Department of Mechanical and Materials Engineering, Masdar Institute, Khalifa University of Science and Technology, P.O. Box 54224, Abu Dhabi, United Arab Emirates.
Phys Chem Chem Phys. 2018 Sep 12;20(35):22636-22644. doi: 10.1039/c8cp03633k.
The surface wettability of graphite has gained a lot of interest in nanotechnology and fundamental studies alike, but the types of adsorptions that dominate its time resolved surface property variations in ambient environment are still elusive. Prediction of the intrinsic surface wettability of graphite from first-principles simulations offers an opportunity to clarify the overall evolution. In this study, by combining experimental temporal Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and static contact angle measurements with density functional theory (DFT)-predicted contact angles and DFT AFM force simulations, we provide conclusive evidence to demonstrate the role played by water adsorption in the evolution of surface properties of aged graphite in ambient air. Moreover, this study has the merit of linking DFT-predicted adhesive energy at the solid/liquid interface and cohesive energy at the liquid/liquid interface with the DFT AFM-predicted force of adhesion through the Young-Dupre equation. This establishes the basis of the quantum surface wettability theory by combining two independent atomic-level quantum physics simulation methodologies.
石墨的表面润湿性在纳米技术和基础研究中都引起了广泛关注，但在环境中主导其时间分辨表面特性变化的吸附类型仍难以捉摸。从第一性原理模拟预测石墨的固有表面润湿性为澄清整体演变提供了机会。在这项研究中，我们通过结合实验的时间傅里叶变换红外光谱、原子力显微镜（AFM）和静态接触角测量以及密度泛函理论（DFT）预测的接触角和 DFT AFM 力模拟，提供了确凿的证据，证明了水吸附在空气中老化石墨表面特性演变中的作用。此外，这项研究通过杨氏-杜普雷方程将固体/液体界面上的 DFT 预测粘附能和液体/液体界面上的内聚能与 DFT AFM 预测的粘附力联系起来，这通过结合两种独立的原子级量子物理模拟方法为量子表面润湿性理论奠定了基础。
