Pervaporation using polymeric membranes offers an attractive alternative to distillation for energy efficient separation of dilute alcohol-water mixtures that result from the fermentation of biomass during the biofuels production process. In recent work, we used molecular dynamics simulations to demonstrate the viability of polyacrylate gels as candidate materials for pervaporation membranes for separating dilute alcohol-water mixtures. Specifically, we showed that dynamics of water molecules is strongly coupled with polymer dynamics in swollen gels whereas ethanol molecules do not exhibit such strong coupling. In practical applications, the polymeric pervaporation membranes are supported on a solid substrate which typically consists of another polymeric material such as polysulfone or cellulose acetate. The interaction between the gel and the polymeric support will affect the dynamics of the gel atoms, which in turn, will have an effect on solvent dynamics in the swollen supported gel.<br/><br/>In this work, we have used molecular dynamics simulations to study water and ethanol molecule dynamics in polyacrylate gels that are supported on a polysulfone substrate. The polyacrylate gels studied in this work are poly butyl acrylate, 50-50 random copolymer of butyl acrylate and 2-hydroxy ethyl acrylate, and poly 2-hydroxyethyl acrylate. Solvent dynamics in the polysulfone supported polyacrylate gels is compared with our previous results for the solvent dynamics in the same gels but in the absence of the polysulfone support. The results are used to elucidate the mechanism of solvent molecule diffusion in supported polymeric membranes.

Dynamics of solvent molecules in polyacrylate gels supported on a polymeric substrate

253rd National Meeting (2017)

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