Percolation transition of hydration water at hydrophilic surfaces

✍ Scribed by A. Oleinikova; I. Brovchenko; A. Geiger

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 679 KB
• Volume: 364
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/j.physa.2005.09.049

✦ Synopsis

An analysis of water clustering is used to study the quasi-2D percolation transition of water adsorbed at planar hydrophilic surfaces. Above the critical temperature of the layering transition (quasi-2D liquid-vapor phase transition of adsorbed molecules) a percolation transition occurs at some threshold surface coverage, which increases with increasing temperature. The location of the percolation line is consistent with the existence of a percolation transition at the critical point. The percolation threshold at a planar surface is weakly sensitive to the size of the system when its lateral dimension increases from 80 to 150 A ˚. The size distribution of the largest water cluster shows a specific two-peaks structure in a wide range of surface coverage: the lower-and higher-size peaks represent contributions from non-spanning and spanning clusters, respectively. The ratio of the average sizes of spanning and non-spanning largest clusters is about 1.8 for all studied planes. The two-peak structure becomes more pronounced with decreasing size of the planar surface and strongly enhanced at spherical surfaces.