Experimental and Theoretical Studies on the Corrosion ...

Research ArticleExperimental and Theoretical Studies on the CorrosionInhibition of Brass in Hydrochloric Acid byN-(4-((4-Benzhydryl Piperazin-1-yl) Methyl Carbamoyl)Phenyl) Furan-2-Carboxamide

N Zulfareen 1 T Venugopal2 and K Kannan2

1Department of Chemistry Mahendra Engineering College Namakkal 637503 India2Department of Chemistry Government College of Engineering Salem 636011 India

Correspondence should be addressed to N Zulfareen fareenshagmailcom

Received 30 January 2018 Accepted 15 May 2018 Published 2 July 2018

Academic Editor Flavio Deflorian

Copyright copy 2018 N Zulfareen et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The corrosion inhibition effect of N-(4-((4-Benzhydryl piperazin-1-yl) methyl Carbamoyl) Phenyl) Furan-2-Carboxamide (BFC)on brass in 1M HCl has been investigated using weight loss method potentiodynamic polarization electrochemical impedancespectroscopy (EIS) and cyclic voltammetry (CV) The result reveals that BFC acts as a mixed type corrosion inhibitor with morepronounced effect on anodic domain and the inhibition efficiency of BFC increases with increase in temperature ranges from 30∘Cto 60∘C AC impedance implies that Rct value of BFC increases with increase in concentration CV indicates that the addition ofinhibitor controls the oxidation of the copper on the brass metalThe structural confirmation of BFCwas carried out by the spectralstudies like FT-IR 1HNMR 13CNMR and the molecular weight was confirmed by LC-MS Surface characterization of brass withBFC was analysed using scanning electron microscope (SEM) Quantum chemical parameter was used to calculate the electronicproperties of BFC in order to confirm the correlation between the inhibitor effect and molecular structure of BFC BFC has morenegative charge on nitrogen and oxygen atom which facilitates the adsorption of BFC on the surface of brass

1 Introduction

Copper and its alloys are one of the most important nonfer-rous materials having a wide range of applications in indus-tries due to its electrical conductivity thermal conductivityease of fabrication resistance to biofouling and mechanicalproperties Copper and copper based resources are intention-ally or unintentionally exposed to acid solutions Howevercopper and its alloys are corrosion resistance towards theatmosphere and many chemicals due to the formation ofcuprous oxide layer when exposed to the atmosphere Theyare susceptible to corrosion problems in acidmedium such asdezincification and pitting corrosion [1]

The most important method for corrosion protection isby the addition of organic inhibitors on the brass Manyof the inhibitors are organic compounds containing nitro-gen oxygen sulphur Phosphorous and aromatic rings that

cause adsorption on the metal surface [2] Nowadays thesynthesized Mannich base compounds have been of interestin order to obtain efficient corrosion inhibitors since theyprovide much greater inhibition efficiency compared tocorresponding amines and aldehydes The presence of C=Ngroup in Mannich base enhances the adsorption ability andinhibition efficiency

The present work reports on the anticorrosive behaviourof a Mannich base namely N-(4-((4-Benzhydrylpiperazin-1-yl) methyl Carbamoyl) Phenyl) Furan-2-Carboxamide (BFC)for brass in hydrochloric acid solution The kinetics of disso-lution and dezincification mechanism of brass in hydrochlo-ric acid solution was investigated using electrochemicalstudies For this purpose electrochemical technique suchas potentiodynamic polarization electrochemical impedancespectroscopy (EIS) and cyclic voltammetry in the presenceand absence of BFC were studied [3]

HindawiInternational Journal of CorrosionVolume 2018 Article ID 9372804 18 pageshttpsdoiorg10115520189372804

2 International Journal of Corrosion

O

4 Amino benzamide

O O

Cl

2 Furoyl chloride

O

O

NH

O

N-(4-Carbamoylphenyl)Furan-2-Carboxamide

+

MDC THF

RT 24 hrs（2

（2 （2

Figure 1 Synthesis of CFC

(a) FT-IR spectrum of CFC (b) 13C spectrum of CFC

(c) 1H spectrum of CFC (d) LC-MS spectrum of CFC

Figure 2

It is also aimed to study the quantumchemical parametersand thermodynamic feasibility of the inhibitor using the sur-face coverage of brassThe interaction of inhibitor (BFC) wascorrelated with coefficient of their molecular orbitals highestoccupied molecular orbital (HOMO) lowest unoccupiedmolecular orbital (LUMO) energy difference (ΔE) betweenEHOMO and ELUMO atomic charges and dipole momentsThecoordination of ligand to the surface of metal was confirmedby FT-IRThe characterization of BFCwas further confirmedby NMR and LC-MS

2 Experiment

21 Synthesis of CFC N-(4-Carbamoylphenyl)Furan-2-Carboxamide (CFC) was prepared by a procedure similar tothat reported in the literature 4-Amino benzamide (300g

00220 mol) and 2-furoyl chloride (3428 g 00264 mol)were dissolved in mixture of MDC (70 ml) and THF (25 ml)Triethylamine (777g) was added and the mixture was stirredin the presence of nitrogen atmosphere for 24 hours Thereaction mixture was washed with water filtered and driedover high vacuum pump The CFC was characterized byspectral techniques like FT-IR NMR and LC-MS Figure 1represents the synthesis of CFC

22 Characterization of CFC Yeild 93white solidmp186-190∘C IR (KBr ]max cmminus1 3387 3179(NH St Amide) 1658(C=O) 1617 (NH Bend Amide) 1400 (CN Amide) 14741527 (C=C) 1179 (C-O furan) 841 (CH Aroop) 1H NMR(400 MHz DMSO-d6) d(ppm) 671(1H Furan) 736 (1Hfuran) 780-784 (4H) 785-787 (2H Amide) 795 (1H furan)1036 (1H Amide) 13CNMR (400MHz DMSO-d6) d(ppm)

International Journal of Corrosion 3

O

O

NH

O


N

NH

Benzhydryl piperazine

+ +

N

N NHO

O

NH

O

N-(4-((4-benzhydrylpiperazin-1-yl)methylcarbamoyl)phenyl)furan-2-carboxamide

HCHO

Ethanol

Formaldehyde

（2

（2

90∘C 48 hrs

Figure 3 Synthesis of BFC

120575 1121 1150 1192 1281 1291 1411 1450 1472 1562(C=O)1673 (C=O)MS (EI)mz ()= 23102 Figures 2(a) 2(b) 2(c)and 2(d) represent the FT-IR 13C 1H and LC-MS of CFCrespectively

23 Synthesis of BFC The mixture of CFC (00130 mol 3 g)benzhydryl piperazine (00130 mol 11363 g) and formalde-hyde (001956 mol 0587 g) were dissolved in ethanolThereaction mixture was refluxed for 48 hrs at 90∘C The whitesolid obtained was filtered washed with cold ethanol andfollowed by petroleum ether The resulting mass is dried andrecrystallized from ethanol [4]TheBFCwas characterized byspectral techniques like FT-IR NMR and LC-MS Figure 3represents the synthesis of BFC

24 Characterization of BFC Yield 90 white solidmp190-198∘C IR (KBr ]max cmminus1 3265 (NH) 3058 3029(CH Ar) 2942 2808 2757 2698 (CH Aliph) 1663 (C=O)1591 (NH bend) 1534 1472 (C=C) 1335 (C-N amide) 1188(C-O furan) 1138 (C-O) 1027 (C-N Amine) 841 (CH Aroop) 1H NMR (300 MHz CDCl3) d(ppm) 246 (4H) 271(4H) 424 (s 1H) 435 (d 2H J=6 HZ) 659-663(m 2H)715-720 (m 2H) 724-731 (m 5H) 743(d 4H J=84 HZ)755-756(m 1H) 777 (d2H J=87 HZ) 785 (d 2H J=87HZ) 823 (s 1H) 13C NMR (300 MHz CDCl3) d(ppm)120575 MS (EI) mz () = 49444 Figures 4(a) 4(b) 4(c) and

