Ultrasonic study of water adsorbed in nanoporous glasses
Ultrasonic study of water adsorbed in nanoporous glasses
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纳米多孔玻璃吸附水的超声研究
DOI：
10.1103/physreve.108.024802
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发表时间：
2023
影响因子：
2.4
通讯作者：
Gor, Gennady Y.
中科院分区：
文献类型：
--
作者：
Ogbebor, Jason;Valenza, John J.;Ravikovitch, Peter I.;Karunarathne, Ashoka;Muraro, Giovanni;Lebedev, Maxim;Gurevich, Boris;Khalizov, Alexei F.;Gor, Gennady Y.
限制在纳米孔中的流体的热力学性质与在整体中观察到的不同。为了研究纳米约束对水可压缩性的影响，我们对两个纳米孔玻璃样品进行了吸水实验，同时测量了纵波和横波在这些样品中的传播速度。这些测量得到了作为相对湿度的函数的充满水的纳米多孔玻璃的纵向和剪切模数，我们在Gassmann理论中利用它来推断承压水的体积模数。分析表明，在相同温度下，承压水的体积弹性模量(与压缩系数成反比)明显高于主体水。此外，模数与拉普拉斯压强呈线性关系。对于水，这是一种极性流体，其结果与之前报道的非极性流体的实验和数值数据一致。这种相似性表明，无论分子间作用力如何，受限流体都比整体流体更坚硬。考虑纳米孔中的流体硬化对于准确解释充满流体的纳米多孔介质中的波传播测量可能是重要的，包括在岩石物理、催化和其他应用中，例如在多孔材料表征中。
Thermodynamic properties of fluids confined in nanopores differ from those observed in the bulk. To investigate the effect of nanoconfinement on water compressibility, we perform water sorption experiments on two nanoporous glass samples while concomitantly measuring the speed of longitudinal and shear ultrasonic waves in these samples. These measurements yield the longitudinal and shear moduli of the water-laden nanoporous glass as a function of relative humidity that we utilize in the Gassmann theory to infer the bulk modulus of the confined water. This analysis shows that the bulk modulus (inverse of compressibility) of confined water is noticeably higher than that of the bulk water at the same temperature. Moreover, the modulus exhibits a linear dependence on the Laplace pressure. The results for water, which is a polar fluid, agree with previous experimental and numerical data reported for nonpolar fluids. This similarity suggests that irrespective of intermolecular forces, confined fluids are stiffer than bulk fluids. Accounting for fluid stiffening in nanopores may be important for accurate interpretation of wave propagation measurements in fluid-filled nanoporous media, including in petrophysics, catalysis, and other applications, such as in porous materials characterization.