(20c) Complex Multicomponent Transport through Polymeric Membranes
Polymeric membranes are utilized for a wide variety of applications: from energy production and desalination to batteries and dialysis. They are used so frequently due to their low energy requirement, low carbon footprint and selectivity in transporting molecules. Multicomponent transport through dense polymeric membranes is a complex topic whose experimental study has traditionally required aliquotic sampling which invokes hydrostatic pressure issues, complicating calculations immensely and has therefore received relatively little attention. Consequently, single component transport experiments have been used to describe membrane permeability and ideal selectivity and ultimately for selecting a membrane for a particular process. In this work, multicomponent, in-situ attenuated total reflectance Fourier-transform infrared spectroscopy is utilized to quantify multicomponent concentrations over time in diffusion cell experiments without the need for aliquotic sampling. The permeability and solubility of Nafion® 117 to acetone, ethanol, methanol and n-propanol are determined for single solute and multiple solute solutions to examine the impact of co-permeants through solute-solute interactions and multiple solute-membrane interactions on membrane transport behavior. Ultimately, we find these interactions can impact both the absolute and relative magnitudes of membrane permeabilities to different solutes which should be accounted for when describing membrane transport behavior.