Study On Electrodeposition Poly-8-hydroxyquinoline And Its Composite Film On Nickel Substrate And Its Performances

:The anticorrosion technology of electrodeposited nickel substrate was researched in this paper. By the methods of cyclic voltammetry and constant potential,8-hydroxyquinoline was electro-polymerization at the surface of electrodeposited nickel substrate and formed a bright, smooth, pale yellow film, which achieved perfect preservative effect. The optimal process conditions, obtained by single factor experiments under various conditions, are as follows:the best condition of cyclic voltammetry method to synthesize corrosion-resistance polymer film is:the concentration of8hydroxyquinoline is0.002mol/L, sodium hydroxide is0.4mol/L, the scan rate is30mv/s, and scan8laps; the best condition of constant potential method to synthesize corrosion-resistance polymer film is:the deposition potential is0.5V, the concentration of8-hydroxyquinoline is0.002mol/L, sodium hydroxide is0.4mol/L, deposition time is500s. Further study showed that the addition of phenol in the monomer solution can improve the preservative effect of films, the optimal process conditions are as follows:the best condition of cyclic voltammetry method to synthesize poly phenol and ploy-8-hydroxyquinoline is: concentration ratio of8-hydroxyquinoline and phenol is1:30, concentration of the monomer solution is0.021mol/L, NaOH concentration is0.8mol/L, the scan rate is100mv/s, and scan6laps; the best condition of constant potential method to synthesize poly phenol and ploy-8-hydroxyquinoline is:the deposition potential is0.3V, concentration ratio of8-hydroxyquinoline and phenol is3:1, monomer concentration is0.020mol/L, NaOH concentration is0.8mol/L deposition time is500s.Soaked in brine for weeks experiments, consistent with the results of ferric chloride slit experiment and Tafel polarization curves, and they all show constant potential deposition method better than cyclic voltammetry under the same conditions, and the composite films of poly phenols and poly-8-hydroxyquinoline were superior to poly8-hydroxyquinoline. We calculated the formula of composite films, which was (C9H5NO) m (C6H4O) n, m:n=28. Optical microscopy and scanning electron microscopy have shown that composite films have a good coverage in the surface film formation. The mechanism of film forming was deduced through the analysis of the infrared spectrum. Electrochemical impedance spectrum shows that composite films greatly extend the corrosion process during the formation of the electric double layer, and thus play a preservative effect.