UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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Conference: Bucharest University Faculty of Physics 2004 Meeting


Section: Optics, Spectroscopy, Plasma and Lasers


Title:
Morphological and gas permeation studies of porous polymeric membranes treated in radiofrequency plasma


Authors:
A. Lazea, L.I. Kravets *, B. Albu **, E. Raiciu, G. Dinescu


Affiliation:
National Institute for Laser, Plasma and Radiation Physics, PO Box MG 16 Magurele Bucharest, 76900 Romania; e-mail: dinescug@alpha1.infim.ro

*Joint Institute for Nuclear Research, Flerov Laboratory of Nuclear Reactions, Dubna, Russia

** Research Centre for Membranes and Macromolecular Materials,

Bucharest, Romania


E-mail
dinescug@alpha1.infim.ro


Keywords:
porous polymeric membranes; plasma treatment of polymers; Atomic Force Microscopy; gas permeation


Abstract:
It is well known that porous polymeric membranes, with different size and shape of the pores, have many applications which include processes of micro- and ultra-filtrations. The specific application depends on the method of membrane preparation and of the material used. The enlargement of the application range, as example by plasma modification of membrane characteristics is desirable. In this contribution the changes observed on the morphology, surface topography and gas permeation properties of the polyethylene terephthalate track membranes and polysulfone (PSF) membranes due to radiofrequency (RF) plasma treatments are presented. The discharge configuration (external annular electrodes or parallel plate electrodes) and the plasma parameters as: type of gas (argon, air), radiofrequency power (10-100 W) and time of exposure (20 c -15 min) play an important role in the modifications observed by morphological and permeation measurements. The morphology and topography of the membranes before and after plasma treatments were investigated by Scanning Electron Microscopy (SEM) for polysulfone membranes and Atomic Force Microscopy (AFM) for track membranes. The characteristics regarding pore size was obtained using Coulter Porometer II and gas permeation. It was observed that after plasma treatment both types of membranes present modification of the pore sizes and permeation properties. A decrease in the pore size can be realized for the polysulfone membranes and both the decrease (for small treatment time) or increase (for long treatment time) in of pore size for the track membranes. These changes are depending on the treatment type.