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Modeling of transport of small molecules in polymer blends: Application of effective medium theory
Author(s) -
Sax J.,
Ottino J. M.
Publication year - 1983
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760230310
Subject(s) - miscibility , materials science , percolation threshold , thermal diffusivity , thermodynamics , percolation (cognitive psychology) , statistical physics , binary number , polymer , volume fraction , percolation theory , consistency (knowledge bases) , diffusion , computer science , chemistry , physics , mathematics , conductivity , electrical resistivity and conductivity , composite material , arithmetic , quantum mechanics , neuroscience , biology , artificial intelligence
This article concerns itself with the prediction of effective diffusion coefficients of small permeants in binary polymer blends of varying degrees of miscibility and microstructural order. Several models have been critically evaluated with the help of previously published experimental data and in terms of consistency of morphological information provided by small permeants serving as morphological probes. Completely random, two‐phase media have been modeled in terms of Effective Medium Theory with the coordination number ( z ) describing the average morphology. A comprehensive analysis of experimental data has shown a correlation between z and various physical situations. Near the percolation threshold, z attains a maximum value while, above it, z tends to decrease with increasing content of the conductive component. Accurate predictions of effective diffusivity can be made for volume fractions between 0.3 and 0.8 by letting z = 6. Evidence for phase inversion was studied in terms of models with ordered microstructure and transport data.