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\usepackage{setspace} |
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\usepackage{endfloat} |
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\usepackage{caption} |
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\usepackage{tabularx} |
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\usepackage{longtable} |
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\usepackage{graphicx} |
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\usepackage{multirow} |
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\usepackage{multicol} |
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\usepackage[version=3]{mhchem} % this is a great package for formatting chemical reactions |
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\usepackage[square, comma, sort&compress]{natbib} |
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\usepackage{url} |
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|
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\begin{document} |
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|
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\newcolumntype{A}{p{1.5in}} |
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\newcolumntype{B}{p{0.75in}} |
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|
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\title{Simulations of heat conduction at thiolate-capped gold |
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surfaces: The role of chain length and solvent penetration} |
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|
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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\subsection{Effect of Chain Length} |
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|
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< |
We examined full coverages of five chain lengths, n = 4, 6, 8, 10, 12. In all cases, the hexane solvent was unable to penetrate into the thiolate layer, leading to a persistent 2-4 \AA \, gap between the solvent region and the thiolates. The trend of interfacial conductance is mostly flat as a function of chain length, indicating that the length of the thiolate alkyl chains does not play a significant role in the transport of heat across the gold/thiolate and thiolate/solvent interfaces. There is, however, a peak in conductance for a chain length of 6 (hexanethiolate). This may be due to the equivalent chain lengths of the hexane solvent and the alkyl chain of the capping agent, leading to an especially high degree of vibrational overlap between the thiolate and solvent. Strong vibrational overlap would allow for efficient thermal energy transfer across the thiolate/solvent interface. |
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> |
We examined full coverages of five chain lengths, n = 4, 6, 8, 10, 12. As shown in table \ref{table:chainlengthG}, the trend of interfacial conductance is mostly flat as a function of chain length, indicating that the length of the thiolate alkyl chains does not play a significant role in the transport of heat across the gold/thiolate and thiolate/solvent interfaces. In all cases, the hexane solvent was unable to penetrate into the thiolate layer, leading to a persistent 2-4 \AA \, gap between the solvent region and the thiolates. While the identity of the alkyl thiolate capping agent has little effect on the interfacial thermal conductance, the presence of a full monolayer of capping agent provides a two-fold increase in the G value relative to a bare gold surface. |
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> |
\begin{longtable}{p{4cm} p{3cm}} |
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\caption{Computed interfacial thermal conductance (G) values for bare gold and 100\% coverages of various thiolate alkyl chain lengths.} |
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\\ |
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\centering {\bf Chain Length (n)} & {\bf G (MW/m$^2$/K)} \\ \hline |
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\endhead |
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\hline |
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\endfoot |
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\centering bare gold & 30.24 \\ |
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\centering 4 & 59.44 \\ |
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\centering 6 & 60.18 \\ |
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\centering 8 & 60.95 \\ |
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\centering 10 & 58.21 \\ |
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\centering 12 & 58.79 |
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\label{table:chainlengthG} |
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> |
\end{longtable} |
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|
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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% MIXED CHAINS |
