Solid-liquid surface free energy of Lennard-Jones liquid on smooth and rough surfaces computed by molecular dynamics using the phantom-wall method
Solid-liquid surface free energy of Lennard-Jones liquid on smooth and rough surfaces computed by molecular dynamics using the phantom-wall method
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DOI：
10.1063/1.3458796
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发表时间：
2010-07-28
影响因子：
4.4
通讯作者：
Mueller-Plathe, Florian
中科院分区：
文献类型：
--
作者：
Leroy, Frederic;Mueller-Plathe, Florian
考虑了不同的Lennard-Jones固液界面模型。在该体系中，或者改变固液之间的相互作用强度，或者改变固体表面的形貌。在所有情况下，相对于参考固液界面的固液界面自由能变化通过热力学积分方法量化[F. Leroy等人，Macromol.快速通信30，864（2009）]，称为幻影墙方法。此外，测定了液-汽表面自由能。将此结果与杨氏方程相结合，用于圆柱形液滴的接触角计算。它使我们能够表明，放置在光滑固体表面上的液滴的接触角的变化相对于固液相互作用强度可以通过忽略固体-蒸汽表面自由能的贡献时，固液相互作用是弱的。我们还表明，粗糙度的实施，通过平行的凹槽的密度是不同的，可以产生更高或更低的固液表面自由能，这取决于光滑界面的固液表面自由能。当光滑表面与液体具有良好的相互作用时，粗糙度导致较低的表面自由能，而当光滑表面与液体具有松散的相互作用时，粗糙度导致较高的表面自由能，尽管发现这种影响很弱。整套结果的一致性，以及与现有的类似系统的结果的协议，显示了这里采用的热力学积分方法的能力，以捕捉界面热力学量的变化时，修改的化学性质或地形的固体表面接触一个给定的液相。(C)2010年美国物理学会。[doi：10.1063/1.3458796]
Different model Lennard-Jones solid-liquid interfaces have been considered. In the systems, either the interaction strength between solid and liquid was varied, or the topography of the solid surface was modified. In all situations, the solid-liquid interfacial free energy variations with respect to a reference solid-liquid interface were quantified by means of a thermodynamic integration method [F. Leroy et al., Macromol. Rapid Commun. 30, 864 (2009)], referred to as the phantom-wall method. Additionally, the liquid-vapor surface free energy was determined. This result was combined with Young's equation for contact angle calculations of cylindrical liquid droplets. It allowed us to show that the change in contact angle of a droplet placed on smooth solid surfaces with respect to solid-liquid interaction strength could be obtained by neglecting the solid-vapor surface free energy contribution when the solid-liquid interaction was weak. We also showed that the implementation of roughness by means of parallel grooves whose the density was varied could yield either higher or lower solid-liquid surface free energy, depending on the solid-liquid surface free energy of the smooth interface. Roughness led to lower surface free energy when the smooth surface had favorable interaction with the liquid, while it led to a higher surface free energy when the smooth surface had loose interactions with the liquid, though the effect was found to be weak. The consistency of the whole set of results, as well as agreement with the existing results on similar systems, shows the ability of the thermodynamic integration method employed here to capture the variation of interfacial thermodynamic quantities when modifying either the chemical nature or the topography of a solid surface in contact with a given liquid phase. (C) 2010 American Institute of Physics. [doi:10.1063/1.3458796]