In all cases, the ITR at the hematite/water interface was found to be very small (∼ 0.3 m 2 K GW -1 ). This is due to the strong interfacial hydrogen bonding between the hydroxylated hematite surface and the water film. The contribution of the water film thermal resistance, increased with film thickness, however, was generally not a large contributor to the total ITR, as shown in Figure ). Instead, the total ITR is dominated by the liquid-liquid (PAO/water) interface. Water and alkanes such as PAO4 exhibit low solubility, which is known to lead to a large ITR. The water/PAO4 ITR was found to be dependent on the structure of the water film near the interface. The water/PAO4 ITR is presented as a function of the water film thickness, for each forcefield, in the Supporting Information (Figure ). For The 1.0 ML films exhibit the highest water/PAO4 ITR for all water-containing systems. This was likely due to the more rigid structure of the water at the water/PAO4 interface. For higher water coverages of ≥ 1.5 ML (Figure ??(d-f)), overlap is observed in the density profiles of PAO4 and water; however, this is likely due to CW fluctuations, which blur the intrinsic structure of the interface, rather than penetration of the PAO4 into the water film. As the water near the PAO4 becomes less structured and more similar to bulk water, the water/PAO4 ITR decreases slightly compared to the 1.0 ML case. Further increasing water film thickness abover 1.5 ML is found to have a negligible impact on the water/PAO4