化水平和键对阳离子交换膜中氧化运输机制的影响
Lunliang Ma1,2,3, Tao Wang2,3,4
1Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
ChemSusChem
|April 9, 2025
概括
了解阳离子交换膜 (AEM) 中的氧化物运输是提高性能的关键. 这项研究使用分子动力学模拟来揭示水合和结合如何影响氧化物扩散机制.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 计算化学的计算化学
背景情况:
- 在离子交换膜 (AEM) 中的氧化运输对于电化学应用至关重要.
- 影响运输的因素包括水分,毛孔结构和离子相互作用.
- 高性能AEM的合理设计需要对这些机制有深刻的了解.
研究的目的:
- 探索膜性质和氧化物运输机制之间的相关性.
- 为增强AEM中的氧化物导电性提供理论见解.
- 阐明水化外,孔腔形态和键在AEM性能中的作用.
主要方法:
- 使用ReaxFF分子动力学 (MD) 模拟.
- 使用RDAnalyzer进行数据分析.
- 研究了固体阻碍,水分水平和扩散机制之间的相关性.
主要成果:
- 较高的固体阻碍降低了cationic组水化中的水.
- 增加的水分水平有助于扩大毛孔,并增强自由氧化物扩散.
- 强键 (SHB) 和格罗特苏斯扩散之间存在强烈的相关性,这解释了某些AEM的高导电性.
结论:
- 膜水合水平和固体阻碍显著影响氧化物扩散通路.
- 强键直接与高效的Grotthuss扩散有关,这对于高导电性至关重要.
- 这项工作提供了一个理论框架,通过合理设计来优化AEM中的氧化物运输.
相关概念视频
Pore Transport and Ion-Pair Transport
311
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
311
Ion Exchange
421
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...
421
Aqueous Solutions and Heats of Hydration
14.2K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
14.2K
Potentiometry: Membrane Electrodes
320
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at...
320
Ions as Acids and Bases
23.0K
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
23.0K
Solubility Equilibria: Ionic Product of Water
911
Pure water is a weak electrolyte; only a small amount ionizes into hydrogen and hydroxide ions. At any given temperature, the concentration of undissociated water is almost constant, so the ionic product of water is the product of the hydrogen and hydroxide ion concentrations, denoted as Kw. The square root of Kw gives the individual ion concentrations.
The ionic product of water varies with temperature, and its value is 1.0 x 10−14 at standard experimental conditions. Per Le...
The ionic product of water varies with temperature, and its value is 1.0 x 10−14 at standard experimental conditions. Per Le...
911


