This is an open access article under the CC BY license: Al-Khwarizmi Engineering Journal Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, March, (2023) P. P. 81- 98 Expired Colxacillin, Amoxicillin, and Ceflaxin Drugs as Inhibitors for Low Carbon Steel Corrosion in Sodium Chloride Ameer Jawad* Shatha K. Muallah** Kafa Khalaf Hammud*** *,** Department of Bio-Chemical Engineering / Al-Khwarizmi Engineering College/ Baghdad University/ Baghdad/ Iraq ***Ministry of Science and Technology/Baghdad/ Iraq *Email: Amir.jawad74@yahoo.com **Email: drshathamuallah@gmail.com ***Email: kafaa_khalaf@yahoo.com (2022 November 16 2022; Accepted Augest 22Received ) https://doi.org/10.22153/kej.2023.11.003 Abstract The ability to inhibit corrosion of low carbon steel in a salt solution (3.5%NaCl) has been checked with three real expired drugs (Cloxacillin, Amoxicillin, Ceflaxin) with variable concentrations (0, 250, 500, 750) mg/L were examined in the weight loss. The inhibition efficiency of the Cloxacillin 750 mg/L showed the highest value (82.8125 %) and the best inhibitor of the rest of the antibiotics. The different concentrations of Cloxacillin drug (0, 250, 500, 750) mg/L and temperature (25, 35, 45, 55) oC were studied as variables with potentiodynamic polarization, Scanning Electron Microscopy (SEM) for surface morphology and electrochemical impedance spectroscopy (EIS) depending on current values and the resistance of charge to calculate the inhibition efficiency. The main observations of these tests were that polarization curves showed a mixed-type inhibition of expired Cloxacillin. The inhibition efficiency increased with increasing Cloxacillin concentration but not with increasing temperature. Keywords: Polarization, Inhibitor, Expired Drugs, Cloxacillin, Amoxicillin, Ceflaxin, Salt corrosion. 1. Introduction Due to the good mechanical properties of low Carbon steel alloy, this material is the generally used in processing plants and household applications, availability, and comparatively low cost[1, 2]. Chloride-containing solutions, like seawater, are in most cases, corrosive because the depolarization impacts carbon ions, the main case is the low resistance of low carbon steel to corrosion [3, 4]. It has been found that one of the preferable ways of keeping metals from corrosion comprises the use of expired antibiotics as corrosion inhibitors. The prevention or decreasing of corrosion impacts on metals like low carbon steel by using expired antibiotics is a method created because of the toxicity of many corrosion inhibitors, therefore; the researchers in the corrosion field selected compounds that are friendly to the environment, safe, and non-toxic such as pharmaceutical drugs [5]. Their capability to make a complex with metal ions on the metal surfaces through their functional groups. Perfectly the drugs soluble in the water besides their high purity and inexpensively as expired antibiotics are important factors in choosing expired drugs as corrosion inhibitors [6]. These characteristics would support the employment of expired drugs as corrosion inhibitors in various aqueous solutions. Generally, expired antibiotics are large surface area materials, including functional groups (N) with an effective cover above the surface of low- carbon steel for the adsorption process[7, 8, 9]. mailto:Amir.jawad74@yahoo.com mailto:kafaa_khalaf@yahoo.com https://doi.org/10.22153/kej.2023.11.003 Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 82 The following table gives a comparison of (Inhibition Efficiency) IE percentage between various antibiotics (Table 1.). Table 