Fabrication and characterization of poly(phenylene ether-ether sulfone) based nanofiltration membranes modified by titanium dioxide nanoparticles for water desalination

Asymmetric poly(1,4-phenylene ether-ether-sulfone) (PPEES)-blend-poly ethylene glycol nanocomposite nanofiltration membranes were prepared using phase inversion technique with N-methyl pyrrolidone as solvent and titanium dioxide (TiO2) nanoparticles as inorganic filler additive. The effect of additive concentration in casting solution on membrane physico-chemical properties was studied. Morphological study was carried out employing scanning electron microscopy. To characterize the prepared membranes, water flux and salt rejection were used as criteria. The effect of TiO2 content in casting solution on membrane mechanical property (tensile strength) and its water content and contact angle were also studied. Results showed that adding the TiO2 nanoparticles in the membrane matrix caused a sharp increase of water flux (WF) from 15.72 to 133.85 L/m2·h. Results revealed that salt rejection was declined initially by the increase of TiO2 nanoparticle content up to 0.05 wt.% in the membrane matrix but with more additive loading, it began rising. The membrane's tensile strength was improved by the increase of TiO2 concentration in casting solution. The water content and contact angle experiments showed that the membrane hydrophilicity generally was improved by the addition of TiO2. The increase of feed pH value was associated with the salt rejection enhancement.