Effect of Polyethylene Glycol 12000 on Morphology and Corrosion Behavior of TiO(OH)(2)/MnO2/PEG(12000) Composite Electrodeposited on Pure Copper

In this study, TiO(OH)(2)/MnO2/PEG(12000) composite was elaborated on pure copper in a two-step deposition process in the presence of 1% w/v of polyethylene glycol 12000 (PEG(12000)). The influence of PEG(12000) on the composite morphology, composition and surface roughness was studied by SEM-EDS and AFM techniques. The results show that a porous composite of a multilayer structure with PEG(12000) dispersed spherical particles was synthesized. Though the roughness homogeneity of TiO(OH)(2)/MnO2/PEG(12000) was slightly improved, carbon content ranges from 5 to 12 At% reflecting an adsorption process of PEG(12000) during the composite deposition. Results were confirmed by XPS technique, which provides further evidence about the existence of PEG(12000). High-resolution C1s and O1s signals affirm the presence of the characteristic C-O bond, resulting from the coupling of PEG(12000) on the composite surface. The electrochemical corrosion was evaluated in chloride medium by OCP measurements and linear polarisation curves. It was found that the corrosion resistance of TiO(OH)(2)/MnO2 composite was improved markedly in the presence of PEG(12000). The stability of TiO(OH)(2)/MnO2/PEG(12000) composite was also studied by following the evolution of impedance parameters during immersion time in 0.05 M NaCl medium completed by a characterization of the composite morphology and composition at the end of immersion by SEM-EDS and XPS analysis. The composite indicates good stability due to the formation of PEG-CuCl complexes, capable of limiting the infiltration of Cl- ions in both the composite and the substrate surfaces.