title: In situ formation of silver nanoparticles on thin-film composite reverse osmosis membranes for biofouling mitigation.
abstract: The potential to incorporate silver nanoparticles (Ag-NPs) as biocides in membranes for water purification has gained much interest in recent years. However, a viable strategy for loading the Ag-NPs on the membrane remains challenging. This paper presents a novel, facile procedure for loading Ag-NPs on thin-film composite (TFC) reverse osmosis membranes. Reaction of silver salt with a reducing agent on the membrane surface resulted in uniform coverage of Ag-NPs, irreversibly bound to the membrane, as confirmed by XPS, TEM, and SEM analyses. Salt selectivity of the membrane as well its surface roughness, hydrophilicity, and zeta potential were not impacted by Ag-NP functionalization, while a slight reduction (up to 17%) in water permeability was observed. The formed Ag-NPs imparted strong antibacterial activity to the membrane, leading to reduction of more than 75% in the number of live bacteria attached to the membrane for three model bacteria strains. In addition, confocal microscopy analyses revealed that Ag-NPs significantly suppressed biofilm formation, with 41% reduction in total biovolume and significant reduction in EPS, dead, and live bacteria on the functionalized membrane. The simplicity of the method, the short reaction time, the ability to load the Ag-NPs on site, and the strong imparted antibacterial activity highlight the potential of this method in real-world RO membrane applications.
authors: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.
authors: Moshe
authors: M
authors: Ben-Sasson
authors: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors: Xinglin
authors: X
authors: Lu
authors: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.
authors: Edo
authors: E
authors: Bar-Zeev
authors: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.
authors: Katherine R
authors: KR
authors: Zodrow
authors: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA.
authors: Siamak
authors: S
authors: Nejati
authors: Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA.
authors: Genggeng
authors: G
authors: Qi
authors: Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA.
authors: Emmanuel P
authors: EP
authors: Giannelis
authors: Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520-8286, USA. Electronic address: menachem.elimelech@yale.edu.
authors: Menachem
authors: M
authors: Elimelech
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D057219:Biofouling / Q000517:prevention & control*; D015169:Colony Count, Microbial; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D009995:Osmosis; D010539:Permeability / Q000187:drug effects; D056951:Photoelectron Spectroscopy; D012492:Salts / Q000737:chemistry; D012834:Silver / Q000494:pharmacology*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D008567:Membranes, Artificial; D012492:Salts; D014867:Water; D012834:Silver
keywords: Biofouling; Biofouling control; Silver nanoparticles; Thin-film composite membranes