AI Article Synopsis
- The study uses molecular dynamics simulations to analyze how alkyl chains affect the thermal properties of fullerene derivatives, particularly C60 and its derivative PCBM.
- The findings reveal that C60 shows a length-dependent thermal conductivity that measures 0.2 W m(-1) K(-1) at room temperature, while PCBM's conductivity plateaus around 0.075 W m(-1) K(-1) at approximately 20 nm.
- The differences in thermal conductivity behaviors are attributed to factors like reduced group velocities, diminished acoustic phonon frequency ranges, and significant scattering of low-frequency phonons caused by the mismatch in vibrational density between C60 and the alkyl chains in PCBM.
Article Abstract
In order to study the effects of alkyl chain on the thermal properties of fullerene derivatives, we perform molecular dynamics (MD) simulations to predict the thermal conductivity of fullerene (C60) and its derivative phenyl-C61-butyric acid methyl ester (PCBM). The results of non-equilibrium MD simulations show a length-dependent thermal conductivity for C60 but not for PCBM. The thermal conductivity of C60, obtained from the linear extrapolation of inverse conductivity vs. inverse length curve, is 0.2 W m(-1) K(-1) at room temperature, while the thermal conductivity of PCBM saturates at ~0.075 W m(-1) K(-1) around 20 nm. The different length-dependence behavior of thermal conductivity indicates that the long-wavelength and low-frequency phonons have large contribution to the thermal conduction in C60. The decrease in thermal conductivity of fullerene derivatives can be attributed to the reduction in group velocities, the decrease of the frequency range of acoustic phonons, and the strong scattering of low-frequency phonons with the alkyl chains due to the significant mismatch of vibrational density of states in low frequency regime between buckyball and alkyl chains in PCBM.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523858 | PMC |
| http://dx.doi.org/10.1038/srep12763 | DOI Listing |
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