The preparation of gas separation membranes with high permselectivity is the key for CO2 efficient recovery. To improve the CO2 separation performance of membrane
halloysite nanotubes (HNTs) with hollow and tubular structure were incorporated into polyvinylamine (PVAm) aqueous solution to fabricate PVAm-HNTs coating solutions. PVAm-HNTs/polysulfone (PSf) mixed matrix membranes (MMMs) were prepared by coating PVAm-HNTs solutions on PSf ultrafiltration membranes. The PSf membrane is the supporting layer
and PVAm-HNTs coating layer is the functional layer
which is the key for CO2 separation. The structure and morphology of HNTs were characterized by XRD and SEM. The morphology and structure of the membranes were analyzed by FTIR and SEM. The effects of HNTs content
feed pressure
and the thickness of PVAm-HNTs coating layer were systematically investigated by using pure CO2 and N2 pure gas. The CO2/N2[15/85(volume)] mixed gas separation performance also were investigated. The good interfacial interaction is attributed to the electrostatic attraction between PVAm and negatively charged HNTs. At testing temperature of 25℃ and feed gas pressure of 0.1 MPa
PVAm-HNTs/PSf-1%(mass) MMMs with wet coating thickness of 50 μm exhibited long-term performance stability
and the CO2separation performance maintained high CO2 permeability of 178 GPU with CO2/N2 selectivity of 83 for CO2/N2 mixed gas over 120 h.