Improvement in performance of g-C3N4 nanosheets blended PES ultrafiltration membranes including biological properties

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2021-08, Vol.623, p.126571, Article 126571
• Main Authors: Sert, Buse, Ozay, Yasin, Harputlu, Ersan, Ozdemir, Sadin, Yalcin, M. Serkan, Ocakoglu, Kasim, Dizge, Nadir
• Format: Article
• Language: English
• Subjects: Antimicrobial; Biofilm inhibition; DNA cleavage; G-C3N4; Ultrafiltration nanocomposite membrane
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2021.126571

This study aims to investigate the modification of polyethersulphone (PES) membrane with graphitic carbon nitride (g-C3N4) nanosheets for improving the antifouling and separation performance. The nanocomposite membranes were fabricated with blending of different g-C3N4 nanosheets (0.50, 1.00, and 2.00 wt%) into PES and they were synthesized by the phase inversion method. The fabricated g-C3N4 nanosheets and composite membranes were analyzed for their morphology. Scanning electron microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) mapping were used to detect the distribution of g-C3N4 nanosheets on membrane surface, whereas surface roughness of membrane was evaluated by atomic force microscopy (AFM). The composite membrane surface was found to be hydrophilic (67.54°), while the water flux of the composite membrane was found to be 254.8 L/m2/h for 2.00 wt% g-C3N4/PES membrane. The bovine serum albumin (BSA) separation tests indicated that the composite membrane supplied 98.5% BSA rejection ratio. Moreover, a significant improvement in antifouling characteristics were verified from BSA filtration experiments. g-C3N4 was also investigated for some of its biological properties such as antioxidant, antimicrobial, DNA cleavage, biofilm inhibition, and bacterial viability effect. g-C3N4 showed good free radical scavenging activity and moderate chelating activity at 500 mg/L. It was also determined that single-strand DNA cleavage activities occurred at all tested concentrations. g-C3N4 exhibited significant antibiofilm activity and inhibitory effects on E. coli vitality as 90.9%, 97.1%, and 98.9% at 250, 500, and 1000 mg/L, respectively. This study provides a simple and useful guideline to create a UF membrane resistant against organic fouling and expand its practical applications for wastewater treatment. [Display omitted] •Graphitic carbon nitride (g-C3N4) nanoparticles were prepared and embedded into PES membrane.•g-C3N4 improved the antifouling and separation performance of the composite membrane.•The single-strand DNA cleavage activities occurred at all tested concentrations antioxidant.•g-C3N4 exhibited significant antibiofilm activity on E. coli vitality as 98.9% at 1000 mg/L.