Codeposition of copper and tin from acidic sulfate solutions containing polyethylene glycols. Effect of length of the hydrocarbon chain |
| |
Authors: | Arvydas Survila Dalia Bražinskienė Stasė Kanapeckaitė Zenius Mockus Vitalija Jasulaitienė |
| |
Institution: | (1) Institute of Chemistry, A. Goštauto 9, 01108 Vilnius, Lithuania |
| |
Abstract: | Voltammetry and electrochemical impedance spectroscopy technique were applied to study the effect of polyethylene glycols
(PEG) with different molecular mass on Cu(II) and Sn(II) reduction kinetics in acidic sulfate solutions. Tetraethylene glycol
was found to be the surface-active oligomer on both Cu and Sn substrates that holds the shortest (–CH2–CH2–O–)m chain. The exchange current density of the rate-limiting step Cu2+ + e → Cu+ falls drastically with an increase in the molecular mass of PEG. An addition of PEG into halide-free Sn(II) solutions results
in the significant inhibition of Sn(II) reduction in the entire range of cathodic polarizations including the region of limiting
current. Inhibition degree also increases with PEG molecular mass. In contrast with Cu|Cu(II) system, formation of adsorption
layers on Sn electrodes proceeds significantly slower. Underpotential deposition of Sn(II) is observed in the region of Cu(II)-limiting
current. The characteristic current minimum arises in the region where free Sn phase is thermodynamically stable. It deepens
with the length of the hydrocarbon chain of PEG. The fall of current density seems to arise from the inhibitive PEG adsorption
on tin atoms that are still not incorporated into general Cu–Sn lattice. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |