Citrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditions

Handle URI:
http://hdl.handle.net/10754/561400
Title:
Citrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditions
Authors:
Gutierrez, Leonardo; Aubry, Cyril; Cornejo, Mauricio; Croue, Jean Philippe
Abstract:
Fate and transport studies of silver nanoparticles (AgNPs) discharged from urban wastewaters containing effluent organic matter (EfOM) into natural waters represent a key knowledge gap. In this study, EfOM interfacial interactions with AgNPs and their aggregation kinetics were investigated by atomic force microscopy (AFM) and time-resolved dynamic light scattering (TR-DLS), respectively. Two well-characterized EfOM isolates, i.e., wastewater humic (WW humic) and wastewater colloids (WW colloids, a complex mixture of polysaccharides-proteins-lipids), and a River humic isolate of different characteristics were selected. Citrate-coated AgNPs were selected as representative capped-AgNPs. Citrate-coated AgNPs showed a considerable stability in Na+ solutions. However, Ca2+ ions induced aggregation by cation bridging between carboxyl groups on citrate. Although the presence of River humic increased the stability of citrate-coated AgNPs in Na+ solutions due to electrosteric effects, they aggregated in WW humic-containing solutions, indicating the importance of humics characteristics during interactions. Ca2+ ions increased citrate-coated AgNPs aggregation rates in both humic solutions, suggesting cation bridging between carboxyl groups on their structures as a dominant interacting mechanism. Aggregation of citrate-coated AgNPs in WW colloids solutions was significantly faster than those in both humic solutions. Control experiments in urea solution indicated hydrogen bonding as the main interacting mechanism. During AFM experiments, citrate-coated AgNPs showed higher adhesion to WW humic than to River humic, evidencing a consistency between TR-DLS and AFM results. Ca2+ ions increased citrate-coated AgNPs adhesion to both humic isolates. Interestingly, strong WW colloids interactions with citrate caused AFM probe contamination (nanoparticles adsorption) even at low Na+ concentrations, indicating the impact of hydrogen bonding on adhesion. These results suggest the importance of solution conditions and capping agents on the stability of AgNPs in solution. However, the characteristics of organics would play a crucial role in the fate and transport of these nano contaminants in urban wastewaters and natural water systems.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC)
Citation:
Citrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditions 2015:150731155106009 Langmuir
Publisher:
American Chemical Society (ACS)
Journal:
Langmuir
Issue Date:
31-Jul-2015
DOI:
10.1021/acs.langmuir.5b02067
Type:
Article
ISSN:
0743-7463; 1520-5827
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b02067
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorGutierrez, Leonardoen
dc.contributor.authorAubry, Cyrilen
dc.contributor.authorCornejo, Mauricioen
dc.contributor.authorCroue, Jean Philippeen
dc.date.accessioned2015-08-02T13:51:21Zen
dc.date.available2015-08-02T13:51:21Zen
dc.date.issued2015-07-31en
dc.identifier.citationCitrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditions 2015:150731155106009 Langmuiren
dc.identifier.issn0743-7463en
dc.identifier.issn1520-5827en
dc.identifier.doi10.1021/acs.langmuir.5b02067en
dc.identifier.urihttp://hdl.handle.net/10754/561400en
dc.description.abstractFate and transport studies of silver nanoparticles (AgNPs) discharged from urban wastewaters containing effluent organic matter (EfOM) into natural waters represent a key knowledge gap. In this study, EfOM interfacial interactions with AgNPs and their aggregation kinetics were investigated by atomic force microscopy (AFM) and time-resolved dynamic light scattering (TR-DLS), respectively. Two well-characterized EfOM isolates, i.e., wastewater humic (WW humic) and wastewater colloids (WW colloids, a complex mixture of polysaccharides-proteins-lipids), and a River humic isolate of different characteristics were selected. Citrate-coated AgNPs were selected as representative capped-AgNPs. Citrate-coated AgNPs showed a considerable stability in Na+ solutions. However, Ca2+ ions induced aggregation by cation bridging between carboxyl groups on citrate. Although the presence of River humic increased the stability of citrate-coated AgNPs in Na+ solutions due to electrosteric effects, they aggregated in WW humic-containing solutions, indicating the importance of humics characteristics during interactions. Ca2+ ions increased citrate-coated AgNPs aggregation rates in both humic solutions, suggesting cation bridging between carboxyl groups on their structures as a dominant interacting mechanism. Aggregation of citrate-coated AgNPs in WW colloids solutions was significantly faster than those in both humic solutions. Control experiments in urea solution indicated hydrogen bonding as the main interacting mechanism. During AFM experiments, citrate-coated AgNPs showed higher adhesion to WW humic than to River humic, evidencing a consistency between TR-DLS and AFM results. Ca2+ ions increased citrate-coated AgNPs adhesion to both humic isolates. Interestingly, strong WW colloids interactions with citrate caused AFM probe contamination (nanoparticles adsorption) even at low Na+ concentrations, indicating the impact of hydrogen bonding on adhesion. These results suggest the importance of solution conditions and capping agents on the stability of AgNPs in solution. However, the characteristics of organics would play a crucial role in the fate and transport of these nano contaminants in urban wastewaters and natural water systems.en
dc.language.isoenen
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b02067en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.langmuir.5b02067.en
dc.titleCitrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditionsen
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalLangmuiren
dc.eprint.versionPost-printen
dc.contributor.institutionCurtin Water Quality Research Centre, Department of Chemistry, Curtin University, Australiaen
dc.contributor.institutionFacultad del Mar y Medio Ambiente, Universidad del Pacifico, Guayaquil, Ecuadoren
dc.contributor.institutionMasdar Institute of Science and Technology, Abu Dhabi-United Arab Emiratesen
dc.contributor.institutionEscuela Superior Politécnica del Litoral, Guayaquil, Ecuadoren
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorCroue, Jean-Philippeen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.