Determination of the surface of dendritic electrolytic zinc powders and evaluation of its fractal dimension

Resumo

The area of dendritic deposits of zinc deposits prepared by electrolysis from zincate electrolyte, which contained 0.3 mol/dm³ ZnO and 4 mol/dm³ NaOH, is determined. The application of electrochemical methods has made it possible to measure the in situ surface without removing the dendrite deposit from the cathode. The specific deposit surface found using chronopotentiometry is 0.144 ± 0.002 m²/g, while according to the result of impedance spectroscopy it is 11.61 ± 0.14 m²/g. The surface of powders prepared from dendrite deposits is 21.26 ± 0.62 m² according to the data of the BET method. It is shown that the difference in these values is associated with the resolving ability of methods applied. It is established that the surface of dendritic deposits possesses fractal properties. The fractal dimension of the specific surface is calculated and the results of measurements performed by different methods are compared using the scaling relationship.