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

Abstract

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.

Electrokinetic and Electroconvective Effects in Ternary Electrolyte Near Ion-Selective Microsphere

“…It should be mentioned that real resins may have macropores filled with uncharged solution. There are several modeling approaches to describe such systems [ 26 ]. In the current paper, the complex structure of a real ion-exchange particle is not taken into account for the sake of simplicity.…”

Approaches to the Modification of Perfluorosulfonic Acid Membranes

“…Many reviews describe advances in the field of hybrid materials, with a primary focus on different modification methods and materials for FC, among which PFSA membranes are highlighted in a single section [ 12 , 14 , 55 , 66 , 67 , 68 , 69 , 70 , 71 ]. In a recent review, the features of ion transport and water transfer in ion-exchange polymer membranes, including PFSA membranes, were discussed and approaches to modeling transport processes in such membranes, including hybrid membranes, were described [ 72 ]. At the same time, there are limited examples in the literature that discuss the possibility and reasons for changes in properties during modification of PFSA membranes as a result of physical and chemical treatment.…”

Study of the Thermochemical Effect on the Transport and Structural Characteristics of Heterogeneous Ion-Exchange Membranes by Combining the Cell Model and the Fine-Porous Membrane Model

“…It is known that the degradation of ion-conducting membranes used in metal-ion batteries [ 32 , 33 ], as well as in fuel cells [ 28 , 29 , 34 , 35 ], determines the duration of their life cycle [ 21 , 29 , 30 ]. To quantitatively describe this process and predict changes in the physicochemical characteristics of membranes, a few available models can be used, a complete and detailed overview of which is presented in [ 36 ]. Two models, namely the homogeneous model of a fine-porous membrane and the heterogeneous cell model, have been proven successful in describing the processes of water and ion transfer during reverse osmosis, nano-, ultra-, and microfiltration, and electrodialysis.…”