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An absorption model for the thickness effect in hydrophilic films
Author(s) -
Yoshida Cristiana M. P.,
Antunes Antonio C. B.,
Alvear Celso,
Antunes Aloísio J.
Publication year - 2005
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2004.00907.x
Subject(s) - diffusion , adsorption , permeability (electromagnetism) , materials science , water vapor , chemical engineering , moisture , absorption (acoustics) , absorption of water , flux (metallurgy) , chemical physics , chemistry , composite material , thermodynamics , organic chemistry , membrane , biochemistry , physics , metallurgy , engineering
Summary The permeability parameters for moisture transmission through hydrophilic films are well known to be thickness dependent, this effect appearing in permeability studies based on diffusion models. In our model we assume that, besides diffusion, some of the water vapour of the diffusion flux is removed by the hydrophilic components of the films. This water is immobilized and becomes hydration water of the hydrophilic molecules. This paper describes a diffusion–adsorption model, with thickness‐independent parameters, which explains this phenomenon.