米材料的关键后合成方法.
- 阴离子交换 (CE) 已得到充分发展,但离子交换机制需要进一步研究.
- 魔法大小集群 (MSC) 是量子点 (QD) 合成中的关键中间体.
研究的目的:
- 在基于的MSC中实现和阐明离子交换的反应途径.
- 了解纳米材料中间体中控制离子交换的基本机制.
- 提供QD在合成过程中的转化过程的见解.
主要方法:
- 在基于的MSC中研究了离子交换.
- 包括拆卸,交换和组装步骤的阐明反应路径.
- 描述了离子交换过程的动力学和机制.
主要成果:
- 基于Cd的MSC中的离子交换是通过共价无机复合物 (CIC) 介导的阶段性分子间过渡进行的.
- 该过程包括三个步骤:从MSC拆解到CIC,从CIC内部进行离子交换,以及从CIC重新组装到MSC.
- 组装步骤是决定速度的,遵循第一阶段的动力学 (k_obs = 0.01 min−1对于CdSe-MSCs到CdS-MSCs).
- 外来离子活动会影响反应动力学,但不会影响整个反应路径.
结论:
- 该研究阐明了MSC中的离子交换机制,确定了CIC作为关键中间体.
- 这些发现提供了通过离子交换更深入地了解QD合成和纳米材料设计.
- 这项工作为功能性纳米材料的更有控制的合成铺平了道路.
相关概念视频
Ion Exchange
592
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
592
Ion-Exchange Chromatography
496
Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...
496
Ionic Crystal Structures
14.3K
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...
14.3K
Size-Exclusion Chromatography
585
In size-exclusion chromatography (SEC), also known as molecular-exclusion or gel-permeation chromatography, molecules are separated based on their sizes. This technique is important for separating large molecules such as polymers and biomolecules. The two classes of micron-sized stationary phases encountered in SEC are silica particles and cross-linked polymer resin beads. Both materials are porous, but their pore sizes vary significantly.
Silica particles offer advantages such as rigidity,...
Silica particles offer advantages such as rigidity,...
585
Ionic Bonding and Electron Transfer
41.6K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
41.6K
Trends in Lattice Energy: Ion Size and Charge
23.9K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.9K

