Relationship between spatial and spectral properties of ionic solutions: The distributed impedance of an electrolytic cell

Nonlinear Conductivity of Fullerenol Aqueous Solutions

“…The impedance modulus is characterized by a plateau, whereas the phase angle indicates values around zero. The value of the impedance in this region, almost given by its real part, is well represented by a bulk resistance ( R b ), defined by sample geometry and its conductivity . At still higher frequencies, we can see a region of decreasing impedance modulus and also decreasing values of phase angle, which approach −90°.…”

“…The value of the impedance in this region, almost given by its real part, is well represented by a bulk resistance (R b ), defined by sample geometry and its conductivity. 21 At still higher frequencies, we can see a region of decreasing impedance modulus and also decreasing values of phase angle, which approach -90°. The value of the impedance associated with this spectral region is consistent with a bulk capacitance (C b ) having the dielectric constant of water.…”

“…The first term in λ represents electrophoretic effects, the second and third terms (proportional to h 1 and h 2 ) describe the relaxation due to the spatial offset between the moving hydrogen and potassium clouds and the fullerenol anions. We have shown that conductivity of a KCl aqueous solution has a linear dependence over a wide range of ionic concentrations. In this sense, we assumed that potassium ions behave ideally even at the higher concentration values used here, presenting standard mobility equal to μ K = μ K ° = 7.62 × 10 −8 m 2 s −1 V −1 .…”

“…A typical spectrum is shown in Figure , where both sets of data, modulus and phase angle, are presented. We were able to fit all data to an empirical impedance model consisting of dumped circuit elements describing a series circuit of the form Z ( ω ) = 1 i normalω C normale + i normalω W normale + R normale − 1 + 1 i normalω W normald + R normald − 1 + 1 i normalω C normalb + i normalω W normalb + R normalb − 1 …”