Effects of preparation parameters on CO2/N2 gas permselectivity of polyether thin film composite membrane

In this work, ether oxide (EO)‐based multilayer composite membranes were prepared via interfacial polymerization (IP) of trimesoyl chloride (TMC) and polyetheramine (PEA) on polydimethylsiloxane precoated polysulfone support membrane. The effects of preparation parameters, such as monomer concentrations, reaction time, and heat‐treatment temperature on the membrane performance were investigated. The optimal preparation parameters have been concluded. The results showed the increasing monomers concentration of both PEA and TMC can lead to the decrease of CO2 permeance and increase of CO2/N2 selectivity. The optimal monomers concentration was found. When monomer concentrations are higher than the optimal values, the CO2 permeance decreases continually while CO2/N2 selectivity only shows a very limited improvement with the further increase of monomers concentration. The reaction time has similar effects on membrane performance as the monomers concentration. The effect of heat‐treatment temperature was also studied. With the increasing heat‐treatment temperature, the CO2 permeance shows a decrease tendency, while the CO2/N2 selectivity shows a maximum at 80 °C. When PEA is 0.013 mol L−1, TMC is 0.020 mol L−1, reaction time is 3 min, and heat‐treatment temperature is 80 °C, the optimum preparation conditions are achieved with CO2 permeance of 378.3 gas permeation unit (GPU) and CO2/N2 selectivity of 51.7 at 0.03 MPa. This work may help to design and fabricate gas separation membranes with desired performance.