Properties and performance of polyethersulfone membranes modified with halloysite and titanate nanotubes
Ultrafiltration polyethersulfone (PES) membranes were prepared by wet phase inversion method. Halloysite nanotubes (HNTs), hydrothermally synthesized titanate nanotubes (TNTs) or their mixture (HNTs/TNTs, weight ratio 50/50) were applied as nanofillers (NFs). N,N – dimethylformamide was used as a solvent, and deionized water was applied as a non-solvent. Some well dispersed aggregates as well as larger agglomerates of the NFs were observed on the surface of the membranes examined by atomic force microscopy. The retention of poly(ethylene glycol) (20 kDa) applied as a model organic compound, by the modified and unmodified membranes was similar and did not exceed 10%. The rejection of 500 kDa dextran ranged from 84 to 92%, and was the highest for the membrane modified with HNTs. A 71% improvement of pure water flux, compared to the neat membrane, was observed in the case of the membrane modified with the HNTs/TNTs. The best antifouling performance during bovine serum albumin filtration exhibited the HNTs-modified membrane.