1, Examples of pharmaceutical inhibitors with their IE percentage[1]. Inhibitor Sample Medium IE % Carvedilol Carbon steel HCl 98.94 Amifloxacin Mild steel 17.1 Enrofloxacin Mild steel 18.3 Cefotaxime Mild steel 90.0 A b sA b s N S O H N O NH2 O HO Amoxicillin C16H19N3O5S M.Wt. 365.4 gm/mole N O NH O NH2 S O HO Cephalexin C16H17N3O4S M.Wt. 347.4 gm/mole N O Cl O N H N O S O OH Cloxacillin C19H18ClN3O5S M.Wt. 435.9 gm/mole HO Fig.1. Chemical structure of the expired drugs used in the test with molecular weights for each one. Here, the main goal is to test the corrosion– inhibition relationship as its rate and its effects on the low carbon steel in a medium of (NaCl) with the absence and presence of an inhibitor and on another occasion when the inhibitor is used in different concentrations with different temperatures. The inhibitors, as shown in the experimental section, were real expired antibiotics because of their cost and economical serving forwarding limitation of environmental pollution with pharmaceutically active compounds. 2. Experimental Methods 2.1 Materials The sample is low carbon steel with a chemical composition of “weight %” (0.18 Carbon, 0.9 Manganese, 0.05 Sulphur and the rest is Iron). The expired drugs "Cloxacillin, Amoxicillin, and Ceflaxin” were tested as corrosion inhibitors. The antibiotics were collected from (Samara`a drugs industry, Iraq, Samara) as a pure expired antibiotics for two years. Sodium Chloride solution NaCl as a corrosive medium from CDH company, India. 2.2 Weight loss method The experiments of this method were done by immersion of low carbon steel specimens with size (3x3x1) cm 3 in 3.5% NaCl (2 g of salt in 60 ml of water) solution for five days. Also, low carbon steel was immersed in the same corrosive media with the presence of one of the three bioactive inhibitors (250, 500, 750) mg/L for a period of 5 days. The obtained results were Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 83 tabulated in Table 2. using the equations listed below [10]. The specimens are cleaned before and after the test using a different aluminum paper of various degrees (p40, p50, p100, p140, p220). 𝐼𝐸% = 𝜃 ∗ 100 … (1) 𝐼𝐸% = 1 − 𝑊𝑖𝑛ℎ 𝑊𝑓𝑟𝑒𝑒 …(2) 𝑐𝑜𝑟𝑟𝑜𝑠𝑖𝑜𝑛 𝑟𝑎𝑡𝑒 = 𝑤𝑒𝑖𝑔ℎ𝑡 𝑙𝑜𝑠𝑠 (𝑔𝑟𝑎𝑚𝑠)∗𝑘 𝑎𝑙𝑙𝑜𝑦 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑔 𝑐𝑚3 ∗𝑒𝑥𝑝𝑜𝑠𝑒𝑑 𝑎𝑟𝑒𝑎∗𝑒𝑥𝑝𝑜𝑠𝑢𝑟𝑒 𝑡𝑖𝑚𝑒(ℎ𝑟) …(3) Where IE% is the inhibition efficiency, 𝜃 is the surface coverage while 𝑊𝑖𝑛ℎ and 𝑊𝑓𝑟𝑒𝑒 are the weight loss in the presence and absence of inhibitor respectively. 2.3 Electrochemical tests From weight loss results, the inhibitor Cloxacillin shows the best results in protecting metal surfaces due to the high molecular weight of the inhibitor [11]. Cloxacillin was chosen to complete the other tests as SEM and electrochemical tests. The electrochemical tests were done in a three-electrode cell with platinum as the counter electrode, saturated calomel as the reference electrode (SCE), and low carbon steel as the working electrode. Open circuit potentials OCP were carried out in the electrolyte before running the electrochemical measurements [12]. The specimens were immersed in the electrolyte for 30 min, followed by OCP measurement for 60 min. When calculating the corrosion current, the method can be used is the Stern-Geary by extrapolation of anodic and cathodic Tafel lines to the point that gives logicorr and the conformable corrosion potential (Ecorr) for inhibitor-free salt and different concentration of the antibiotics used. All practical experiments were done at 25 ◦ C [13]. 