4(d) represent the FT-IR 13C 1H and LC-MS of CFCrespectively

25 Medium The standard solution of 1M hydrochloric acidwas prepared using double distilled water The concentrationof the inhibitor BFC ranges from 020 mM to 161 mM in 1Mhydrochloric acid All the solutions were prepared in doubledistilled water

26 Brass Sample The chemical composition of workingelectrode brass electrode [Cu (6066) Zn (3658) Sn(102) and Fe (174) was used in rectangular form havingdimension of 30 cm length and width 02 cm thicknesswith an exposed area of 76 cm2 for weight loss methodThe specimen was mechanically ground with 320 400 600800 1000 and 1200 emery paper washed in acetone and bi-distilled water then dried and placed in a cell

27 NMR Analysis NMR and 13C NMR spectrum of theMannich bases BFCwere recorded on a BrukerAC 300 F (300and 400 MHz) NMR spectrometer using CDCl3 DMSO assolvents and TMS as an internal standard

28 Weight Loss Measurements Weight loss experimentswere carried out according to the method described pre-viously [5] Weight loss measurements were performed byimmersing the brass coupons in 100 ml of 1M HCl solution


40000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400000

5101520253035404550556065707580859095

1000

T 326523

305843

302927294237

288088

280824

275798

269824

236586194700

189780

181104

166387

159186153485

147272145019

141726

137170

133569

129465

118898

113876

107616104284102734

100267

96709

92590

84192

78195

74600

70337

6227252642

4753943028

Wavelength (＝Ｇ-1)

(a) FT-IR spectrum of BFC

(b) 13C spectrum of BFC (c) 1H spectrum of BFC

(d) LC-MS spectrum of BFC

Figure 4

with and without various amounts of inhibitor for 2 hours byvarying the temperatures range from 30∘C to 60∘C After theelapsed time the specimens were taken out washed driedand weighed accurately Triplicate test was performed forboth blank and inhibitor and the average valueswere reportedwith standard deviation The inhibition efficiency (IE) andsurface coverage (120579) was determined by the following

IE (or) 120578 = W0 minusW1W0

times 100 (1)

120579 = W0 minusW1W0

(2)

where W1 and W0 are the weight loss values in the presenceand absence of inhibitor

29 Electrochemical Measurement A three-electrode systemconsisting of brass coupons of 10 cm2 area exposed as work-ing electrode (WE) platinum sheet as a counterelectrode(CE) and saturated calomel electrode (SCE) as a referenceelectrode was used for electrochemical measurements The


entire test was performed in atmospheric condition withoutstirring Experiments were carried out in ElectrochemicalWorkstationModel 608 DE Series in 1MHCl in the presenceand absence of inhibitor Prior to the electrochemical mea-surements a stabilization period of 30 minutes was allowedwhich is enough to attain stable Ecorr value Potentiodynamicpolarization measurement was performed with the potentialrange of plusmn200 mV and the scan rate is 10 mV sminus1 Theinhibition efficiency (IE) and corrosion rate (CR) werecalculated by using the following

IE (or) 120578 = [1ndash( i1015840corricorr

)] times 100 (3)

CR (mmpy) = 3270 timesM times icorr120588 times Z (4)

where i1015840corr and icorr are the corrosion current density ofbrass in the absence and presence of BFC M is atomic massof metal 120588 is density of corroding metal and Z is number ofelectrons transferred per metal atom (Z=2) [6]

After polarization measurements electrochemicalimpedance was carried out by varying the frequency from100 MHz to 100 KHz [7] The following equation is usedto calculate inhibition efficiency (120578) and double layercapacitance (Cdl) of BFC was calculated by

(120578) = Rict 1 minus R0ct 1Ri

ct 1(5)

Cdl = 12 times 314 times fmax times Rct (6)

where R0ct 1 and Rict 1 are charge transfer resistance in the

absence and presence of BFC fmax is the frequency and Rctare the charge transfer resistance

210 DFT Study Quantum chemical calculations were per-formed using DFT method and the structural parame-ters were geometrically optimized using functional hybridRB3LYP with electron basis set 6-311G (dp) for the atomsAll the calculations were performed with Gaussian 09 Thequantum chemical parameters like EHOMO ELUMO energygap (ΔE= ELUMO - EHOMO) dipole moment (120583) absoluteelectronegativity (120594) global hardness (120578) global softness (120590)and Mulliken charge were calculated

3 Results and Discussion

31 Weight Loss Method Table 1 indicates the effect of con-centration of BFC on the corrosion of brass in 1M HCl Fromthe table the inhibition efficiency (IE) of BFC increases withan increase in the concentration of inhibitor and temperature[8] The maximum inhibition efficiency obtained by thismethodwas found to be 7737 at a concentration of 141mMand further increase in the concentration and temperatureof inhibitor (161 to 201 mM 60∘C) did not cause anyappreciable change in the efficiency of BFCThis is due to thesurface blocking effect of inhibitor on themetal by adsorptionand film formation mechanism and also due to the presence

of protonated nitrogen and the oxygen atom of BFC Thepresence of nitrogen and oxygen atompresent in BFC absorbsquickly on the metal surface with formation of an insolublestable film this makes the inhibitor more effective

32 Tafel PolarizationMeasurements Figures 5(a) 5(b) 5(c)and 5(d) indicate the potentiodynamic polarization curvesfor the brass electrode in 1M HCl solution with and withoutdifferent concentrations of BFC at 60∘C 50∘C 40∘C and30∘C It was clear that the current density decreases with thepresence of BFCwhich indicates that inhibitor is adsorbed onthe surface of metal The values of corrosion potential (Ecorr)and corrosion current density (icorr) are obtained by Tafelextrapolation method anodic (ba) and cathodic (bc) Thesepolarization curves indicate that there is a clear reduction ofboth anodic and cathodic currents in the presence of BFCcompared with Blank solution

The rate of corrosion for brass decreases as the concen-tration of BFC increases with respect to temperature Thepresence of inhibitor decreases the rate of corrosion andicorr prominently with an increase in the concentration ofinhibitor related to a shift of corrosion potential (Ecorr) tomore positive [9ndash11]

Further the inhibition efficiency of BFC increases withan increase in concentration and temperature It is due tophysisorption of BFC molecule adsorbed at low temperatureon brass surface which is altered to chemisorptions at highertemperature The maximum inhibition efficiency of BFC wasfound to be 8679 in 141 mM at 60∘C

The corrosion kinetic parameters like corrosion potential(Ecorr) corrosion current density (icorr) and anodic (ba)and cathodic (bc) slopes in the presence and absence ofinhibitor obtained from polarization curves were summa-rized in Table 2 The corrosion current density (icorr) is morecompared with the inhibitor because in HCl there is noinhibitor to cover brass surface Hence dissolution of metaloccurs on the surface of brass The presence of inhibitorminimizes the acid attack due to the formation of compactand coherent layer on the surface of copper The additionof inhibitor manifests the shift Ecorr to a positive directionwhich suppresses hydrogen evolution and metal dissolutionreaction [12]

