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Multi-instrumental characterization of carbon nanotubes dispersed in aqueous solutions
Chang, X., Matt Henderson, AND D. Bouchard. Multi-instrumental characterization of carbon nanotubes dispersed in aqueous solutions. Presented at 248th ACS National Meeting and Exposition, San Francisco, CA, August 10 - 14, 2014.
Previous studies showed that the dispersion extent and physicochemical properties of carbon nanotubes are highly dependent upon the preparation methods (e.g., dispersion methods and dispersants). In the present work, multiwalled carbon nanotubes (MWNTs) are dispersed in aqueous solutions in the presence of surfactants (e.g., sodium dodecyl sulfate and Pluronic), natural organic matters (e.g., Suwannee River humic, Suwannee River fulvic acid), and a polysaccharide (alginate) via ultrasonication or long term magnetic stirring. The prepared MWNTs suspensions are characterized with a variety of instruments to determine their properties and environmental behaviors. Dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AF4) are employed to determine the size and size distribution of prepared samples: Preliminary results indicate that MWNTs suspended in the same solution by ultrasonication and stirring have similar hydrodynamic diameters but quite different size distributions. Quartz crystal microbalance (QCM) and atomic force microscopy (AFM) techniques are employed to evaluate the deposition of MWNTs with different dispersants on crystal sensor surfaces. To evaluate the effects of size and coatings on interactions with model membranes and membranes (e.g., lipid bilayers and cell lines), AF4 fractionated MWNTs sub-samples are further characterized by QCM and AFM to determine their deposition behaviors and changes in membranes mechanical properties, respectively.
Presented at the 248th ACS National Meeting and Exposition August 10-14, 2014, San Francisco, CA.
Record Details:Record Type: DOCUMENT (PRESENTATION/SLIDE)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL EXPOSURE RESEARCH LAB
ECOSYSTEMS RESEARCH DIVISION