Moses M. Solomon

In-situ preparation, characterization and anticorrosion property of polypropylene glycol/silver nanoparticles composite for mild steel corrosion in acid solution

A novel polypropylene glycol/silver nanoparticles (PPG/AgNPs) composite was prepared in-situ using natural honey as the reducing and capping agent. Characterization of the composite was done by UV-Vis spectroscopy, FTIR, TEM, XRD, and EDS. The TEM results reveal that the nanoparticles are spherical in shape. XRD and EDS results confirm the presence of elemental silver in the polymer matrix. The influence of the prepared composite on the corrosion inhibition of mild steel in 0.5M H2SO4 solution was studied by weight loss, electrochemical, SEM, EDS, and water contact angle measurements. Results show that PPG/AgNPs is effective inhibitor for mild steel in 0.5M H2SO4 solution and adsorbs onto the metal surface via chemisorption mechanism. Maximum inhibition efficiency of 94% is afforded by the highest studied concentration of PPG/AgNPs at 333K from weight loss measurements. Potentiodynamic polarization results reveal that the composite acts as a mixed-type corrosion inhibitor. Adsorption of PPG/AgNPs composite onto the mild steel surface follows Temkin adsorption isotherm. The SEM, EDS, and water contact angle images confirm the formation of PPG/AgNPs protective film on the mild steel surface.

Carboxymethyl Cellulose/ Silver Nanoparticles Composite: Synthesis, Characterization and Application as a Benign Corrosion Inhibitor for St37 Steel in 15% H2SO4 Medium.

This study has been designed to boost the inhibition efficiency and stability of carboxymethyl cellulose (CMC) and this objective has been achieved by incorporating silver nanoparticles (AgNPs) generated in situ by reduction of AgNO3 using natural honey into CMC matrix. Characterization of CMC/AgNPs composite was done using transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectroscopy (UV-vis), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS). Weight loss, electrochemical (dynamic electrochemical impedance spectroscopy, electrochemical impedance spectroscopy, and potentiodynamic polarization) supported by surface assessment (SEM, atomic force microscope, and FTIR) techniques are deployed for the anticorrosion studies of CMC/AgNPs on St37 specimen in 15% H2SO4 medium. CMC/AgNPs performs better than CMC. At 25 °C, optimum inhibition efficiency of 93.94% is afforded by 1000 ppm of CMC/AgNPs from DEIS method. Inhibition efficiency of 96.37% has been achieved from weight loss method at 60 °C. CMC/AgNPs is found to retard both the anodic and cathodic reactions and the adsorption is explained using Langmuir adsorption isotherm. AFM and SEM graphics reveal smoother surface for St37 sample in the acid solution containing inhibitor than inthe solution without the inhibiting agent. FTIR and EDS results show that CMC/AgNPs molecules were adsorbed on the metal surface.

Recent Developments on the Use of Polymers as Corrosion Inhibitors - A Review

The use of corrosion inhibitors is the one the most economical and practical means of controlling metallic corrosion in different corrosive media. Interest on the use of eco-friendly organic compounds as corrosion inhibitors has extended to the use of polymers to inhibit metallic corrosion. The use of polymers as corrosion inhibitors has attracted attention and has gained wide acceptance in recent times. This has been attributed to a number of factors namely: (i) they are low cost and stable to metallic materials in acid media, (ii) they possess multiple adsorption sites, (iii) through their functional groups, they form complexes with metal ions and on the metal surface these complexes occupy a large area, thereby blanketing the surface and protecting the metal from corrosive agents present in the solution. A number of synthetic and natural polymers as metallic corrosion inhibitors have been investigated and reported. As an update to previous review work on the use of polymers as corrosion inhibitors, the present review presents most of the contributions made to the literature on the use of polymers as corrosion inhibitors of diverse metals in different corrosive media in the last four (2010-2013) years. Metals have continued to be a choice raw material in areas such as structural, fabrication, electrical and electrochemical, hot-dip galvanizing, etc. This usage stem from the many interesting properties of metals which include: high melting and boiling points; characteristic lustre; malleability; ductility; hardness with great tensile strength; relatively high densities; and good conductivity. Unfortunately, these properties deteriorate when metals interact with certain elements that recur within their environments; a process which is technically called corrosion. The rate and extent to which metal corrode depend on two broad factors: the nature of the metal and the nature of the corroding environment. The nature of the metal encompasses the position of the metal in galvanic series (metals in the active zone of the galvanic series corrode faster than those in the noble zone), overvoltage (reduction in overvoltage of the corroding metal promotes corrosion process), relative areas of anodic and cathodic parts (when two dissimilar metals are in contact, the corrosion of the anodic part varies as the ratio of the area of cathodic part), purity of metal (impurities present in a metal give rise to heterogeneous state which form minute electrochemical cell and as a consequence, corrosion of the anodic part is accelerated), physical state of the metal (grain size, stress orientation of crystals, etc. affect corrosion rate), nature of surface film (the specific volume ratio which is the ratio of

