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Molecular Dynamics Simulations of Helium Permeation in Polyimides with a Bulky Dianhydride and a Fluorinated Diamine
Author(s) -
Neyertz Sylvie
Publication year - 2007
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.200700017
Subject(s) - helium , polyimide , diamine , molecular dynamics , permeation , polymer , materials science , polymer chemistry , chemical physics , chemistry , computational chemistry , organic chemistry , membrane , composite material , biochemistry , layer (electronics)
Fully‐atomistic molecular dynamics (MD) simulations have been carried out to model helium transport through four different glassy polyimides. While the polymer matrices had been pre‐validated, specific parameters and combination rules were used here in order to describe helium‐helium and helium‐polymer interactions. Gas permeabilities are in very good agreement with experimental evidence. Two ways to decrease chain cohesion and improve gas transport were considered – the replacement of an ODPA by a bulky BCDA dianhydride, and the substitution of a site on an ODA diamine by a CF 3 . The fluorinated polyimide appears to be the most promising material with more heterogeneity in the void‐space distribution, the highest model permeability and fewer constraints from an experimental point of view.