Surface modification of porous polymeric membranes by RF-plasma treatment

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.