ABSTRACT Wrinkles are inevitable on the surface of graphene. It leads to changes in the properties of water in graphene slit pore. We investigated how surface wrinkles influence the structure and behaviour of water in graphene slit pores by molecular simulation. Our results show that structure and behaviour of water are influenced by pore width and surface roughness type. With the increase of pore width, the influence of roughness becomes weaker. Due to surface wrinkles, highly-ordered arrangements like square or diamond structure appear in 7 Å rough slits. This is the first work where highly-ordered water structure is found in slit pores under normal temperature and pressure. Wrinkles strengthen hydrogen bonding network, but it doesn’t always increase the number of hydrogen bonds, which depends on pore width and surface roughness type. The diffusion coefficient significantly decreases in wrinkled slit pores along X-Y plane. Surprisingly, the diffusion coefficient of water in non-rough direction in 9 Å wide slit with parallel wrinkles (9par) even exceeds that in 9 Å wide pristine slit. The number of hydrogen bonds in 9par is also very special. This work would further contribute to the design of directional transport of water in wrinkled graphene slit pore.

中文翻译：

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表面皱纹对石墨烯狭缝孔隙中水性质的影响

摘要石墨烯表面不可避免地会出现皱纹。它导致石墨烯狭缝孔中水的性质发生变化。我们通过分子模拟研究了表面皱纹如何影响石墨烯狭缝孔中水的结构和行为。我们的结果表明，水的结构和行为受孔隙宽度和表面粗糙度类型的影响。随着孔隙宽度的增加，粗糙度的影响变弱。由于表面皱纹，在 7 Å 粗糙狭缝中会出现方形或菱形结构等高度有序的排列。这是首次在常温常压下在狭缝孔隙中发现高度有序的水结构。皱纹加强了氢键网络，但它并不总是增加氢键的数量，这取决于孔隙宽度和表面粗糙度类型。沿 XY 平面的褶皱狭缝孔的扩散系数显着降低。令人惊讶的是，在具有平行皱纹的 9 Å 宽狭缝 (9par) 中，水在非粗糙方向上的扩散系数甚至超过了 9 Å 宽原始狭缝中的扩散系数。9par中的氢键数量也很特别。这项工作将进一步有助于设计皱纹石墨烯狭缝孔中的水定向传输。