Max Planck Institute for Polymer Research , Department of Physics at Interfaces, 55128 Mainz, Germany.
Langmuir. 2017 Mar 14;33(10):2477-2484. doi: 10.1021/acs.langmuir.6b02982. Epub 2017 Mar 2.
In this work we present a comprehensive experimental study to determine the contact forces between individual metal oxide nanoparticles in the gas-phase using atomic force microscopy. In addition, we determined the amount of physisorbed water for each type of particle surface. By comparing our results with mathematical models of the interaction forces, we could demonstrate that classical continuum models of van der Waals and capillary forces alone cannot sufficiently describe the experimental findings. Rather, the discrete nature of the molecules has to be considered, which leads to ordering at the interface and the occurrence of solvation forces. We demonstrate that inclusion of solvation forces in the model leads to quantitative agreement with experimental data and that tuning of the molecular order by addition of isopropanol vapor allows us to control the interaction forces between the nanoparticles.
在这项工作中，我们使用原子力显微镜进行了一项全面的实验研究，以确定气相中单个金属氧化物纳米粒子之间的接触力。此外，我们还确定了每种颗粒表面的物理吸附水量。通过将我们的结果与相互作用力的数学模型进行比较，我们证明仅使用范德华和毛细作用力的经典连续体模型不能充分描述实验结果。相反，必须考虑分子的离散性质，这导致界面处的有序排列和溶剂化力的出现。我们证明，在模型中包含溶剂化力可以使实验数据与实验数据达到定量一致，并且通过添加异丙醇蒸气来调节分子有序性可以控制纳米颗粒之间的相互作用力。
