Carlson Shane R, Schullian Otto, Becker Maximilian R, Netz Roland R
Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Germany.
J Phys Chem Lett. 2024 Jun 20;15(24):6325-6333. doi: 10.1021/acs.jpclett.4c01143. Epub 2024 Jun 10.
Accurate simulation models for water interactions with graphene and graphite are important for nanofluidic applications, but existing force fields produce widely varying contact angles. Our extensive review of the experimental literature reveals extreme variation among reported values of graphene-water contact angles and a clustering of graphite-water contact angles into groups of freshly exfoliated (60° ± 13°) and not-freshly exfoliated graphite surfaces. The carbon-oxygen dispersion energy for a classical force field is optimized with respect to this 60° graphite-water contact angle in the infinite-force-cutoff limit, which in turn yields a contact angle for unsupported graphene of 80°, in agreement with the mean of the experimental results. Interaction force fields for finite cutoffs are also derived. A method for calculating contact angles from pressure tensors of planar equilibrium simulations that is ideally suited to graphite and graphene surfaces is introduced. Our methodology is widely applicable to any liquid-surface combination.
用于水与石墨烯和石墨相互作用的精确模拟模型对于纳米流体应用至关重要，但现有的力场会产生差异很大的接触角。我们对实验文献的广泛综述揭示了报道的石墨烯-水接触角值之间存在极大差异，并且石墨-水接触角聚集成新剥离的（60°±13°）和非新剥离的石墨表面组。在无限力截止极限下，针对此60°石墨-水接触角优化了经典力场的碳-氧色散能，这反过来又得出无支撑石墨烯的接触角为80°，与实验结果的平均值一致。还推导了有限截止的相互作用力场。介绍了一种从平面平衡模拟的压力张量计算接触角的方法，该方法非常适合石墨和石墨烯表面。我们的方法广泛适用于任何液体-表面组合。
