Corrosion Control Of Metals Biology Essay

Urine ( CU ) add-on was evaluated at five different temperatures in the scope from 30-70 C by weight loss measurings. CU acts as a good inhibitor for the corrosion of mild steel in 1.5 M H2SO4. The

value of suppression efficiency additions with increasing both inhibitor concentration and solution

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temperature. Approach: The surface assimilation of CU components on the mild steel surface obeys the

Langmuir surface assimilation isotherm proposing a monolayer surface assimilation of CU species. Thermodynamic

parametric quantities for CU surface assimilation and mild steel corrosion were evaluated. The negative values of ( DGoads )

stress the spontaneousness of the surface assimilation procedure and stableness of the adsorbed bed. Consequences: The

estimated high, positive value of DHoads ensures that CU species is adsorbed chemically on mild steel

surface. All values of E*

app for mild steel corrosion in inhibited solutions were lower than that for the

uninhibited solution bespeaking the happening of chemosorption mechanism. Decision: The surface

morphology of mild steel in absence and presence of inhibitor revealed that with increasing both CU

concentration and solution temperature, mild steel surface is modified and looks smooth. Good

correlativity between the inhibitor components and its repressive action was obtained.

Cardinal words: Corrosion, thermodynamic, chemosorption, sulphuric acid, environmentally friendly

inhibitor, inhibitor components, natural inhibitors, works resources, non-toxic, reaction

invariables, natural merchandises

Introduction

Etre, 2006 ) , artemisia oil ( Benabdellah et al. , 2006 ) ,

Zenthoxylum alatum infusion ( Chauhan and

Corrosion control of metals is an of import activity Gunasekaran, 2007 ) , Fenugreek Leaves infusion ( Noor,

of proficient, economical, environmental and aesthetical 2007 ) , Justicia gendarussa ( Satapathy et al. , 2009 ) have

importance. Therefore, the hunt for new and efficient been reported to be good inhibitors for steel in acid

corrosion inhibitors has become a necessity to procure solutions. As noticed, all the old natural inhibitors

metallic stuffs against corrosion. Over the old ages, were obtained from works resources. In recent plants

considerable attempts have been deployed to happen suited ( Noor, 2004 ; 2008 ) , Camel s Urine ( CU ) obtained from

compounds of organic beginning to be used as corrosion animate being beginning was reported as corrosion inhibitor for

inhibitors in assorted caustic media, to either halt or mild steel in HCl solutions. Camel s piss can be

detain the maximal onslaught of a metal ( Umoren et al. , classified as environmentally friendly inhibitor, because

2008 ) . However, the known jeopardy effects of most microbiological survey on CU proved its high efficiency

man-made organic inhibitors and the demand to develop against a figure of infective bugs when

inexpensive, non-toxic and environmentally benign procedures compared with some antibiotics. Furthermore, the

hold now made research workers to concentrate on the usage of effectual component of CU was isolated and tested as

natural merchandises. These natural organic compounds are antineoplastic agent which is labeled as PM 701 ( Moshref

either synthesized or extracted from aromatic herbs, et al. , 2006 )

spices and medicative workss. By and large talking, inhibitors are found to protect

Recently, assorted natural merchandises from works steel corrosion in acerb solutions by adsorbing onto

beginnings e.g. , Zenthoxylum-alatum fruits extract steel surface. Adsorption isotherms such as Langmuir

( Gunasekaran and Chauhan, 2004 ) , Telfaria ( 1917 ) surface assimilation isotherm, surface assimilation isotherm,

Occidentalis infusion ( Oguzie, 2005 ) , Khilla infusion ( El-Flory ( 1942 ) and Huggins ( 1942 ) surface assimilation isotherm

Matching Writer:

Ehteram A. Noor, Department of Chemistry, Science Faculty for Girls, King Abdulaziz University,

Jeddah, Saudi Arabia Tel: +00966 ( 0505537707 ) Facsimile: +00966 ( 022652112 )

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and Frumkin ( 1964 ) surface assimilation isotherm are used to

clarify the suppression mechanism of inhibitors. If

the surface assimilation isotherm for a given inhibitor is

specified at different temperatures, thermodynamic

parametric quantities for the surface assimilation procedure would be

estimated, giving a good aid to propose the

suppression mechanism. Furthermore the thermodynamic

activation parametric quantities for the corrosion procedure are

besides of import to explicate the surface assimilation phenomenon

of inhibitor.

