Nanoconfined liquids may have significantly different properties from their bulks. This can be prominent for nanofluids due to the interaction between nanoparticles and solid/liquid interface, which is studied under different configurations (including confined, sessile, and freestanding forms) in the present work by calculating a typical thermophysical property (the specific heat capacity) using the molecular dynamics simulation method. It is found that the copper-water nanofluid film has a relatively higher specific heat capacity than the water film with the same thickness; and the specific heat capacity is closely related to the configuration: the confined nanofluid film has the highest value, followed by the sessile and freestanding nanofluid films. The reason behind this is explored in terms of interface effects: the influence of nanoparticles on the interface energy and hence specific heat capacity is weaker than the plate which has adjacent liquid molecules with highly impacted molecular structure; and compared to the symmetrical density distributions in confined and freestanding films, the asymmetry in the sessile film causes changes of the interfacial parameters including mean square displacement, radial distribution function, and vibration density of state of water molecules. Thus, this work provides insight into the variation of thermophysical properties for nanofluids with various forms of nanoconfinement or configurations in applications such as distillation, evaporation, and interface separation.

纳米受限液体可能具有与其体积显着不同的特性。由于纳米颗粒和固/液界面之间的相互作用，这对于纳米流体来说可能是突出的，这在目前的工作中通过计算典型的热物理特性（比热容）在不同配置（包括受限、固定和独立形式）下进行了研究使用分子动力学模拟方法。发现铜-水纳米流体膜比相同厚度的水膜具有相对较高的比热容；并且比热容与配置密切相关：受限纳米流体薄膜的值最高，其次是固定和独立的纳米流体薄膜。这背后的原因是从界面效果方面探讨的：纳米颗粒对界面能和比热容的影响比相邻的液体分子对分子结构影响较大的板要弱；与密闭膜和独立膜中的对称密度分布相比，固着膜的不对称性引起了界面参数的变化，包括均方位移、径向分布函数和水分子态的振动密度。因此，这项工作提供了对具有各种形式的纳米限制或配置的纳米流体在蒸馏、蒸发和界面分离等应用中的热物理特性变化的洞察。