Virginia Tech
Spectral and Physicochemical Characteristics of nC60 in Aqueous Solutions
Abstract
dc:description.abstractDespite 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.
Degree
thesis:*- Name thesis:degree_name
- Ph. D.
- Level thesis:degree_level
- doctoral
- Discipline thesis:degree_discipline
- Environmental Engineering
- Department dc:contributor.department
- Environmental Engineering
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 2011
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Chang, Xiaojun
- Chair dc:contributor.committeechair
-
- Vikesland, Peter J.
- Committee members dc:contributor.committeemember
-
- Morris, John R.
- Little, John C.
- Marr, Linsey C.
Subjects
dc:subject × 5Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
- Language dc:language.iso
- en_US
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-08042011-202452
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/77152