International Journal of Scientific & Engineering Research, Volume 7, Issue 8, August-2016 ISSN

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1 International Journal Scientific & Engineering Research, Volume 7, Issue 8, August Adsorption and surface morphological studies Corrosion Inhibition Mild Steel using bioactive compounds in chloride medium S.Chitra 1, B.Anand 2 1 Center for Research, Mahendra Engineering College, Namakkal, Tamilnadu, India. 2 Department Chemistry, Sir Theagaraya College Arts and Science, Chennai. 1 chitrachem@gmail.com Abstract Corrosion has been chronic problem to industries and has increased cost production. Seaweeds are a rich source unique bioactive compounds which are used as corrosion inhibitor for mild steel corrosion now a day. The inhibition mild steel corrosion in chloride environment was investigated using adsorption and surface morphological methods. The obtained result revealed that sea weed performed well as corrosion inhibitor in chloride environment.the inhibition efficiency increases with increase in additive concentration. The results obtained shows that various concentrations bioactive compounds inhibited corrosion in chloride solution through adsorption inhibitor molecule on mild steel surface by blocking its active sites. The use sea weeds (bioactive compounds) as an inhibitor for corrosion mild steel in chloride environment is advocated in this study. Key words: Bioactive compounds, Chloride, Corrosion, SEM, Mild steel. 1. Introduction study corrosion behaviour mild steel in sodium Many researchers have studied effects chloride solution and its control by using inhibitor marine various types organic inhibitors on corrosion algae Cladophoropsis sundanensis extract. The inhibitor resistance mild steel in different environment [1]. Most sea weed extract (SWE) was extracted with ethanol using previous studies were focused on inhibition soxhelt extractor from marine algae Cladophoropsis metals organic sundanensis. The inhibitive efficiencies inhibitor were compounds containing N, S and O atoms as corrosion determined by weight loss, adsorption parameter and inhibitors [2]. A lot research has been done with scanning electron microscopy techniques. naturally occurring substances since y are known to be 2. Materials and methods eco-friendly and with little or no side effect on 2.1.Preparation Specimen in HCl or H2SO4 solutions using humans. Among naturally occurring substances reported in corrosion study metals like brass, aluminium, tin and mild steel, re leave extracts, gums and exudates, dyes, oils from plant materials, plant seeds and fruits, and anti-bacterial drugs [3]. The mild steel when immersed in aqueous environment gets corroded due to its rmodynamic instability [4]. Therefore, corrosion behaviour and inhibition mild steel in sodium chloride environment have been given attention by several workers during last few years. The present work includes According to ASTM method as reported already [5], cold rolled mild steel strips were cut into pieces 5cm 1 cm having following composition (in percentage) % C=0.017; Si=0.007; Mn=0.196; S=0.014;P=0.009; Ni=0.013; Mo=0.015; Cr=0.043 and Fe= was used. The samples were polished, drilled a hole at one end and numbered by punching. During study, samples were polished with various grades SiC abrasive papers (from grits 120 to 1200) and degreased using Acetone. 2016

International Journal Scientific & Engineering Research, Volume 7, Issue 8, August-20

2 International Journal Scientific & Engineering Research, Volume 7, Issue 8, August Preparation inhibitor The seaweed 42 The coupons were cleaned and immersed in Cladophoropsis sundanensis containers that contain chloride medium known collected from Ramaeshwaram coastal region was picked concentration. We used glass hooks to hold coupons in with hand and immediately washed with sea water to medium. All experiments were done at room remove foreign and sand particles. Then sea weed temperature. All specimens were weighted before as air dried at room temperature and it is refluxed in immersion in medium. After every experiment, ethanol for six hours using soxhelt extractor. Residue was specimens were taken out from container, dried with concentrated and evaporated. Finally dried extracts warm air, polished with emery papers and reweighed used as inhibitor. after several washing with distilled water and acetone Determination Corrosion rate From initial and final weights specimens, The marine algae Cladophoropsis sundanensis loss weights was calculated [7]. ethanol extracts was used as inhibitor for this experiment. Corrosion Rate = 534 * W / D* A* T The corrosive medium used was 2M solution NaCl. It Where W is weight loss (g), D is density was prepared by appropriate dilution analytical grade specimen (7.85 g/cm3), A is surface area specimen NaCl with distilled water without furr (cm3) and t is immersion time. purification [6]. Table 1: Weight loss values and calculated inhibition efficiency for mild steel corrosion in 2M NaCl in presence and absence Cladophoropsis sundanensis extract. Inhibitor Concentration (M) Blank 1*10-4 2*10-4 3*10-4 4*10-4 5*10-4 ( 4 hrs) Mass Loss (6 hrs) IE% Mass Loss IE% Figure 1: Comparison inhibition efficiency Cladophoropsis sundanensis extract in various concentrations for 4hrs and 6hrs. 2016

International Journal Scientific & Engineering Research, Volume 7, Issue 8, August-2016 43 Table 2: Thermodynamic parameters for adsorption Cladophoropsis sundanensis in 2M NaCl on mild steel.

