Nanofiltration membrane based on hyperbranched polyethyleneimine-functionalised multiwalled carbon nanotubes for Pb(II) removal from water

Using polysulfone (PSf) as the substrate, a polyamide thin-film composite membrane was synthesised via interfacial polymerisation of hyperbranched polyethyleneimine-functionalised multiwalled carbon nanotubes (HPEI/MWCNTs) and trimesoyl chloride (TMC). The prepared HPEI/MWCNT/PSf nanocomposite membrane was evaluated for the removal of Pb(II). The morphology and physicochemical properties of the prepared membranes were characterised using scanning electron microscopy (SEM), contact angle measurements and flux measurements. The adsorption studies were evaluated using inductively coupled plasma optical emission spectroscopy (ICP-OES). The prepared composite membranes (HPEI/MWCNT/PSf) showed improved Pb(II) removal and enhanced hydrophilicity. The modified membranes were found to be more hydrophilic (contact angle = 63.23°) compared to the neat PSf membrane (contact angle = 122.22°). The water flux for the modified membranes increased linearly with applied pressure. The HPEI/MWCNT/PSf-1% membrane adsorbed more than 95% of Pb(II) ions within 10 minutes.