In the present survey the writers attempt to analyze the

repressive action of CU for mild steel corrosion in 1.5M

H2SO4 at five different temperatures ( 30-70 C ) by

utilizing weigh loss method. Assorted thermodynamic

parametric quantities for inhibitor surface assimilation every bit good as for mild

steel corrosion in absence and presence of different

concentrations of CU were estimated and discussed.

MATERIALS AND METHODS

Specimens: The experiments were performed with mild

steel rods of the undermentioned composing ; C: 0.250, Mn:

0.480, Si: 0.300, Ni: 0.040, Cr: 0.060, Mo: 0.020, S:

0.021, P: 0.019 and the balance is Fe.

Inhibitor: The camel s urine sample is extracted from

female camel ( one humped ) with age around 4-5 old ages,

early in the forenoon. Physically, the fresh extracted

urine appears clear, amber xanthous and watery.

Solutions: The aggressive solution ( 1.5M H2SO4 ) was

prepared by dilution of analytical class reagent with

deionized H2O. The needed concentrations ( 1, 2, 6,

10 and 14 v/v % ) of inhibitor were prepared by thining

with 1.5 M of H2SO4 solutions.

Corrosion rate measurings: Weight loss method

was employed for mild steel corrosion rate

measurings in absence and presence of assorted

concentrations of CU at different temperatures. Prior to

each experiment, the mild steel specimen of 1.0 centimeters in

diameter and 5.0 centimeter in length was abraded with a series

of emery survey from 220-1000 classs. Then, it was

washed several times with deionized H2O so with

ethyl alcohol and dried utilizing a watercourse of air. After weighing

accurately, it was immersed in 100 milliliter flask, incorporating

50 milliliter of solution. After 90 min, the specimen was

taken out, washed, dried and weighed accurately. The

trial was performed in absence and presence of different

inhibitor concentrations and different temperatures ( 3070

C ) . The rate of weight loss was calculated ( rWL, milligram

cm.2 min.1 ) as follows Eq. 1:

W – Tungsten

rWL = 1 2 ( 1 )

S.t

Where:

W1 and W2 = The specimen weight before and after

submergence in the tried solution

S = The surface country of the specimen

T.

= The terminal clip of each experiment

The corrosion rates in the absence ( roWL ) and

presence ( rWL ) of an inhibitor are used to measure its

suppression efficiency by utilizing the undermentioned Eq. 2:

IE % = ( 1 -r

owl ) 100 ( 2 ) rWL

Surface morphology surveies: Characteristic characteristics

of mild steel surface after submergence in 1.5 M H2SO4

in absence and presence of low ( 1 % ) and high ( 10 % )

concentrations of CU at 30 and 70 C were

investigated by optical micrographs utilizing microscope

of the type ( Leitz METALLUX3 microscope

WETZLAR, Germany ) .

Consequence

Table 1 represents the corrosion rates of mild steel

in 1.5 M of H2SO4 solution in absence and presence of

assorted concentrations of CU ( 1-14 milliliter % ) .

Figure 1 show the relationship between logr and

logCinh at different temperatures which is in conformity

with the undermentioned Eq. 3 ( Noor and Al-Moubaraki, 2003 ) :

log r= log r+ Blog C isoniazid

( 3 )

Where:

Cinh = The concentration of the inhibitor

R = The corrosion rate when the concentration of

inhibitor becomes unity

B = A invariable for the studied reaction

Table 1: Mild steel corrosion rates in 1.5 M H2SO4 in absence

and presence of different concentrations of CU at different

temperatures

Corrosion rate 105 ( g cm-2 min-1 )

Cinh ( mL % ) 30 40 50 60 70

0 0.739 2.295 4.483 12.294 31.22

1 0.493 0.750 1.505 2.001 3.408

2 0.459 0.627 0.912 1.112 1.743

6 0.241 0.249 0.418 0.572 0.853

10 0.156 0.177 0.241 0.467 0.637

14 0.134 0.126 0.176 0.203 0.303

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Table 2: Kinetic parametric quantities ( B, R and r2 ) for mild steel corrosion in

1.5M H2SO4 solution incorporating CU at different

temperatures

2

T ( oC ) -B R ( g cm-2 min-1 )

