Skip to Main content Skip to Navigation
Journal articles

Colloidal and chemical stabilities of iron oxide nanoparticles in aqueous solutions: the interplay of structural, chemical and environmental drivers

Abstract : Nanoparticle (NP) stability in aqueous environments is dependent upon many parameters including environmental conditions, NP concentrations as well as NP intrinsic characteristics. In this study, the effects of pH and surface modifications on the colloidal and chemical stabilities of nanosized magnetite (Fe3O4), maghemite (γ-Fe2O3) and hematite (α-Fe2O3) are investigated. Because changes in surface charge affect the size distribution of NP, pH plays a key role in driving the colloidal stability. More NP aggregation is observed at pH values close to the pH of zero point of charge (pHzpc). Coating of magnetite with humic acid (HA) and phosphatidylcholine (PC) affects the electrostatic interactions and then the colloidal behavior of NP. The rapid transformation of magnetite into maghemite through air oxidation results in significant modification of both surface charge and specific surface area of NP. Because the maghemite almost exclusively formed µm-scale aggregates, the colloidal stability of magnetite is expected to be hindered in oxic environments. For hematite, the particle size distribution data emphasize the influence of both pH and intrinsic surface properties in the colloidal stability. These findings may have strong implications for an accurate prediction of the transformation and mobility of Fe-nanoparticles under environmentally relevant conditions and thus their fate in nature.
Document type :
Journal articles
Complete list of metadatas

https://hal-insu.archives-ouvertes.fr/insu-01737100
Contributor : Isabelle Dubigeon <>
Submitted on : Wednesday, September 23, 2020 - 1:20:51 PM
Last modification on : Wednesday, September 23, 2020 - 1:20:51 PM

Identifiers

Citation

Edwige Demangeat, Mathieu Pédrot, Aline Dia, Martine Bouhnik-Le-Coz, Fabien Grasset, et al.. Colloidal and chemical stabilities of iron oxide nanoparticles in aqueous solutions: the interplay of structural, chemical and environmental drivers. Environmental science‎.Nano, Royal Society of Chemistry, 2018, 5 (4), pp.992-1001. ⟨10.1039/C7EN01159H⟩. ⟨insu-01737100⟩

Share

Metrics

Record views

236