(587f) Transport Behavior of Crosslinked PEGDA Membranes to Methanol and Sodium Acetate

Understanding molecular transport behavior in hydrated membranes is important for various applications from desalination to energy conversion devices, such as photoelectrochemical CO₂ reduction cell. In such device, CO₂ is simultaneously being reduced into valuable chemicals, such as methanol and acetate, and a hydrated membrane is placed in between cathode and anode cells to minimize the permeation of CO₂ reduction products from cathode to anode. Due to the complex nature of capturing the transport of multiple solutes in liquid phase, multi-solute transport in hydrated membranes have not been studied thoroughly. Previously, our group proposed an in-situ ATR-FTIR method to measure the concentration of multiple solutes simultaneously. Here we use this method to study the transport behavior of a series of UV crosslinked poly(ethylene glycol) diacrylate (PEGDA, n = 13) membranes with different pre-polymerization water contents to two CO₂ reduction products, methanol and acetate, in co-permeation. Changes in membrane permeability to these solutes is observed with changing prepolymerization water content, and in the presence of the co-solute. We evaluate these changes in terms of polymer structures, water-polymer interactions, solute-polymer interactions, and solute-solute-polymer interaction.