A high performance PVAm–HT membrane containing high-speed facilitated transport channels for CO2 separation

A PVAm–HT membrane is fabricated by establishing a hydrotalcite (HT) channel in a polyvinylamine (PVAm) fixed carrier membrane. The flexible PVAm fixed carrier membrane material as a matrix membrane is beneficial to get high permeance. Simultaneously, the HT channels can be used as high-speed facilitated transport channels, in which the movable carbonate can actively meet CO2 and help to increase the CO2/N2 selectivity of membranes as in liquid membranes or in ion exchange membranes. Moreover, the unobstructed HT channels are conducive to transport CO2 rapidly and they can increase the chain spacing of polymers; these are beneficial to further enhance the permeance of membranes. In addition, the charged layers of HT provide necessary stability for movable carriers due to the electrostatic attraction. Thus, the PVAm–HT membrane obtains high permeance and high selectivity, as well as good stability. The CO2 permeance of the PVAm–HT membrane reaches 3187 GPU and the CO2/N2 selectivity of the PVAm–HT membrane reaches 296 at 0.11 MPa.