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Gas separation properties of organosilicon plasma polymerized membranes
Author(s) -
Roualdes Stéphanie,
Van der Lee Arie,
Berjoan René,
Sanchez José,
Durand Jean
Publication year - 1999
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690450718
Subject(s) - organosilicon , membrane , plasma polymerization , polydimethylsiloxane , monomer , polymerization , analytical chemistry (journal) , permeation , hexamethyldisiloxane , x ray photoelectron spectroscopy , refractive index , diffusion , thin film , materials science , chemical engineering , porosity , polymer chemistry , chemistry , plasma , polymer , chromatography , organic chemistry , nanotechnology , biochemistry , physics , quantum mechanics , engineering , optoelectronics , thermodynamics
Thin films were polymerized from different organosilicon compounds in a radio‐frequency plasma deposition process. The properties of the layers were characterized with respect to the deposition rate, the density, the refractive index, and the chemical structure determined by FTIR and XPS analysis. The qualification of the films for gas‐selective membranes was tested on different porous substrates using N 2 , H 2 , O 2 , CO 2 , and CH 4 . Both structure and permeation performances of the synthesized films were correlated with the composite plasma parameter V/F·M (V: input voltage; F: monomer flow rate; M: monomer molecular weight). At low V/F·M ratio, the thin layers are mainly constituted of the [(CH 3 ) 2 –Si(–O) 2 ] environment (monomer and polydimethylsiloxane one). Increasing the V/F·M results in a more “inorganic” chemical structure, higher O/Si ratio, refractive index, and density, the materials tend toward a silicalike structure. Concurrently, the prepared membranes have solution–diffusion‐controlled or Knudsen‐like separation factors, depending on whether plasma conditions are soft or hard.