In this study, the effect of elongation on structural variables and the performance of PEI intermediate fiber contact membrane separation for CO2 uptake was investigated. The membranes were synthesized using wet spinning and simultaneous stretching. The effect of elongation on polymer solutions with different concentrations of polymer and also on polymer solutions containing different concentrations of clay nanoparticles was studied. The prepared membranes were determined by gas permeability test, mass porosity measurement, contact angle test, water-liquid inlet pressure test and gas adsorption test.