ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The sorption isotherms of carbon dioxide in a polyimide film sample were measured by a pressure decay method at 30, 40, 50, and 60°C and pressures up to 1.7 MPa. The mean permeability coefficients at the same temperatures were measured by a variable volume method at applied upstream pressures up to 3 MPa. The sorption equilibria at these temperatures were found to be well described in terms of a dual-mode sorption model. The pressure dependences of the mean permeability coefficients at these four levels of temperatures did not satisfactorily follow a dual-mode mobility model, but could be well simulated by a modified mobility model that both the Henry's law (D) and Langmuir (H) populations execute four kinds of diffusive movements such as D → D, D → H, H → D, and H → H. The diffusion coefficients of D → D, D → H, and combined H → H and H → D steps were determined by comparing the experimental permeability data with those predicted via this modified mobility model. The temperature dependences of such diffusion coefficients were consistent with Arrhenius-type equations within the covered temperatures.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1988.070350608
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