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...
| Authors: | , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2014 |
| Country: | Brasil |
| Institution: | Universidade Federal do Rio Grande do Sul (UFRGS) |
| Repository: | Repositório Institucional da UFRGS |
| Language: | English |
| OAI Identifier: | oai:www.lume.ufrgs.br:10183/205113 |
| Online Access: | http://hdl.handle.net/10183/205113 |
| Access Level: | Open access |
| Keyword: | Dinâmica molecular Materiais nanoporosos Transformações de fase Termodinâmica Difusão |
| Summary: | 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. |
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