Role of Confinement and Surface Affinity on Filling Mechanisms and Sorption Hysteresis of Water in Nanopores

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• 作者：Ezequiel de la Llave ; Valeria Molinero ; Damian A. Scherlis
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：January 19, 2012
• 年：2012
• 卷：116
• 期：2
• 页码：1833-1840
• 全文大小：509K
• 年卷期：v.116,no.2(January 19, 2012)
• ISSN：1932-7455

文摘

The liquid鈥搗apor transition in cylindrical pores is studied as a function of pore size and hydrophilicity through molecular dynamics simulations with the mW coarse-grained model of water. We identify two distinct filling mechanisms, depending on whether the water鈥損ore interaction is smaller or larger than the water鈥搘ater interaction. In the former case (that we term hydrophobic pore), the formation of the condensed phase proceeds gradually with filling, through the nucleation of a water cluster which grows toward the center of the cavity. In hydrophilic pores, instead, the condensed phase develops in conditions of supersaturation, which in principle become more extreme with increasing pore radius and surface affinity. For highly hydrophilic interfaces (those with adsorption energy for water above 10 kcal/mol), the equilibrium and dynamical properties of water in confinement turn out to be practically independent of water affinity.