Many researchers discussed about the corrosion potentialof inhibitor if the potential shift exceeds with plusmn85mV withrespect to the potential of uninhibited solution the inhibitoracts as either anodic or cathodic type in addition to thatEcorr vary within plusmn50mV and then the inhibitor is mixed typeinhibitor In this present study BFC acts as a mixed typeinhibitor and undergoes both cathodic reaction (hydrogenevolution) and anodic reaction (metal dissolution) [13]Therewas no definite trend observed for cathodic Tafel slope andanodic Tafel slope indicates that BFC was first adsorbed onthe surface and impeded by merely blocking the reactionsites of the metal without affecting the reaction mechanism[14 15] The result obtained from polarization technique wasin good agreement with conventional weight loss method

33 Electrochemical Impedance Spectroscopy Nyquist plot ofbrass in 1M HCl solution in the absence and presence of


Table 1 Weight loss measurements of brass in IM HCl with BFC from 30∘C to 60∘C

SNo Temp (∘C) Con of inhibitor (mM) Corrosion rate (mmpy) Surface coverage(120579) Inhibition efficiency (IE)1 30∘C Blank 35781 - -

020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737

different concentration of BFC at 60∘C 50∘C 40∘C and30∘C was shown in Figures 6(a) 6(b) 6(c) and 6(d) TheNyquist plot consists of a large capacitive loop at highfrequency followed by a small inductive loop at low frequencyvalue The high frequency capacitive loop is due to chargetransfer resistance of the corrosion process and electricaldouble layer [16] At lower frequency the loop is attributedto the relaxation process of the adsorbed intermediates bycontrolling the anodic process [17]The impedance spectra ofBFC were deviated from perfect semicircle due to frequencydispersion effect as a result of roughness and in-homogeneityon themetal surface [18 19] Furthermore the diameter of thecapacitive loop in presence of BFC is higher than in HCl andits magnitude is a function of the inhibitor concentration

The values of charge transfer resistance (Rct) and doublelayer capacitance (Cdl) obtained from the Nyquist plot andthe calculated inhibition efficiency value were reported inTable 3 From the table it is obvious that the value of Cdldecreases as the concentration of inhibitor increases Thedecrease in Cdl value is due to increase in local dielectricconstant and increase in electrical double layer suggestingthat the inhibitor undergoes adsorption by forming a pro-tective layer on the metal surface with dissolution [20 21]The maximum inhibition efficiency of BFC was found to be9107 at 60∘C for 141 Mm of BFC

To fit the experimental impedance data of brass a simpleRandlersquos equivalent circuit was shown in Figure 6(e) in theabsence and presence of BFC In Figure 6(e) (Rs) is solution


Table 2 Tafel polarization parameters for brass in 1M HCl with BFC from 30∘C to 60∘C

SNo Temp (∘C) Conc of inhibitor (mM) Ecorr (VSCE) -ba (mV decminus1) -bc (mV decminus1) icorr (mA cmminus2) IE1 30∘C Blank -0483 685 678 3846 -

020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679

resistance (Rct1) is charge transfer resistance with porousstructure on brass surface (Rct2) is charge transfer resistancewith adsorption of inhibitor on brass surface and it acts as aresistor (W) is Warburg impedance (CPE1) is first constantphase element and (CPE2) is second constant phase elementIn this Randlersquos equivalent circuit (CPE) is used instead of apure capacitor owing the frequency dispersion of semicircle

The rough solid electrode a constant phase element and(ZCPE) were described by the following

(ZCPE) = Y0minus1 (i120596)ndashn (7)

where Y0 is a proportionality factor 120596 is the angularfrequency and n is the CPE exponent whose value liesbetween 0 and 1 and it is used as a gauge of in-homogeneity orroughness on the brass surface The n-values of first constantphase element (CPE 1) lie between 047 to 076 representingdouble layer capacitanceAddition of inhibitor increases the n

value thereby decreasing the CPEThe second constant phaseelement (CPE 2) is nearly Warburg impedance [22]

34 Cyclic Voltammetry Measurements The mechanism ofcopper corrosion in HCl solution has been studied by manyresearchers and the main reaction that can take place in theacidic medium is given as follows [23 24]

Cu(s) + Clminus(aq) 999445999468 CuCl(aq) + e (8)

CuCl(aq) + Clminus(aq) 999445999468 CuCl2minus(aq) (9)

CuCl2minus(aq) 999445999468 Cu2+(aq) + 2Clminus(aq) + eminus (10)

2CuCl2minus(aq) + 2OHminus(l)997888rarr Cu2O(s) + 4Clminus(aq) +H2O(aq)

(11)


(a) Potentiodynamic polarization curves of BFC for brass in 1MHCl at 60∘C (b) Potentiodynamic polarization curves of BFC for brass in 1M HCl at50∘C

(c) Potentiodynamic polarization curves of BFC for brass in 1MHCl at 40∘C (d) Potentiodynamic polarization curves of BFC for brass in 1M HCl at30∘C

Figure 5

Cu2O(s) + 12O2(aq) + Clminus(aq) + 2H2O(aq)

997888rarr Cu2 (OH)3 +OHminus(12)

In this mechanism CuCl(aq) is adsorbed on the surface ofcopper electrode In acidic medium the presence of CuCl(aq)layer is destroyed and the rate of corrosion is more In pres-ence of inhibitor theCuCl(aq) layer adsorption is strongwhichis formed on the surface of copper acts as protective layerthereby preventing the oxidation of copper The dissolutionof CuCl2

minus(aq) takes place from CuCl(aq) occurring according

to (10) Further there is an opportunity of oxidation reaction(11) and (12)

The cyclic voltammogram for brass in 1M HCl in theabsence and presence of inhibitor was shown in Figures 7(a)7(b) 7(c) and 7(d) at 60∘C 50∘C 40∘C and 30∘C It wasobserved that bare brass shows an oxidation peaks at theforward scan of 0289V (SCE) The formation of oxidationpeak is due to the Cu2+ or due to the formation of an insolubleCu2O or due to hydroxychloride reactions from (9)-(12) Inreverse sweep also there is a reduction peak occurring at-0468V (SCE) which is due to the reduction of Cu2+ andinsoluble Cu2O layer formed during the oxidation process

The cyclic voltammogram as shown in Figures showsthe effect of the addition of various concentrations of theinhibitor It is interesting to note that two main changes haveoccurred with the addition of the inhibitor First one exhibitsonly one peak for brass in both forward and reverse sweepat around -012V(SCE) for the forward scan and +0214 forthe reverse sweep The reduction in the Volt is attributed toadsorption of the inhibitor on the brass surface The secondchange is the reduction of the oxidation and reduction peakwhich diminishes drastically with the addition of the inhibi-tor This observation indicates that the inhibitor added tothe solution is adsorbed on the brass surface effectively andreduces the oxidation of the copper in the brass

By comparing the cyclic voltammogram of brass andBFC modified brass the addition of inhibitor diminishesthe oxidation and reduction peak drastically and there areshifts of peak potential from positive to negative directionrespectively These observations reveal that the addition ofinhibitor is adsorbed on the surface of brass effectively andreduces the oxidation of the copper in the brass

The cyclic voltammogram of brass and various concen-trations of the inhibitor was carried out at the voltage rangeof -12V to 1V and scan rate was 005V These range was fixed


(a) AC impedance curves of BFC for brass in 1M HCl at 60∘C (b) AC impedance curves of BFC for brass in 1M HCl at 50∘C

(c) AC impedance curves of BFC for brass in 1M HCl at 40∘C (d) AC impedance curves of BFC for brass in 1M HCl at 30∘C

(e) Randlersquos Equivalent circuit used to fit the impedance spectra

Figure 6

to carry out the oxidation and reduction potential of Zn andcopper ions in various oxidation state

