Tailored Polyether Sulfone Membrane with MoS2- CeO2 Heterostructured Nanomaterials for Highly Efficient Oil-in-Water Separation

Abstract

This research aims to develop efficient nanofillers using 2D Molybdenum Disulphide (MoS2) edges along with interlayers modified with 1D Cerium Dioxide (CeO2), which can be used to develop advanced antifouling membranes for filtering oily wastewater. Nano MoS2-CeO2 was synthesized using a simple ultrasonic-assisted method. Nano MoS2-CeO2 at various weight percentages (0 wt.%, 0.5 wt.%, 1 wt.%, and 1.5 wt.%) were incorporated into the Polyethersulfone/ N-methyl-2-pyrrolidone/ Polyvinylpyrrolidone (PES/NMP/PVP) membrane matrix; consequently, fabricated via (non-solvent induced phase separation) NIPS. The synthesized ultrafiltration (UF) membranes underwent as set of characterizations including using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), fourier transform- infrared (FT-IR), X-ray diffractometer (XRD) and thermal gravimetric analysis (TGA). Also, the membranes’ mean pore size, porosity, water contact angle (WCA), zeta potential, pure water flux (PWF) and mechanical strength were thoroughly assessed. An addition of nano MoS2-CeO2 up to 0.5 wt.% significantly enhanced the membrane porosity to 68.5%, with a pore size of 64 nm and a surface smoothness of (root mean squared) RMS 2.7 nm (±0.5). PES membranes with 0.5 wt.% nano MoS2-CeO2 showed enhanced hydrophilicity, exhibiting a WCA value of around 52°. The nanomodified membranes also had negatively charged surfaces, with a zeta potential of -27 mV at pH 7. The ideal M-0.5 membrane showed a 64% increase in PWF compared to the pristine membrane. The M-0.5 membrane demonstrated outstanding oil-in-water (O/W) separation performance with fluxes of 333, 277, and 235 LMH (liter per meter squared per hour) and oil rejections of 96, 98, and 99% for 100, 500, and 1000 ppm O/W feed solutions, respectively. M-0.5 maintained a high flux recovery ratio (FRR) of 88.3% and a low irreversible fouling rate (Rir) of 11.6% after five filtering cycles with O/W emulsion. The findings indicate that the PES/nano MoS2-CeO2 membrane (0.5 wt.%) has outstanding filtering efficiency and can be reused effectively, demonstrating a promising technique for treating oily wastewater.

Date of Award	8 May 2024
Original language	American English
Supervisor	SHADI Hasan (Supervisor)