Development, Characterization, and Evaluation of Hydrophilic and Self-Cleaning Composite Membranes for Treating Waters Contaminated with 4-Nitrophenol and Dyes

초록

Polysulfone (PSf) membranes are used to treat contaminated waters due to their stability toward chemicals contact at elevated temperatures. However, polysulfone membranes possesses poor surface hydrophilicity, causing filtration and fouling related issues; hence, the usability of PSf membranes decreases. In this study, PSf-, graphene oxide- (GO-), and titania-based hydrophilic nanocomposite membranes were prepared using the solution casting method. The synthesized membranes were characterized and examined through X-ray diffraction (XRD), Fourier transform infrared spectroscopy and scanning electron microscopy (SEM), water contact angle, thermogravimetric analysis, porosity, solvent content, and tensile strength studies. The synthesized membranes demonstrated better hydrophilicity and higher porosity. The addition of nanofillers reduced the water contact angle from 80.87 (polysulfone, PSf) to 59.77 (polysulfone and GO titania, PSf/GO-TiO2). Similarly, the addition of nanofillers increased the porosity from 0.0067 (PSf) to 0.027 (PSf/GO-TiO2). Young's modulus, elongation at break, and toughness increased from 3,928.56 to 4,802.88 MPa, 2.288% to 2.857%, and 74.11 to 76.890 J/g for PSf and PSf/GO-TiO2, respectively. The synthesized membranes displayed self-cleaning and water-oil mixture separation properties. The membranes were applied by following the decrease in the absorption maxima for the degradation of methyl orange (MO) and 4-nitrophenol (4-NP). At room temperature, native PSf membrane caused 29% and 43% photocatalytic degradation of MO and 4-NP, respectively, whereas polysulfone, GO, and TiO2 composite membrane (PGT) caused a maximum of 54% and 62% degradation of MO and 4-NP, respectively.

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