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dc.contributor.authorDavid, Calin
dc.contributor.authorGalceran i Nogués, Josep
dc.contributor.authorRey Castro, Carlos
dc.contributor.authorPuy Llorens, Jaume
dc.contributor.authorCompanys Ferran, Encarnació
dc.contributor.authorSalvador, José
dc.contributor.authorMonné Esquerda, Josep
dc.contributor.authorWallace, Rachel
dc.contributor.authorVakourov, Alex
dc.date.accessioned2016-09-09T11:09:04Z
dc.date.issued2012
dc.identifier.issn1932-7447
dc.identifier.urihttp://hdl.handle.net/10459.1/57783
dc.description.abstractThere is a current debate on whether the toxicity of engineered ZnO nanoparticles (NPs) can be traced back to their nanoscale properties or rather to the simple fact of their relatively high solubility and consequent release of Zn2+ ions. In this work, the emerging electroanalytical technique AGNES (Absence of Gradients and Nernstian Equilibrium Stripping), which is specially designed to determine free metal ion concentration, is shown to be able to measure the Zn2+ concentration resulting from dissolution of ZnO nanoparticles dispersed in aqueous salt solutions. Three NP samples from different sources (having average primary particle diameters of 6, 20, and 71 nm) were tested and compared with bulk ZnO material. The enhanced solubility of the nanoparticles with decreasing primary radius allows for an estimation of the surface energy of 0.32 J/m2 . AGNES also allows the study of the kinetics of Zn2+ release as a response to a change in the solution parameters (e.g., pH, ZnO concentration). A physicochemical model has been developed to account for the observed kinetic behavior. With this model, only one kinetic parameter is required to describe the time dependence of the free Zn2+ concentration in solution. Good agreement with this prediction is obtained when, starting from an equilibrated NP dispersion, the pH of the medium is lowered. Also, the independence of this parameter from pH, as expected from the model, is obtained at least in the pH range 7−9. When dissolution is studied by dispersing ZnO nanoparticles in the medium, the kinetic parameter initially decreases with time. This decrease can be interpreted as resulting from the increase of the radius of the clusters due to the agglomeration/ aggregation phenomena (independently confirmed). For the larger assayed NPs (i.e., 20 and 71 nm), a sufficiently large pH increase leads to a metastable solubility state, suggesting formation of a hydroxide interfacial layer.ca_ES
dc.description.sponsorshipResearch leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under grant agreement no. 229244 (ENNSATOX), from the Spanish Ministry of Education and Innovation (Projects CTQ2009-07831 and CTM2009-14612), and from the “Comissionat per a Universitats i Recerca del Departament d’Innovacio, Universitats i Empresa de la Generalitat de Catalunya”.ca_ES
dc.language.isoengca_ES
dc.publisherAmerican Chemical Societyca_ES
dc.relationMCINN/PN2008-2011/CTM2009-14612-C02-01ca_ES
dc.relationMCINN/PN2008-2011/CTQ2009-07831ca_ES
dc.relation.isformatofReproducció del document publicat a https://doi.org/10.1021/jp301671bca_ES
dc.relation.ispartofJournal of Physical Chemistry C, 2012, vol. 116, núm. 21, p. 11758-11767ca_ES
dc.rights(c) American Chemical Society, 2012ca_ES
dc.subject.otherQuímica analíticaca_ES
dc.subject.otherIons metàl·licsca_ES
dc.subject.otherZinc -- Toxicologiaca_ES
dc.subject.otherMetalls pesants -- Toxicologiaca_ES
dc.titleDissolution Kinetics and Solubility of ZnO Nanoparticles Followed by AGNESca_ES
dc.typearticleca_ES
dc.identifier.idgrec017645
dc.type.versionpublishedVersionca_ES
dc.rights.accessRightsinfo:eu-repo/semantics/restrictedAccessca_ES
dc.identifier.doihttps://doi.org/10.1021/jp301671b
dc.relation.projectIDinfo:eu-repo/grantAgreement/EC/FP7/229244
dc.date.embargoEndDate10000-01-01


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