Iranian Nanotechnology Society International Journal of Nanoscience and Nanotechnology 1735-7004 20 4 2024 12 15 Effect of TiO2-MWCNTs Nanocomposite on the Performance of Mixed Matrix Nanofiltration Membranes: Manganese Ion Removal 231 248 729781 10.22034/ijnn.2025.2024498.2490 EN Sedigheh Daroumi University of Tehran, Tehran, Iran 0000-0002-7056-5264 Ramin Yavari Nuclear Fuel Cycle School, Nuclear science and technology Research institute, (NSTRI), P.O.Box. 11365-8486, Tehran, Iran Mohammad Ali Aroon School of Chemical Engineering, College of Engineering, University of Tehran,Tehran, Iran 0000-0002-2775-8271 Takeshi Matsuura Industrial Membrane Research Laboratory, Chemical Engineering Department, University of Ottawa, Ottawa, Canada Journal Article 2024 03 08 This study aims to investigate the removal of manganese ions from aqueous residues of the chemical industries using neat and mixed matrix polyethersulfone (PES) membranes. Functionalized multi-walled carbon nanotubes (MWCNTs), titanium dioxide nanoparticles (TiO2), and multi-walled carbon nanotubes/titanium dioxide nanoparticles (TiO2-functionalized MWCNTs hybrid) were used as the fillers in the mixed matrix membranes to improve the membrane performance. MWCNTs were oxidized and functionalized using nitric acid. TiO2 and TiO2-functionalized MWCNTs nanoparticles were synthesized by the sol-gel method and Sun et al.’s method, respectively. These nanoparticles were characterized by transmission electron microscopy (TEM) and nitrogen adsorption/desorption isotherms (BET). Both neat and mixed matrix PES membranes were fabricated by the phase inversion method and characterized by SEM and contact angle measurement. They were further subjected to the filtration test for manganese removal. SEM images showed that all the tested membranes have an asymmetric structure with a top-dense control layer supported by a sublayer with finger-like pores. Results of the contact angle test demonstrated adding each of these particles (functionalized MWCNTs, TiO2, and TiO2-functionalized MWCNTs) reduced the contact angle and, thus, increased the hydrophilicity of the membrane. The results of the filtration tests are as follows; Adding 0.1% functionalized MWCNTs could increase the membrane flux to 28.65 L/m2s (with 89.3% manganese ions rejection), adding 0.1% TiO2 increased the manganese ion rejection percentage to 92.06% (with a flux of 8.97 L/m2s) and adding 0.1% TiO2-functionalized MWCNTs hybrid increased the flux to 26 L/m2s (with 87.04% manganese ions rejection). https://www.ijnnonline.net/article_729781_6a56cdfdd8c7199dd1006ab086fa2778.pdf