R

30o 0.5 0.564 0.96

40o 0.7 0.847 0.98

50o 0.8 1.574 0.99

60o 0.8 2.028 0.94

70o 0.8 3.381 0.96

Fig. 1: Dependence of mild steel corrosion rate on the

concentration of CU in 1.5M H2SO4 at different

temperatures

Fig. 2: Consequence of CU concentration on the suppression

efficiency of mild steel corrosion in 1.5M

H2SO4 solution at different temperatures

The ulterior parametric quantity gives a step for the

inhibitor public presentation. The kinetic parametric quantities ( B and

R ) and correlativity coefficient ( r2 ) were estimated from

the consecutive lines shown in Fig. 1 and listed in Table 2.

Figure 2 shows the fluctuation of IE % with the

concentrations of CU at different temperatures. Most of

the corrosion suppression is achieved between 1 % and

6 % of CU with merely little betterments at 10 % or

higher. In general, the inhibitor efficiency was observed

to be increased with increasing both CU concentration

and solution temperature.

The surface assimilation of inhibitor species, Inh, on a metal

surface in aqueous solution should be considered as a

topographic point money changer reaction:

Inh + nH O U Inh + nHO ( 4 )

aq 2ads ads 2aq

where, n is the figure of H2O molecules displaced by

one molecule of inhibitor.

When the equilibrium of the procedure described in

Eq. 4 is reached, it is possible to plot the grade of

surface coverage ( q ) as a map of inhibitor

concentration at changeless temperature by different

mathematical looks which are called surface assimilation

isotherms theoretical accounts. Several surface assimilation isotherms were

tested and was found the best description of the

surface assimilation behaviour of the studied inhibitor is by the

Langmuir surface assimilation isotherm Eq. 5:

Cinh. 1

=+ Cinh. ( 5 )

q Kads.

where, Kads is the equilibrium invariable of surface assimilation

procedure. The secret plan of Cinh versus Cinh for CU at different

Q

temperatures gives a consecutive line as shown in Fig. 3. It is

found that all the additive correlativity coefficients ( r2 ) are

about equal to 1.00 and all the inclines are really

near to integrity. From the intercepts of the consecutive lines, Kads

values at different temperatures were obtained.

It is good known that the free energy DGads of

surface assimilation is related to Kads by Eq. 6 ( Noor and Al-

Moubaraki, 2008 ) :

DGads.

log K =- logC – ( 6 )

ads. HO

2 2.303RT

where, CH O is the concentration of H2O molecules

2

and must hold the same unit as that used for inhibitor.

The standard free energies of CU surface assimilation ( DGo ) at

ads

different temperatures were calculated. A secret plan of DGads

versus T in Fig. 4 gave the heat of surface assimilation ( DHads )

and the information of surface assimilation ( DSads ) harmonizing to the

thermodynamic basic Eq. 7 ( Babakhouya et al. , 2010 ) :

DG =D H – TDS ( 7 )

ads ads ads

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Table 3:

Adsorption parametric quantities ( ( Kads, DGads, DHads and ( DSads ) for

CU on mild steel surface in 1.5M H2SO4 solution at

different temperatures

T ( C ) Kads DGads DHads DSads

… ..

( mL1L ) ( kJ mol1 ) ( kJ mol1 ) ( J K1mol1 )

30o 0.0404 -9.330

40o 0.1702 -13.40

50o 0.1941 -14.18 60.01 231

60o 0.4735 -17.10

70o 0.7738 -19.03

Fig. 3: Langmuir isotherm for surface assimilation of CU on

mild steel surface in 1.5M H2SO4 at different

temperatures

Fig. 4: The fluctuation of DGads with T

Table 4: Activation parametric quantities ( E # , DH # and DS # ) for mild steel

app

corrosion in 1.5M H2SO4 solution in absence and presence

of different concentrations of CU

isoniazid. C #

app E DH # DS #

milliliter % ( kJ mol-1 ) ( kJ mol-1 ) ( J K-1mol-1 )

0 79.17 76.49 -90.82

1 41.92 39.24 -217.44

2 27.97 25.29 -264.04

6 28.87 26.19 -267.45

10 30.73 28.06 -264.51

14 18.01 15.33 -308.12

The thermodynamic informations obtained for CU

utilizing the surface assimilation isotherm are collected in

Table 3.

