Stability of Water Confined between Supported Self-Assembled Monolayers
Stability of Water Confined between Supported Self-Assembled Monolayers
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受支撑的自组装单分子层之间限制的水的稳定性
DOI：
10.1021/acs.jpcb.2c00588
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Sharma, Sumit
中科院分区：
文献类型：
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作者：
Mehrani, Ramin;Sharma, Sumit
我们提出了一个热力学参数表明，限制在两个疏水性自组装单分子膜（SAM）之间的水的蒸发和冷凝自由能垒变化更逐渐与SAM的疏水性相比，限制在两个裸露的疏水表面（无SAM）之间的水的情况下。我们验证了我们的理论，通过计算自由能配置文件之间的两个自组装膜和两个裸露的表面不同的疏水性限制的水。我们的研究结果的一个含义是存在的三个制度的稳定性的承压水作为一个功能的自组装膜的疏水性。与没有SAM的裸露平面表面相比，高度疏水的SAM起到稳定液态的作用，而弱疏水的SAM稳定受限水的蒸气态。对于中间疏水性，自组装膜降低了蒸发和冷凝自由能势垒。这些结果表明，SAM的疏水性对承压水的行为的影响是不平凡的，比以前认为的更丰富。
We present a thermodynamic argument showing that the evaporation and condensation free-energy barriers of water confined between two hydrophobic self-assembled monolayers (SAMs) vary more gradually with the SAM hydrophobicity as compared to the case of water confined between two bare hydrophobic surfaces (no SAMs). We validate our theory by calculating the free-energy profiles of water confined between two SAMs and between two bare surfaces of different hydrophobicities. An implication of our findings is the existence of three regimes of stability of confined water as a function of the hydrophobicity of the SAMs. In comparison to bare planar surfaces with no SAMs, the highly hydrophobic SAMs act to stabilize the liquid state, whereas weakly hydrophobic SAMs stabilize the vapor state of confined water. For intermediate hydrophobicities, the SAMs reduce both the evaporation and the condensation free-energy barriers. These results imply that the effects of SAM hydrophobicity on the behavior of confined water are nontrivial and richer than previously thought.