INVESTIGATION OF POLYMER MORPHOLOGY OF INTEGRAL-ASYMMETRIC MEMBRANES BY ESR AND RAMAN-SPECTROSCOPY AND ITS COMPARISON WITH HOMOGENEOUS FILMS

Symmetric (homogeneous) and asymmetric membranes (non-homogeneous) mad e of poly(phenylene oxide) (PPO) and symmetric membranes made of polya mide (PA) were studied by electron spin resonance (ESR), using the nit roxide spin as a probe, and by Raman scattering. These studies indicat ed that the morphology of the polymer chains in the asymmetric membran e was slightly different than in the symmetric membrane. This differen ce may be due to the different morphology of the polymer chain in the dense layer (top layer) of the asymmetric membrane. Raman scattering o f PA membranes could not be observed due to the high intensity of the fluorescence. From the ESR study of PA membranes it was noticed that t here was no significant decaying effect on the membranes due to time a nd air (atmosphere) for a long period.