1
Supplementary Material
Synthesis and inhibition effect of novel Tri-cationic surfactant on
carbon steel corrosion in 0.5 M H2SO4 solution
A.S. El-Tabeia, M.A. Hegazya,*, A. H. Bedairb, M.A. Sadeqb
a
b
Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo, Egypt
Faculty of Science, Al-Azhar Univ., Chemistry Dept., Nasr City, Cairo, Egypt
*
Corresponding author. Tel.: +20 1002653529; fax: +20 222747433.
E-mail address: mohamed_hgazy@yahoo.com (M.A. Hegazy).
2
Caption of figures
Fig. 1: 1HNMR spectrum of N-((pyridin-2-ylamino)(pyridin-3-yl)methyl)pyridin2-amine.
Fig. 2: Mass spectrum of N-((pyridin-2-ylamino)(pyridin-3-yl)methyl)pyridin-2amine.
Fig.
3:
FITR
spectrum
of
2,2'-(((1-dodecylprydinium
bromide)-3-
yl)methylene)bis(azanediyl)bis(1-dodecylprydinium bromide).
Fig.
4:
1
HNMR
spectrum
of
2,2'-(((1-dodecylprydinium
bromide)-3-
yl)methylene)bis(azanediyl)bis(1-dodecylprydinium bromide
Fig. 5. Suggested equivalent circuit model for the studied system.
Fig. 6: Effect of temperature on the inhibition efficiency obtained by weight loss
method for carbon steel in 0.5 M H2SO4 in presence of different
concentrations of the synthesized Tri-cationic surfactant at various
temperatures.
Fig. 7: Langmuir isotherm adsorption model of the synthesized Tri-cationic
surfactant on the carbon steel surface in 0.5 M H2SO4 at different
temperatures.
Fig. 8: The relationship between (ln Kads and 1/T) for carbon steel in different
concentration of the synthesized Tri-cationic surfactant.
3
Fig. 9: Arrhenius plots (ln k vs. 1/T curves) for carbon steel dissolution in absence
and presence of different concentrations of the synthesized Tri-cationic
surfactant in 0.5 M H2SO4 solution.
Fig. 10: Relationship between ln k/T and the reciprocal of the absolute
temperature of carbon steel in different concentration of the synthesized
Tri-cationic surfactant.
4
Relative intensity (%)
Chemical shift (ppm)
Fig. 1
5
Fig. 2
6
Fig. 3
7
Fig. 4
8
Fig. 5
9
100
90
ηw (%)
80
70
60
50
20 °C
40
40 °C
60 °C
30
4.9
4.4
3.9
-log C (M)
Fig. 6
10
3.4
2.9
0.0012
0.0010
C/θ (M)
0.0008
0.0006
0.0004
0.0002
0.0000
0.0000
20 °C
0.0002
0.0004
0.0006
C (M)
Fig. 7
11
40 °C
0.0008
60 °C
0.0010
11.3
ln Kads (M-1)
11.2
11.1
11.0
10.9
10.8
3.0
3.1
3.2
3.3
(1/T)x103 (K-1)
Fig. 8
12
3.4
2.5
ln k (mg cm-2 h-1)
1.5
0.5 H₂SO₄
0.00001M
0.00005M
0.0001M
0.0005M
0.001M
0.5
-0.5
-1.5
-2.5
-3.5
3.0
3.1
3.2
3.3
(1/T) x 103 (K-1)
Fig. 9
13
3.4
-3
ln (k/T) (mg cm-2 h-1 K-1)
-4
0.5 H₂SO₄
0.00001M
0.00005M
0.0001M
0.0005M
0.001M
-5
-6
-7
-8
-9
3.0
3.1
3.2
3.3
3.4
(1/T) x 103 (K-1)
Fig. 10
Table 1
Activation parameters for carbon steel in 0.5 M H2SO4 in the absence and presence of
different concentrations of Tri-cationic surfactant
14
Conc. of inhibitor
Ea
∆H*ads
∆S*ads
M
kJ mol-1
kJ mol-1
J mol-1 K-1
0.00
35.12
32.53
-76.64
1x10-5
28.68
26.09
-102.76
5x10-5
27.77
25.18
-110.27
1x10-4
25.40
22.81
-121.93
5x10-4
25.19
22.60
-129.33
1x10-3
19.59
17.00
-149.71
3. Results and discussion
The chemical structure confirmation of the synthesized Tri- cationic surfactant
N-((pyridine-2-ylamino)(pyridine-3-yl)methyl)pyridine-2-amine
FTIR spectra
FTIR
spectrum
of
N-((pyridin-2-ylamino)(pyridin-3-yl)methyl)pyridin-2-amine
showed the characteristic bands (cm-1) at 3248 (N-H), 3091, 3059, 3022 (py-H), 2925,
2853, (C-H aliphatic), 1605 (C=N).
