High-performance membranes comprising polyaniline nanoparticles incorporated into polyvinylamine matrix for CO2/N2 separation

Polyaniline nanofibers, netlike polyaniline nanofibers and polyaniline nanosheets were prepared by chemical oxidative polymerization. Scanning electron microscopy (SEM) was employed to characterize morphology of the polyaniline (PANI) nanoparticles . The nanocomposite membranes were prepared by blending PANI nanoparticles with polyvinylamine (PVAm) as the active layer and polysulfone (PS) as the support layer. The surface and cross-section morphology and crystallization of nanocomposite membranes were measured by SEM and XRD. The permselectivity of nanocomposite membranes was investigated by the pure CO 2 and N 2 gases and gas mixture containing 20   vol.% CO 2 and 80   vol.% N 2 . The results demonstrate that the inclusion of the PANI nanoparticles to PVAm increases the gas permeance and selectivity of the membranes due to chain packing disruption of PVAm and N 2 barrier property of PANI nanoparticles. The influences of PANI nanoparticles, PVAm and the interaction between PANI and PVAm on gas transport properties of nanocomposite membranes have been discussed. At CO 2 partial pressure of 0.02   MPa, the nanocomposite membrane containing 17   wt.% PANI nanosheets displayed a CO 2 permeance of 1200   GPU and a CO 2 /N 2 selectivity of 120. The permeance increased about 852% and the selectivity increased about 137% compared with the PVAm/PS membrane. The separation performance stability of the PVAm/PS membrane and PANI–PVAm/PS membrane was investigated and no deterioration in membrane permselectivity was observed.