35 Dezincification Factor by AAS Dezincification factor isused tomeasure the percentage of copper and zinc ion presentin the HCl solution from weight loss method using atomicabsorption spectroscopy (AAS) (Elico-India) Dezincifica-tion factor is calculated by the following equation where theconcentration of zinc and copper is in ppm [25]

Dezincification factor (Z) = (119885119899119862119906) 119904119900119897119906119905119894119900119899(119885119899119862119880)119860119897119897119900119910 (13)

Dezincification of 1M HCl and the optimum concen-tration of the inhibitor (700ppm) were shown in Table 4From the table it was observed that copper and zinc both areleached in the HCl solution The ratio of copper to zinc ionpresent in the HCl solution was much lesser than in the alloy

This is due to the diffusion of ion and it is mainlycontrolled by the dissolution of the alloy Copper is lessleached than zinc in HCl solution because Eo

(cu2+Cu) forcopper (+034V) has a positive value and Eo

(Zn2+Zn) for Znis (-076) negative The diffusion of ion is very much relatedto the size of the ion zinc (II) ion having an atomic radius


(a) CV for brass in 1M HCl in the absence and presence BFC at 60∘C (b) CV for brass in 1M HCl in the absence and presence BFC at 50∘C

(c) CV for brass in 1M HCl in the absence and presence BFC at 40∘C (d) CV for brass in 1M HCl in the absence and presence BFC at 30∘C

Figure 7

of 0074nm diffuses faster than the copper (II) ion whichhas atomic radius of 0096nm The leaching of copper andzinc ion was minimized by the addition of the inhibitor Butthe percentage of the zinc present in inhibitor was muchhigher than the copper The dezincification factor of BFC is3422 compared with 1MHCl which was 6216This indicatesthat the dezincification factor is reduced by the additionof inhibitor by 2794 Results reveal that BFC inhibits thedezincification of brass in 1MHCl at optimum concentrationefficiently [26]

36 Langmuir Adsorption Isotherm The corrosion actionof BFC was characterized by various adsorption isothermlike Langmuir Freundlich Temkin Flory-Huggins and El-Awady All these adsorption isotherms follow a generalexpression as given in the following

f (120579 x) e(minus2a 120579) = KC (14)

where f(120579x) is the configurational factor 120579 is the surfacecoverage K is the constant of the adsorption process andcan be equated to equilibrium constant C is the inhibitors

concentration expressed in molarity and a is the molecularinteraction parameter By careful examination of the R2 valueof the various isotherm Langmuir isotherm was found to fitwell with the data of corrosion inhibition Langmuir isothermmodel for the adsorption of BFC on the Brass surface can berepresented as follows [27]

C120579 = 1

K+ C (15)

Plot of C 120579 versus C for various temperatures of BFC isshown in Figure 8 Table 5 shows the values of R2 slope ΔGand Kads The table implies that the slope of the line for theadsorption isotherm is greater than 112 at all temperatureswhich shows that each molecule of BFC occupies more thanone site of adsorption in the brass metal Higher adsorptioncapacity of BFC means there would be higher corrosionefficiency on the brass

The inhibition of corrosion mechanism of the BFC onthe surface of brass was monitored using the surface cover-age Tafel polarization was used for the measurement of the


Table 3 AC impedance parameters for brass in 1M HCl with BFC from 30∘C to 60∘C

SNo Temp (∘C) Concof inhibitor (mM) Rct(ohm cm2) Cdl(ohm 120583Fcm2) IE 1 30∘C Blank 289 2980 -

020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107

Table 4 Solution analysis by AAS for brass in 1M HCl with BFC

Conc of inhibitor (ppm) Solution Analysis Dezincification factor Inhibition ()Cu (ppm) Zn (ppm) Cu Zn

1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211

Table 5 Equilibrium and statistical parameter for adsorption of MFC on Brass surface in 1M HCl

Temperature (K) R2 Kads slope ΔG303 0979 3276 1452 -305087313 0984 3839 1345 -31931323 0991 4735 1294 -33514333 0983 4135 1124 -3417


0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C

Figure 8 Plot of C 120579 versus C for various temperature with BFC

surface coverage 120579 at different inhibitor concentration Cal-culation of surface coverage (120579) calculation was given in thefollowing formula

120579 = 119881o minus VVo

(16)

ΔGoads = minusRT (ln 555Kads) (17)

where Vo is the corrosion rate without inhibitor and Vis the corrosion rate with inhibitor Various isotherms weretried with the value of 120579 and the best fit was found and asdescribed earlier Langmuir isotherm showed the best fitΔGo

ads was calculated using (17) and is give in Table 5 andthe value at 60∘Cwas found to be -3417kJmol Table 5 showsa high value of Kads and the negative sign of ΔGo

ads whichindicates the as already discussed strong adsorption of BFCand surface of alloy ΔGo

ads values can be used to determinewhether physical or chemical adsorption has occurred onthe surface of the alloy When ΔGo

ads value is less than -20kJmol physical adsorption (physisorption) is considered tobe the major contributor to the adsorption process becauseof the Vander walls forces of attraction between the alloyand the inhibitor and when ΔGo

ads value is lesser than-30 kJmol then contribution by chemical adsorption ishigh From the table it can be seen BFC shows ΔGo

adsvalue more negative than -30kJmol at all temperature so itcan be seen that chemical adsorption contributes to higherpercentage of adsorption of BFC on the alloy surface At hightemperature ΔGo

ads becomes more negative which suggestthat chemical bond formation takes place to a larger extentat high temperature compared to low temperature

37 Effect of Temperature The effect of temperature on theinhibition action of BFC was studied at different temperatureranges from 30∘C to 60∘C using Tafel polarization methodandEISmeasurement It was observed that change in temper-ature changes the rate of the corrosion and rate of adsorption

0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)

Figure 9 Arrhenius plot of log Icorr versus 1T 10minus3for the effect oftemperature on the performance of BFC on brass in 1M HCl

of the BFC on the alloy surface Increase in temperatureincreases both the chemical adsorption and also the corrosionrate Increase in the corrosion rate was found to be high inblank compared to the alloy in the presence of the inhibitoras a result the corrosion inhibition efficiency of the BFCincreases with increase in temperature Rapid desorption ofthe inhibitor etching ofmetal chemisorption of the inhibitordecomposition of the inhibitor and rearrangement of theinhibitor are the various process that can take place whenthe temperature increases At high temperature BFC formsstrong covalent coordinate bond compared to the physicaladsorption which dominates at low temperature At eachtemperature there is an equilibrium between the adsorptionand desorption of the inhibitor on the surface of the brassalloy When the temperature changes the equilibrium isshifted and a new equilibrium is reached with BFC the shiftin equilibrium is towards the adsorption towards the alloysand an increase in the K value could be observed

Arrhenius equation and transition state equations can beused to calculate the activation energy enthalpy of adsorp-tion and entropy of adsorptionTheArrhenius and transitionstate plots are shown in Figures 9 and 10 The equationfor the calculation of activation energy and thermodynamicparameter is given in the following

log (Icorr) = minusEa(2303RT) + logA (18)

Icorr = RTNh

exp(ΔSlowastR

) exp(minusΔHlowastRT

) (19)

In these equations Icorr represents the corrosion currentR is the universal gas constant T is the absolute temperatureN is the Avogadro number h is the plankrsquos constant ΔSlowast isthe entropy change for the adsorption process and ΔHlowast isthe enthalpy change

Figure 9 represents the plot of log (Icorr) versus 1 (Tx 10minus3K) for blank and various concentration of inhibitorsA straight line was obtained Slope of the plot of (18) was