The thermodynamic activation parametric quantities were

calculated from Arrhenius-type secret plan ( Eq. 8 ) and

passage province equation ( Eq. 9 ) ( Faiku et al. ,

2010 ) :

E #

log r= log A – app. ( 8 )

2.303RT

R R DS # DH #

log ( ) = [ ( log ( ) ) + ( ) ] .

( 9 )

T hN 2.303R 2.303RT

where,

E # , DH # and DS # are the evident activation

app

energy, the heat content of activation and the information of

activation. A is the frequence factor which has the same

unit as that of the corrosion rate.

Figure 5 shows the typical secret plans of logr versus 1

Thymine

R 1

while Fig. 6 shows the secret plans of log versus ; straight

Terrestrial time

lines with good correlativity coefficients were obtained.

All thermodynamic activation parametric quantities were

estimated and listed in Table 4.

Figure 7 gives the dependance of both E # and DH #

app

of mild steel corrosion in 1.5 M H2SO4 on the

concentration of CU.

Figure 8 illustrates thhe optical micrographs for

mild steel surface before and after submergence for

90 min in 1.5 M H2SO4 at 30 and 70 C. While

Fig. 9 and 10 illustrate the structural characteristics of

mild steel surface in 1.5M H2SO4 in absence and

presence of 1 and 10 % of CU at 30 and 70 C,

severally.

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Fig. 5: Arrhenius secret plans for mild steel corrosion rates in

1.5M H2SO4 in absence and presence of

different concentration of CU

Fig. 6: Passage province secret plans for mild steel corrosion

rates in 1.5M H2SO4 in absence and presence of

different concentration of CU

Fig. 7: Dependence of both evident activation energy

and enthalpy alteration of mild steel corrosion in

1.5 thousand H2SO4 on the concentration of CU

Fig. 8: Micrographs for mild steel surface before ( A )

and after submergence for 90 min in 1.5M H2SO4

at 30 C ( B ) and 70 C ( C )

Discussion

Consequence of CU concentration on mild steel corrosion at

different temperatures: The collected informations in Table 1

can be summarized as follows:

At changeless temperature, mild steel corrosion rate

tends to diminish dramatically with increasing CU

concentration. This consequence indicates the good

inhibitive belongingss of the studied inhibitor

At changeless concentration, mild steel corrosion rate

additions with increasing solution temperature

obeying Arrhenius relationship

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Fig. 9:

Micrographs for mild steel surface in 1.5M

H2SO4 in absence ( A ) and presence of 1 % ( B )

and 10 % ( C ) of CU at 30 C

The present consequences are in good understanding with

those obtained antecedently by ( Noor, 2004 ) when CU

had been studied as corrosion inhibitor for mild steel in

HCl solution at different temperatures. On the other

manus, The informations in Table 2 was interpreted as below:

As was observed the reaction invariables ( B ) have

negative mark, bespeaking that the mild steel

corrosion rate is reciprocally relative to the

concentration of CU. However, the absolute value

of changeless B additions with increasing temperature

up to 50 C and so no alteration in B value was

observed with farther addition in temperature. This

consequence indicates that CU becomes more effectual as

corrosion inhibitor with increasing temperature and

at comparatively high temperatures no appreciable

alteration in the suppression efficiency was observed

Fig. 10: Micrographs for mild steel surface in 1.5M

H2SO4 in absence ( A ) and presence of 1 % ( B )

and 10 % ( C ) of CU at 70 C

The obtained correlativity coefficients

( 0.94 r2 0.99 ) indicate that the corrosion rates of

mild steel in the presence of different

concentrations of CU fit good Eq. 3. Extra

grounds of the quality of tantrum is presented in Fig.

11 in which predicted values of R are plotted

against the corresponding experimental values of

different concentrations of CU. Reasonable

understandings between experimental and predicted

consequences are obtained

The inhibitor action could be explained by

Fe ( Inh ) ads reaction intermediate as follows Eq. 10

( Dubey and Singh, 2007 ) :

Ns +

Fe

+ Inh U Fe ( Inh ) ads U Fe + Inh + n vitamin E ( 10 )

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Fig. 11: Experimental values against predicted values of

mild steel corrosion rate in 1M H2SO4 solution

incorporating different concentrations of CU at

different temperatures

The adsorbed bed combats the action of sulfuric

acerb solution and enhances protection of the metal

surface ( Quraishi et al. , 2000 ) . When there is

deficient Fe ( Inh ) ads to cover the metal surface ( if the

inhibitor concentration was low or the surface assimilation rate

was slow ) , metal disintegration would take topographic point at sites

on the mild steel surface which are free of Fe ( Inh ) ads.

