New effective modification of classical permeation cell for the evaluation of gas sorption in membrane during transport process

Membrane processes are currently among promising separation procedures for the separation of gaseous mixtures because they are relatively simple and energy-efficient. Their advantage is also the possibility to optimize the separation process by using suitable membranes for the given mixture. On the other hand, the search for suitable membranes requires testing the transport properties of a large number of membranes prepared from different materials. Therefore, the use of quality testing equipment for membrane characterization that provides reliable and swift results is highly desirable.

The group of Dr. Uchytil has been involved in testing the transport of gases through polymeric membranes for a long time and designed and constructed several test apparatuses in cooperation with the mechanical workshops of our institute. Current permeation apparatuses used in foreign laboratories only provide data on gas permeability and diffusivity but do not allow the determination of gas sorption in the given membrane material. We are able to evaluate all these data necessary to describe the gas transport through the polymeric membrane and determine the separation efficiency of the polymeric material of the membrane using the new device from one experiment.

Our newly designed and constructed permeation apparatus, which is based on the simple idea that the difference between the flow of gas permeating into and out of the membrane corresponds to the sorbed gas in the membrane, allows the increase of the amount of gas sorbed in the membrane to be measured during the experiment. This is achieved thanks to the special design of the permeation cell, where the emphasis was placed on the size of the closable volumes above and below the membrane so that the amount of gas in the membrane is comparable to the amount of gas enclosed in these volumes.

We were pleased that our article was selected by the editor (Editor’s Choice Articles) as the July article of the month in the prestigious Journal of Membrane Science based on the reviewers’ comments.

Illustration of the principle of evaluating gas sorption in a polymer membrane based on a permeation experiment

• Setnickova, K.; Jiriste, L.; Maly, M.; Petrickovic, R.; Tseng, H-H. and Uchytil, P.: An approach for evaluating gas sorption in polymer matrix membranes based on balancing incoming and outgoing membrane mass fluxes. J. Membr. Sci. 2022, 661(5) 120867-1200879. https://doi.org/10.1016/j.memsci.2022.120867