Aggregation of stabilized TiO2 nanoparticle suspensions in the presence of inorganic ions
Journal
Environmental Toxicology and Chemistry
Journal Volume
31
Journal Volume
31
Journal Issue
8
Journal Issue
8
Pages
1693-1698
Start Page
1693
End Page
1698
ISSN
15528618
Date Issued
2012-08
Author(s)
Abstract
The present study aims to evaluate the effect of inorganic ions on the aggregation kinetics of stabilized titanium dioxide (TiO 2) nanoparticle (NP) suspension, an NP mode widely used in consumer goods and in aquatic environments. The point of zero charge of stabilized TiO 2 NPs was approximately pH 6.5. The particle size of the stabilized TiO 2 NP suspensions increased with the increase in salt concentrations. The additional salts caused the shift of zeta potentials of TiO 2 suspensions to a lower value. The TiO 2 NPs aggregated more obviously in the presence of anions than cations, and the effect of divalent anions was larger than that of monovalent anions. The critical coagulation concentration (CCC) values for commercial TiO 2 NP suspensions with positive surfaces were estimated as 290 and 2.3meq/L for Cl - and SO42-, respectively. These CCC values of stabilized TiO 2 NP suspensions are higher than those of TiO 2 NP powders, indicating greater stability of the commercial stabilized TiO 2 NP suspensions. The effects of commercial TiO 2 NP suspensions still need to be explored and defined. Derjaguin-Landau-Verwey-Overbeek (DLVO) analysis can explain the aggregation behaviors of stabilized TiO 2 NP suspensions. Such an understanding can facilitate the prediction of NP fate in the environment.
Subjects
Attachment efficiency
Critical coagulation concentrations (CCC)
Ions
Nanoparticle suspension
SDGs
Type
journal article