Tailoring the Surface Chemistry of Anion Exchange Membranes with Zwitterions: Toward Antifouling RED Membranes

Abstract

Fouling is a pressing issue for harvesting salinity gradient energy with reverse electrodialysis (RED). In this work, antifouling membranes were fabricated by surface modification of a commercial anion exchange membrane with zwitterionic layers. Either zwitterionic monomers or zwitterionic brushes were applied on the surface. Zwitterionic monomers were grafted to the surface by deposition of a polydopamine layer followed by an aza-Michael reaction with sulfobetaine. Zwitterionic brushes were grafted on the surface by deposition of polydopamine modified with a surface initiator for subsequent atom transfer radical polymerization to obtain polysulfobetaine. As expected, the zwitterionic layers did increase the membrane hydrophilicity. The antifouling behavior of the membranes in RED was evaluated using artificial river and seawater and sodium dodecylbenzenesulfonate as the model foulant. The zwitterionic monomers are effective in delaying the fouling onset, but the further build-up of the fouling layer is hardly affected, resulting in similar power density losses as for the unmodified membranes. Membranes modified with zwitterionic brushes show a high potential for application in RED as they not only delay the onset of fouling but they also slow down the growth of the fouling layer, thus retaining higher power density outputs.

Amphoteric Membrane Loaded with a Noble Metal-Free Hollow Spherical NiCoP@rGO Bifunctional Electrocatalyst for Alkaline Water Electrolyzers

“…Water electrolysis (WE) is a promising route for large-scale production of pure H 2 and O 2 using acidic/alkaline membranes. Acidic water electrolysis utilizes a proton exchange membrane (PEM), but noble metal catalysts, slow reaction kinetics, utilization of costly acid-tolerant hardware, and high capital cost, are serious drawbacks. , Recently, alkaline water electrolyzers using anion exchange membranes (AEM) received serious attention due to the use of nonprecious metal catalysts and low operating and capital costs. − Now, enormous efforts were rendered to reduce the water electrolysis cost by developing high-performance membrane separators and nonprecious metal catalysts …”

Simultaneous Fractionation, Desalination, and Dye Removal of Dye/Salt Mixtures by Carbon Cloth-Modified Flow-electrode Capacitive Deionization

“…The carbon cloth layer also endows the unit with unique features, including (i) promoting dye dissociation, (ii) enhancing electroconvection at the IEM/solution interfaces, (iii) adsorbing dye components through electrosorption, and (iv) enabling active antifouling. Although the FDR treatment of dye/salt mixtures by CC-FCDI is still far from achieving complete resource recovery and zero-liquid discharge, this study can provide guidance to the fouling control in the FCDI-based desalination processes, the development of novel AT&AD layers to broaden the application of FCDI, , and the selective resource recovery from various organic/salt mixtures using the AT&AD layer-modified FCDI.…”

A Study on Biofouling and Cleaning of Anion Exchange Membranes for Reverse Electrodialysis

“…Antifouling membranes were fabricated by surface modification of a commercial Fujifilm type I AEM with zwitterionic layers by Pintosi et al [ 11 ]. The antifouling behavior of the membranes in RED was evaluated using artificial river and seawater and sodium dodecyl benzenesulfonate (SDBS) as the model foulant.…”