<p> Since its discovery in 1985, buckminsterfullerene (C<sub> 60</sub>) has been extensively studied due to its unique properties and it's now being produced in multi-ton quantities. The ability to form stable aqueous C<sub>60</sub> colloids (known as nano-C<sub>60</sub> or <i>n</i>C<sub> 60</sub>) and the availability of these in natural systems at environmentally-relevant concentrations led to significant interest concerning the environmental health and safety of these colloidal aggregates. Addressing two issues with regard to this material's environmental health and safety concerns we have looked at the oxidative mechanism of these <i>n</i>C<sub>60</sub> colloidal aggregates and their thermal stability. For making accurate kinetics and measurements on oxidation caused by aqueous-<i>n</i>C<sub>60</sub> colloidal dispersions, we have developed experimental methods utilizing dihydrorhodamine 123 (DHR123) as a sacrificial probe molecule to monitor oxidation by fluorescence spectroscopy and kinetic models to explain observed oxidation. Evaluation of the oxidative behavior of fullerene colloids has been determined using the oxidation rate as a function of <i>n</i>C<sub>60</sub> concentration, <i> n</i>C<sub>60</sub> surface area, number of colloidal particles and C<sub> 60</sub>O content, operating where necessary under inert atmosphere and oxygen rich conditions. The effect of temperature on these colloids plays a significant role in both their synthesis and reactivity. Given that the colloids are mainly composed of C<sub>60</sub> and C<sub>60</sub>O, C<sub>60</sub>O might play a significant role in stabilizing the colloid, hence increasing the temperature might cause thermally-activated reactions with C<sub>60</sub>O. Thermal stability of these colloids prepared by all four primary <i>n</i>C<sub>60 </sub> synthesis methods has been investigated. Incorporation of C<sub>60 </sub> into polymers is of potential interest for applications, for sequestration to address potential environmental health and safety issues, and as a component in novel architectures. A new composite material was developed by encapsulating C<sub>60</sub> into cross-linked polymer network formed by γ-cyclodextrin. A simple synthesis route to achieve composite membranes of intercalated C<sub> 60</sub> in the polymer network is presented.</p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:3728840 |
| Date | 22 October 2015 |
| Creators | Hikkaduwa Koralege, Rangika S. |
| Publisher | Oklahoma State University |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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