With high inhibitor concentration a compact and

coherent inhibitor bed signifiers on mild steel surface,

cut downing the onslaught on the metal surface. Hence, the

suppression efficiency is so straight relative to the

fraction of the surface covered with adsorbed inhibitor.

Figure 2 implies that most of the corrosion

suppression is achieved between 1 % and 6 % of CU with

merely little betterments at 10 % or higher. In general,

the inhibitor efficiency was observed to be increasing

with increasing both CU concentration and solution

temperature. These consequences can be discussed as follows:

The addition in IE % with increasing CU

concentration is attributed to the interaction

between the inhibitor species and mild steel surface

taking to adsorb the former on the latter. The

adsorbed measure additions with inhibitor

concentration and consequently more active

corrosion centres were reduced ( Shetty et al. , 2006 ;

Achary et al. , 2008 ) . On the other manus, the limited

alteration in IE % at comparatively higher concentrations

of CU may be related to come up impregnation with

inhibitor species ( Noor, 2009 )

The addition in IE % with increasing temperature

was interpreted in the literature by different ways.

Amar and El Khorafi ( 1973 ) , related this to specific

interactions between the metal surface and the

inhibitor molecules. Considered that with addition

in temperature some chemical alterations occur in the

inhibitor molecules taking to an addition in the

negatron densenesss at the surface assimilation centres of the

molecule doing betterment in inhibitor

efficiency eventually. Considered that the addition of

IE % with increasing temperature is a consequence of

alteration in the nature of surface assimilation manner ; the

inhibitor species are being physically adsorbed at

lower temperatures while chemosorption is

favoured as temperature additions

To turn out the chemosorption procedure for CU species

on mild steel surface, some thermodynamic

considerations for both inhibitor surface assimilation and

corrosion activation must be evaluated.

Thermodynamic-adsorption considerations:

Obviously, Fig. 4 shows the dependance of DGads on T,

bespeaking a good correlativity among the

thermodynamic parametric quantities. The negative values of

DGads ( Table 3 ) stress the spontaneousness of the

surface assimilation procedure and the stableness of the adsorbed

bed on the steel surface. As was observed the values

of DGads go more negative with increasing

temperature, bespeaking that the surface assimilation power of

CU increases with the addition of temperature. On the

other manus, the high positive value of DHads ( Table 3 )

ensures that CU species adsorbed chemically on mild

steel surface, while the accompanied big, positive

value of DSads ( Table 3 ) indicates that an addition in

perturbing takes topographic point in traveling from reactants to the

metal-adsorbed species reaction composite. Similar

consequences were reported in recent plants ( Bentiss et al. ,

2005 ; Noor, 2007 ) .

Thermodynamic-activation considerations: The

obtained informations in Table 4 can be interpreted as below.

#

The values of both Eapp and DH # in absence and

presence of different concentrations of CU are

positive, bespeaking that the corrosion procedure is

endothermal

#

The lower values of Eapp in the inhibited solutions

as compared to that of the uninhibited solution

suggest chemosorption mechanism for the CU

species on mild steel in the studied medium

( Popova et al. , 2003 ) . This consequence is in good

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understanding with the obtained thermodynamic informations

of surface assimilation ( Table 3 )

#

The lessening in Eapp with CU concentration ( Fig. 7 )

supports the thought of chemosorption mechanism. This

was attributed by ( Hoar and Holliday, 1953 ) to a

slow rate of inhibitor surface assimilation with a end point

closer attack to equilibrium during the

experiments at the higher temperature. Furthermore,

( Riggs and Hurd, 1967 ) explained that the lessening

in activation energy of corrosion at higher degrees of

suppression arises from a displacement of the net corrosion

reaction from that on the exposed portion on the

metal surface to the covered 1

#

Eapp -Cinh relation ( Fig. 7 ) shows a tableland in the

concentration scope from 2-10 % which may be

attributed to that with increasing inhibitor

concentration, the covered country with inhibitor

species additions and the metal surface becomes

near to be saturated, taking to limited alteration in

the evident activation energy. While at 14 % of

CU concentration a bead in E # value was

app

observed which indicates that the metal surface

may be wholly blocked with chemically

adsorbed inhibitor species taking to foster

#

lessening in the Eapp

As expected DH # values have the same tendency as

#

that for Eapp, detecting that the latter is larger than

the former. Noor ( 2007 ) attributed this consequence to

the gaseous reaction ( hydrogen development )

associated with the corrosion procedure which may

lead to a lessening in the entire volume of the

corrosion system. So, harmonizing to the footing of

thermodynamics the inequality E # & A ; gt ; DH # is true.

