Electrode polarization, recognition

All derivatives of the benzo-hydroxamic acid inhibited copper corrosion more effectively than BHA itself. The efficiency was affected much more by hydrophobic bulkiness in the phenyl ring than by the electronpushing or electron-attracting character of the substituents. The results attained by electrode impedance spectroscopy and quartz crystal nanobalance techniques led to recognition that the higher efficacy was not due to the inductive effect of the substituents, as both chloro and methyl substitution led to enhanced inhibition. The most important factor is the hydrophobic bulkiness. In the inhibition process, the inhibitor molecule is attached to the copper surface by the polar group (CON"), and the apolar hydro-phobic moiety may block the metal surface... 

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