1070-4272/01/7409-1500$25.00C2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 9, 2001, pp. 1500!1505. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 9,
2001, pp. 1457!1462.
Original Russian Text Copyright + 2001 by Ekilik, Berezhnaya, Svyataya.
AND CORROSION PROTECTION OF METALS
Acridine Derivatives as Inhibitors of Copper Dissolution
V. V. Ekilik, A. G. Berezhnaya, and M. N. Svyataya
Rostov State University, Rostov-on-Don, Russia
Received December 8, 2001
Abstract-Copper dissolution in an acidified chloride solution containing or not containing some acridine
derivatives and potassium iodide was studied as influenced by the potential, stirring of the solution, time,
Acridines inhibit corrosion and anodic dissolution
of a number of metals, primarily iron  and some
alloys . The influence of these compounds on
particular steps of copper dissolution was not studied.
To study copper dissolution, chronoammograms at
constant potential E and polarization curves at the
potential increasing stepwise were recorded in 1 M
NaCl + 0.01 M HCl solutions purged with purified
argon or neon. Prior to the measurements, a Teflon-
reinforced copper disk electrode with the working
surface area of 0.2 cm
was trimmed at a rotation rate
m = 1050 rpm with an abrasive paper with a grain size
decreasing form 2 to 0, polished with an MgO sus-
pension applied on chamois, and polarized at the
cathodic potential E lower by 200 mV than the corro-
sion potential E
. The measurements were per-
formed on stationary and rotating (m = 2703
1050 rpm) electrodes in a three-electrode cell with
separated catholyte and anolyte. A saturated silver
chloride electrode was used as the reference electrode.
The copper oxidation state n was determined by
coulometry under galvanostatic conditions with con-
trol of E.
10-Methylacridinium iodide (no. 1), acridinium
chloride (no. 2), 9-aminoacridinium chloride (no. 3),
9-aminoacridine (no. 4), and, for comparison, 10
KI (no. 5) were used as inhibitors. In some cases the
concentration dependences were studied.
The inhibitor efficiency was estimated from the
deceleration coefficient K, i.e., the factor by which the
process is decelerated.
Prior to the study of the inhibitor efficiency, let us
consider the kinetics and mechanism of anodic dis-
solution of copper, which appreciably determines the
inhibiting power of the additives. The degree of de-
celeration of hydrogen depolarization also affects
and hence the corrosion resistance of copper.
The anodic polarization curves recorded on a sta-
tionary electrode (Fig. 1) can be separated into several
characteristic sections. Tafel straight lines with an-
gular coefficient b
= 60 mV, observed in the potential
range from 30.2 to 30.1 V, indicate reversible dis-
solution to form Cu
[6, 7]. Then the curves pass
log i [A m
Fig. 1. Polarization curves at (1, 5) 25, (2) 35, (3) 45, and
(4)55oC and a rate of the disk electrode rotation of (134) 0
and (5) 1050 rpm in the solution free from the inhibitors.
(E) Potential and (i) current density.