0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm

Figure 10 Transition state plot for brass corrosion with and withoutBFC in 1 M HCl at 60∘C

used for the calculation of Ea and Table 6 shows the resultsAn increase in Ea was observed when the temperaturedecreases Radovici classification of the inhibitor was appliedto BFC inhibition on Brass surface Inhibitors were classifiedaccording to their behaviour at high temperature Therewere three cases when energy of activation of inhibitor isequal to energy of activation of blank then with change intemperature there would not be any increase or decrease ofinhibition In the second case when the enthalpy of activationof the blank is greater than enthalpy of activation of inhibitorthen with increase in temperature there would be an increasein the corrosion inhibition in the last condition when Eaof the blank is less than Ea of inhibitor then increase intemperature decreases the inhibition efficiency [28 29]

BFCmolecules has heteroatoms like oxygen and nitrogenwhich can form bonds with the brass surface and can formcovalent coordinate bond With increase in temperature thereaction rate increases as the number of covalent bond forma-tions increases since the activation energy for the formationof the covalent bond decreases Hence more attraction by theheteroatom of the BFC with the brass metal increases thesurface coverage and decrease in the corrosion was observed

It can be inferred from the table that the activation energyis lowest at (11542) 700 ppm for the adsorption of BFCon the brass surface Table 6 shows that at the inhibitorconcentration of 700 ppm the activation energy value is thelowest which is also the optimum condition of inhibitorconcentration

The plot of log (IcorrT) versus 1000T was shown inFigure 10 ΔHo and ΔSo are calculated from the slope andintercept of straight line is obtained and the values are givenin Table 6 ΔHo and ΔSo values at optimum condition ofinhibitor in 1M HCl on the brass surface (1493 kJmol and-13978 J(mol K)) are less than the values in the absence ofinhibitor The desorption of the solvent molecule and theattraction of the inhibitor towards the surface of the brass

makes ΔSo negative because one molecule of inhibitor des-orbs more than 1 molecule of the solvent So the randomnessdecreases on the surface of the brass hence decreases inentropy are observed

38 Surface Analysis The surface morphology of the cor-roded and inhibited brass specimen was studied by the FT-IRand SEM analysis

381 FT-IR Analysis The FT-IR spectrum of BFC wasrecorded by coating the inhibitors on the KBr discThe FT-IRspectrum of the brass specimen in the presence and absenceof inhibitor was immersed in 1M HCl solution After theelapsed time the specimenswere cleanedwith double distilledwater and dried at room temperature with cold air Then itis characterized by Perkin Elmer MakendashModel Spectrum RX(FT-IR)

FT-IR spectrum of brass in 1 M HCl BFC and brass in1 M HCl with BFC was shown in Figures 11(a) 4(a) and11(b)The corresponding peak values are presented in Table 7The broad peak at 373261 cmminus1 is assigned to superficialabsorbed water stretching mode of an OH The stretchingfrequency of secondary amine shifts from 321655 to 332956cmminus1 due to lone pair of electrons present in the nitrogenatom which coordinates with Cu2+ to form a complex Apeak between 1300 to 160211 cmminus1 indicates the presence ofsecondary amide of BFC The peak at 103287 cmminusi indicatesthe formation of complex The peaks between the ranges of400 to 700 cmminus1 were mainly due to ZnO2 and CuO2

382 SEM Analysis The brass specimen was polished withvarious grades of emery sheet rinsed with distilled waterdegreased with acetone The SEM images of brass wererecorded using a scanning electron microscope (standardJEOL 6280 JXXA and LEO 435 VP model electron)

The surface morphology of brass sample in 1M HClsolution in the absence and presence of BFC at optimumconcentration of 181 mM was shown in Figures 12(b) and12(c) The surface of brass metal was badly damaged inHCl solution for 2 hours indicating that there is significantcorrosion However in presence of BFC the surface of brassis smooth implying that the corrosion rate is controlledThisimprovement in surface morphology is due to the formationof a stable protective layer of BFC on brass surface

39 Quantum Chemical Calculations To study the effect ofmolecular structure on inhibition efficiency quantum chem-ical calculationwas performedusingRB3LYP6-311Gmethodand the calculations were carried out by the geometricaloptimization of BFC According to Fukuirsquos frontier molec-ular orbital theory the ability of the inhibitor is associatedwith frontier molecular orbital highest molecular orbital(HOMO) lowest unoccupied molecular orbital (LUMO)and dipole moment (I) The optimization structure of BFCEHOMO ELUMO and Mulliken charges was shown in Fig-ures 13(a) 13(b) 13(c) and 13(d) The energies of frontierorbital theory (EHOMO and ELUMO) are the most importantparameters to predict the reactivity of chemical species Ithas been observed that EHOMO is associated with electron


(a) FT-IR peak values of brass in 1 M HCl (b) FT-IR peak values of brass in 1 M HCl with BFC

Figure 11

(a) (b) (c)

Figure 12 (a) SEM image of brass before immersion (polished) (b) SEM image of brass in IM HCl (c) SEM image of brass in IM HCl withBFC

donating ability of a molecule The inhibition efficiency ofBFC increases with increase in EHOMO High EHOMO valueindicates that themolecule has a tendency to donate electronsto an appropriate acceptor molecule In addition to that ifthe value of ELUMO is less it easily accepts electrons from thedonar molecules [30ndash33]

Computed parameters such as EHOMO ELUMO energygap (ΔE= ELUMO - EHOMO) dipole moment (120583) absoluteelectronegativity (120594) global hardness (120578) and global softness(120590) were calculated and shown in Table 5 To calculate thequantum chemical parameters120594 and 120578 the following equationwas used [34ndash36]

120594 = ELUMO + EHOMO2 (20)

120578 = ELUMO minus EHOMO2 (21)

The inverse of global hardness (120578) is designated as globalsoftness (120590) and it is calculated by the following equation

By calculating these hardness and softness properties thestability and reactivity of inhibitor molecule are measured

120590 = 1120578 (22)

The energy band gap between EHOMO and ELUMO (ΔE) ofthe molecule is used to expand theoretical models that arequalitatively able to explain the structure and conformationbarriers inmolecular system Hardmolecule has large energygap whereas soft molecule has low gap Soft molecules aremore reactive than hard ones due to the donation of electronsto the acceptors It is eminent that smaller the value of ΔE ofan inhibitor the higher the inhibition efficiency of molecule[37 38]

From Table 8 it is obvious that BFC has higher EHOMOvalue (-00627 eV) which indicates that it donates electronsand the value of ELUMO is less (-00282 eV) which implies thatit accepts the electronsThe energy band gap value for BFC islow (00345 eV) due to the stable nature on the metal surfacewhich affirmed the corrosion resistance of brass in 1M HClThe dipolemoment (120583) value of BFC is 49349 which is bigger


(a) Optimized molecular structure of BFC (b) Frontier molecular orbital density distribution of BFC (HOMO)

(c) Frontier molecular orbital density distribution of BFC (LUMO) (d) Mulliken charges for BFC molecule

Figure 13

Table 6 Thermodynamic parameters for corrosion of brass in 1M HCl with BFC

Concentration (ppm) Ea(kJmol) A (Acm2) ΔHo(kJmol) ΔSo(JKmol) ΔGo(kJmol)303 313 323 333

Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724

than the dipole moment of water (188 Debye) indicatingthat there is a strong dipole-dipole interaction between theinhibitor molecule and brass surface Molecule exhibitinglower energy difference (ΔE) value readily undergoes chargetransfer interface on themetal surface thereby increasing theinhibition efficiency [39ndash42]

