Permeability and Equivalent Circuit Model of Ionically Conductive Mortar Using Electrochemical Workstation

Abstract

Ionically conductive mortar is a new Portland cement-based construction material prepared by permeating electrolyte solution into porous mortar specimen. The conductive mechanism of ionically conductive mortar is the directional movement of internal free ions under external electric field. Because of the strong electrochemical properties of ionically conductive mortar, electrochemical workstation was used to test the performance of ionically conductive mortar. The open-circuit potential during the permeation process of ionically conductive mortar was tested. The results show that the change of open-circuit potential can effectively reflect the permeability rate of the samples with different porosity and electrolyte mass fraction. Besides the permeation of specimen, electrochemical workstation was also used to test the EIS (electrochemical impedance spectroscopy) of permeated specimens with different porosity, concentration of electrolyte solution, and different kinds of electrolyte solution. The quasi-Randles circuit model was then used to establish an equivalent circuit of ionically conductive mortar. Finally, the relation between parameter of circuit and the porosity or electrolyte solution was established. The test results show that solution resistance of the equivalent circuit and real resistivity of specimens is linearly correlated. This shows the equivalent circuit can effectively reflect the real resistivity of ionically conductive mortar, and the variation of electronic component parameters of equivalent circuit conforms to the conductive mechanism of ionically conductive mortar.

Palmyra palm flower biomass-derived activated porous carbon and its application as a supercapacitor electrode

“…EIS results of all three electrodes, developed from activated carbons synthesized at different temperatures, are shown in Figure 5d. At high frequencies, the Nyquist plot is a depressed semicircle, followed by a more or less visible sloping line in the high to the middle-frequency region and a prominent inclined vertical tail at low frequencies [28]. Such a shape of Nyquist plots is characteristic of the impedance response of highly porous capacitive electrodes, where an inclined vertical line at low frequencies is directly attributed to a non-ideal capacitive response of electrode material [29].…”

Sensitive determination of uric acid at zinc layered hydroxide-sodium dodecyl sulphate-propoxur nanocomposites

“…The investigation of interfacial redox reaction kinetics of [Fe(CN)6] 3-/4redox probe at LZH-SDS-PRO/ /MWCNT paste electrode was done by using the EIS method. The charge transfer resistance, Rct values were estimated as diameters of semicircles appearing in high-frequency regions of Nyquist plots, where the diffusion process is represented by straight-line plots at lower frequencies [28]. In the inset of Figure 4, the Randles equivalent circuit used for fitting measured impedance spectra is presented.…”

Toward a better understanding of multifunctional cement-based materials: The impact of graphite nanoplatelets (GNPs)

“…For all the samples, progressive cement hydration clearly led to increased pore solution resistance (Rs) due to the decreased amount of the evaporable free water, accompanied by reduced interconnectivity of the capillary pore network [29,57] (Table 4). Thus, in the case of the neat mortar, the hydration process led to the previously observed trend of electrical resistivity (Fig.…”

“…An opposite trend was observed in the case of samples cured for 14 and 28 days, the Rs values being, respectively, 2080 Ω and 4562 Ω, 1528 Ω and 1589 Ω, 2069 Ω and 2610 Ω for the control sample, G2, and G4 (Table 4). This result suggests that the GNP-modified mortars maintained during the hydration time a higher degree of pore interconnectivity with respect to the neat sample, with G2Nan being more efficient than G4Nan [57,58].…”