Dielectric relaxation and dc conductivity on the PVOH-CF3COONH4 polymer system

Castillo, José; Chacón, M.; Castillo, Roberto; Vargas, R.A.; Bueno, Paulo Roberto; Varela, José Arana

doi:10.1007/s11581-009-0320-x

Cited by 21 publications

(10 citation statements)

References 43 publications

(59 reference statements)

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“…4). The behaviors observed in the electric response of the polymers studied in this work are similar to those observed in other solid ionic conductors, whether they are crystalline, polymer, or glass [7,22].…”

Section: Moisture Determinationsupporting

confidence: 80%

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Study of dc conductivity, transport mechanism, and dielectric relaxation in cassava starch membranes plasticized with glycerol

Ayala

Agudelo

Paz

et al. 2011

Ionics

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In the current work, we studied dc conductivity and its relaxation in glycerol-plasticized starch membranes at various concentrations using impedance spectroscopy in frequency ranges between 20 Hz and 3 MHz and temperature ranging from 303 K to 423 K. We observed thermally activated dc conductivity following the Arrhenius model: ln s ¼ ln s o À E s =k B T , where the activation energy, E σ , diminished as glycerol increased. Non-Debye relaxation phenomena were observed in the actual portion of the conductivity as a function of the frequency, s 0 w ð Þ $ w n n % 1 ð Þ. Also, the symmetry of the relaxation peak observed in the imaginary part of the electric module remained unaltered as a function of temperature and glycerol content in the membranes, corresponding to a constant exponent, β=0.80±0.02, if we assume the ФðtÞ ¼ exp À t=t ð Þ b h i correlation function in the ionic transport. The angular velocity, ω p , registering the maximum peak, M ″ max , was fitted to the Arrhenius model, ln w ¼ ln w o À E w =k B T , finding great similarity between E ω and E σ values for each sample, indicating that the corresponding ionic processes have the same origin, in other words, due to the correlated jump of the charge carriers. The independence found between n and β indicates that the correlation processes or cooperative effects among ions in these materials deviate from the empirical description expressed by Ф(t). However, these processes were identical when varying temperature glycerol content in the membranes, as suggested by the M″(ω) spectra.

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Section: Moisture Determinationsupporting

confidence: 80%

“…They have also been employed in obtaining solid batteries, sensors, corrosion barriers, and electrochemical and electrocatalysis devices [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Study of dc conductivity, transport mechanism, and dielectric relaxation in cassava starch membranes plasticized with glycerol

Ayala

Agudelo

Paz

et al. 2011

Ionics

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“…G/PS = 0.5) that is attributed to the charge transfer across the sample/electrode interface . The profiles observed in the frequency dependence of σ are similar to those observed in other material with disordered structure , and usually described by the Jonscher's expression :

σ^{'} (ω) = σ_{0} + A {(\frac{ω}{ω_{normalp}})}^{n},

where σ 0 is the dc‐conductivity and ω p /2π is a crossover frequency. Lines in the figure are fits to Eq.…”

Section: Resultssupporting

confidence: 69%

“…, and the imaginary part of the electric modulus ( M ″) ( β = 1.114/Δ; n = 1 − β ), suggest that the nature of the ionic conductivity in its long range (dc‐conductivity) regime and the highly dispersive region at high frequencies do not obey the same mechanism. However, the activation energies E σ and E ω for the temperature dependence of the dc‐conductivity and ω p are close to one another, suggesting that the long‐range transport conductivity ( σ 0 ) and the mobile ion relaxation, characterized by ω p , have common origin, that is, due to ion jumps .…”

Section: Discussionmentioning

confidence: 81%

Influence of glycerol content on the electrical properties of potato starch films

2013

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Effects of glycerol (G) and temperature (T) on the electrical properties of potato starch (PS) films were investigated by impedance spectroscopy measurements in the radio frequency range (20 Hz–3 MHz). The membranes were prepared by a solution casting method with weight fraction glycerol/potato starch (G/PS) = 0.1, 0.3, and 0.5 and characterized by DSC, FTIR, and moisture content measurements. The dc‐conductivity (σ0) of all compositions increases with the glycerol concentration and temperature, reaching the value of 5.2 × 10−5/Scm at 423 K, for G/PS = 0.5. The real part of the conductivity shows power–law frequency dependence (fn, n ≈ 0.98) at frequencies higher than a crossover frequency (fp). The imaginary part of the electric modulus plots shows non‐Debye asymmetrical peaks at about the frequency fp and it is characterized by a “stretched” exponential parameter β ≈ 0.8. The temperature dependence of σ0, fp (both showing an Arrhenius‐type behavior) and DSC data shows a phase boundary at about 353 K for all compositions. Results are discussed in terms of correlation effects in ion motion that takes place in a separate second phase in the G/PS films with composition G/H2O.

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“…Thus, the contribution by DC conductivity should be removed from the imaginary part of the dielectric constant in order to clearly see the relaxation effects. Accordingly, the corrected dielectric loss was determined by subtracting bulk DC conductivity contribution σ dc /ε 0 ω from the calculated ε″ [41]. The frequency dependent of the corrected dielectric loss is shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Electrical and complex dielectric behaviour of composite polymer electrolyte based on PEO, alumina and tetrapropylammonium iodide

Bandara

Karunathilaka

Ratnasekera

et al. 2017

Ionics

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In this study, the electrical, dielectric and morphological analysis of composite solid polymer electrolytes containing polyethylene oxide, alumina nano-fillers and tetrapropylammonium iodide are conducted. The temperature dependence of conductivity shows activation energy of 0.23, 0.20 and 0.29 eV for electrolytes containing 0, 5 and 15 wt.% alumina, respectively, when data fitted to the Arrhenius equation. These activation energy values are in good agreement with those determined from dielectric measurements. The result confirms the fact that conductivity is activated by both the mobility and the charge carrier density. The conductivity isotherms demonstrated the existence of two peaks, at 5 and 15 wt.% Al 2 O 3 composition. The highest conductivity values of 2.4 × 10 −4 , 3.3 × 10 −4 and 4.2 × 10 −4 S cm −1 are obtained for the sample with 5 wt.% Al 2 O 3 at 0, 12 and 24°C, respectively, suggesting an enhancement of conductivity compared with that of alumina free samples.

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Dielectric relaxation and dc conductivity on the PVOH-CF3COONH4 polymer system

Cited by 21 publications

References 43 publications

Study of dc conductivity, transport mechanism, and dielectric relaxation in cassava starch membranes plasticized with glycerol

Study of dc conductivity, transport mechanism, and dielectric relaxation in cassava starch membranes plasticized with glycerol

Influence of glycerol content on the electrical properties of potato starch films

Electrical and complex dielectric behaviour of composite polymer electrolyte based on PEO, alumina and tetrapropylammonium iodide

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