Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
Department of Electronic Science and Engineering, Kyoto University, Katsura, Nishikyo, Kyoto 615-8510, Japan.
J Chem Phys. 2013 Dec 14;139(22):224710. doi: 10.1063/1.4839775.
The density of a liquid is not uniform when placed on a solid. The structured liquid pushes or pulls a probe employed in atomic force microscopy, as demonstrated in a number of experimental studies. In the present study, the relation between the force on a probe and the local density of a liquid is derived based on the statistical mechanics of simple liquids. When the probe is identical to a solvent molecule, the strength of the force is shown to be proportional to the vertical gradient of ln(ρDS) with the local liquid's density on a solid surface being ρDS. The intrinsic liquid's density on a solid is numerically calculated and compared with the density reconstructed from the force on a probe that is identical or not identical to the solvent molecule.
当液体放置在固体上时，其密度并不均匀。结构液体推动或拉动原子力显微镜中使用的探针，这在许多实验研究中得到了证明。在本研究中，基于简单液体的统计力学，推导出探针上的力与液体局部密度之间的关系。当探针与溶剂分子相同时，力的强度被证明与固体表面上液体局部密度 ρDS 的 ln(ρDS)的垂直梯度成正比。固体上液体的本征密度被数值计算，并与探针上的力重建的密度进行比较，探针与溶剂分子相同或不相同。
