No abstract

No abstract

International audienceThe effect of quaternary ammonium compounds on the electrodeposition of ZnCo alloys from an alkaline chloride-gluconate electrolyte was studied. A thermodynamic analysis was performed which indicated that Zn(OH)₄^2- should be the predominant zinc species, whereas for cobalt the mixed hydroxy-gluconate complexes CoL₃(OH)₂ and CoL(OH)₂ are expected to be prevalent. The electrodeposition of the alloy from this alkaline medium was found to be anomalous, but increasing the cobalt content in the bath caused the cobalt content in the deposit to increase. The effects of three quaternary ammonium compounds, N-benzyl-3-carboxylpyridinium chloride (3NCP), N-benzyl-triethylammonium chloride, and tetraethylammonium hydroxide, on the electrochemical behavior of ZnCo deposition were studied. The incorporation of these additives in the electrolytes modified the composition, morphology, and crystallographic structure of the ZnCo-alloy deposits. Cyclic voltammetry indicated the formation of several alloy phases as cobalt was added to these zinc baths. 3NCP had the greatest impact on the process, limiting the Co content and changing the structure of the deposit

No abstract

Key Comparison CCQM-K36.2016 was a follow-up comparison for K36 and provided updated support for the corresponding calibration and measurement capability (CMC) entries in the BIPM CMC database. It aimed to demonstrate the capabilities of the participating NMIs to measure electrolytic conductivity of aqueous electrolyte solutions in the conductivity range 0.15 S m−1 to 1.5 S m−1 and in the conductivity range 1.5 mS m−1 to 15 mS m−1. To this end electrolytic conductivity of a potassium chloride solution (nominal conductivity 0.5 S m−1) and of a HCl solution (nominal conductivity 5 mS m−1) had to be measured. 17 NMIs participated in the comparison. The key comparison reference value (KCRV) of the KCl solution was (0.50999 +/-0.00032) S m−1 and the KCRV of the HCl solution was (4.9877 +/-0.012) mS m−1. Both values were estimated from the medians of the results considered eligible for KCRV calculation. They were given with their expanded uncertainties (95% coverage). The majority of the 0.5 S m-1 results were consistent with the KCRV. Two institutes showed a small inconsistency, one outlier was observed. The conductivity of the HCl solution showed a small, but steady linear drift of 0.00006843 mS m−1 per day during the measurement period and was corrected for KCRV calculation. Some institutes reported unstable measurement conditions for this solution. The results of seven participants have been inconsistent with the KCRV. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).