Calculating thermal transport coefficients of reverse micelles using molecular dynamics simulations and normal mode analysis

Ultrafast vibrational studies of reverse micelles reveal that energy transfer from the water inside the reverse micelle to non-polar solvent can be more rapid than energy transfer from the surfactant directly to the solvent [1]. To address computationally the flow of heat in this system, we have calculated thermal transport coefficients for a reverse micelle formed by sodium di-2-ethylhexylsulfosuccinate (AOT) in isooctane over the temperature range 200 K--350K. Because of a ``glassy'' topology of the reverse micelle we adopted Allen-Feldman theory [2] to calculate thermal transport coefficients, which we have applied to calculate thermal transport coefficients for other soft matter in the past [3]. At room temperature, the thermal conductivity and thermal diffusivity of the reverse micelle was found to be 0.13 W/mK and 5.86 {\AA}$^{2}$/ps respectively, the former agreeing well with experimental values in polyalphaolefins solvent. \\[4pt] [1] J. C. Deak, Y. Pang, T. D. Sechler, Z. Wang, D. D. Dlott, \textit{Science} \textbf{306}, 473 (2004).\\[0pt] [2] P. B. Allen, J. L. Feldman, \textit{Phys. Rev. B} \textbf{48}, 12581 (1993).\\[0pt] [3] D. M. Leitner, \textit{J. Chem. Phys}. \textbf{130}, 195101 (2009).