Effect of current density, concentration of ternary electrolyte and type of cations on the monovalent ion selectivity of surface-sulfonated graft anion-exchange membranes: modelling and experiment

Artificial ion-exchange and other charged membranes, such as biomembranes, are self-organizing nanomaterials built from macromolecules. The interactions of fragments of macromolecules results in phase separation and the formation of ion-conducting channels. The properties conditioned by the structure of charged membranes determine their application in separation processes (water treatment, electrolyte concentration, food industry and others), energy (reverse electrodialysis, fuel cells and others), and chlore-alkali production and others. The purpose of this review is to provide guidelines for modeling the transport of ions and water in charged membranes, as well as to describe the latest advances in this field with a focus on power generation systems. We briefly describe the main structural elements of charged membranes which determine their ion and water transport characteristics. The main governing equations and the most commonly used theories and assumptions are presented and analyzed. The known models are classified and then described based on the information about the equations and the assumptions they are based on. Most attention is paid to the models which have the greatest impact and are most frequently used in the literature. Among them, we focus on recent models developed for proton-exchange membranes used in fuel cells and for membranes applied in reverse electrodialysis.

/pdf/ion-and-water-transport-in-ion-exchange-membranes-for-power-1zil9cig.pdf

Ion and Water Transport in Ion-Exchange Membranes for Power Generation Systems: Guidelines for Modeling

The way to increase the monovalent ion selectivity of FujiFilm® anion-exchange membranes by cerium phosphate modification for electrodialysis desalination

В последние годы в связи с резким увеличением спроса на литий возрос интерес исследователей к проблеме его извлечения (получения): согласно базе данным Scopus, за 2021 г. по данной проблеме опубликовано около 3000 научных статей. Усилия многих специалистов направлены на разработку новых, более экономичных и экологичных, мембранных технологий извлечения лития, взамен применяемых реагентных методов. В обзоре представлена актуальная информация о традиционных и перспективных методах извлечения лития из природных растворов и растворов, получаемых при утилизации использованных батарей. Основное внимание уделено мембранным методам. Классифицированы и проанализированы известные подходы, описаны экспериментальные и теоретические аспекты мембранного разделения ионов, обсуждены известные механизмы разделения и их математические модели. Рассмотрены сравнительно хорошо развитые на лабораторном уровне баро- и электромембранные методы, которые ориентированы на выделение ионов лития и других однозарядных катионов из смешанных растворов, содержащих в больших количествах магний и кальций. Проведено сравнение результатов применения коммерческих и лабораторных мембран. Проанализированы новейшие подходы, позволяющие эффективно выделять ионы лития из смеси однозарядных катионов, в том числе перспективные гибридные электробаромембранные методы.  Библиография — 295 ссылок.

Selective recovery and re-utilization of lithium: prospects for the use of membrane methods

The scientific community has shown great interest in the selectivity of anion-exchange membranes (AEMs), particularly regarding their ability to monovalent-ions selective transport. In this work, we have studied the selectivity of an original anion-exchange membrane and a layer-by-layer (LbL) surface-modified membrane in the electrodialysis (ED) desalination of sodium chloride and sodium sulfate mixture in a lab-scale cell. The effect of various experimental factors on the desalination process and the selectivity of the separation of ions with different charges, such as the composition of the concentrate compartment, electrolyte concentrations in the concentrate and diluate compartments (0.004–0.5 M), the specific current value (0.82–9.0 mA/cm2), the desalination time, and the stirring of solution were considered. To explain the observed patterns, diffusion experiments and numerical simulations using the COMSOL® software package were carried out. Our findings demonstrate that the method chosen for conducting the benchmark desalination of a mixture of chlorides and sulfates can significantly affect the values of the selectivity coefficients and the accuracy of their determination for both standard and surface-modified membranes. For the latter, varying the desalination conditions leads to improved P(Cl/SO4) due to modification of up to 40 %. 

On the analysis of monovalent-ion selectivity of anion-exchange membranes

Bilayer ion-exchange membranes consisting of a thick heterogeneous membrane layer and a thin homogeneous membrane layer are studied theoretically and experimentally for their electrochemical properties such as overall and partial current–voltage curves, external and internal diffusion-limited currents, effective transference numbers, and specific selectivity for counterions and coions to be separated. For a diffusion layer (I)/modifying layer (II)/substrate membrane (III)/diffusion layer (IV) system in ternary solutions of electrolytes, we develop and verify a four-layer mathematical model with quasi-equilibrium boundary conditions. For the conditions of small current densities and limiting currents, we obtain analytical expressions for calculations of the limiting current, effective transference numbers, and specific selectivity coefficients. A numerical approach to calculating the specific selectivity coefficients is proposed. The mathematical model is verified for two electromembrane systems: one system is an anisotropic bilayer membrane with its MK-41 and MF-4SK polymer matrices having the same type of charge in a mixed CaCl2 + NaCl solution, and in another one its MA-41 and MF-4SK matrices have opposite types of charge in a mixed Na2SO4 + NaNO3 solution. The transport parameters of both the modifying film (MF-4SK) and initial membranes (MK-40 and MA-41) are determined in single-component and mixed electrolyte solutions in separate experiments.

Electrochemical Properties and Selectivity of Bilayer Ion-Exchange Membranes in Ternary Solutions of Strong Electrolytes

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. V. Sharafan

Author Tools

Chat about Author

Papers

Electrochemical Properties and Selectivity of Bilayer Ion-Exchange Membranes in Ternary Solutions of Strong Electrolytes