Patel Harshit A, Garde Shekhar, Keblinski Pawel
The Howard P. Isermann Department of Chemical & Biological Engineering and Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Nano Lett. 2005 Nov;5(11):2225-31. doi: 10.1021/nl051526q.
Systems with nanoscopic features contain a high density of interfaces. Thermal transport in such systems can be governed by the resistance to heat transfer, the Kapitza resistance (RK), at the interface. Although soft interfaces, such as those between immiscible liquids or between a biomolecule and solvent, are ubiquitous, few studies of thermal transport at such interfaces have been reported. Here we characterize the interfacial conductance, 1/RK, of soft interfaces as a function of molecular architecture, chemistry, and the strength of cross-interfacial intermolecular interactions through detailed molecular dynamics simulations. The conductance of various interfaces studied here, for example, water-organic liquid, water-surfactant, surfactant-organic liquid, is relatively high (in the range of 65-370 MW/m2 K) compared to that for solid-liquid interfaces ( approximately 10 MW/m2 K). Interestingly, the dependence of interfacial conductance on the chemistry and molecular architecture cannot be explained solely in terms of either bulk property mismatch or the strength of intermolecular attraction between the two phases. The observed trends can be attributed to a combination of strong cross-interface intermolecular interactions and good thermal coupling via soft vibration modes present at liquid-liquid interfaces.
具有纳米级特征的系统包含高密度的界面。在这类系统中，热传输可能受界面处的热传递阻力即卡皮查电阻（RK）的支配。尽管软界面无处不在，比如不混溶液体之间或生物分子与溶剂之间的界面，但关于此类界面热传输的研究报道却很少。在此，我们通过详细的分子动力学模拟，将软界面的界面热导1/RK表征为分子结构、化学性质以及跨界面分子间相互作用强度的函数。与固液界面（约10 MW/m2 K）相比，此处研究的各种界面，如水-有机液体、水-表面活性剂、表面活性剂-有机液体的热导相对较高（在65 - 370 MW/m2 K范围内）。有趣的是，界面热导对化学性质和分子结构的依赖性不能仅用体相性质不匹配或两相之间分子间吸引力的强度来解释。观察到的趋势可归因于跨界面强分子间相互作用以及液-液界面处存在的软振动模式带来的良好热耦合。