In this present work the value of 120590 is (5813) high therebyincreasing the inhibition efficiency of BFC which is in goodagreement compared with experimental values The absoluteelectronegativity (120594) and global electrophilicity (120596) of BFCwere 00454 and 02094 which indicated the stability andreactivity of inhibitor molecule

The adsorption centers of inhibitor molecules were anal-ysed by usingMulliken chargesTheMulliken charges of BFCmolecule reveal that the heteroatom (N) has more negativecharge compared with other atoms which implies that theadsorption of brass metal is due to the electron donation ofan electronegative atom (N) to the metal surface

4 Conclusions

The structure of the synthesized compound BFC was con-firmed by spectral data Weight loss measurement indicatesthat the inhibition efficiency of BFC increases with anincrease in concentration and temperature ranges from 30∘Cto 60∘C Polarization measurements imply that BFC acts as amixed type inhibitor and it controls both hydrogen evolutionand metal dissolution process The inhibition efficiency ofBFC obtained from AC impedance is in good agreementcompared with the conventional weight loss and polarizationmethods

Cyclic voltammetry study reveals that the addition ofinhibitor reduces the oxidation of copper on the surface ofbrass Adsorption isotherm shows that BFC obeys Langmuiradsorption isotherm and the reaction is exothermic Theinhibition efficiency of BFC was closely related to quantumchemical parameters The purity of the inhibitor was con-firmed by LC-MS


Table 7 FT-IR analysis of brass in 1 M HCl BFC and brass in 1 M HCl with BFC

FT-IR peak values Possible groupsBrass in 1 M HCl (cmminus1) BFC(cmminus1) Brass in 1 M HClwith BFC

(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine

---- 305843302927 304561 C-H asymmetric stretch

---- ----- ---- C-H symmetric stretch

290186

294237280824275798269824

292613285475 120575HOH

169573 160177 ---- 160211 Absorbed moisture---- 166337 ---- C=O---- 159186 156035 Amide I band

---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag

Table 8 Quantum chemical parameters for BFC

Inhibitor EHOMO (eV) ELUMO (eV) ΔE (eV) 120583(D) 120578 (eV) 120590 (eV) 120594 120596BFC -00627 -00282 00345 49349 00172 5813 00454 02094

Data Availability

The data used to support the findings of this study areavailable from the corresponding author upon request

Conflicts of Interest

The authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] J R Xavier S Nanjundan and N Rajendran ldquoElectrochemicalAdsorption Properties and Inhibition of Brass Corrosion inNatural Seawater byThiadiazole Derivatives Experimental andTheoretical Investigationrdquo Industrial amp Engineering ChemistryResearch vol 51 no 1 pp 30ndash43 2011

[2] A K Singh M A Quraishi and E E Ebenso ldquoInhibitive effectof cefuroxime on the corrosion of mild steel in hydrochloricacid solutionrdquo International Journal of Electrochemical Sciencevol 6 no 11 pp 5676ndash5688 2011

[3] V P Singh P Singh and A K Singh ldquoSynthesis structural andcorrosion inhibition studies on cobalt(II) nickel(II) copper(II)

and zinc(II) complexes with 2-acetylthiophene benzoylhydra-zonerdquo Inorganica Chimica Acta vol 379 no 1 pp 56ndash63 2011

[4] Nagham Mahmood and Aljamali ldquoSynthesis and Charac-terization of Fused Rings from Mannich Basesrdquo Journal ofKerbalaUniversity vol 11 2 pages 2013

[5] D Karthik D Tamilvendan and G Venkatesa Prabhu ldquoStudyon the inhibition of mild steel corrosion by 13-bis-(morpholin-4-yl-phenyl-methyl)-thiourea in hydrochloric acid mediumrdquoJournal of Saudi Chemical Society vol 18 no 6 pp 835ndash8442014

[6] P Preethi Kumari P Shetty and S A Rao ldquoElectrochemicalmeasurements for the corrosion inhibition of mild steel in 1 Mhydrochloric acid by using an aromatic hydrazide derivativerdquoArabian Journal of Chemistry vol 10 no 5 pp 653ndash663 2017

[7] A Y Musa A A H Kadhum A B Mohamad A R DaudM S Takriff and S K Kamarudin ldquoA comparative study ofthe corrosion inhibition of mild steel in sulphuric acid by 44-dimethyloxazolidine-2-thionerdquo Corrosion Science vol 51 no10 pp 2393ndash2399 2009

[8] S Pooja R K Upadyay and C Alok ldquoA comparative studyof corrosion inhibitive efficiency of some newly synthesizedMannich bases with their parent amine for Al in HCl solutionrdquo


Research Journal of Chemical Sciences vol 1 no 5 pp 29ndash352011

[9] K F Khaled S S Abdel-Rehim and G B Sakr ldquoOn the cor-rosion inhibition of iron in hydrochloric acid solutions PartI Electrochemical DC and AC studiesrdquo Arabian Journal ofChemistry vol 5 no 2 pp 213ndash218 2012

[10] K F Khaled and A El-Maghraby ldquoExperimental Monte Carloand molecular dynamics simulations to investigate corrosioninhibition of mild steel in hydrochloric acid solutionsrdquo ArabianJournal of Chemistry vol 7 no 3 pp 319ndash326 2014

[11] R V Saliyan and A V Adhikari ldquoCorrosion inhibition ofmild steel in acid media by quinolinyl thiopropano hydrazonerdquoIndian Journal of Chemical Technology vol 16 no 2 pp 162ndash1742009

[12] E M Sherif R M Erasmus and J D Comins ldquoInhibitionof copper corrosion in acidic chloride pickling solutions by 5-(3-aminophenyl)-tetrazole as a corrosion inhibitorrdquo CorrosionScience vol 50 no 12 pp 3439ndash3445 2008

[13] A K Singh ldquoInhibition of mild steel corrosion in hydrochlo-ric acid solution by 3-(4-((Z)-indolin-3-ylideneamino)phenyli-mino)indolin-2-onerdquo Industrial amp Engineering Chemistry Re-search vol 51 no 8 pp 3215ndash3223 2012

[14] G Quartarone L Bonaldo and C Tortato ldquoInhibitive actionof indole-5-carboxylic acid towards corrosion of mild steel indeaerated 05M sulfuric acid solutionsrdquoApplied Surface Sciencevol 252 no 23 pp 8251ndash8257 2006

[15] S T Selvi V Raman and N Rajendran ldquoCorrosion inhibitionof mild steel by benzotriazole derivatives in acidic mediumrdquoJournal of Applied Electrochemistry vol 33 no 12 pp 1175ndash11822003

[16] Sudheer and M Quraishi ldquoElectrochemical and theoreticalinvestigation of triazole derivatives on corrosion inhibitionbehavior of copper in hydrochloric acid mediumrdquo CorrosionScience vol 70 pp 161ndash169 2013

[17] CMA Brett ldquoOn the electrochemical behaviour of aluminiumin acidic chloride solutionrdquo Corrosion Science vol 33 no 2 pp203ndash210 1992

[18] N Fishelson A Inberg N Croitoru andY Shacham-DiamandldquoHighly corrosion resistant bright silvermetallization depositedfrom a neutral cyanide-free solutionrdquoMicroelectronic Engineer-ing vol 92 pp 126ndash129 2012

[19] M Lebrini M Lagrenee H Vezin M Traisnel and F BentissldquoExperimental and theoretical study for corrosion inhibition ofmild steel in normal hydrochloric acid solution by some newmacrocyclic polyether compoundsrdquo Corrosion Science vol 49no 5 pp 2254ndash2269 2007

