Polyethersulfone/amine grafted silica nanoparticles mixed matrix membrane: A comparative study for mebeverine hydrochloride wastewater treatment

Abstract

In the present work, uncoated silica nanoparticles (SiO2 NPs) and polyethylenimine (PEI) coated silica nanoparticles (SiO2-g-PEI NPs) were individually impregnated within a polyethersulfone (PES) polymeric matrix via the classical phase inversion technique. The performance of both prepared mixed matrix membranes was compared by mebeverine hydrochloride (MBV) separation from aqueous pharmaceutical wastewater. The nanoparticles content varied between 0.7 and 1 % in the polymeric matrix to probe their optimum performance. A comprehensive characterization for both NPs and nanocomposite membranes was performed by a series of characterization tools including Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Analysis spectroscopy, Contact Angle (CA) and Tensile Strength. For first time, the suggested interaction mechanism of both PES/SiO2 and PES/SiO2-g-PEI membrane's surface with the feed molecules has been elucidated. Results revealed that the nanocomposite membrane prepared with 0.9 wt% SiO2-g-PEI has possessed the optimum performance in terms of surface porosity (89.96 ± 1.7 %), CA (49 ± 1.8°), mean pore radius (13.55 ± 0.41 nm), and mechanical properties (tensile strength 10.16 MPa). Almost complete removal (up to 99.99 %) against MBV molecules was observed together with a high water flux reached (140 ± 1.28 LMH). Besides, during the prolonged operation (up to 250 hrs), this optimum membrane (DS0.9) manifested a stable performance along with a remarkable flux recovery ratio (95.4 %). For pharmaceutical pollutants removal, the DS0.9 membrane performance has surpassed those attained by nascent PES and mixed matrix membranes modified with SiO2. The study enclosed novel and powerful insights about the potential of SiO2-g PEI in tailoring membrane performance.