Thermal relaxation mechanism and role of chemical functionalization in fullerene solutions.
- Resource Type
- Article
- Authors
- Shenogin, Sergei; Keblinski, Pawel; Bedrov, Dmitry; Smith, Grant D.
- Source
- Journal of Chemical Physics. 1/7/2006, Vol. 124 Issue 1, p014702. 7p. 1 Black and White Photograph, 1 Chart, 7 Graphs.
- Subject
- *FULLERENES
*MOLECULAR dynamics
*RELAXATION (Nuclear physics)
*HEAT transfer
*FLUCTUATIONS (Physics)
*ENERGY dissipation
- Language
- ISSN
- 0021-9606
Using molecular-dynamics simulations we investigate thermal relaxation of C60 and C84 molecules suspended in octane liquid. Pristine fullerenes exhibit relatively slow relaxation due to weak thermal coupling with the liquid. A comparison of the interfacial transport characteristics obtained from relaxation simulations with those obtained from equilibrium simulations and fluctuation-dissipation theorem analysis demonstrates that the relaxation process involves two main steps: (i) energy flow from high- to low-frequency modes within the fullerene, and (ii) energy flow from low-frequency fullerene modes to the liquid. Functionalization of fullerenes with alkene chains leads to significant reduction of the thermal relaxation time. The relaxation time of functionalized fullerenes becomes independent from the functionalizing chain length beyond ∼10 carbon segments; this can be understood in terms of thermal conductivity along the chain and heat transfer between the chain and the solvent. [ABSTRACT FROM AUTHOR]