Kinetic equations for difussion in the presence of entropic barriers

We use the mesoscopic nonequilibrium thermodynamics theory to derive the general kinetic equation of a system in the presence of potential barriers. The result is applied to a description of the evolution of systems whose dynamics is influenced by entropic barriers. We analyze in detail the case of...

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Detalles Bibliográficos
Autores: Reguera, D. (David), Rubí Capaceti, José Miguel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2001
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/18785
Acceso en línea:https://hdl.handle.net/2445/18785
Access Level:acceso abierto
Palabra clave:Física estadística
Termodinàmica
Sistemes no lineals
Matèria condensada
Statistical physics
Thermodynamics
Nonlinear systems
Condensed matter
Descripción
Sumario:We use the mesoscopic nonequilibrium thermodynamics theory to derive the general kinetic equation of a system in the presence of potential barriers. The result is applied to a description of the evolution of systems whose dynamics is influenced by entropic barriers. We analyze in detail the case of diffusion in a domain of irregular geometry in which the presence of the boundaries induces an entropy barrier when approaching the exact dynamics by a coarsening of the description. The corresponding kinetic equation, named the Fick-Jacobs equation, is obtained, and its validity is generalized through the formulation of a scaling law for the diffusion coefficient which depends on the shape of the boundaries. The method we propose can be useful to analyze the dynamics of systems at the nanoscale where the presence of entropy barriers is a common feature.