Potential decay curves

FIGURE 12.11 Potential decay curves recorded after switching off the current (a) at short times (b) at long times. 

Integrating this equation between the limits of f = 0 and t, taking into account that at f = 0 the potential E = E, and performing simple transformations, we obtain an equation for the potential decay curve ... 

Fig. 14. Coulostatic potential decay curve for a copper electrode in an electroless copper plating bath (M. Suzuki et al., 1982 [22]).

Suzuki et al. [22] demonstrated that this method may be used to measure the plating rate of electroless nickel and copper plating processes. An example of a potential decay curve is shown in Fig. 14. The authors also demonstrated the validity of Eq. (25) and determined the K values of various plating systems. 

Schematic representation of several forms of anodic polarization curves and associated potential decay curves following release of potentiostatic control...

Fig. 3 Surface potential decay curves at 90 °C of i-PP films containing different concentrations of Irganox 1010 top) and Irgafos 168 (bottom)...

In Fig. 27, the surface potential decay curves of positively charged PPE/PS blend films with three different compositions are presented as a function of the annealing time at 90 °C and compared to neat PS and PPE films. Two blends with 50 wt% PS and 75 wt% PS show a significantly improved electret behavior in comparison to neat PPE. Particularly, the PPE/PS blend 75/25 is capable of maintaining 98%... 

Fig. 12. Temperature surface potential decay curves after negative corona charge.

Fig. 16. Isothermal surface potential decay curves for porous and solid PP films at room temperature (A, , negative charged, A,D,o positive charged).

Figure 8 - Electrode Potential Decay Curves of the SCA and the General Zone Anodes after 30 Minutes of Oxygen Evolution Reaction at 45 mA/cm in Zinc Electrolyte at 38°C and with...

Figure 6.15. Potential decay curves for nickel-copper and nickel-copper-zinc alloys in 1A/ H2SO4, 25°C (two time scales). Pure copper behaves like Alloy D [36].

To estimate the possible concentration limits for adsorbed chlorine, we determined the electrode capacity from the potential decay curves. Similar measurements were made by Stender and Ksenzhek[315] for porous graphite anodes. They found that the true capacity of a unit graphite surface is close to that of a double layer in order of magnitude. 

If in the potential range corresponding to the polarization curve the concentration of adsorbed azide radicals depended strongly on the potential (as was assumed by Thomas), we should observe high pseudocapacitance of the order of iUUO jjF cm on the curves for potential decay after the current has been switched off (this value of capacitance is obtained for the linear part of the charging curve presented in [371]). Actually, however, the capacity calculated from the slope of the initial section of the potential decay curve for T = 0 turned out to be equal to 70 )jF per square centimeter of the visible surface. 

The potential decay curves in (p vs. log t coordinates are straight lines for a sufficiently long time. The slopes of these straight lines virtually coincide with the slope of polarization curves. This means that when measurement for polarization curves are made slowly, the state of the electrode surface remains the same as in the case of a rapid potential decay. The logarithmic region of the potential decay curve gives a capacity value equal to 95 ... 

In order of magnitude, the value of capacity observed by us corresponds to the double layer capacity. The double layer capacity obtained from adsorption measurements for platinum in this potential range is equal to 70 pF cm [374]. A small divergence in the capacity values obtained from the initial and logarithmic sections of the potential decay curves is apparently associated with a slow establishment of adsorption equilibrium for anions. 

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