2.3.1 Tafel polarization A Potentiostat was used in this test, and kinetics parameters were found from Tafel curves such as corrosion current (Icorr), cathodic Tafel slope (βc), anodic Tafel slope (βa), corrosion potential Ecorr and IE%. The experiment was done by using three concentrations of Cloxacillin as corrosion inhibitor (0, 250, 500, and 750) mg/L, with four degrees of temperature (25, 35, 45, and 55) ◦ C for each concentration of inhibitor. 2.3.2 Electrochemical Impedance Spectroscopy (EIS) Electrochemical Impedance Spectroscopy (EIS) was carried out at open circuit potential in the frequency range of (10 -1 -10 5 ) Hz. EIS plots are found in the Nyquist and bode diagrams. The electrochemical studies were carried out with an electrochemical CS 310 CorrTest workstation, Iraq, Baghdad, University of Baghdad (Al Khwarizmi Engineering College). Fig. 2. Randle circuit in Impedance spectroscopy. 2.4 Surface study Surface morphology as an indicator of how much salts affect the pieces of low carbon steel and how the corrosion inhibitors resist the corrosion and save the surface is tested by a Scanning Electron Microscope (SEM). The specimens with Cloxacillin (inhibitor) were chosen for SEM by the Tescan mirah3 instrument (Dansh Bryan Company, Tehran, Iran ) where the scanned area was (1-6) μm. 3. Result and Discussion 3.1 Weight loss test Weight loss measurements of low carbon steel samples were reported after 5 days for three real expired drugs (Cloxacillin, Amoxicillin, Ceflaxin) as shown in Table 2. The maximum IE, % at Cloxacillin 750 mg/L showed the highest value (82.8125 %) and the best inhibitor of the rest of the antibiotics. Table 3 showed the weight loss in the absence of inhibitors. Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 84 Table 2, Weight loss results of the three bioactive inhibitors. [W free = 0.064 gm] Table 3, Weight loss results in the absence of inhibitor. 3.2 Electrochemical tests Potentiodynamic polarization measurements have been carried out. Potentiodynamic polarization curves for low carbon steel metal in 3.5% NaCl solution with different concentrations of Cloxacillin expire drug are displayed in Figures (3-5) with different temperature (25, 35, 45, 55) o C. Cloxacillin was chosen for the test of Tafel curves because it gave the best result in the weight loss experiment as 82% IE%. May be noticed Table 4, the anodic and cathodic Tafel slopes (βa, βc) curves with the presence of inhibitors and which turns lower current density (Icorr). It can be observed in the presence of inhibitors both the anodic and cathodic curves are shifting towards lower current density. Which reveals that inhibitor molecules are adsorbed on the metal surface. Although the corrosion potential of the metal nearly remain constant, there is a slight shift towards more positive potential at higher concentrations with respect to the corrosion potential observed in the absence of inhibitor. Figures (3-6) show the effect of inhibitor concentration and temperature on current density and voltage with four temperature degrees (25, 35, 45, 55)◦C respectively. It is noticed that the same concentration of the inhibitor with different temperature sometimes increases and other decreases, but at 750 mg/l of Cloxacillin at 35 o C gives minimum corrosion rate. Table 4, Electrochemical study of Cloxacillin Inhibitor name Antibiotic conc., mg/L W inh, gm Surface coverage ( θ) IE, % Cloxacillin 250 0.023 0.640625 64.0625 500 0.021 0.671875 67.1875 750 0.011 0.828125 82.8125 Amoxicillin 250 0.033 0.484375 48.4375 500 0.030 0.53125 53.1250 750 0.021 0.671875 67.1875 Ceflaxin 250 0.034 0.46875 46.8750 500 0.031 0.515625 51.5625 750 0.028 