Motivated by practical implementation of transition-metal oxide-graphene heterostructures, we use all atom molecular dynamics simulations to study dynamics of water in a nano slit bounded by a transition metal oxide surface, namely, TiO$_2$ termination of SrTiO$_3$, and graphene. The resultant asymmetric, strong confinement produces square ice-like crystallites of water pinned at TiO$_2$ surface and drives enhanced hydrophobicity of graphene via the proximity effect to the hydrophilic TiO$_2$ surface. This importantly brings in dynamic heterogeneity, both in translational and rotational degrees of freedom, due to coupling between the slow relaxing, strongly adsorbed water layer at the hydrophilic oxide surface, and faster relaxation of subsequent water layers. The heterogeneity is signalled in ruggedness of the effective free energy landscapes. We discuss possible implications of our findings in drug delivery.

中文翻译：

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捕获在过渡金属氧化物-石墨烯纳米限制中的水的动力学。

受过渡金属氧化物-石墨烯异质结构的实际实施的启发，我们使用所有原子分子动力学模拟来研究由过渡金属氧化物表面包围的纳米狭缝中水的动力学，即 SrTiO$_3$ 的 TiO$_2$ 终止，和石墨烯。由此产生的不对称、强约束产生固定在 TiO$_2$ 表面的方形冰状水微晶，并通过与亲水性 TiO$_2$ 表面的邻近效应驱动石墨烯的疏水性增强。由于亲水氧化物表面缓慢弛豫、强吸附水层与后续水层更快弛豫之间的耦合，这很重要地带来了平移和旋转自由度的动态异质性。有效自由能源景观的坚固性表明了异质性。