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| Titel: |
Dielectric Spectroscopy of Conducting Polyaniline Polymer |
| Auteur: |
Ghanem, H. M. El Attar, H. Ahmad, H. Sayid Abduljawad, S. |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 55 (2006) nr. 9 pagina's 663-679 |
| Jaar: |
2006-09-01 |
| Inhoud: |
The dielectric spectroscopy of conducting polyaniline polymers (PANI) in the form of emeraldine base and emeraldine salt was carried out in the temperature range 30 to 80°C and in the frequency range 1 Hz to 1 MHz. The imaginary part of the impedance (Z'') versus frequency exhibits a relaxation peak, the positions of the peaks are shifted toward lower frequencies for concentrations below 0.1 M, whereas the peaks are shifted to higher frequencies for concentrations above 0.1 M. The PANI samples were protonated (doped) externally with various concentrations of aqueous sulfuric acid in the range of 0.05 to 0.2 molar. The thermal behavior of undoped and doped PANI samples has been analyzed, using thermal gravimetric analysis and differential scanning calorimetry techniques, and reveal that transition in the thermal behavior has been observed for concentrations above 0.1 molar. The a.c. conductivity measurements reveal that insulator to metal transition in the conductivity of these samples was observed for acid concentration greater than 0.1 molar. The a.c. conductivity for the protonated samples bellow 0.1 molar follows an Arrhenius behavior ∂σ/∂T < 0 with two activation energies, while ∂σ/∂T > 0 for acid concentration greater than 0.1 M. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 7 van 45 gevonden artikelen
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