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Polymers are known, in general as insulating materials but the conjugated polymers have interesting electrical properties. PANI is the most attractive conducting polymer because of its low cost, high stability, good electrical conductivity and good for many applications such as molecular electronics. Pure Polyaniline salt, and protonation PANI by H...
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... electronic transport properties of PANI can be changed by doping. [4] The aspect which attracted our interest is the protonated structure of polyaniline in the acidic media ( Fig.1) Polyaniline in its sulfonated form shows a close structure with the ion conducting polymers, where the inorganic anions are represented by HSO4 -species. ...
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... frequency depended of the measured total conductivity σt at different applied voltage. Fig.10shows the A.C conductivity HCl protonation at different voltage. ...
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... increasing the applied voltage the behavior was not systematic, σac,is obtained by subtracting the d.c conductivity, from the measured total conductivity according to Eq.2.The variation of conductivity with frequency revels that the charge transport mechanism can be considered to be semiconductor. [17] The frequency exponent s, can be calculated from the slope of the straight lines in fig.11, the value of exponent s is listed in table 2. From table 2, the exponent s was found to be increase with increasing of applied voltage except the 1V sample. ...
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... The frequency exponent s, can be calculated from the slope of the straight lines in fig.11, the value of exponent s is listed in table 2. From table 2, the exponent s was found to be increase with increasing of applied voltage except the 1V sample. Fig.12 shows total conductivity of pure and protonation PANI by HCl at 2V it's clear from this figure that the conductivity of protonation PANI by HCl is higher than that of pure ...
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... oxidation structures of PANI were strongly dependent on the applied voltage and dopant type, so the impedance curves of the samples were measured at different applied voltage and different dopant type. The Cole-Cole plots obtained at 2V for pure PANI and doped samples at voltages of (0.5, 1and 2) V, are given in Figures (14. a-c) and (15). All impedance curves had a semicircle in the high-frequency region; this can be described by the double layer capacitance in parallel with the ionic charge-transfer resistance (Rct). The high- frequency intercept of the semi-circle on the real axis yielded the ohmic resistance (Rs).Polarizability (α) is a measure of the ...
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... parameter α can be determined from the location of the center of the Cole-Col circles, of which only an arc lies above Z-axis. Figures (14.a-c) and (15) depicts a Cole- Cole plot between Z' and Z for pure and protonation PANI.It's evident from this plot that relaxation process differs from the monodispersive Debye process (for which α=0). The parameter α, was determined from the angle subtended by the radius of the circle with the Z-axis passing through the origin of Z'-axis is listed in table 3 the value of α between 0 and 1, describes the broad distribution of relaxation times in system .The Cole-Cole plot confirms the effect of applied voltage, As the results show that the polarizability increases with increasing of applied voltage.Relaxation time τ also was calculated from top of semicircle and listed in table 3. AC equivalent circuits for pure and protonation PANI, which represent the effect of applied voltage and type of dopant on the electrical conductivity and polarization of the material have been proposed.In general, for a given data set there exists more than one equivalent circuit which gives a reasonable fitting. ...
