• Saberi M, Dadkhah AA, Hashemifard SA, Modeling of simultaneous competitive mixed gas permeation and CO2 induced plasticization in glassy polymers, J Membrane Sci 499, 164–171, 2016

Plasticization behavior of polymeric membranes, in presence of a second component in the feed is different from plasticization of pure CO₂ due to competitive sorption. This study focused on a mathematical model proposed for permeation of mixed gases in glassy polymers considering the plasticization case. It was assumed that diffusion coefficient for all components were exclusively a function of plasticizing component. In this study, the partial immobilization model was employed to determine fraction of mobile sorbed gases. The model parameters were calculated by fitting experimental data from literature. Plasticization parameter (β) decreased for both CO₂ and N₂ by increasing fraction of N₂  in the feed. It means that plasticization of glassy polymers was suppressed. This decrease was caused by competitive sorption between CO₂ and N₂. Indeed N₂ in the feed acts as an anti-plasticizer. In addition, permeances of the feed gas components were declined in comparison to pure gases, which might be attributed to reduction of sorption and occupying Langmuir sites with the second component. The proposed model accurately predicted the permeation behavior of CO₂ as plasticizer and N₂ in presence of plasticization, therefore, it is capable of giving a useful tool to enhance our knowledge related to permeability and selectivity behavior of mixed gas systems in glassy polymeric membranes.

http://dx.doi.org/10.1016/j.memsci.2015.09.044