High pressure induced phase transition and superdiffusion in anomalous fluid confined in flexible nanopores

The behavior of a confined spherical symmetric anomalous fluid under high external pressure was studied with Molecular Dynamics simulations. The fluid is modeled by a core-softened potential with two characteristic length scales, which in bulk reproduces the dynamical, thermodynamical, and structura...

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Detalles Bibliográficos
Autores: Bordin, José Rafael, Krott, Leandro Batirolla, Barbosa, Marcia Cristina Bernardes
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Brasil
Institución:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositorio:Repositório Institucional da UFRGS
Idioma:inglés
OAI Identifier:oai:www.lume.ufrgs.br:10183/205113
Acceso en línea:http://hdl.handle.net/10183/205113
Access Level:acceso abierto
Palabra clave:Dinâmica molecular
Materiais nanoporosos
Transformações de fase
Termodinâmica
Difusão
Descripción
Sumario:The behavior of a confined spherical symmetric anomalous fluid under high external pressure was studied with Molecular Dynamics simulations. The fluid is modeled by a core-softened potential with two characteristic length scales, which in bulk reproduces the dynamical, thermodynamical, and structural anomalous behavior observed for water and other anomalous fluids. Our findings show that this system has a superdiffusion regime for sufficient high pressure and low temperature. As well, our results indicate that this superdiffusive regime is strongly related with the fluid structural properties and the superdiffusion to diffusion transition is a first order phase transition. We show how the simulation time and statistics are important to obtain the correct dynamical behavior of the confined fluid. Our results are discussed on the basis of the two length scales.