Köhler Mateus Henrique, Bordin José Rafael, da Silva Leandro B, Barbosa Marcia C
Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970, Porto Alegre, RS, Brazil.
Phys Chem Chem Phys. 2017 May 24;19(20):12921-12927. doi: 10.1039/c7cp02058a.
In this paper the transport properties of water confined inside hydrophobic and hydrophilic nanotubes are compared for different nanotube radii and densities. While for wider nanotubes the nature of the wall plays no relevant role in the water mobility, for small nanotubes the hydrophobic confinement presents a peculiar behavior. As the density is increased the viscosity shows a huge increase associated with a small increase in the diffusion coefficient. This breakdown in the Stokes-Einstein relation for diffusion and viscosity was observed in the hydrophobic, but not in the hydrophilic nanotubes. The mechanism underlying this behavior is explained in terms of the structure of water under confinement. This result indicates that some of the features observed for water inside hydrophobic carbon nanotubes cannot be observed in other nanopores.
在本文中，针对不同的纳米管半径和密度，比较了限制在疏水和亲水纳米管内的水的传输特性。对于较宽的纳米管，管壁性质对水的迁移率没有显著影响，而对于小纳米管，疏水限制呈现出特殊行为。随着密度增加，粘度大幅增加，而扩散系数仅有小幅增加。这种扩散与粘度之间的斯托克斯 - 爱因斯坦关系的破坏在疏水纳米管中被观察到，而在亲水纳米管中未观察到。这种行为背后的机制根据受限水的结构进行了解释。该结果表明，在其他纳米孔中无法观察到疏水碳纳米管内水所呈现的某些特性。
