Since their discovery in 1991, carbon nanotubes, and especially single walled carbon nanotubes (SWNTs), have attracted significant attention due to their unique structural, mechanical, and electronic characteristics. Although many potential applications for carbon nanotubes have been suggested, several key obstacles currently preclude their practical commercial applications. One of these is their lack of solubility and processability. In order to address this issue, a number of covalent and non-covalent nanotube functionalization techniques have recently been reported in the literature. These methods allow for the manipulation of nanotube properties, such as their solubility, through the attachment of various chemical moieties. Although most of these methods involve covalent attachment of structures to either the ends or sidewalls of SWNTs, several examples of non- covalent functionalization have also been reported. Pyrene, with its flat and
aromatic structure, has been shown to form strong pi-pi stacking interactions with the surface of SWNTs. With this in mind, we explored several methods towards SWNT solubilization with diblock copolymers through non-covalent polymer- nanotube interactions. Living free radical polymerizations (SFRP, ATRP) were employed to produce diblock copolymers with narrow polydispersity. Commercial and synthetic monomers with different functionalities could be utilized to produce polymers with varying properties. Specifically, we used polymers such as polystyrene, poly(methyl methacrylate), poly(t-butyl acrylate) and poly(acrylic acid) as one block of our diblock copolymers. The second block was composed of synthetic pyrene-functionalized monomers mixed with different amounts of monomers that match the composition of the first block. It was found that, upon mixing these diblock copolymers with insoluble nanotubes in various solvents, the nanotubes were partially solubilized through pi-pi stacking with the pyrene- containing blocks. / Thesis / Master of Science (MS)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/25279 |
| Date | January 2003 |
| Creators | Wang, Clair |
| Contributors | Adronov, Alex, Chemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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