Polymeric membranes can be modified by surface treatment with glow discharg
e created by non-polymerizable gases, with low power radio-frequency (rf) p
lasma. The purpose of this work is to study the influence of the exposure t
ime, the supplied power and the nature of the gas on the permeability of th
e treated membranes. Asymmetric porous substrates of polysulfone (PSf) were
used and their surfaces were modified with inorganic gas plasma (ammonia),
Three rf power levels, respectively 5, 10 and 15 W were used. Treatment ti
me ranged from 1 to 50 min. The chemical and structural characterization of
the membranes before and after the surface modification was done by means
of Atomic Force Microscopy (AFM), Scanning electron microscopy (SEM) and X-
ray photoelectron spectroscopy (XPS). The permeated flow of pure gases (N-2
and CO2) was measured using conventional gas permeation cell at room tempe
rature. (C) 2001 Elsevier Science B.V. All rights reserved.