(651d) Salt Transport of Phenyl Acrylate-Based Anion Exchange Membrane with Different Crosslinkers for Artificial Photosynthesis

Anion exchange membranes (AEMs) are crucial components in artificial photosynthesis devices that use photoelectrochemistry to convert CO₂ into valuable products. These membranes facilitate the movement of charge carriers between electrodes while restricting the transport of CO₂ reduction products such as formate and acetate. Despite their importance, there is a scarcity of studies on the fundamental transport mechanisms in AEMs used in artificial photosynthesis. In this work, we present the development of a phenyl acrylate-based membrane that is functionalized with (3-acrylamidopropyl) trimethylammonium chloride (APTA) and crosslinked using two different crosslinkers: poly(ethylene glycol) diacrylate (PEDGA) and N,N'-methylenebisacrylamide (MBAA). By varying the crosslinkers and APTA content, we were able to modify the membrane's water volume fraction and control its transport propertie. The water volume fraction of a membrane has a direct impact on its salt permeability and ionic conductivity. As a result, membranes with higher ionic conductivity tend to have higher salt permeability, creating a trade-off between desirable transport properties for artificial photosynthesis applications. According to our observations, Young's modulus rises with increasing crosslinker content due to higher crosslink density, and MBAA-contained films exhibit higher yield strength than PEGDA-contained films. Additionally, decreasing permeabilities to solutes with increasing fixed charge density is caused by decreasing water volume fraction, and these permeabilities are in the following order: NH₄Cl> KCl> KOFm> KOAc> NaOFm> NaOAc, most likely because of variations in hydration diameters.