Magnetic‐field‐induced Fe3O4@CNTs dispersion in the separation layer to improve the performance of composite ultrafiltration membrane

Abstract It is of great significance to regulate carbon nanotubes (CNTs) dispersed in the separation layer of membranes to improve the properties of membranes. In this work, ferric oxides coated carbon nanotubes (Fe 3 O 4 @CNTs) are prepared by solvothermal method, and then are added to the casting solution to prepare Fe 3 O 4 @CNTs/poly(ethersulfone)/sulfonated polysulfone composite ultrafiltration membranes. The result shows that Fe 3 O 4 @CNTs migrate to the separation layer of membranes under the induction of a low‐intensity magnetic field. The surface and overall porosity of the membranes increase and the surface roughness of the membranes decreases. The contact angle of composite ultrafiltration membranes decreases from 78.0° to 60.1°, indicating an improvement of hydrophilicity. The pure water permeance of the composite ultrafiltration membranes increases from 240.1 to 524.7 L m −2 h −1 while retaining a high bovine serum albumin rejection (>96.8%). Moreover, the antifouling property of the composite ultrafiltration membranes is significantly improved, and the flux recovery ratio increased from 56.2% to 80.9%.