Expansion or contraction of slit pores due to gas uptake

Adsorption inside a slit pore of flexible width w is explored, with a focus on how w varies as a function of the external pressure P of a gas in equilibrium with the adsorbate within the pore. The analysis is first carried out in general, using a minimization of the thermodynamic grand potential ene...

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Detalhes bibliográficos
Autores: Ancilotto, F., Cole, M.W., Grosman, A., Hernandez, Ester Susana, Toigo, F.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/57008
Acesso em linha:http://hdl.handle.net/11336/57008
Access Level:acceso abierto
Palavra-chave:Capillary Condensation
Imbibition
Physisorption in Pores
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:Adsorption inside a slit pore of flexible width w is explored, with a focus on how w varies as a function of the external pressure P of a gas in equilibrium with the adsorbate within the pore. The analysis is first carried out in general, using a minimization of the thermodynamic grand potential energy of the system. This leads to an equation predicting both the gas uptake N as a function of chemical potential μ and the expansion (or contraction) of the pore in response to the adsorbate's pressure. The resulting equilibrium behavior depends on the elastic parameters of the host material. Explicit results are derived for three adsorption systems: a low density fluid, Ar (a classical fluid at finite temperature T) in a graphite pore and 4He within a Au pore at T=0. The resulting behaviors include some situations where the pore expands and others for which it contracts. The difference arises from the sign of the thermodynamic response of the fluid as a function of slit width. © 2011 Springer Science+Business Media, LLC.