0.562500 56.2500 Solution kind Original weight (g) Final weight (g) The difference in weight(g) Corrosion rate (mm/a) NaCl 7.03 6.9834 0.064 0.182 Conc., mg/L Temp.oC Ecorr (V/SCE) I corr*10 -6(A/cm2) Corrosion rate (mm/a) βa(V/dec) βc(V/dec) IE% Blank 25 -0.95073 15.5 0.18200 267.47 112.79 - 35 -0.72475 21.4 0.25097 86.564 456.7 - 45 -0.86188 69.2 0.81135 252.57 156.08 - 55 -0.77695 15.1 0.17756 77.437 231.38 - 250 25 -0.78254 6.91 0.081114 71.752 200.77 55.3 35 -0.84599 4.60 0.053967 82.62 147.35 78.5 45 -0.84487 6.07 0.071241 88.361 150.83 91.2 55 -0.83344 4.46 0.05821 77.581 140.9 70.5 500 25 -0.77939 6.50 0.076252 71.197 212.99 58.0 35 -0.80915 7.07 0.082971 73.877 137.09 66.9 45 -0.79384 11.7 0.13686 70.256 211.44 83.1 55 -0.82055 8.67 0.10175 74.232 173.69 42.7 750 25 -0.75942 1.95 0.22825 67.527 67.527 87.4 35 -0.85093 3.51 0.041119 86.244 86.244 83.6 45 -0.84281 5.58 0.065418 79.704 79.704 91.9 55 -0.84777 5.70 0.066828 88.548 88.548 62.4 Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 85 Fig. 3. Variation of inhibitor concentration on current density and voltage at 25 o C. Fig. 4. Variation of inhibitor concentration on current density and voltage at 35oC Fig. 5. Variation of inhibitor concentration on current density and voltage at 45oC Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 86 Fig. 6. Variation of inhibitor concentration on current density and voltage at 55 oC. 3.3 Electrochemical Impedance Spectroscopy (EIS) In these experiments, Cloxacillin was used with 3.5% NaCl solution at different temperature degrees by using an electrical circuit called Randle circuit where Cdl is called double-layer capacitor, Rct is the charge transfer resistance and Rsol is the solution resistance as shown in Table 4 [14]. Experimental results of this method are shown in Figures (7-14) Nyquist, Bode and (log(f)-log(z)) and (f)-phase) diagrams of low- carbon steel, which were obtained in 3% of NaCl solution in the absence and presence of various concentrations of Cloxacillin are shown. It can be seen from Figures (7a-14a) the Nyquist plot of the metal shows a depressed semi-circular shape. The obtained graphs (7b,c-14b,c) showed how bio- inhibitor affected the real and imaginary resistance introduced where Zʺ is the imaginary resistance, Zʹ is the real resistance, f is the frequency and θ ◦ is the phase values. (a) 50 -50 -150 -250 -350 -450 -550 -650 -750 -100 0 100 200 300 400 500 600 700 Z' '/Ω cm 2 Z'/Ωcm 2 Blank concentration of inhibitor FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 87 (b) (c) Fig. 7. The EIS test for blank concentration of inhibitor at 25◦C with the fitting result. . (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz Blank concentration of inhibitor FitResult 200 0 -200 -400 -600 -800 -1000 -1200 -1400 -200 0 200 400 600 800 1000 1200 1400 Z' '/Ω cm 2 Z'/Ωcm 2 Blank concentration of inhibitor FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 88 (b) (c) Fig. 8. The EIS test for blank concentration of inhibitor at 35◦C with the fitting result. . (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz Blank concentration of inhibitor FitResult 100 -100 -300 -500 -700 -900 -1100 -200 0 200 400 600 800 1000 Z' '/Ω cm 2 Z'/Ωcm 2 Blank concentration of inhibitor FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 89 (b) (c) Fig. 9. The EIS test for blank concentration of inhibitor at 45◦C with the fitting result.. