Electronic Supplementary Material (ESI) for RSC Advances.
This journal is © The Royal Society of Chemistry 2015
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Adsorption behavior of gluten hydrolysate on mild steel in 1M HCl and its
role as a green corrosion inhibitor
Pialee Roy,1 Tarunesh Maji,1 Sukalpa Dey,2 Dipankar Sukul*1
1Department
2Dr
of Chemistry, National Institute of Technology, Durgapur, West Bengal, 713209, India.
B C Roy Engineering College, Durgapur, West Bengal, 713206, India.
* Corresponding author;
E-mail: [email protected]; Tel: +91 9434788066
1
Fig. S1 Equivalent circuit model used to fit the impedance spectra.
2
E vs SCE/V
-0.3
-0.4
323K
-0.5
313K
303K
293K
-0.6
-0.7
-8
-7
-6
-5
-4
-3
log(I/Acm-2)
-2
-1
Fig. S2 Potentiodynamic polarization curves for mild steel in 1 M HCl in presence of 500 ppm
gluten hydrolysate at different temperatures.
3
140
120
-Zimg(cm2)
100
80
60
293K
303K
40
313K
20
0
323K
0
20
40
60
80
2
Zreal(cm )
100
120
140
Fig. S3 Nyquist plots for mild steel in 1 M HCl in presence of 500 ppm gluten hydrolysate at
different temperatures.
4
96
100 ppm
250 ppm
500 ppm
1000 ppm
d
c
b
a
W(%)
94
92
90
88
290
295
300
305 310
T(K)
315
320
325
Fig. S4 Variation of inhibition efficiency (from weight loss method) of gluten hydrolysate with
temperature towards corrosion of mild steel in 1M HCl.
5
log (CR mg cm-2 h-1K-1)
Blank
100 ppm
250 ppm
500 ppm
1000 ppm
-2.0
-2.5
-3.0
-3.5
-4.0
0.0031
0.0032
0.0033
-1
1/T(K )
0.0034
Fig. S5 Arrhenius plots of log (CR/T ) vs. 1/T for mild steel in 1 M HCl without and with
different concentrations of gluten hydrolysate.
6
Table S1 Corrosion parameters from weight loss measurement for mild steel at different
immersion time in 1M HCl.
Temperature (K)
Inhibitor conc. (ppm)
Time (Hour)
CR ((mg cm-2 h-1)
303
BLANK
2
5
24
48
72
2
5
24
48
72
2
5
24
48
72
2.5
1.9
1.263
0.785
0.36
250
1000
0.23
0.19
0.12
0.11
0.103
0.175
0.148
0.093
0.073
0.0727
Inhibition efficiency 𝜂𝑊(%)
90.8
90
90.5
85.9
71.3
93
92.2
92.6
90.6
79.8
7