Return to search

Spectral and Physicochemical Characteristics of nC60 in Aqueous Solutions

Despite its extremely low solubility in water, fullerite C₆₀ can form colloidally stable aqueous suspensions containing nanoscale C₆₀ particles (nC₆₀) when it is subject to contact with water. nC₆₀ is the primary fullerene form following its release to the environment. The aim of the present study was to provide fundamental insights into the properties and environmental impacts of nC₆₀. nC₆₀ suspensions containing negatively charged and heterogeneous nanoparticles were produced via extended mixing in the presence and absence of citrate and other carboxylates. These low-molecular weight acids were employed as simple surrogates of natural organic matter. The properties of nC₆₀ were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and UV-Vis spectroscopy. nC₆₀ produced in the presence of carboxylate differs from that produced in water alone (aq/nC₆₀) with respect to surface charge, average particle size, interfacial properties, and UV-Vis spectroscopic characteristics. Importantly, regularly shaped (spheres, triangles, squares, and nano-rods) nC₆₀ nanoparticles were observed in carboxylate solutions, but not in water alone. This observation indicates that a carboxylate-mediated 'bottom-up' process occurs in the presence of carboxylates. Changes in the UV-Vis spectra over time indicate that reactions between C₆₀ and water or other constituents in water never stop, potentially leading to significant morphologic changes during storage or as a result of simple dilution. These results suggest that studies examining the transport, fate, and environmental impacts of nC₆₀ should take the constituents of natural waters into consideration and that careful examination on the properties of the tested nC₆₀ should be conducted prior to and during each study. / Ph. D.

Identiferoai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/77152
Date08 September 2011
CreatorsChang, Xiaojun
ContributorsEnvironmental Engineering, Vikesland, Peter J., Morris, John R., Little, John C., Marr, Linsey C.
PublisherVirginia Tech
Source SetsVirginia Tech Theses and Dissertation
Languageen_US
Detected LanguageEnglish
TypeDissertation, Text
Formatapplication/pdf, application/pdf
RightsIn Copyright, http://rightsstatements.org/vocab/InC/1.0/

Page generated in 0.0023 seconds