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HERO ID
193450
Reference Type
Journal Article
Title
Characterization of size, surface charge, and agglomeration state of nanoparticle dispersions for toxicological studies
Author(s)
Jiang, JK; Oberdorster, G; Biswas, P
Year
2009
Is Peer Reviewed?
Yes
Journal
Journal of Nanoparticle Research
ISSN:
1388-0764
EISSN:
1572-896X
Volume
11
Issue
1
Page Numbers
77-89
Language
English
DOI
10.1007/s11051-008-9446-4
Web of Science Id
WOS:000262125200008
URL
http://www.springerlink.com/index/10.1007/s11051-008-9446-4
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Abstract
Characterizing the state of nanoparticles (such as size, surface charge, and degree of agglomeration) in aqueous suspensions and understanding the parameters that affect this state are imperative for toxicity investigations. In this study, the role of important factors such as solution ionic strength, pH, and particle surface chemistry that control nanoparticle dispersion was examined. The size and zeta potential of four TiO2 and three quantum dot samples dispersed in different solutions (including one physiological medium) were characterized. For 15 nm TiO2 dispersions, the increase of ionic strength from 0.001 M to 0.1 M led to a 50-fold increase in the hydrodynamic diameter, and the variation of pH resulted in significant change of particle surface charge and the hydrodynamic size. It was shown that both adsorbing multiply charged ions (e.g., pyrophosphate ions) onto the TiO2 nanoparticle surface and coating quantum dot nanocrystals with polymers (e.g., polyethylene glycol) suppressed agglomeration and stabilized the dispersions. DLVO theory was used to qualitatively understand nanoparticle dispersion stability. A methodology using different ultrasonication techniques (bath and probe) was developed to distinguish agglomerates from aggregates (strong bonds), and to estimate the extent of particle agglomeration. Probe ultrasonication performed better than bath ultrasonication in dispersing TiO2 agglomerates when the stabilizing agent sodium pyrophosphate was used. Commercially available Degussa P25 and in-house synthesized TiO2 nanoparticles were used to demonstrate identification of aggregated and agglomerated samples.
Keywords
Nanoparticle; Toxicology; Nanotoxicology; Health; Safety; Ultrasonication; Nanotechnology; Environment;QUANTUM DOTS; ULTRAFINE PARTICLES; PULMONARY TOXICITY; CELLULAR TOXICITY; CARBON-NANOTUBES; IN-VITRO; NANOMATERIALS; BRAIN; STABILIZATION; SPECTROMETRY
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•
Nanoscale Silver
External Review Draft
Final Case Study
Introduction to Document, Silver and Nanoscale Silver
Transport, Transformation and Fate
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