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New approaches to enhance the CO2 selectivity of fast permeable gas separation membranes


The only viable solution to reduce 20% of the greenhouse gas emissions is to develop and implement carbon dioxide (CO2) capture and sequestration technologies. Despite the development of new polymeric materials for CO2 capture membranes such as thermal rearranged polymers (TR), polymers with intrinsic micro porosity (PIM), hybrid polymer-nanoparticles membranes, only few membranes have arrived to testing at pilot scale. This clearly indicates the need of new strategies for membrane fabrication.
Material and Methods
Most of the gas separation membranes for CO2 separation are based on increasing either the CO2 solubility or CO2 diffusivity over N2 by using different methods to increase the free volume of polymers and their sieving capacity.
Our approach is based on modifying in precise and controlled manner polymers and polymeric membranes with CO2 reactive groups. This represents a new approach in gas separation membranes that mitigates the risks associated with use of polymer blends, addition of various CO2 enhancement materials (nanoparticles, etc): incompatibility between materials, poor and limited dispersion of particles, reproducibility and difficulty in preparing membranes.
Results and Discussion
In this paper, we will report new approaches on membrane preparation by modifications of high permeable but low selective polymers such as poly(trimethylslilylproyne) (PTMSP), polydimethylsiloxane (PDMS) and polyvinyl alcohol PVA. The membranes and polymers are modified with CO2-philic groups and will discuss the influence of various parameters on membranes structure and their separation performances. A variety of new functionalities are integrated, for instance amino groups, by applying various modification techniques and procedures. The membranes structure is characterized by SEM pictures and FT-IR. The density of amino groups is determined by an innovative method and is correlated with the results from mixed gas permeation testing using a synthetic flue gas: 10 % CO2 in N2, fully humidified.
It was observed that uniformity of the modifications play a major role on membranes separation properties and is dependent on various factors. Excessive crosslinking reduced the expected CO2 flux for PVA membranes, and needed to be further investigated and eliminated. The structural changes of polymers (PTMSP) were confirmed by 1HNMR and the amine content was estimated as well. The amine content of modified PTMSP was low, indication a small percentage of the monomer units in the polymer chains were modified.
Depending on the polymer and modification method, significant CO2/N2 selectivity enhancement was documented.




  • Research Council of Norway (RCN) / 254791





  • SINTEF Industry / Biotechnology and Nanomedicine
  • SINTEF Industry / Process Technology
  • Norwegian University of Science and Technology

Presented at





09.07.2018 - 13.07.2018





View this publication at Cristin