Smooth surfaces molecular dynamic simulations

The molecular dynamics simulation indicated that, unlike polarization (which oscillates), the disruption of hydrogen bonding varies smoothly in the vicinity of the surface and constitutes therefore a better choice as an order parameter. There were a number of computational approaches13 14 16 and lattice model calculations17 which related the hydration force to the disruption of the hydrogen bonding networks when two surfaces approach each other. 

The second difficulty can be removed if one assumes that in the vicinity of an interface the water is organized in icelike layers. The electrical interactions between the water dipoles of successive layers lead indeed to an oscillatory behavior of the polarization [35], If the surface is not perfectly flat, of if the water is not perfectly organized in water layers, the statistical average smooth out the polarization oscillations [35], The latter results have been also supported by molecular dynamics simulation, in which the surface dipoles were allowed to move [36], Let us now examine in detail how the correlation between neighboring dipoles occurs. 

Kim, C. K., Kubota, A., and Economou, D. J., Molecular-dynamics simulation of silicon surface smoothing by low-energy argon cluster impact. J. Appl Phys 86, 6758-6762 (1999). Kohn, W., and Sham, L. J., Self-consistent equations including exchange and correlation effects. 

Since lijima identified carbon nanotubes (CNTs) in 1991, CNTs have been investigated in various fields and become extremely desirable for a wide range of applications. CNTs, with diameters in nanometer scale and a smooth surface may offer a very unique molecular transport through their pores. In fact, several studies in recent years suggest that the water transport through single-walled carbon nanotubes (SWNT) would become much faster than the transport rate that the continuum hydrodynamic theory would predict. This was attributed by Molecular Dynamic (MD) simulation to the smoothness of the nano-tube wall [1,2]. 

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