Performance evaluation of poly (methacrylic acid) as corrosion inhibitor in the presence of iodide ions for mild steel in H2SO4 solution

The inhibition performance of poly (methacrylic acid) (PMAA) and the effect of addition of iodide ions on the inhibition efficiency for mild steel corrosion in 0.5 M H2SO4 solution were investigated in the temperature range of 303–333 K using electrochemical, weight loss, scanning electron microscopy (SEM), and water contact angles measurements. The results show that PMAA is a moderate inhibitor for mild steel in 0.5 M H2SO4 solution. Addition of small amount of KI to PMAA significantly upgraded the inhibition efficiency up to 96.7%. The adsorption properties of PMAA and PMAA + KI are estimated by considering thermodynamic and kinetic parameters. The results reveal that PMAA alone was physically adsorbed onto the mild steel surface, while comprehensive adsorption mode characterized the adsorption of PMAA + KI. Adsorption of PMAA and PMAA + KI followed Temkin adsorption isotherm. The SEM and water contact angle images confirmed the enhanced PMAA film formation on mild steel surface by iodide ions.

Comparative Study of the Corrosion Inhibition Efficacy of Polypropylene Glycol and Poly (Methacrylic Acid) for Mild Steel in Acid Solution

The performance of polypropylene glycol (PPG) and poly (methacrylic acid) (PMAA) as corrosion inhibitors for mild steel in acid solution was assessed by weight loss, electrochemical (electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic polarization), and surface analysis (water contact angles) techniques. Results obtained showed that both polymers inhibited mild steel corrosion but PPG was the best inhibitor. Inhibition efficiency increased with the increase in inhibitor concentration but decreased with temperature rise. Polarization results show that both PPG and PMAA behaved as a mixed-type inhibitors. The adsorption of the polymers onto the mild steel surface followed Temkin adsorption isotherm model. The variation of inhibition efficiency with temperature point toward physical adsorption which is supported by the kinetic and thermodynamic parameters derived from the experimental data. Water contact angle measurement results show that the polymers were adsorbed onto the mild steel surface. GRAPHICAL ABSTRACT

Effect of polyvinylpyrrolidone – polyethylene glycol blends on the corrosion inhibition of aluminium in HCl solution

Purpose – The purpose of this paper is to investigate the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and blended formulations on the corrosion inhibition of aluminium in HCl solutions at 30-60°C and to study the mechanism of action. Design/methodology/approach – The inhibitive effect of the homopolymers and polymer blend was assessed using weight loss and hydrogen evolution methods at 30 and 60°C. The morphology of the corroding aluminium surface without and with the additives was visualized using atomic force microscopy. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption. Findings – Results obtained show that inhibition efficiency (η%) increases with increase in concentration of the polymers but decreases with increase in temperature. The inhibition efficiency of the homopolymers and their blends decreased with rise in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two...

Synergistic corrosion inhibition effect of 1-ethyl-1-methylpyrrolidinium tetrafluoroborate and iodide ions for low carbon steel in HCl solution

Abstract Investigation into the corrosion inhibition of low carbon steel in 0.1-M HCl solution by 1-ethyl-1-methylpyrrolidinium (EMTFB) and the effect of KI addition on the inhibition efficiency was carried out using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy and surface analysis (scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX)) techniques. Results show that EMTFB suppresses low carbon steel dissolution in the corrosive environment. Inhibition efficiency increased with the increase in EMTFB concentration. Addition of iodide ions to EMTFB raises inhibition efficiency from 75 to 98%. PDP results indicate that EMTFB affects majorly anodic reactions while EMTFB + KI act as cathodic-type inhibitor. The adsorption of EMTFB onto low carbon steel surface is by physical adsorption mechanism and follows Langmuir adsorption isotherm model. SEM and EDAX results confirm the adsorption of EMTFB alone and in combination with KI onto the steel surface.

