Monte Carlo analysis of frequency domain thermoreflectance data for quantitative measurement of interfacial thermal conductance at solid-liquid interfaces modified with self-assembled monolayers

A Monte Carlo method, implemented for quantifying confidence bounds on thermoreflectance (TR) measurements of interfacial thermal conductance G at solid-liquid interfaces modified with self-assembled monolayers (SAMs) is presented in this paper. Our results with the new confidence bounds position our experimental data on surfaces modified with SAMs comparable to the work of Ge et al. and Harikrishna et al.. However, contrary to previous results shown in the literature, our data showed that G decreases as work of adhesion increases between Au and H2O. Our results indicate that G could be influenced by factors beyond a simple work of adhesion, an indication also seen from the work of Park et al.. To solidify this finding, further investigation with a wider range of surface energies with hysteresis effects accounted for should be conducted to better understand G dependence on surface wettability. We also measured and analysed fluorinated fluids such as Galden HT80 in attempt to provide us some insights from another perspective, as this study has not been seen in literature previously. However, this has proven to be challenging due to the lack of sensitivity when measuring with current TR sensor design. Incorporating a more sensitive TR sensor for low thermal conductivity liquid measurements could allow us to measure more exotic but applicable fluids with confidence, and it could potential be the key to a more complete understanding of G dependence on surface wettability.