80 (a) (b) Figure 2: Langmuir s adsorption isorm for mild steel in 2M NaCl containing various concentrations Cladophoropsis sundanensis extract. [11].

3 International Journal Scientific & Engineering Research, Volume 7, Issue 8, August Table 2: Thermodynamic parameters for adsorption Cladophoropsis sundanensis in 2M NaCl on mild steel. Medium Concentration in (M) Surface coverage (θ) Gads KJ / mol-1 Kx (10-2 M-1) NaCl 5* (a) (b) Figure 2: Langmuir s adsorption isorm for mild steel in 2M NaCl containing various concentrations Cladophoropsis sundanensis extract. [11]. After immersing in inhibitor containing Figure 3: SEM images : (a) mild steel immersed in 2M NaCl and (b) mild steel immersed in Cladophoropsis sundanensis extract. 3. Results and discussion 3.1 Weight loss study Inhibition efficiency environmentally safe Cladophoropsis sundanensis extracts was tested in 2M solution NaCl solution against mild steel at room temperature by weight loss technique. Results obtained from weight loss measurements are as shown in Table 1. From obtained result, it is clear that corrosion mild steel significantly decreased by introduction extract into corrosive medium [12-13]. The increase IE seems to be proportional to its corresponding concentration with time [14]. It was revealed that adsorption and coverage extract on surface effectively inhibit corrosion by its bioactive compounds [15]. It has been observed that corrosion rates mild steel in corroding medium were reduced on addition different concentrations inhibitor. As it is believed that action corrosion inhibitors solution, entire metal surface was covered with a follows by adsorption on metal surface by layer formed with inhibitor as a barrier to corrosion, as inhibitor molecules using ir adsorption centers, it is denoted by rougher over abrasions. important 2.4 Surface characterization The mild steel immersed in blank solution and in inhibitor solution for a period 4 hour and 6 hour was removed, rinsed with double-distilled water, dried and observed in a scanning electron microscope to examine surface morphology [8-10]. The surface morphology measurements mild steel were examined using scanning electron microscope. In comparison SEM micrograms, re were a rough surface on mild steel in absence extract and a smooth surface with deposited extract in presence Cladophoropsis sundanensis extract. This confirms that extract inhibited corrosion mild steel through adsorption inhibitor molecules on metal surface to find out possible adsorption mechanism by examining experimental data with 2016

4 International Journal Scientific & Engineering Research, Volume 7, Issue 8, August possible adsorption isorms [16]. The surface coverage absence and presence extract are shown in Figure 3 (θ) was measured for all inhibitor concentrations in image (a) and (b), respectively. The SEM micrographs NaCl solution that was assessed by weight loss data, and mild steel surface in Figure 3 (a) show roughness detailed adsorption behavior was explained. The metal surface, which indicates corrosion surface in linear-relationship can be obtained on plotting c/θ as a chloride medium. The surface observed was very rough function c, with a slope unity [17]. It was found that and heavily damaged due to metal dissolution [19]. Clear linear correlation coefficients clearly prove that defects and cracks were observed on corroded surface. adsorption sea weed extract from 2M NaCl solutions However, presence inhibitor suppresses rate on Mild steel obeys Langmuir adsorption corrosion, and surface damage has been diminished isorm, as shown in figure 2. considerably [Figure 3 (b)] as compared to blank 3.2. Adsorption Parameter solution [Figure 3(a)], suggesting formation a protective Basic information on interaction between inhibitor film at mild steel surface. It can be elucidated inhibitor and mild steel surface can be proved by that surface coverage increases, which in turn results adsorption isorm and in general, inhibitors can in formation insoluble complex on surface function eir by physical (electrostatic) adsorption or metal - inhibitor complex, and surface is covered by a chemisorption with thin layer inhibitors which control dissolution metal. To acquire more information about interaction between inhibitor mild steel. molecules and metal surface, different adsorption 4. Conclusion isorms were tested. A linear-relationship can be 1. The inhibition efficiency Cladophoropsis obtained on plotting c/θ as a function c, with a slope sundanensis on corrosion mild steel in 2M NaCl unity [18]. The rmodynamic parameters K and increases on increasing concentration ΔGads for adsorption studied inhibitors on extract. Adsorption inhibitor molecules mild steel is obtained by Langmuir s adsorption extract on mild steel surface is found to obey isorm are plotted in Figure 2 and obtained values Langmuir adsorption isorm. are given in Table 2. It was found that linear 2. The negative values ΔG0ads for addition correlation coefficients clearly prove that adsorption inhibitors indicate that process adsorption sea weed extract from 2M NaCl solutions on mild studied inhibitors is spontaneous in nature and steel corrosion obeys Langmuir adsorption isorm. exormic. The negative values ΔG 0ads for addition 3. inhibitors indicate that process adsorption studied inhibitors is spontaneous in nature Inhibition efficiency values were found to show good trend with weight-loss method studies. 4. Surface morphological studies confirm that 3.3. Scanning electron microscopy analysis metal corrosion inhibition mild steel is due to surface adsorption The SEM images Mild steel specimens immersed in 2M NaCl for four hour and six hour in 2016 extract on surface.

