Corrosion and Dye

Weight loss, thermometric and potentiometric methods have been used to study the corrosion inhibition of aluminum in HCl solution by four newly synthesised Mannich bases viz 3-oxo, 3-phenyl, N,N-dimethyl propanamine hydrochloride (MB₁), 3,5-dioxo,5-phenyl N,N-dimethyl pentanamine hydrochloride(MB₂), 2,2-dimethyl,3-oxo N,N dimethyl butanamine hydrochloride (MB₃) and 3-oxo N,N-dimethyl butanamine hydrochloride((MB₄).Results of inhibition efficacies obtained from said methods are in good agreement with each other. Efficacy of inhibitor increases with increasing concentration of inhibitor as well as that of HCl solution.

The adsorption and inhibition of Aluminium corrosion in 1.0 M HCl using different concentrations of extracts of Baissea axillaris was investigated at 303 and 323K using weight loss technique. Weight loss and corrosion rate increased with increase in temperature both for the free acid and inhibited solutions, with marked reluctance to increase in both observable in for the presence of the extracts, varying with the extract concentration. Inhibition efficiency increased with increase in the concentration of the extract. The maximum inhibition efficiency of 86.3% was obtained for 10 µg/L extract but decreased to 68.4 % on increasing the temperature from 303 K to 323 K. The adsorption was best described by the Temkin and Langmuir adsorption isotherm from where negative Gibbs free energy change was obtained indicating spontaneous adsorption while negative heat of adsorption was obtained indicating exothermicity. Activation Energy was deduced from the Arrhenius equation while thermodynamic approach yielded the heat of adsorption.

Two cationic surfactants namely; N-(2-hydroxyehtyl)-N,N-dimethyldodecane-1-aminium bromide (I) and , N-(2-(2-mercaptoacetoxy)ethyl)-N,N-dimethyl dodecan-1-aminium bromide (II) were synthesized and characterized using FTIR and NMR spectroscopic methods. The two synthesized surfactants were evaluated as corrosion inhibitors for X- 65 type carbon steel in oil wells formation water under CO2 environment at 50 0C and antimicrobial agents against sulfate reducing bacteria (SRB). It was found that the percentage inhibition efficiency (?%) was increased by increasing the inhibitor concentration until the critical micelle concentration (CMC) is reached. Potentiodynamic polarization curves indicated that the inhibitors under investigation act as mixed type. The data obtained from electrochemical impedance spectroscopy (EIS) were analyzed to model the corrosion inhibition process through equivalent circuit. The nature of the protective film formed on carbon steel surface was analyzed by SEM and EDX techniques. The serial dilution method was used to evaluate the inhibiting effect of these compounds on the sulfate reducing bacteria growth. The results showed that the prepared compounds have good antimicrobial activities against the SRB as well as they have acceptable efficiency as corrosion inhibitors for X- 65 type carbon steel in oil wells formation water.

Corrosion inhibition efficiency of newly synthesized Schiff’s bases viz. N-(4-N,N’ dimethyl amino benzal)-1- naphthyl amine (SB₁), N-(4-methoxy benzal)-1-naphthyl amine (SB₂) and N-(4-methoxy benzal)-2- amino pyridine (SB₃) for aluminium in HCl solution was studied using weight loss, potentiometric and thermometric  methods. Inhibition efficiency was found to be increase with increasing concentration of inhibitor as well as with acid strength. Results obtained by all methods have been found in good agreement with each other. Results revealed that SB₂ is better corrosion inhibitor than SB₁ and SB₃. Maximum efficiency was found 99.23% in 2.5N HCl solution for 0.4% concentration of SB₂.

Corrosion is the primary means by which metals deteriorate. Most metals corrode in contact with water and also moisture in the air, acids, bases, salts, aggressive metal polishes and other corrosive solids and liquid chemicals. A suitable, effective and economical method has to be adopted depending upon the metal and its environment. Mild steel is of high industrial value. Metals, when subjected to surface treatment such as painting, enameling etc. should have clean surface, free from rust or oxide scales. For removing these rusts and scales, metals are immersed in acid solutions known as acid pickling bath. Generally hydrochloric acid is used in pickling bath. However, now- a- days sulphuric acid has replaced hydrochloric acid as pickling solution due to its economic advantage.

This work was aimed to prepare four non ionic surfactants based on tolyl triazole (I, II, III and IV), and evaluate their efficiency as corrosion inhibitors for X – 65 type carbon steel in deep oil well formation using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The experimental results showed that these inhibitors revealed a very good corrosion inhibition even at low concentrations. It was found that, the adsorption ability of the surfactant molecules on carbon steel surface increased with the increase of both ethylene oxide units and molecular size. Critical micelle concentration (cmc) represents the key factor for the selected surfactants. Potentiodynamic polarization curves indicate that the inhibitors under investigation act as mixed type i.e., promoting retardation of both anodic and cathodic discharge reactions. Also, EIS data showed that both (I %) and charge transfer resistance (Rt) are increased where as electrochemical double layer resistance (Cdl) is decreased. Finally, scanning electron microscope (SEM) and energy dispersive X- rays analysis (EDX) were used to study the nature of the protected film formed on carbon surface.

Electropolishing of copper in phosphoric acid is considered as corrosion rate of copper and due to the economic importance of copper there are several researches deals with acceleration and inhibition of this process. From the previous studies this process may be controlled by the presence of some materials which may cause acceleration or inhibition of this process. In this paper the electropolishing process inhibited with different ratio by addition of some organic phenols derivatives by addition with concentration ( 10-5 - 10-2 mol. l -1 ).The results reveal that organic phenols have strongest inhibitive effect ranging from 4.92 to 40.98 % and the thermodynamic parameters and as well as adsorption isotherm were given.

The dye, Grey BL was adsorbed on an absorbent prepared from mature leaves of the Arasu tree (ficus relegosia) leaves powder(ALP). In order to understand the adsorption behavior of Arasu Biomass Carbon, batch type experiments, effect of PH Contact time, Carbon dose are conducted and properly examined. At PH 7 the dye studies could be removed effectively. The Isothermal data fitted with both Langmuir and Freundlich model. The adsorption processes followed the first order rate kinetics. Mathematical Equations have been designed for the wide range of applications. The results in this study indicated that Arasu Leaves Powder was an attractive candidate for removing dye from industrial effluent and waste water.

The use of sumac plant extract as corrosion inhibitor for ?-brass in nitric acid solution was investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) measurements. It was found that sumac extract behaves as inhibitor. The inhibition efficiency increases with increasing sumac concentration, but decreases with raising the temperature. The adsorption of sumac on the ?-brass surface follows Langmuir's adsorption isotherm. The effect of the temperature on the corrosion rate of ?-brass in 1M nitric acid was studied. Potentiodynamic polarization studies showed that sumac extract is mixed type inhibitor and the results obtained from different techniques are in good agreement.

Weight loss and thermometric methods have been used to study the corrosion inhibition efficiency of aluminium in HCl solution by naturally occurring Commiphora wightii and four newly synthesised Mannich bases. Result of inhibition efficiencies obtained from both methods are in good agreement with each other. Efficiencies of inhibitors increase with increasing concentration of inhibitor.The efficiencies of mannich bases have been compared with naturally occurring Commphora wightii.The efficiency of Commiphora wightii has been found much more than Mannich bases.