Abstract：
Water under soft nanoconfinement features physical and chemical properties fundamentally different from bulk water; yet, the multitude and specificity of confining systems and geometries mask any of its potentially universal traits. Here, we advance in this quest by resorting to lipidic mesophases as an ideal nanoconfinement system, allowing inspecting the behavior of water under systematic changes in the topological and geometrical properties of the confining medium, without altering the chemical nature of the interfaces. By combining Terahertz absorption spectroscopy experiments and molecular dynamics simulations, we unveil the presence of universal laws governing the physics of nanoconfined water, recapitulating the data collected at varying levels of hydration and nanoconfinement topologies. This geometry-independent universality is evidenced by the existence of master curves characterizing both the structure and dynamics of simulated water as a function of the distance from the lipid-water interface. Based on our theoretical findings, we predict a parameter-free law describing the amount of interfacial water against the structural dimension of the system (i.e., the lattice parameter), which captures both the experimental and numerical results within the same curve, without any fitting. Our results offer insight into the fundamental physics of water under soft nanoconfinement and provide a practical tool for accurately estimating the amount of nonbulk water based on structural experimental data.
摘要：
软纳米约束下的水具有与散装水根本不同的物理和化学性质；然而，限制系统和几何形状的多样性和特殊性掩盖了其任何潜在的普遍特征。这里,我们通过求助于脂质中间相作为理想的纳米约束系统来推进这一探索，允许在约束介质的拓扑和几何特性的系统变化下检查水的行为，而不改变界面的化学性质。通过结合太赫兹吸收光谱实验和分子动力学模拟,我们揭示了控制纳米承压水物理学的普遍定律的存在，概括了在不同水合和纳米约束拓扑水平下收集的数据。主曲线的存在证明了这种与几何形状无关的普遍性，该主曲线表征了模拟水的结构和动力学，作为与脂质-水界面距离的函数。根据我们的理论发现，我们预测了一个无参数定律，该定律描述了相对于系统结构尺寸的界面水量(即，晶格参数)，在同一条曲线中捕获实验和数值结果，没有任何拟合。我们的结果提供了对软纳米约束下水的基本物理学的见解，并提供了一种实用的工具，用于根据结构实验数据准确估计非散装水的量。
