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Pure and mixed gas permeation through a composite polydimethylsiloxane membrane
Author(s) -
Sadrzadeh Mohtada,
Amirilargani Mohammad,
Shahidi Kazem,
Mohammadi Toraj
Publication year - 2011
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1551
Subject(s) - permeation , polydimethylsiloxane , materials science , membrane , polymer , permeability (electromagnetism) , chemical engineering , gas separation , phase inversion , composite number , sorption , diffusion , analytical chemistry (journal) , polymer chemistry , chromatography , composite material , organic chemistry , adsorption , thermodynamics , chemistry , biochemistry , engineering , physics
A thin polydimethylsiloxane (PDMS) layer on polyethersulfone (PES) support was synthesized and pure and mixed gas permeation of C 3 H 8 , CH 4 , and H 2 through it was measured. At first, a macroporous PES support was prepared by using the phase inversion method and characterized. Then, a thin layer of PDMS was coated over the support. Finally, permeation behavior of the synthesized composite membrane was investigated by pure and mixed gas experiments under various operating conditions. The synthesized PDMS/PES membrane showed much better gas permeation performance than others reported in the literature. Pure gas experiments showed that increase in the transmembrane pressure increases the permeability coefficient of heavier gases, C 3 H 8 , while decreases those of lighter ones, CH 4 and H 2 . Exactly opposite behavior was observed in mixed gas experiments due to the competitive sorption and diffusion in the plasticized polymer matrix. Temperature was realized to induce similar effects on the permeability of pure and mixed gases. As expected, in rubbery membranes such as PDMS, permeability values of more condensable gases decrease with increasing temperature, whereas those of permanent gases increase. In the case of mixed gas experiments, increase in the C 3 H 8 concentration in feed led to increase in the permeabilities of all the components due to the C 3 H 8 ‐induced swelling of the PDMS film. High C 3 H 8 /H 2 and C 3 H 8 /CH 4 ideal selectivities of 22.1 and 14.7, respectively, at a transmembrane pressure of 7 atm as well as reasonable C 3 H 8 separation factor (SF) values for all mixed gas experiments (in the range of 8.1–16.8) demonstrated the ability of the synthesized PDMS/PES membrane for the separation of organic vapors from permanent gases. Copyright © 2009 John Wiley & Sons, Ltd.