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 40 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz Blank concentration of inhibitor FitResult 50 -50 -150 -250 -350 -450 -550 -100 0 100 200 300 400 500 Z' '/Ω cm 2 Z'/Ωcm 2 Blank concentration of inhibitor FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 90 (b) (c) Fig. 10. The EIS test for blank concentration of inhibitor at 55◦C with the fitting result. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz Blank concentration of inhibitor FitResult 100 -100 -300 -500 -700 -900 -1100 -1300 -200 0 200 400 600 800 1000 1200 Z' '/Ω cm 2 Z'/Ωcm 2 750 mmg inhibitor FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 91 (b) (c) Fig. 11. The EIS test for 750 mg/l concentration of inhibitor at 25◦C with the fitting result. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz 750 mmg inhibitor FitResult 50 -150 -350 -550 -750 -950 -200 0 200 400 600 800 Z' '/Ω cm 2 Z'/Ωcm 2 750 mmg FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 92 (b) (c) Fig. 12. The EIS test for 750 mg/l concentration of inhibitor at 35◦C with the fitting result. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 20 0 -20 -40 -60 -80 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz 750 mmg FitResult 50 -50 -150 -250 -350 -450 -550 -650 -100 0 100 200 300 400 500 600 Z' '/Ω cm 2 Z'/Ωcm 2 750 mmg FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 93 (b) (c) Fig. 13. The EIS test for 750 mg/l concentration of inhibitor at 45◦C with the fitting result. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. (a) 40 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz 750 mmg FitResult 50 -50 -150 -250 -350 -450 -550 -650 -100 0 100 200 300 400 500 600 Z' '/Ω cm 2 Z'/Ωcm 2 750 mmg FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 94 (b) (c) Fig. 14. The EIS test for 750 mg/l concentration of inhibitor at 55◦C with the fitting result. (a) Nyquist plot, (b, c) Bod (log versus |z|), and phase angle (log f versus ∝𝟎) plots. It was noticed that the impedance spectra exhibit a semi-circle caused by the frequency dispersion effect which means that the corrosion of low carbon steel in NaCl solution was controlled by a charge transfer process[15]. The diameter of the capacitive loop in the presence of an inhibitor was larger than in the absence of the inhibitor (blank concentration) and increased with inhibitor concentration. This observation conflicts with the increasing impedance of inhibited metal with increasing concentration. This irregular behavior is generally caused by the roughness and inhomogeneity of the alloy surface [5]. The charge transfer resistance Rct value increased with increasing of concentration. But it turns out that the capacitance values (Cdl) of the double-layer decrease, and this decrease is expected in the presence of the local dielectric constant. This causes an increase in the thickness of the electrical double layer [16]. It is observed from Table 5 the 750 mmg concentration of Cloxacillin at 45 o C give the maximum IE% and maximum Rct . 40 20 0 -20 -40 -60 -80 -100 10 -2 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 θ ° f/Hz 750 mmg FitResult Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 95 Table 5, Values of the EIS test for absence and presence of Cloxacillin. Conc.mg/l Temp.C RCt IE% Cdl 𝝁𝒇 Blank 25 174.65 - 0.543 Blank 35 600.01 - 0.345 Blank 45 347.95 - 0.231 Blank 55 135.86 - 0.124 750 25 835 88.04 0.431 750 35 955 83.78 0.335 750 45 1135 90.46 0.211 750 55 795 60.76 0.105 3.4 Surface Analysis The SEM micrographs for low carbon steel in presence and absence of 750 mg/L of Cloxacillin are shown in Figure 15(a-d). It is obviously seen from Figure 15a that the metal surface is strongly damaged in the absence of the inhibitor. In Figure 15d showed that the film is stable and protective which support the results of electrochemical measurements which are discussed above. (a) (b) (c) (d) Fig. 15. SEM of (a) blank (b) 250 mg/L (c) 500 mg/L (d) 750 mg/L of Cloxacillin. 