In situ generated silver nanoparticles embedded in polyethersulfone nanostructured membranes (Ag/PES) for antimicrobial decontamination of water

Abstract

BACKGROUND: The general performance of polymeric membranes is hindered by the build-up of microbial foulants both on the surface and inside the pores. This justifies the inclusion of antimicrobial agents within the membranes in order to circumvent the biofouling process. A nonsolvent-induced phase separation process was used to fabricate the membranes following the in situ reduction of silver (Ag) in the polymer dope solution. Fourier transform infrared, atomic force microscopy (AFM), scanning and transmission electron microscopy, and drop shape analyzer were used to study different properties of the membranes.RESULTS: Based on the results of AFM and contact angle measurements, the inclusion of Ag nanoparticles (NPs) improved the membrane hydrophilicity. The disk diffusion method was applied to study the antimicrobial properties of the membranes. The fabricated Ag/ polyethersulfone (PES) membranes showed antimicrobial activity against representatives of both Gram-positive and -negative bacteria, and this was confirmed by the zones of inhibition (11 mm for Escherichia coli; 13 mm for Bacillus cereus). From this a general proposed antimicrobial mechanism via the generation of reactive oxygen species (ROS) was provided. CONCLUSION:The fabricated Ag/PES membranes can perform a dual function of complete microbial inactivation and ultrafiltration of polluted water to provide better quality water with reduced membrane fouling.

Catalytic degradation of methyl orange using beta cyclodextrin modified polyvinylidene fluoride mixed matrix membranes imbedded with in‐situ generated palladium nanoparticles

“…However, small differences in loading of NPs lead to slight differences in contact angle which is also witnessed in Figure 6. These findings are also supported by Patala et al 69 who embedded Ag NPs in PES membranes. The minimum and maximum loading of Ag NPs was 0.05% and 0.25%, respectively, and their contact angle difference was 0.97°.…”

“…However, small F I G U R E 5 Membranes' SEM images; left to right (cross-section 600x, cross-section 3000x, and top surface 3000x) [Color figure can be viewed at wileyonlinelibrary.com] differences in loading of NPs lead to slight differences in contact angle which is also witnessed in Figure 6. These findings are also supported by Patala et al 69 who embedded Ag NPs in PES membranes. The minimum and maximum loading of Ag NPs was 0.05% and 0.25%, respectively, and their contact angle difference was 0.97 .…”

Synthesis of graphene oxide and their incorporation in nanostructured polyethersulfone membranes: Study of antibacterial and dyes adsorption properties

“…Some advantages of the use of nanostructures as additives in PES membranes include the enhancement of permeability, selectivity, high resistance to fouling, solute avoidance, processability, and high dimensional stability, [18,19] in addition to their antibacterial behavior against Gram (+) and Gram (À) microorganisms. [20,21] However, the poor nanoparticle dispersion into the membrane can generate a loss of selectivity and decrease their mechanical performance. [22,23] It has been claimed that carbon-derived nanostructures embedded in PES enhance the pure water flux, salts rejection, and heavy metals removal, attributed to the nanoparticles amount and their dispersion in the polymer matrix, [22,24,25] due to their enhanced surface reactive area, capable of adsorbing dyes.…”