5 International Journal Scientific & Engineering Research, Volume 7, Issue 8, August-2016 References: Singh, A.K. and Quraishi, M.A. (2011), Investigation Gaikwad, A. B. ; Patil, P.P.; Sudeshna Chaudhari. effect disulfiram on corrosion mild steel in Curr. App. Phy. 2009, 9, hydrochloric acid solution, Corrosion Science, Vol. Dandelot, S.; Robles, C.; Pech, N.; Cazaubon,A. Aqua. 53 No. 4, pp Wang, B., Du, M., Zhang, J. and Gao, C.J. (2011), Bot. 2008, 88(4), Ravichandran, R.; Nanjudan, S.; Rajendran,N. App. Electrochemical and surface analysis studies on Surf. Sci., 2004, 236, corrosion inhibition Q235 steel by imidazoline Du, X.S.; Su, Y.J. ; Li, J.X.; Qiao, L.J.; Chu,W.Y. Corr. derivative against CO2 corrosion, Corrosion Science, Sci. 2012, 60, Vol. 53 No. 1,pp Ramananda; Mayanglambam, S.; Vivek Sharma; 18. Montecinos, S. and Simison, S.N. (2011), Study Gurmeet Singh. Portu. Electrochim.Acta. 2011, 29(6), corrosion products formed on a multiphase CuAlBe alloy in a sodium chloride solution by micro-raman Khadraoui, A.; Khelifa, A.; Boutoumi, H.; Mettai, B.; and in situ AFM measurements, Applied Surface Karzazi, Y.; Hammouti, B. Portu.Electrochim. Acta. 8. Science, Vol. 257 No. 17, pp Sathirachinda, N., Pettersson, R., Wessman, S. and 2014, 32(4), Khadraoui, A.; Khelifa, A.; Boutoumi, H.; Mettai,B.; Pan, J.(2010), Study nobility chromium nitrides Karzazi, Y.; Hammouti, B. Portu.Electrochim. Acta. in isormally aged duplex stainless steels by using 2014, 32(4), SKPFM and SEM/EDS, Corrosion Science, Vol. 52 Ejikeme, P. M.; Umana, S. G.; Onukwuli, O. No. 1,pp D.;Hammouti, B. Portu. Electrochim. Acta. 2012,30(5), Muna K. Irshedat; Eyad M. Nawafleh; Tareq T.Bataineh; Riyadh Muhaidat; Mahmoud A. AlQudah; Ahmed A. Alomary; Hammouti, B.Portu. Electrochim. Acta. 2011, 31(1), Ranjana ; Nandi, M. M. Ind. J. Chem. Tech..2011, 18, Ranjana; Ranu Banerjiee ; Nandi, M. M., Ind. J.Chem. Tech. 2013, 20, Al-Mhyawi, S. R.Orient. J. Chem., 2014, 30(2), Megahed, H. E. Portu. Electrochim. Acta. 2011, 29(4), B.Anand, V. Balasubramanian, E-Journal Chemistry. 8(1) (2011):p A.K. Singh, M.A. Quraishi, Adsorption properties and inhibition mild steel corrosion in hydrochloric acid solution by ceftobiprole, J. Appl. Electrochem.41 (2011)

INFLUENCE OF MURRAYA KOENIGII (CURRY LEAVES) EXTRACT ON THE CORROSION INHIBITION OF CARBON STEEL IN HCl SOLUTION

http://www.rasayanjournal.com Vol.3, No.1 (2010),74-81 ISSN: 0974-1496 CODEN: RJCABP INFLUENCE OF MURRAYA KOENIGII (CURRY LEAVES) EXTRACT ON THE CORROSION INHIBITION OF CARBON STEEL IN HCl SOLUTION A.