3.5 The mechanism of inhibition The adsorption of expired antibiotics are to be the first step at the alloy/solution interface done in the mechanism of corrosion inhibition in the salt solution medium[17]. This becomes acceptable for the first step during the adsorption of an antibiotics drug as organic materials on the surface of the alloy, and this involves by substituting one or more water molecules adsorbed on the surface of the alloy[18], as in equation below[19] : Organic (inhibitor) + xH2O→ organic ( adsorbed) + x H2O … (3) Ameer Jawad Al-Khwarizmi Engineering Journal, Vol. 19, No. 1, P.P. 81- 98 (2023) 96 4. Conclusion The studied of expired antibiotics drugs, (cloxacillin, amoxicillin, cephalexin) can be used as good organic inhibitors for corrosion in salt solution on the low carbon steel metal in 3% NaCl as a salt solution. Cloxacillin has better inhibition, because of its high molecular weight, molecular surface, and functional groups as compared to the two others expired antibiotic drugs. Increasing the concentration of antibiotics increased the inhibition efficiency and decreased corrosion rate. The minimum corrosion rate appears at temperature 35 ◦ C with 750 mg/l concentration of Cloxacillin. EIS plots indicated that Rct values increase whereas Cdl values decrease in presence of Cloxacillin. The changes in the impedance parameters confirmed the strong adsorption of the inhibitor on the steel surface. SEM studies revealed that Cloxacillin form protective surface film. 5. References [1] A. S. Fouda, M. A. El Morsi, and T. 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(2023) 81-98، صفحة 1، العدد19لدمجلة الخوارزمي الهندسية المج امير جواد خلف 98 المضادات الحيوية المنتهية الصالحية )الكولكساسبلين و االموكسيسيلين والسيفالكسين( الحاصل للحديد القليل الكاربون في محلول ملح كلوريد الصوديوم للصدأكمثبطات مير جواد خلف* شذى كاظم عبد اللطيف** كفاء حمود خلف***أ *،**قسم الهندسة الكيميائية االحيائية/ كلية الهندسة الخوارزمي/ جامعة بغداد/ العراق بغداد/ العراق***وزارة العلوم والتكنولوجيا/ Amir.jawad74@yahoo.com :البريد االلكتروني* drshathamuallah@gmail.com**البريد االلكتروني: kafaa_khalaf@yahoo.com***البريد االلكتروني: الخالصة ة أدوية منتهية % كلوريد الصوديوم( بثالث 3,5تم التحقق من القدرة على منع التآكل في الفوالذ منخفض الكربون في محلول ملح ) حص والف (EIS) كيميائيةوالتحليل الطيفي للمقاومة الكهرو الكهربي،واستقطاب الجهد الوزن،الصالحية. تم اختبار التثبيط باستخدام إنقاص موكسيسيلين، تم فحص ثالثة عقاقير منتهية الصالحية )كلوكساسيلين، أ الوزن،في إنقاص . لتشكل السطح (SEM) المجهري اإللكتروني ة التركيز لكل المضادات تزداد مع زياد الطريقة تبين أن كفاءة التثبيط ( ملجم / لتر بهذه750، 500، 250، 0سيفالكسين( بتركيزات متغيرة ) سيلين أفضل مثبط لبقية وهذا جعل الكلوكسا (،٪82.8125ملجم / لتر من الكلوكساسيلين أعلى قيمة لكفاءة التثبيط ) 750الحيوية. حيث أظهر .المضادات الحيوية ( درجة 55، 45، 35، 25( ملجم / لتر ودرجة الحرارة )750، 500، 250، 0ساسيللين )تمت دراسة تأثير التراكيز المختلفة لعقار كلوك لقيم الحالية ومقاومة الشحنة ااعتمادًا على (EIS) مئوية كمتغيرات مع االستقطاب الديناميكي الفعال والتحليل الطيفي للمقاومة الكهروكيميائية وكساسيللين ا من نوع الكلذه االختبارات هي أن منحنيات االستقطاب أظهرت تثبيطًا مختلطً كانت المالحظات الرئيسية له. لحساب كفاءة التثبيط .منتهي الصالحية. زادت كفاءة التثبيط مع زيادة تركيز الكلوكساسيلين ولكن ليس مع زيادة درجة الحرارة mailto:Amir.jawad74@yahoo.com*البريد mailto:Amir.jawad74@yahoo.com*البريد mailto:drshathamuallah@gmail.com mailto:kafaa_khalaf@yahoo.com