Thin film nanocomposite membranes filled with MCM-41 and SBA-15 nanoparticles for brackish water desalination via reverse osmosis

Abstract

This work aimed to investigate the impact of filling MCM-41 and SBA-15 nanoparticles (NPs) on the performance of thin film nanocomposite membranes that applied in reverse osmosis, where SBA-15 is firstly reported here for this purpose. The membranes were prepared via the interfacial polymerization reaction between m -phenylenediamine (MPD) aqueous solution and trimesoyl chloride (TMC)-isooctane solution on a support sheet of polyethersulfone. The reaction time in the presence of NPs was investigated by fixing MPD contact time at 75 s; it was found that 30 s is the optimum TMC contact time. Different loading ratios in the range of 0-0.15 wt% were applied to fill the NPs inside the membranes. Scanning electron microscope (SEM), X-ray Diffractometer (XRD), Fourier-transform infrared spectroscopy (FTIR), and N 2 adsorption/desorption tests were used to study the NPs characterizations. While SEM, contact angle, mechanical strain and strength, and membrane performance tests were conducted to study the membranes properties. Results showed that in both nanoparticles (i.e. MCM-41 and SBA-15) cases, 0.1 wt% was the optimum filling percentage. When SBA-15 was loaded, water flux increased from 40 to 74.17 L.m −2 .h −1 (LMH), and NaCl rejection increased from 95.1 to 98.5% comparing with the plain membrane. While when the optimum MCM-41 ratio was loaded, water flux and NaCl rejection raised to 60 LMH and 96.9%, respectively. The performance test conditions were 15 bar, 25 °C, and 2500 NaCl feed concentration. • MCM-41 and SBA-15 NPs were filled in TFN membranes. • Both additives improved the membranes performance. • SBA-15 is firstly reported as a filler for RO application. • SBA-15 effect was higher on the membranes water flux and salt rejection.