Tesis
Análise das propriedades dinâmicas e estruturais da água confinada entre placas hidrofóbicas
Fecha
2013-04-26Registro en:
KIPPER, Ana Claudia. Analysis of structural and dynamic properties of water confined between hydrophobic plates. 2013. 75 f. Dissertação (Mestrado em Física) - Universidade Federal de Santa Maria, Santa Maria, 2013.
Autor
Kipper, Ana Claudia
Institución
Resumen
In this work we studied the properties of confined water by graphene sheets via Classical
Molecular Dynamics. The main objective of this dissertation is to understand how the
structural and dynamic properties of confined water can be changed due to the geometric
confinement, including the density profile, formation of layering, the average number
of hydrogen bonds and the diffusion process of water molecules. The confinement geometry
is formed by two graphene sheets aligned parallel with respect to one another
separated by a distance "d". Both the distance "d" as the system temperature were varied
to obtain different degrees of confinement and thermodynamic conditions. Values used
were d=7, 9, 11, 15, 20, 25 and 30Å and T=280, 300 and 320K. Furthermore, all simulations
were carried out with GROMACS (GROningen Machine for Chemical Simulations)
code in a NVT ensemble (particle number, volume and pressure are kept constant) and
using SPC/E (Simple Point Charge/Extend) water model. For these systems have been
found that confinement induces the formation of layers of water molecules and the number
of layers depend on the degree of confinement. Due to this structure, we analyzed
the average number of hydrogen bonds with water molecules and these molecules in the
respective diffusion layers (central and near the confining walls). It was concluded that the
formation of layers is directly related to the breaking of hydrogen bonds.