Impact of PEGMA on transport and co-transport of methanol and acetate in PEGDA-AMPS cation exchange membranes

Understanding multi-component transport behavior in membranes with varied internal structures and functionalities is critical for the rational design of that will be challenged separation of, or come contact with, solutions. One interesting application ion exchange CO2 reduction cells as these interact multiple products (e.g. methanol acetate) whose permeation must controlled, they readily oxidize back to by-products anode chamber. Previously, co-transport acetate various pendant groups, such sulfonate (-SO3-), carboxyl (-COOH), ethylene oxide (-CH2CH2OH), poly(ethylene oxide) (-(CH2CH2O)5H, PEO), was investigated, where permeabilities suppressed PEO-containing films co-permeation methanol. Here, we further examine this by preparing three chemically different crosslinked a constant crosslinker, glycol) diacrylate (PEGDA), content remaining between comonomer, methacrylate (PEGMA), sulfonate-containing 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) (i.e. PEGDA-PEGMA, PEGDA-AMPS/PEGMA, PEGDA-AMPS). For each chemistry, structurally distinct are prepared varying pre-polymerization water content, leading differences volume fraction (and thereby free volume). We observe diffusivities PEGMA-free (PEGDA-AMPS) increased co-diffusion, while those PEGMA-containing (PEGDA-PEGMA PEGDA-AMPS/PEGMA) decreased. These results suggest strategic addition charge-neutral group charged IEMs valid approach suppress crossover undesired molecules.