Abstract
The work presented in this paper was realized using the polyimide obtained through the polycondensation of the
pyromellitic dianhydride with 4, 4′ - diaminophenyl ether. Polyimide based polymeric membranes were characterized as
regards the a.c. impedance and electrochemical analyses. The experiments put in evidence the influence of the membrane
composition on the electrochemical answer of the sensor. Also, it was put in evidence the action of the electrolyte solutions
upon the selective membranes. Through impedance analysis it was possible to show that the water from the aqueous
electrolyte solution acts not only as a plasticizer for the polymeric matrix, but it also exists as absorbed water on the
membrane surface. Meanwhile, it was concluded that the addition of the lipophilic agent in the selective membrane
composition results in membranes with higher dielectric constant. The dielectric constant of the polymeric matrix of the ionselective
devices based on neutral carriers has an important influence on selectivity.
Keywords
Polyimide polymeric matrix, Plasticizer, Plasticizing effect of electrolyte, a.c. Impedance analysis, Lipophilic additive.
Citation
E. EFTIMIE TOTU, E. RUSE, I. DIACONU, R. GÎRDEA, On the behaviour of polyimide ion-selective membranes in electrolyte solutions, Optoelectronics and Advanced Materials - Rapid Communications, 3, 12, December 2009, pp.1327-1330 (2009).
Submitted at: Nov. 12, 2009
Accepted at: Nov. 23, 2009