Low frequency alternating current conduction and dielectric relaxation in polypyrrole, poly(N-methyl pyrrole), and their copolymers

Abstract

The alternating current (ac) conductivity [σm(ω)], dielectric constant (ε′) and loss (ε″) of polypyrrole (PPY), poly(N-methyl pyrrole) [P(NMPY)] and their copolymers; poly(N-methyl pyrrole–pyrrole [P(NMPY–PY)] have been measured in the frequency range 102–106 Hz and in the temperature range 77–350 K. At 77 K, the ac conductivity can be expressed by the relation; σac=Aωs where the slope s lies in the range 0.72–0.81 for these three polymers and decreases with increase in temperature. The well-defined loss peaks, whose magnitude decreases with the increase in frequency, have been observed in the temperature region where the measured ac conductivity approaches the direct current (dc) conductivity. These loss peaks have been associated with the movement of charge carriers in these polymeric films. The dc conductivity has also been measured in the temperature range 77–350 K and an attempt has been made to correlate it with dielectric data.

Characterization of electrochemically synthesized alkylpyrrole intrinsically conducting polymers

“…A good agreement between eq. (1) fits and displayed in table 7, agree with data reported elsewhere for other disordered conducting [36,37]. It is worthwhile to analyze the values obtained for g in more detail.…”

Evidence of a ratchet effect in nanowires of a conducting polymer

“…In Fig. 4(c) we have shown variation of ǫ of a 30nm sample with temperature obtained from the peak in the capacitance value measured as a function of frequency [31] (refer upper inset in Fig. 4(c)).…”

“…4(c) lower inset) is generally not expected in the hopping process. In the first approximation φ should have been independent of temperature as in polypyrrole dielectric constant ǫ is known to be proportional to T −1 [31] and that would have made U d proportional to T . In Fig.…”

Multiple hopping conduction in interpenetrating polymer network composites of poly pyrrole and poly (styrene-co-butyl acrylate)

“…13 Recently, some studies have been carried out on pure poly pyrrole films. 14,15 In most cases, polaronic hopping conduction has been reported. However, investigations on electrical properties of composite materials containing conducting polymers are few.…”