Performance assessment of poly (methacrylic acid)/silver nanoparticles composite as corrosion inhibitor for aluminium in acidic environment

This article reports the preparation of poly (methacrylic acid)/silver nanoparticles composite (PMAA/AgNPs) by in situ mixing of aqueous solutions of PMAA and 1 mM AgNO3 with natural honey as reducing and stabilizing agent. The prepared PMAA/AgNPs composite was characterized by UV–vis spectroscopy, Fourier transformed infrared, X-ray diffraction and energy dispersive spectroscopy (EDS) while the morphology of the AgNPs in the composite was obtained by transmission electron microscopy (TEM). TEM results revealed that the AgNPs were spherical in shape. The performance of PMAA/AgNPs composite as anticorrosion material for Al in acidic environment was examined by electrochemical, weight loss methods, complemented by surface analysis characterization with scanning electron microscopy (SEM), EDS and water contact angle measurements. Results obtained indicate that PMAA/AgNPs composite is effective corrosion inhibitor for Al in an acid-induced corrosive environment. Inhibition efficiency increased with increase in composite concentration but decreased with rise in temperature. From potentiodynamic polarization results, PMAA/AgNPs composite is found to function as a mixed-type corrosion inhibitor. The adsorption of the composite onto Al surface was found to follow El-Awady et al. adsorption isotherm model. SEM, EDS and water contact angle results confirmed the adsorption of the composite on Al surface.

Synergistic inhibition of aluminium corrosion in H2SO4 solution by polypropylene glycol in the presence of iodide ions

Purpose The purpose of this paper is to evaluate the performance of polypropylene glycol (PPG), as a corrosion inhibitor for aluminium corrosion in 0.5 M H2SO4 solution at 303-333 K and the effect of addition of iodide ions on the corrosion inhibition efficacy of PPG. Design/methodology/approach The corrosion inhibition performance of PPG alone and on addition of iodide ions in the acid medium was evaluated using weight loss and electrochemical [electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR) and potentiodynamic polarization (PDP)] methods as well as surface analysis approach at 303-333 K. The morphology of the corroding aluminium surface without and with the additives was visualised using scanning electron microscopy (SEM). The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption. Findings Results obtained showed that PPG moderately retarded the corrosion of Al in 0.5 M H2SO4 solution. Addition of KI to PPG is found to synergistically improve the inhibitive ability of PPG. From the variation of inhibition efficiency, K_ads, and E_a, with rise in temperature, physisorption mechanism is proposed for the adsorption of PPG and PPG + KI onto the Al surface in 0.5 M H2SO4 solution. Polarisation results showed that PPG and PPG + KI acted as mixed type inhibitor. The adsorption of PPG and PPG + KI, respectively, onto the metal surface followed El-Awady et al. adsorption isotherm model. SEM and water contact angle analysis confirmed the adsorption of PPG and PPG + KI on Al surface. Research limitations/implications The research is limited to aqueous acid environment in aerated condition, and all tests were performed under static conditions. Practical implications The use of PPG as corrosion inhibitor for Al corrosion in acidic medium were reported for the first time. The results suggest that iodide ions could be used to enhance corrosion protection ability of PPG which could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the synergistic effect of iodide ions addition to polymer to control acid-induced corrosion of metal. Originality/value The use of PPG as corrosion inhibitor for Al corrosion in acidic medium were reported for the first time. The results suggest that iodide ions could be used to enhance corrosion protection ability of PPG which could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the synergistic effect of iodide ions addition to polymer to control acid-induced corrosion of metal.

Gum Arabic-silver nanoparticles composite as a green anticorrosive formulation for steel corrosion in strong acid media

A green anticorrosive composite (GA-AgNPs) has been formulated for steel in 15% HCl and 15% H2SO4 media. Characterization of GA-AgNPs is achieved via FTIR, UV-vis, EDAX, and SEM. Gravimetric, electrochemical (EIS, EFM, DEIS, & TP), and surface assessment (SEM, EDAX, AFM, & XPS) techniques have been deployed in the anticorrosion studies. Results from all applied methods potray GA-AgNPs as effective anticorrosive agent. Inhibition is by adsorption mechanism and follows Langmuir isotherm. GA-AgNPs acts as mixed type inhibitor in 15% H2SO4 solution but as anodic type in 15% HCl solution. Results from surface techniques confirm adsorption of GA-AgNPs molecules on specimen surface. Oxides, hydroxides, carbonates, and sulphates (H2SO4 medium) or chlorides (HCl medium) are the corrosion products in the free corrodent according to XPS results. In the presence of composite, both ionic and neutral forms of GA-AgNPS are adsorbed. AgNPs are present on the surface in the form: Ag°, Ag2O, and AgO.