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Aggregation of stabilized TiO 2 nanoparticle suspensions in the presence of inorganic ions
Author(s) -
Shih YangHsin,
Liu WeiSzu,
Su YuhFan
Publication year - 2012
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.1898
Subject(s) - dlvo theory , divalent , coagulation , nanoparticle , suspension (topology) , zeta potential , titanium dioxide , chemistry , chemical engineering , salt (chemistry) , ion , particle size , particle (ecology) , inorganic chemistry , colloid , organic chemistry , psychology , mathematics , psychiatry , homotopy , pure mathematics , engineering , oceanography , geology
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 2.3 meq/L for Cl − and SO 4 2− , 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. Environ. Toxicol. Chem. 2012; 31: 1693–1698. © 2012 SETAC