petrossa Posted July 28, 2010 Share Posted July 28, 2010 (edited) Two-dimensional wetting: The role of atomic steps on the nucleation of thin water films on BaF2(111) at ambient conditions The interaction of water with freshly cleaved BaF2(111) surfaces at ambient conditions (room temperature and under controlled humidity) has been studied using scanning force microscopy in different operation modes. The images strongly suggest a high surface diffusion of water molecules on the surface indicated by the accumulation of water at step edges forming two-dimensional bilayered structures. Steps running along the 〈10〉 crystallographic directions show a high degree of hydrophilicity, as evidenced by small step-film contact angles, while steps running along other directions exhibiting a higher degree of kinks surprisingly behave in a quite opposite way. Our results prove that morphological defects such as steps can be crucial in improving two-dimensional monolayer wetting and stabilization of multilayer grown on surfaces that show good lattice mismatch with hexagonal ice. <snip> V. CONCLUSIONS We have studied the role of steps in the interaction of water with freshly cleaved 111 surfaces of BaF2 single crystals in ambient conditions using different SFM imaging methods and optical microscopy. We have shown the stabilizing effect of steps for the growth of the two-dimensional water patches. Such water patches are preferentially observed on terraces limited by triangular steps created by cleavage. These patches are larger for lower terraces and show a meniscuslike shape that can be related to the different wettability of the steps. We found that steps running along the 1¯10 directions are by far the most hydrophilic steps beating even steps with high density of kinks. Our results prove that morphological defects such as steps can be crucial for improving monolayer wetting and stabilization of multilayer grown on surfaces that show a good lattice mismatch relationship with water molecules forming ice. We believe that a theoretical study of the interaction of water molecules with stepped surfaces would be of great interest in order to clarify the underlying mechanism of water absorption. A realistic situation would need to involve a large number of water molecules per substrate unit cell since the individual molecule scenario may not be representative of a real ambient conditions situation. http://jcp.aip.org/jcpsa6/v132/i23/p234708_s1?bypassSSO= Edited July 29, 2010 by dreamz added link to official article page Link to comment Share on other sites More sharing options...
dreamz Veteran Posted July 29, 2010 Veteran Share Posted July 29, 2010 you should link to the official article page when you can: http://jcp.aip.org/jcpsa6/v132/i23/p234708_s1?bypassSSO=1 Link to comment Share on other sites More sharing options...
petrossa Posted July 29, 2010 Author Share Posted July 29, 2010 you should link to the official article page when you can: http://jcp.aip.org/j..._s1?bypassSSO=1 Sorry? ?copied the wrong link... Tabbed browsers.... Link to comment Share on other sites More sharing options...
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