[20] W Chen S Hong H B Li H Q Luo M Li and N B LildquoProtection of copper corrosion in 05MNaCl solution bymodi-fication of 5-mercapto-3-phenyl-134-thiadiazole-2-thione po-tassium self-assembled monolayerrdquo Corrosion Science vol 61pp 53ndash62 2012

[21] I Ahamad R Prasad and M A Quraishi ldquoAdsorption andinhibitive properties of some new Mannich bases of Isatinderivatives on corrosion ofmild steel in acidicmediardquoCorrosionScience vol 52 no 4 pp 1472ndash1481 2010

[22] D D Macdonald ldquoReview of mechanistic analysis by electro-chemical impedance spectroscopyrdquo Electrochimica Acta vol 35no 10 pp 1509ndash1525 1990

[23] Akabueze and A U Itodo ldquoInhibotary action of 1-phenyl-3-methylpyrazol-5-one(HPMP) and 1-phenyl-3-methyl-4-(p-nitrobenzoyl)-pyrazol-5-one(HPMNP) on the corrosion of

Alpha and Beta brass in HCl solutionrdquo American Journal ofchemistry vol 2 no 3 pp 142ndash149 2012

[24] S K Bag S B Chakraborty A Roy and S R Chaudhuri ldquo2-aminobenzimidazole as corrosion inhibitor for 70-30 brass inammoniardquo British Corrosion Journal vol 31 no 3 pp 207ndash2121996

[25] R Ravichandran S Nanjundan and N Rajendran ldquoEffect ofbenzotriazole derivatives on the corrosion and dezincificationof brass in neutral chloride solutionrdquo Journal of Applied Electro-chemistry vol 34 no 11 pp 1171ndash1176 2004

[26] L CMurulanaMM Kabanda and E E Ebenso ldquoExperimen-tal and theoretical studies on the corrosion inhibition of mildsteel by some sulphonamides in aqueous HClrdquo RSC Advancesvol 5 no 36 pp 28743ndash28761 2015

[27] A Ehsani M G Mahjani R Moshrefi H Mostaanzadeh andJ S Shayeh ldquoElectrochemical and DFT study on the inhibitionof 316L stainless steel corrosion in acidic medium by 1-(4-nitrophenyl)-5-amino-1H-tetrazolerdquo RSC Advances vol 4 no38 pp 20031ndash20037 2014

[28] S Shahabi P Norouzi and M R Ganjali ldquoTheoretical andelectrochemical study of carbon steel corrosion inhibition in thepresence of two synthesized schiff base inhibitors Applicationof fast Fourier transform continuous cyclic voltammetry tostudy the adsorption behaviorrdquo International Journal of Electro-chemical Science vol 10 no 3 pp 2646ndash2662 2015

[29] V S Sastri M Elboujdaini and J R Perumareddi ldquoUtilityof quantum chemical parameters in the rationalization ofcorrosion inhibition efficiency of some organic inhibitorsrdquoCorrosion vol 61 no 10 pp 933ndash942 2005

[30] S Xia M Qiu L Yu F Liu and H Zhao ldquoMoleculardynamics and density functional theory study on relationshipbetween structure of imidazoline derivatives and inhibitionperformancerdquo Corrosion Science vol 50 no 7 pp 2021ndash20292008

[31] E E Ebenso T Arslan F Kandemirli N Caner and I LoveldquoQuantum chemical studies of some rhodanine azosulphadrugs as corrosion inhibitors for mild steel in acidic mediumrdquoInternational Journal of Quantum Chemistry vol 110 no 5 pp1003ndash1018 2010

[32] V S Sastri and J R Perumareddi ldquoMolecular orbital theoreticalstudies of some organic corrosion inhibitorsrdquoCorrosion vol 53no 8 pp 617ndash622 1997

[33] I Lukovits E Klaman and F Zucchi ldquoCorrelation betweenelectronic structure and efficiencyrdquo Corrosion vol 53 pp 617ndash622 2001

[34] R G Pearson ldquoAbsolute electronegativity and hardness appli-cations to organic chemistryrdquoThe Journal of Organic Chemistryvol 54 no 6 pp 1423ndash1430 1989

[35] O Blajiev and A Hubin ldquoInhibition of copper corro-sion in chloride solutions by amino-mercapto-thiadiazol andmethyl-mercapto-thiadiazol An impedance spectroscopy anda quantum-chemical investigationrdquo Electrochimica Acta vol 49no 17-18 pp 2761ndash2770 2004

[36] A Kokalj ldquoOn the HSAB based estimate of charge transferbetween adsorbates and metal surfacesrdquo Chemical Physics vol393 no 1 pp 1ndash12 2012

[37] N Khalil ldquoQuantum chemical apporach of corrosion inhibi-tionrdquo Electrochimica Acta vol 48 pp 2635ndash2640 2003

[38] G Gece ldquoThe use of quantum chemical methods in corrosioninhibitior studiesrdquo Corrosion Science vol 50 pp 2981ndash29922008


[39] M Yadav D Behera S Kumar and R R Sinha ldquoExperimentaland quantum chemical studies on the corrosion inhibitionperformance of benzimidazole derivatives for mild steel inHClrdquo Industrial amp Engineering Chemistry Research vol 52 no19 pp 6318ndash6328 2013

[40] M A Quraishi A Singh V K Singh D K Yadav and A KSingh ldquoGreen approach to corrosion inhibition of mild steel inhydrochloric acid and sulphuric acid solutions by the extract ofMurraya koenigii leavesrdquoMaterials Chemistry and Physics vol122 no 1 pp 114ndash122 2010

[41] R Ganapathi Sundaram and M Sundaravadivelu ldquoSurfaceprotection ofmild steel in acidic chloride solution by 5-Nitro-8-Hydroxy Quinolinerdquo Egyptian Journal of Petroleum vol 27 no1 pp 95ndash103 2018

[42] S K Saha M Murmu N C Murmu I Obot and P BanerjeeldquoMolecular level insights for the corrosion inhibition effective-ness of three amine derivatives on the carbon steel surface inthe adversemediumA combined density functional theory andmolecular dynamics simulation studyrdquo Surfaces and Interfacesvol 10 pp 65ndash73 2018

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

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BiomaterialsHindawiwwwhindawicom

Journal ofEngineeringVolume 2018

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Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in



ChemistryAdvances in


Advances inPhysical Chemistry


BioMed Research InternationalMaterials

Journal of


Na

nom

ate

ria

ls


Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom


O

4 Amino benzamide

O O

Cl

2 Furoyl chloride

O

O

NH

O


+

MDC THF

RT 24 hrs（2

（2 （2

Figure 1 Synthesis of CFC

(a) FT-IR spectrum of CFC (b) 13C spectrum of CFC

(c) 1H spectrum of CFC (d) LC-MS spectrum of CFC

Figure 2

It is also aimed to study the quantumchemical parametersand thermodynamic feasibility of the inhibitor using the sur-face coverage of brassThe interaction of inhibitor (BFC) wascorrelated with coefficient of their molecular orbitals highestoccupied molecular orbital (HOMO) lowest unoccupiedmolecular orbital (LUMO) energy difference (ΔE) betweenEHOMO and ELUMO atomic charges and dipole momentsThecoordination of ligand to the surface of metal was confirmedby FT-IRThe characterization of BFCwas further confirmedby NMR and LC-MS

2 Experiment

21 Synthesis of CFC N-(4-Carbamoylphenyl)Furan-2-Carboxamide (CFC) was prepared by a procedure similar tothat reported in the literature 4-Amino benzamide (300g

