Poly(ethyleneimine) nanofibrous affinity membrane fabricated via one step wet-electrospinning from poly(vinyl alcohol)-doped poly(ethyleneimine) solution system and its application

Poly(ethyleneimine) (PEI) has high affinity for various metal ions and can be used as a chelating agent for the removal of heavy metal cations in wastewater. In this paper, we reported the successful fabrication of crosslinked PEI nanofibrous affinity membranes for removing heavy metal ions via wet-electrospinning from its aqueous solution with the aid of low loading fiber-forming agent poly(vinyl alcohol) (PVA). The coagulating bath for wet-electrospinning was composed of the crosslinking agent glutaraldehyde (GA) and N,N-dimethylformamide (DMF) as a non-solvent. The adsorbability for three heavy metal ions of the PEI nanofibrous affinity membrane doped with PVA was investigated in the aqueous solution. The results showed that the affinity of the membrane to three heavy metal ions was in the order of Cu(II)>Cd(II)>Pb(II), and the equilibrium absorption capacities for the three tested ions (all measured at 100mgL^-1 initial concentration) were 1.05mmolg^-1 (67.16mgg^-1), 1.04mmolg^-1 (116.94mgg^-1), and 0.43mmolg^-1 (90.03mgg^-1), respectively. The PEI nanofibrous affinity membrane adsorbed with heavy metal ions could be regenerated successfully in EDTA aqueous solution without significantly affecting its adsorption efficiency. This study extended the application scope of the PEI membrane for removing of the toxic heavy metal ions from the wastewater.