Title: Effects of material properties on sedimentation and aggregation of titanium dioxide nanoparticles of anatase and rutile in the aqueous phase
Abstract: This study investigated the sedimentation and aggregation kinetics of titanium dioxide (TiO2) nanoparticles with varying material properties (i.e., crystallinity, morphology, and chemical composition). Used in the study were various types of commercially available TiO2 nanoparticles: three spherical anatase (nominal diameters of 5, 10, and 50 nm) and two rutile nanoparticles (10 × 40 and 30 × 40 nm). The 50 nm anatase and 10 × 40 nm rutile showed higher stability in deionized water and 5 mM NaCl solutions at pH 7 than the 5, and 10 nm anatase nanoparticles in sedimentation experiments. In aggregation experiments, critical coagulation concentration values for the 50 nm anatase were the highest, followed by the 10 × 40 nm rutile and the 5 nm anatase nanoparticles in NaCl and CaCl2 solutions. The aggregation kinetics was fitted reasonably well with the Derjaguin–Landau–Verwey–Overbeek (DLVO) equations for the TiO2 nanoparticles tested. Results showed that crystallinity and morphology are not influential factors in determining the stability of TiO2 nanoparticle suspensions; however, the differences in their chemical compositions, notably, the varying concentrations of impurities (i.e., silicon and phosphorus) in the pristine materials, determined the surface charge and therefore the sedimentation and aggregation of TiO2 nanoparticles in the aqueous phase.
Publication Year: 2011
Publication Date: 2011-11-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 102
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