00220 mol) and 2-furoyl chloride (3428 g 00264 mol)were dissolved in mixture of MDC (70 ml) and THF (25 ml)Triethylamine (777g) was added and the mixture was stirredin the presence of nitrogen atmosphere for 24 hours Thereaction mixture was washed with water filtered and driedover high vacuum pump The CFC was characterized byspectral techniques like FT-IR NMR and LC-MS Figure 1represents the synthesis of CFC

22 Characterization of CFC Yeild 93white solidmp186-190∘C IR (KBr ]max cmminus1 3387 3179(NH St Amide) 1658(C=O) 1617 (NH Bend Amide) 1400 (CN Amide) 14741527 (C=C) 1179 (C-O furan) 841 (CH Aroop) 1H NMR(400 MHz DMSO-d6) d(ppm) 671(1H Furan) 736 (1Hfuran) 780-784 (4H) 785-787 (2H Amide) 795 (1H furan)1036 (1H Amide) 13CNMR (400MHz DMSO-d6) d(ppm)


O

O

NH

O


N

NH


+ +

N

N NHO

O

NH

O


HCHO

Ethanol

Formaldehyde

（2

（2

90∘C 48 hrs











40000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400000

5101520253035404550556065707580859095

1000

T 326523

305843

302927294237

288088

280824

275798

269824

236586194700

189780

181104

166387

159186153485

147272145019

141726

137170

133569

129465

118898

113876

107616104284102734

100267

96709

92590

84192

78195

74600

70337

6227252642

4753943028





Figure 4



times 100 (1)

120579 = W0 minusW1W0

(2)






)] times 100 (3)





ct 1(5)

















020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





O

O

NH

O


N

NH


+ +

N

N NHO

O

NH

O


HCHO

Ethanol

Formaldehyde

（2

（2

90∘C 48 hrs











40000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400000

5101520253035404550556065707580859095

1000

T 326523

305843

302927294237

288088

280824

275798

269824

236586194700

189780

181104

166387

159186153485

147272145019

141726

137170

133569

129465

118898

113876

107616104284102734

100267

96709

92590

84192

78195

74600

70337

6227252642

4753943028





Figure 4



times 100 (1)

120579 = W0 minusW1W0

(2)






)] times 100 (3)





ct 1(5)

















020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





40000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400000

5101520253035404550556065707580859095

1000

T 326523

305843

302927294237

288088

280824

275798

269824

236586194700

189780

181104

166387

159186153485

147272145019

141726

137170

133569

129465

118898

113876

107616104284102734

100267

96709

92590

84192

78195

74600

70337

6227252642

4753943028





Figure 4



times 100 (1)

120579 = W0 minusW1W0

(2)






)] times 100 (3)





ct 1(5)

















020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







)] times 100 (3)





ct 1(5)

















020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







020 15742 04278 4278040 13552 04566 4566060 9840 04610 4610080 7174 05052 5052101 6711 05676 5676121 5061 06018 6018141 4770 06149 6149

2 40∘C Blank 65517 - -020 18731 04681 4681040 16874 04707 4707060 15364 04935 4935080 12809 05309 5309101 9781 05866 5866121 6846 06211 6211141 5224 06324 6324

3 50∘C Blank 98182 - -020 50175 04920 4920040 48011 05013 5013060 43521 05367 5367080 37540 05671 5671101 35839 05930 5930121 29743 06388 6388141 22585 06500 6500

4 60∘C Blank 468822 - -020 62743 05486 5486040 58770 05637 5637060 50982 06053 6053080 46418 06652 6650101 44730 07192 7192121 36641 07632 7632141 30150 07737 7737







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







020 -0516 1163 594 1882 5106040 -0548 1054 570 1723 5520060 -0549 1177 488 1570 5917080 -0546 1110 417 1401 6357101 -0550 1162 672 1398 6365121 -0566 1182 687 1354 6479141 -0599 1268 611 1136 7046

2 40∘C Blank -0466 5663 636 5728 -020 -0468 6631 677 2457 5710040 -0470 6178 882 2280 6019060 -0466 8817 870 2161 6227080 -0474 8875 897 1986 6532101 -0478 9957 818 1804 6850121 -0482 1325 850 1629 7156141 -0493 1150 690 1472 7430

3 50∘C Blank -0433 6307 609 8532 -020 -0446 6128 851 3428 5982040 -0451 8695 762 3276 6160060 -0459 1330 784 3174 6279080 -0466 1381 681 2862 6645101 -0472 1168 622 2650 6894121 -0473 8105 890 2266 7344141 -0461 1173 678 1951 7713

4 60∘C Blank -0423 5681 636 9578 -020 -0436 7897 745 3773 6060040 -0437 1132 695 3562 6281060 -0442 1292 798 3118 6744080 -0448 1091 744 3046 6819101 -0451 1017 676 2852 7022121 -0457 1033 906 2312 7586141 -0478 1342 763 1268 8679











(11)




Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







Figure 5














Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls








Figure 6











Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







Figure 7



f (120579 x) e(minus2a 120579) = KC (14)



C120579 = 1

K+ C (15)






020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







020 626 1675 5383040 687 1550 5793060 735 1493 6068080 794 1417 6360101 863 1362 6651121 941 1354 6928141 1036 1139 7210

2 40∘C Blank 217 3820 -020 518 2687 5810040 583 2290 6277060 665 2150 6736080 743 2090 7074101 789 1957 7249121 852 1916 7453141 895 1770 7578

3 50∘C Blank 1067 9750 -020 281 5824 6202040 305 5700 6501060 372 5598 7131080 409 5330 7391101 453 5179 7644121 476 5075 7758141 598 4802 8215

4 60∘C Blank 75 1126 -020 248 9540 6209040 279 9228 6374060 354 8790 6837080 397 8230 7173101 475 7605 7351121 563 7310 8057141 840 6744 9107



1 M HCl 01170 8179 6216 - -BFC (700 ppm) 00524 0804 3422 8107 9211




0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





0

05

1

15

2

25

3

35

4

0 05 1 15C

303 K313 K

323 K333 K

C



120579 = 119881o minus VVo

(16)











0

02

04

06

08

1

12

295 3 305 31 315 32 325 33 335

Blank100 ppm300 ppm

500 ppm700 ppm

(T x -K)

logI

corr

(Acm

-)





Icorr = RTNh

exp(ΔSlowastR


) (19)




0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





0

00005

0001

00015

0002

00025

0003

00035

29 3 31 32 33 34

log

Icor

r T

1000T (K)

Blank100 ppm300 ppm

500 ppm700 ppm















Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls






Figure 11

(a) (b) (c)




120594 = ELUMO + EHOMO2 (20)




120590 = 1120578 (22)






Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







Figure 13



Blank 32824 15720 2071 -110221 5107 5207 5307 5408100 24695 1116 1656 -128532 5197 5314 5431 5548300 20152 1020 1575 -133615 5255 5377 5498 5620500 15974 827 1506 -13739 5290 5415 5540 5665700 11542 611 1493 -139779 5343 5470 5597 5724




4 Conclusions






(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







(cmminus1)373261 ---- ---- 120592 O-H---- 326523 332956

321655 20 Amine



290186

294237280824275798269824

292613285475 120575HOH


---- 153485147272 Amide II band

139465 ----- 138262 120575 OH---- 133560 ------ Furan ring126812 118858 SO4

2minus

---- 113876 C-H102734 103287

80014 ----- ---- 120574 OH---- 84192 68881

58277 Amine wag



Data Availability




References


















































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls












































Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls




Experimental and Theoretical Studies on the Corrosion ...

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Transcript of Experimental and Theoretical Studies on the Corrosion ...