1HNMR
1
spectra
HNMR spectrum (DMSO – d6) spectrum (Supplementary material, Fig. 1) showed δ,
ppm at : 5.81 (2H, 2C-H) and (24 py-H + 4N-H), 6.3825, 6.5751 (4H , 2d, J=5.04
Hz), 6.40695 (1H, d, J= 5.33 Hz), 6.4933 (2H, t, J= 7.65), 6.912 (1H, t, J=7.65 Hz),
7.18265 (2H, d, J= 7.65 Hz ), 7.3722 – 7.3034 (6H, m), 7.5433 (1H), 7.8055 (2H, d,
J= 8.4 Hz), 7.8444 (1H, d, J=4.55 Hz), 7.8857 (1H), 7.9166 (2H, d, J=5.35 Hz),8.3744
15
(1H, d, J=9.2 Hz), 8.4268, 8.7141 (2H, 2d, J=4.6 Hz), 8.49175 (1H, d, J=3.85), 8.6331
(1H, s).
Mass spectra
Mass
spectrum
of
N-((pyridin-2-ylamino)(pyridin-3-yl)methyl)pyridin-2-amine
(Supplementary material, Fig. 2) showed a molecular ion peak M+2 at m/z 279 (66.64
%), 185 (55.82 %, M-C5H4N2), 171, (48.82 %, M-C5H4N2-CH2).
According to the data FTIR, 1HNMR, Mass spectroscopy, the product is a mixture of
two compounds: N-((pyridin-2-lamino)(pyridin-3-yl)methyl)pyridin-2-amine (major)
and N-((2-iminopyridin-1(2H)-yl)(pyridin-3-yl)methyl)pyridin-2-amine (trace).
2,2'-(((1-dodecylprydinium
bromide)-3-yl)methylene)bis(azanediyl)bis(1-
dodecylprydinium bromide)
FTIR spectra
FTIR
spectrum
of
2,2'-(((1-dodecylprydinium
yl)methylene)bis(azanediyl)bis(1-dodecylprydinium
bromide)
bromide)-3(Supplementary
material, Fig. 3) showed characteristic bands (cm-1) at 2924, 2853, (C-H aliphatic),
1663.30 (C=N+).
1HNMR
spectra
Comparing the
1
HNMR spectrum of 2,2'-(((1-dodecylprydinium bromide)-3-
yl)methylene)bis(azanediyl)bis(1-dodecylprydinium
(Supplementary material, Fig. 4) and
1
bromide)
presented
in
HNMR spectrum of N-((pyridin-2-
ylamino)(pyridin-3-yl)methyl)pyridin-2-amine presented in Fig. 2. Fig. 5 showed the
same peaks in Fig. 2 in addition to other peaks δ, ppm at: 0.8150 (9H, CH3), 1.19 (m,
60H, (CH2)30), 3.3218 (6H, +NCH2).
16
The above data of FTIR and 1HNMR spectra confirmed the proposed structure of the
synthesized Tri-cationic surfactant (2,2'-(((1-dodecylprydinium bromide)-3yl)methylene)bis(azanediyl)bis(1-dodecylprydinium bromide)).
17