从分子动力学模拟中了解C-S-H凝孔中的离子扩散:空间分布,能量屏障和结构描述符
Weiqiang Chen1,2,3, Kai Gong1,2,3
1Department of Civil and Environmental Engineering, Rice University, Houston, Texas 77005, United States.
The journal of physical chemistry. B
|September 29, 2025
概括
分子动力学模拟揭示了如何在水泥纳米孔中限制离子和水的运输. 定制纳米通道结构可以通过控制这种离子运动来提高材料的耐用性.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 纳米技术纳米技术
背景情况:
- 了解像水泥材料这样的狭窄环境中的纳米运输至关重要,但在分子层面上了解得很少.
- 纳米孔内的离子和水扩散机制对材料特性和耐用性产生重大影响.
研究的目的:
- 在纳米封闭的-酸盐-酸盐 (C-S-H) 孔中研究 (Na+), (Cl-) 和水扩散的分子水平机制.
- 分析运输行为,热动力学和水泥纳米孔内的结构的空间异质性.
主要方法:
- 利用分子动力学 (MD) 模拟来模拟4纳米C-S-H孔道中的离子和水扩散.
- 进行了扩散性,激活能量障碍和孔径宽度的结构性质的空间分辨率分析.
- 引入了总协调强度 (TCS) 描述符,以将局部液体结构与分子移动性联系起来.
主要成果:
- 在固体-液体界面附近观察到显著的扩散性抑制,恢复到孔隙中心.
- 激活能量和移动性的量化空间变化,揭示了明显的限制效应.
- 确定了从结构控制到水力动力控制的运输模式的过渡,随着距离孔面的距离的增加.
结论:
- 这项研究提供了第一个全面的MD解决水泥纳米孔的运输异质性.
- 这些发现加深了对纳米运输现象的理解,以及它们对孔隙结构和界面化学的依赖.
- 定制纳米通道结构和界面化学提供了一种策略,可以抑制离子入,提高基于水泥的材料的耐用性.
更多相关视频
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
6.0K
06:34In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging
Published on: September 2, 2016
6.8K
相关概念视频
01:24Protein Diffusion in the Membrane
5.5K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
5.5K
01:12Diffusion
216.3K
Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...
216.3K
01:21Diffusion
6.2K
Diffusion is a type of passive transport. In passive transport, a substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. For example, take the diffusion of substances through the air. When someone opens a perfume bottle in a room filled with people, the perfume is at its highest concentration in the bottle and is at its lowest at the edges of the room. The perfume vapor will diffuse, or spread away, from the...
6.2K