Improvement of performance and fouling resistance of polyamide reverse osmosis membranes using acrylamide and TiO₂ nanoparticles under UV irradiation for water desalination

Abstract

The purpose of this research is to explain the surface modification of fabricated polyamide reverse osmosis (RO) membranes using UV-initiated graft polymerization at different irradiation times (15, 30, 60, and 90 s) and various acrylamide concentrations (10, 20, and 30 g L −1 ). Also, coating of membranes surface with various concentrations of TiO 2 nanoparticles (10, 20, 30, and 50 ppm) followed by the same UV irradiation times was investigated. After that, the membranes modification was done by grafting of acrylamide blended with TiO 2 nanoparticles via UV irradiation. The characterization of membranes surface properties and their performance were systematically carried out. The results demonstrated the enhanced hydrophilicity of modified membranes and confirmed the presence of acrylamide and nanoparticles on the membranes surface. Acrylamide-grafted membranes could reach to higher water flux than pristine membrane with little reduction in salt rejection. Moreover, TiO 2 -coated membranes indicated enhancement of water flux continuously with increase in nanoparticles concentration and irradiation time and rejection of membranes was slightly decreased at low irradiation times. Also, RO membranes modified simultaneously with acrylamide and TiO 2 nanoparticles under UV irradiation exhibited improved water flux up to 18%, slightly higher rejection, and considerable better fouling resistance compared with pristine one.

Surface Design of Liquid Separation Membrane through Graft Polymerization: A State of the Art Review

“…It has been reported that UV irradiation was used to graft hydrophilic and foulingresistant poly 2-[(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (PSPE) [102] and PEG [103] to the surface of PA TFC. To improve the anti-fouling capabilities of the PA TFC RO membrane, Asadollahi et al used UV-initiated grafting of acrylamide mixed with TiO 2 nanoparticles [102].…”

“…It has been reported that UV irradiation was used to graft hydrophilic and foulingresistant poly 2-[(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl) ammonium hydroxide (PSPE) [102] and PEG [103] to the surface of PA TFC. To improve the anti-fouling capabilities of the PA TFC RO membrane, Asadollahi et al used UV-initiated grafting of acrylamide mixed with TiO 2 nanoparticles [102]. Due to the overwhelming cross-linking action over chain scission, selective layer densification was seen after a short irradiation duration of <90 s. Due to the inclusion of hydrophilic TiO 2 , the membrane's salt rejection ability enhanced without affecting the water flow.…”

Novel High Flux Poly(m-phenylene isophtalamide)/TiO2 Membranes for Ultrafiltration with Enhanced Antifouling Performance

“…There are only a few works devoted to the application of composite polyamide/TiO 2 in membrane technology, particularly for the preparation of membranes for nanofiltration [ 27 , 28 , 29 , 30 , 31 , 32 ], reverse osmosis [ 33 , 34 , 35 , 36 , 37 , 38 ], pervaporation [ 39 ], and microfiltration [ 40 ]. In [ 27 , 28 , 29 , 30 ], the nanofiltration thin film nanocomposite (TFN) membranes based on PA were subjected to the modification with TiO 2 .…”

“…For reverse osmosis (RO), the modification with TiO 2 of PA membrane was carried out by various approaches: the introduction of fillers into polymer matrix [ 33 ] or the coating of fillers on the surface [ 34 , 35 , 36 , 37 , 38 ]. In [ 33 ], a RO PA membrane was developed by the incorporation of GO and TiO 2 to enhance the salt rejection and filtration performance for purification of drinking water and treatment of wastewater.…”

“…The highest water permeability (0.8 L/(m 2 h bar)), 60% higher compared to the pristine membrane) and higher NaCl rejection (98.45%) were demonstrated for the membrane with two bilayers. In [ 36 ], a RO PA membrane was surface modified by coating with TiO 2 nanoparticles (10, 20, 30 and 50 ppm) on the membrane and using UV-initiated graft polymerization at different irradiation times and various acrylamide concentrations. The TiO 2 -coated membranes demonstrated the increasing water flux with the increase of nanoparticles concentration and irradiation time, and slightly decreased membrane rejection at low irradiation times.…”