Recovery of free volume in PIM-1 membranes through alcohol vapor treatment


Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications. A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scale is soaking them in lower alcohols, such as methanol and ethanol. However, this procedure does not seem applicable at industrial level, and other strategies must be investigated. In this work, a regeneration method with alcohol vapors (ethanol or methanol) was developed to recover permeability of aged PIM-1 membranes, in comparison with the conventional soaking-in-liquid approach. The gas permeability and separation performance, before and post the regeneration methods, were assessed using a binary mixture of CO2 and CH4 (1:1, v:v). Our results show that an 8-hour methanol vapor treatment was sufficient to recover the original gas permeability, reaching a CO2 permeability > 7000 barrer.


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Faiz Almansour is grateful to the Department of Research & Development, Saudi Aramco for funding and supporting his Ph.D. studies. M. Alberto is grateful to EPSRC for funding under the research grant number EP/S032258/1 and R. Bhavsar to EPSRC under grant number EP/M001342/1.

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Correspondence to Patricia Gorgojo.

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Almansour, F., Alberto, M., Bhavsar, R.S. et al. Recovery of free volume in PIM-1 membranes through alcohol vapor treatment. Front. Chem. Sci. Eng. (2021).

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  • polymer of intrinsic microporosity (PIM)
  • PIM-1
  • physical aging
  • gas separation
  • vapor-phase regeneration