Echem analyst 2

Potentiostatic electrochemical impedance spectroscopy (EIS) was performed with a potentiostat/galvanostat/ZRA (Interface 1010E, Gamry Instruments, Warminster, PA, USA). An AC signal with an amplitude of 350 root-mean-square (rms) mV and a constant potential difference of 0.10 V, relative to the open-circuit potential, were applied to the cell. The analysis was carried in a frequency range of 1.8 MHz to 1.0 Hz, at room temperature (18 °C). The AEs were cut into flat sample pieces of regular geometry with a thickness of 2 mm and placed between two stainless steel electrodes (electrode area 1 cm²). Two of these sample pieces, from different parts of the aerogel, were obtained for each AE and its replica. The equivalent electrical circuit reported by Yoon, Hong and Hwang [24 (link)], represented in Scheme 1, is composed of R_AE (representing the bulk resistance of the aerogel) and C_AE (representing the capacitance of the bulk aerogel) in parallel, and in series with C_e (representing the capacitance of the electrode–aerogel interface), where C is constant phase elements, was used to fit the spectra. The fittings were computed with Echem Analyst 2 (version 7.10, Gamry Instruments). The sodium conductivities (σ) of AEs were calculated with Equation (4), where l is the sample’s thickness and A is the contact area between the aerogel and electrode.
$$\sigma =\frac{l}{R_{AE}A}$$

The double-shell
model, as described in Jócsák et al.^{19 (link)} and diagrammed in Figure 2, was used to determine the values of the resistive
and capacitive components of the plant cells being tested. This model
accounts for the electrical resistances of the cell wall/membrane
(R_w), cytoplasm/symplasm (R_cs), and vacuole (R_v), and
the capacitances of the plasma membrane (C_cm) and vacuolar membrane (C_vm).^{19 (link),20 (link)} The double-shell model was chosen in this study because of its high
conformity for other plant tissues.^{20 (link)} Impedance
data were analyzed using EChem Analyst 2 (v. 7.10.0.12461, Gamry Instruments).