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. © 2014 Elsevier Ltd.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: This publication is based on work supported by Award No. KUS-C1-018-02, granted by King Abdullah University of Science and Technology (KAUST). This research was also supported by BARD, the United States - Israel Binational Agricultural Research and Development Fund, Vaadia-BARD Postdoctoral Fellowship to M.B-S. (Award No. FI 452-011) and E.B-Z (FI-474-12). We also acknowledge a graduate fellowship (to X.L.) made possible by the China Scholarship Council (CSC). This material is also based on work supported by the National Science Foundation Graduate Research fellowship under Grant No. DGE-1122492 awarded to K.R.Z. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.