在离子交换膜中的多元件离子平衡和运输
Alaaeldin A E Elozeiri1, Jouke E Dykstra1, Huub H M Rijnaarts1
1Environmental Technology, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands.
Journal of colloid and interface science
|June 27, 2024
概括
这项研究实验性地研究了多个电解质的离子交换膜中的多南平衡. 研究结果显示,离子分数随着离子强度的变化而变化,验证了多南平衡理论,并使准确的流量预测成为可能.
科学领域:
- 电化学 电化学 电化学
- 膜科学 膜科学 膜科学
- 物理化学 物理化学
背景情况:
- 充电物种在离子交换膜接口上重新分配,以最大限度地减少系统的自由能量.
- 了解多纳平衡对于预测跨膜多电解质溶液中的离子行为至关重要.
研究的目的:
- 实验研究多南平衡在阴离子交换膜 (CEM) 与四元电解质溶液 (Na+/Mg2+/K+/Ca2+/Cl-).
- 在模拟的多南透析中计算离子活性系数并评估它们对离子度和流量的影响.
- 为了验证唐南平衡理论,关于离子分数转移与不同的溶液离子强度的变化.
主要方法:
- 在六种商业CEM中实验确定多电解质溶液中的平衡度.
- 使用实验数据和装配参数计算离子活性系数.
- 使用运输模型模拟多南透析,并采用配套的活动系数.
主要成果:
- 在描述离子物种的平衡度时,平均相对误差为3%.
- 单价反离子的等价离子分数随着离子强度的增加而增加,取代了多价离子,符合多南平衡理论.
- 一个活动系数的任意分配没有影响预测的内部离子度或模拟的离子流.
结论:
- 该研究成功地确定了四级电解质溶液中CEM的离子活性系数.
- 唐南平衡原理准确地预测了不同离子强度下的离子再分配.
- 该方法提供了一个强大的框架,用于模拟离子运输和预测复杂的电化学系统中的流量.
相关概念视频
Ion Exchange
574
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...
574
Ion-Exchange Chromatography
442
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...
442
Pore Transport and Ion-Pair Transport
417
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...
417
Potentiometry: Membrane Electrodes
551
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...
551
The Significance of Membrane Transport
25.1K
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
25.1K
Chemical Equilibria: Systematic Approach to Equilibrium Calculations
673
Equilibrium calculations for systems involving multiple equilibria are often complex. For example, to calculate the solubility of a sparingly soluble salt in an aqueous solution in the presence of a common ion, one must consider all the equilibria in this solution. Calculations for these systems can be complicated and tedious, so a systematic approach with a series of steps is often helpful. The process is detailed below.
The first step is to identify all the chemical reactions involved, The...
The first step is to identify all the chemical reactions involved, The...
673


