Review of nanomaterials-assisted ion exchange membranes for electromembrane desalination

Abstract

In order to address the increasing demand for fresh water due to accelerated social and economic growth in the world, water treatment technologies, such as desalination, have been rapidly developed in attempts to safeguard water security. Electromembrane desalination processes, such as electrodialysis and membrane capacitive deionization, belong to a category of desalination technologies, which involve the removal of ions from ionic solutions with the use of electrically charged membranes termed ion exchange membranes. The challenges associated with ion exchange membranes have drawn the attention of many researchers, who have investigated various approaches to enhance their properties. The incorporation of nanomaterials is one of the popular approaches employed. Much research on nanomaterials incorporated ion exchange membranes was conducted for the purpose of fuel cell applications rather than electromembrane desalination. This review reports on the advances in nanomaterials incorporated ion exchange membranes applicable to desalination. The nanomaterials employed in ion exchange membranes fabrication include carbon nanotubes, graphene-based nanomaterials, silica, titanium (IV) oxide, aluminum oxide, zeolite, iron (II, III) oxide, zinc oxide, and silver. The aims of this article are to provide a snap shot of the current status of nanomaterials incorporation in ion exchange membranes, to assess the status of nanomaterials-facilitated ion exchange membranes research for electromembrane desalination, and to stimulate progress in this area.

MCM-41/PVA Composite as a Separator for Zinc–Air Batteries

“…Likewise, excessive filler loading (>2.5 wt.%) can result in material phase separation due to the agglomeration of the fillers. Such observations of the critical threshold of filler loadings are commonly reported for many composite materials [ 26 , 36 ]. Nevertheless, in this work, the electrolyte uptake and ionic conductivity of all prepared membranes are relatively high compared to those reported in the literature based on the similar polymer [ 20 , 22 , 23 ].…”

“…It is acknowledged that combining inorganic fillers to form a polymer matrix composite (PMC) can improve the overall performance in many membrane applications. These applications include fuel cell [ 25 ], ion-exchange membranes in desalination [ 26 ], and redox flow battery [ 27 , 28 ]. They are closely related applications for ZABs.…”

Graphene oxide–polybenzimidazolium nanocomposite anion exchange membranes for electrodialysis

“…Graphene-based nanomaterials have been identified as highly promising candidates for nanocomposite IEMs. 14 In the last decade, graphene oxide (GO) has become the centre of attention as a filler material for membranes in the fields of reverse osmosis, 15 nanofiltration, 16 pervaporation, 17 membrane distillation 18 and gas separation, 19 due to its selective barrier properties, and excellent chemical, mechanical and thermal stability, combined with a high surface area. GO, a 2D nanomaterial derived from graphite, is comprised of carbon sheets decorated with oxygen-containing functionalities on the surface (hydroxyl and epoxide groups) and on the edges (hydroxyl, carbonyl and carboxyl groups).…”

Advancing the conductivity-permselectivity tradeoff of electrodialysis ion-exchange membranes with sulfonated CNT nanocomposites

“…Nanomaterials have been utilized in membrane fabrication to augment fluxes, enhance selectivity, and promote mechanical and chemical stabilities [22,23]. Incorporation of nanomaterial filler into the polymer matrix can yield nanocomposite membranes with improved performance, due to the synergism between polymer and nanomaterial.…”