Multifunctional Thin-Film Nanofiltration Membrane Incorporated with Reduced Graphene Oxide@TiO₂@Ag Nanocomposites for High Desalination Performance, Dye Retention, and Antibacterial Properties

Abstract

High desalination performance, dye retention, and antibacterial properties were achieved with a multifunctional thin-film nanocomposite (MTFN) membrane, fabricated by the incorporation of a novel nanocomposite structure of reduced graphene oxide@TiO2@Ag (rGO@TiO2@Ag) into the polyamide active layer. The specific characteristics of the graphene-based nanocomposite, synthesized by the microwave-assisted irradiation process, favored water channelization and provided superhydrophilicity and antibacterial properties to the MTFN membranes. In comparison with the conventional methods, such as multistep chemical process using strong agents for reduction and long-term energy-consuming hydrothermal process, microwave irradiation facilitated a green, fast, and cost-effective route for the fabrication of GO-based nanocomposites for multifunctional applications. Interfacial polymerization was performed on a polyethersulfone/Si3N4 robust hollow fiber substrate using m-phenylenediamine aqueous solution and 1,3,5-benzenetricarbonyltrichloride organic solution. The structural and chemical characteristics of the synthesized nanocomposites and the MTFN membranes were thoroughly studied by a series of characterization analyses (transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy). The physicochemical properties and the nanofiltration performance of the MTFN membranes were investigated after the incorporation of rGO@TiO2@Ag at various concentrations. The water contact angles confirmed the superb surface hydrophilicity of the MTFN membranes. High permeability (52 L·m–2·h–1), desalination (96% for 1 g/L Na2SO4 feed solution), and dye retention (98% for 0.5 g/L rose bengal feed solution) were recorded for MTFN enriched with 0.2 wt % rGO@TiO2@Ag. A 90% reduction in the number of viable bacteria (Escherichia coli), after 3 h of contact with MTFN membranes, confirmed the superior antibacterial activity of the produced membranes.

2D nanosheet enabled thin film nanocomposite membranes for freshwater production – a review

“…The presence of oxygenated functional groups on the surface of GO nanosheets provides potential active sites for attaching various nanomaterials and functional groups to the surface, aiding evolution of nanohybrid materials based on GO, which have a wide range of applications. 57 GO nanosheets with different metal and metal oxides including Ag, 58,59 Cu, 60 TiO 2 61 and ZnO 62 have been synthesized and successfully incorporated into the PA layer of TFC membrane, which exhibited excellent separation performance with antifouling and anti-bacterial properties. In a recent study, Ag-GO nanosheets were incorporated into the PA layer to fabricate biofouling-resistant TFN membrane (Table S1, ESI, † entry 7).…”

Nanocomposite Membranes for Liquid and Gas Separations from the Perspective of Nanostructure Dimensions

“…Various interesting combinations of nanostructures with different dimensions, including the coupling of 0D/2D nanostructures [ 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 ], 1D/3D nanostructures [ 170 ], 1D/2D nanostructure [ 171 , 172 , 173 ], 3D/2D nanostructures [ 174 , 175 , 176 , 177 , 178 ] have been attempted for liquid separation nanocomposite membranes. A glimpse into these works revealed the huge potential of high surface area 2D nanosheets to serve as a versatile platform for the deposition of other nanostructures while their restacking issue can be simultaneously overcome through the insertion of foreign nanostructures.…”

<p>Poly (lactic-co-glycolic acid)/graphene oxide composites combined with electrical stimulation in wound healing: preparation and characterization</p>

“…Increased GO concentration clearly improved the hydrophilicity of the composites, and this phenomenon may be ascribed to the presence of hydrophilic -OH, C-O-C, and -COOH groups on GO surface. Furthermore, GO can affect composite hydrophilicity by changing surface nanomorphology and topography, 27 which is likely another explanation for the improved hydrophilicity of the composites. Moreover, the hydrophilicity of the scaffold surface enhanced cellular behavior, including initial attachment, proliferation, and differentiation; therefore, the PLGA/GO composites provided a suitable microenvironment for cell attachment and proliferation based on the presence of a more hydrophilic surface relative to other matrices.…”