Many naturally occurring as well as functionalized interfaces are covered with protruding segments or side-chain moieties. These protruding segments influence interfacial properties, and play an important role in diverse physical processes that are understood to be driven by water-mediated interactions, ranging from protein folding, protein dimerization to nanoparticle self-assembly in aqueous media. We have studied the behavior of water confined between two planar hydrophobic surfaces with grafted segments using molecular simulations. We show the presence of these segments makes the confined region significantly more hydrophobic. By systematically varying the flexibility of these segments over a range spanning two orders of magnitude for two different grafting densities, we report that the flexibility of the segments itself has no effect on the free energy profile of confined water. We also find that the evaporation free energy barrier increases and the condensation free energy barrier decreases as the density of the grafted segment is increased.

许多天然存在的以及功能化的界面都覆盖有突出的片段或侧链部分。这些突出的片段影响界面性质，并在各种物理过程中发挥重要作用，这些物理过程被认为是由水介导的相互作用驱动的，范围从蛋白质折叠，蛋白质二聚化到水性介质中的纳米粒子自组装。我们已经使用分子模拟研究了具有接枝链段的两个平面疏水表面之间的水约束行为。我们显示这些片段的存在使受限区域明显更疏水。通过针对两种不同的嫁接密度在两个数量级的范围内系统地改变这些片段的柔韧性，我们报告说，这些部分的灵活性本身对承压水的自由能分布没有影响。我们还发现，随着接枝段密度的增加，无蒸发能垒增加，无冷凝能垒减少。