app

Large and negative values of DS # imply that the

activated composite in the rate finding measure

represents an association instead than a dissociation

measure, intending that a lessening in perturbing takes

topographic point on traveling from reactants to the activated

composite ( March, 1992 ) . However, the value of DS #

lessenings with increasing CU concentrations

Surface morphological surveies: Inspection Fig. 8

through A to C indicates that the sum of corrosion

merchandises every bit good as the size of cavities on mild steel surface

are relative to the solution temperature, intending

that mild steel surface attacked severley by raising the

temperature from 30-70 C. Figure 9 and 10 show

interesting behavior with the add-on of 1 % and 10 %

CU at low and high temperatures. This is that mild

steel surface in the presence of CU is modified and

becomes smooth non merely by increasing CU

concentration but besides by increasing solution

temperature, stressing the chemosorption

mechanism suggested antecedently.

Inhibitor components and surface assimilation mechanism:

Table 5 illustrates the chief components of CU as given,

while Fig. 12 represents the molecular construction of the

chief organic components of CU and their IUPAC

names. Inspection of CU components, reveals that the

organic constituents can be classified as nitrogen-bearing

organic compounds. N-containing organic compounds

were reported in the literature as effectual corrosion

inhibitors for mild steel in acerb solutions ( Shetty et al. ,

2006 ; Popova et al. , 2003 ; Muralidharan et al. , 1995 ;

Ebenso et al. , 1999 ; Noor, 2005 ) .

Chemisorption procedure involves charge sharing or

charge transportation from the inhibitor molecules to the

metal surface. This is possible in instance of positive as

good as negative charges on this surface. The presence

of inhibitor molecules holding comparatively slackly bound

negatrons or hetero atoms ( N in the present work )

with lone-pair negatrons, with a passage metal holding

vacant, low-energy orbital facilitates the

chemosorptions mechanism ( Bentiss et al. , 2005 ) .

Figure 13 shows the suggested chemosorption

mechanism between the vacant d-orbital of Fe atoms

in mild steel surface and the N atoms of CU

organic components. It is impossible to state which

one of these organic components is responsible for

CU inhibitive action. So CU can be treated as a

bundle of inhibitors which may move synergistically.

Table 5: The mean concentration degree of the chief components of

Camel s urine

The constitutional Urea Uric acid Creatinine Chloride Phosphate Sulphate

The concentration 0.195 6.041 0.052 0.45 0.171 7.76

( g L-1 )

Fig. 12: The molecular construction and the IUPAC name

of the chief organic components of CU

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Fig. 13: The suggested chemosorption mechanism

between the vacant d-orbital of Fe atoms in

mild steel surface and the N atoms of the

organic components of CU

Decision

CU acts as a good inhibitor for the corrosion of

mild steel in 1.5 M H2SO4. The suppression

efficiency values increase with the inhibitor

concentration and the solution temperature

The surface assimilation of CU on the mild steel surface

obeys the Modified Langmuir surface assimilation isotherm

suggestion monolayer surface assimilation of CU species

O

The negative values of ( DGads ) emphasize the

spontaneousness of the surface assimilation procedure and the

stableness of the adsorbed bed on the steel surface.

O

DGads values become more negative with

increasing temperature, bespeaking that the

surface assimilation power of CU additions with the addition

of temperature

O

The estimated high, positive value of DHads ensures

that CU species is adsorbed chemically on mild

steel surface

All values of E*

app. for mild steel corrosion in

inhibited solutions were lower than that for the

uninhibited solution bespeaking the happening of

chemosorption mechanism for the CU species on

mild steel in the studied medium

The surface morphology of mild steel in absence

and presence of inhibitor revealed that with

increasing both CU concentration and solution

temperature, mild steel surface is modified and

expressions smooth

Good correlativity between the inhibitor components

and its repressive action was obtained