Abstract This work investigates the effect of the addition of glycerol on the microstructure, corrosion resistance, and efficiency of the electrodeposition process of Cu coating in an acid sulphate solution. The morphology and microstructures of electrodeposits were analyzed using Scanning Electron Microscopy (SEM), Spectrometry X-Ray Diffraction (XRD) and laser scanning confocal microscopy (LSCM). Evaluation of the corrosion resistance was performed in 2.0 mol⋅L−1 NaCl by means of weight loss tests and electrochemical techniques. The addition of glycerol resulted in a decrease in grain and crystallite sizes, a decrease in roughness and an increase in the tensile strain of the coating. The deposition efficiency and the corrosion resistance increased with the addition of glycerol exhibiting a maximum value at the concentration of 0.42 mol⋅L−1, increasing the efficiency of electrodeposition by approximately 96%. This is related to the roughness of the coating, which is minimal at this concentration.

Abstract Core/shell structures of carbon-based materials/ metal oxide have been considered as potential candidates for electrochemical devices due to their improved pseudocapacitance/electrical double layer capacitance and high conductivity/ superior surface area. The development of multiple core-shell structures of MWCNT@MnO2@PPy was analyzed as a standard procedure for mass production of supercapacitor electrodes. The relative concentration of carbon nanotubes in the composite was varied to optimize the double layer capacitance contribution in overall response of device. Resulting structures presented capacitance in order of 272.7 Fg-1 and reasonable cycling performance.

It is shown that conductivity and molar volume in binary rubidium and cesium silicate glasses, both measured at room temperature, obey a common cubic scaling relation due to increase in alkali content. The drastic drop in conductivity up to 15 orders of magnitude for so many ion-conducting binary alkali silicate glasses (in wide composition range) is mainly caused by the structure and the ion content. In particular, it is suggested that the glass network expansion, which is related to the available free volume, is a parameter that could explain the increase in ionic conductivity for these binary systems.

The main objective of this work is to present an analysis and brief discussion of experimental ionic conductivity s data in the binary alkali tellurite system, including on 47 glasses that extend the ionic conductivity range by more than 14 orders of magnitude in a wide compositional range. A 'universal' behavior is obtained, using log sigma or log sigmaT vs. E A/kB T, where E A is the activation enthalpy for conduction, kB is the Boltzmann constant and T is the absolute temperature. This finding further indicates the importance of a scaling factor F recently proposed, that is correlated to the free volume of glass composition. For a given value of E A/kB T, the difference between large and small values of sigma is only one order of magnitude in 87% of these glass systems. The influence of alkali content and temperature was minor on the pre-exponential terms, considering both expressions log10sigma and log10sigmaT. Indeed, the pre-exponential term sigma0 varies around an average value of 50 omega-1cm-1 considering different compositions in this system. The fact that s lies on these single 'universal' curves for so many ion-conducting binary tellurite glasses means that sigma is governed mainly by E A. The composition dependence of the activation enthalpy is explained in the context of the Anderson-Stuart theory.

An analysis and brief discussion of experimental ionic conductivity sigma and activation energy E A in the binary rubidium and cesium silicate systems is presented, exemplified on 23 and 30 glasses respectively, in a wide composition range (5-45 Rb2O and Cs2O mole%). The Anderson and Stuart model has been considered to describe the variation of activation energy E A with alkali concentration in both alkali-silica systems. In this analysis were considered experimental parameters, like shear modulus G and relative dielectric permittivity epsilon. An "universal" finding is obtained using logsigma× E A/kB T in 51 of 53 glasses considering both alkali systems, where E A is the activation energy for conduction, kB is the Boltzmann constant and T is the absolute temperature. This strong correlation by more than 13 (Rb-based glasses) and 15 (Cs-based glasses) orders of magnitude means that sigma is governed mainly by E A. An explanation for this behavior links ionic conductivity and microscopic structure.