NaCl Medium Research Articles

Calcite, the main corrosion inhibitor contained in the raw clay (Rhassoul) of brass in 3% NaCl medium.

Corrosion control of copper alloys such as brass is of great interest to researchers and scientists. Clays become materials of choice as corrosion inhibitors and as their reservoir in corrosive environments. The effect of Rhassoul on the corrosion of Cu-36Zn alloy in 3% NaCl solution has been studied. Electrochemical techniques showed that the optimum concentration was 1g/L showing the highest inhibition efficiency (82%). This concentration was evaluated at five different temperatures. In order to determine the influence of purification, this result was compared to that of the homoionic clay labeled Na+-ST and to the pure calcite. Chemical composition of the brass specimen and solutions were done by inductively coupled plasma atomic emission spectrometry (ICP-AES) and atomic absorption (AA) respectively. The effectiveness of this clay against the dissolution of Zinc reached 61%. XRD technique demonstrated the homoionization of this clay by shifting the basal spacing d001.

A robust method of enhancement of corrosion inhibitive ability of electrodeposited poly-3-amino-5-mercapto-1,2,4-triazole films over copper surface using graphene oxide

A simple and new strategy has been developed to protect metallic copper by forming composite material using graphene oxide (GO) and electropolymerised p-3-amino-5-mercapto-1,2,4-triazole (p-AMTa). The structure and the mechanism of the formation of the polymer and polymer composite were predicted from Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopic (XPS) analysis and Energy Dispersive X-ray (EDX) spectroscopy. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies (PDS) were employed to study the corrosion inhibitive action of p-AMTa + GO composite in 3.5% NaCl medium. The study revealed that, the copper electrode modified with the carbon based polymeric composite suppressed the anodic dissolution of copper thereby increasing its corrosion resistance.

Cadmium(II) determination in production waters from petroleum exploration after its separation from the highly saline matrix mediated by a semipermeable membrane device

This paper reports the development of a novel approach for the separation of Cd(II) from production waters generated during petroleum prospection. The analyte was separated from the highly saline waters as a dithiocarbamate (DDTC) complex using a low-density polyethylene semipermeable membrane device (SPMD) filled with chloroform. The quantification of cadmium(II) in the extracts was performed by graphite furnace atomic absorption spectrometry (GF AAS). Several parameters that could affect the performance of the SPMD (pH of the sample, concentration of DDTC, type and volume of solvent used to fill the device, and extraction time) were evaluated in order to achieve maximum transference of Cd(II) and sensitivity. Under the best conditions, the SPMD was filled with 3.0 mL of CHCl3 and used to extract Cd(II) (as Cd(DDTC)2 complex) from a solution containing 3.75 × 10−4 mol L−1 of sodium dithiocarbamate at pH = 9.0. The SPMD was maintained in contact, under shaking, with the sample solution for 90 min. After that, the inner solvent containing the extracted Cd was collected and diluted to 5.0 mL with ethanol prior to analyte quantification by GF AAS. External calibration was possible using Cd(II) standard solutions prepared in a 10% (m/v) NaCl medium. The limits of detection and quantification of the method were 0.08 and 0.24 µg L−1, respectively. The method was employed for the quantification of Cd(II) in four samples of real production waters with high salinity and in a certified reference material of seawater (MX014, from National Measurement Institute of Australia). Recovery tests were also performed by spiking the samples Cd(II), resulting in the recovery percentages in the range of 90 – 132%.

Influences of 17-4PH Stainless Steel and α + β Titanium Alloy Powders for Corrosion Susceptibility on Friction Stir-Processed AA7075-T651 Aluminium Matrix Composites

Stainless steel (17-4PH) and α + β titanium alloy (Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si) powders have been known for their high strength with low density as well as promising mechanical properties and remarkable corrosion resistance. In view of this, a comparative performance assessment was carried out to evaluate their percentage inhibition performance efficiencies (%IPEs) on the friction stir-processed 7075-T651 aluminium matrix composites (AMC) reinforced with 17-4PH and Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si powders. The process parameters used were the plunge depth of 0.3 mm, processing speed of 20 mm/min, the tilt angle of 3°, the rotational speed of 1500 rpm and 100% inter-pass overlap with double passes. Corrosion study was carried out in a concentration of 3.5% NaCl medium at an ambient temperature of 25 °C using potentiodynamic polarization technique on AA7075-T651/17-4PH AMC and AA7075-T651/Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si AMC with reference to the processed and unprocessed base metal. It was revealed that the AA7075-T651/Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si AMC has higher %IPE of 98.26%, while AA7075-T651/17-4PH AMC exhibited %IPE of 90.57%. The corrosion rate was extraordinarily reduced from 5.0718 to 0.087675 mm/year using α + β titanium alloy powder as corrosion resistance while that of 17-4PH stainless steel reduced to 0.47744 mm/year. The polarization resistance was greatly high when inhibition α + β titanium alloy powder was used and found to be 2240.7 Ω as against 191.06 Ω when 17-4PH stainless steel was used as a corrosion barrier. The SEM images of the corroded samples revealed the presences of pits and intergranular corrosion attack with the trace of flakes on the surfaces.

Persistence of microcystin production by Planktothrix agardhii (Cyanobacteria) exposed to different salinities

ABSTRACTRecent reports predict increases in harmful cyanobacteria in water systems worldwide due to climatic and environmental changes, which would compromise water quality and public health. Among abiotic changes, higher salinities are expected to promote the growth of certain harmful species, such as Planktothrix agardhii, which forms blooms in brackish waters. Since P. agardhii is a common producer of cyanotoxin, we investigated the growth and tolerance of this species when exposed in vitro to a range of salinities, while assessing variations in its microcystin diversity and production in batch cultures during a time-frame experiment spanning 18 days. The study revealed salt acclimation of the brackish P. agardhii, which continued to produce microcystins in salty cultures, while maintaining its growth capacity at low to medium NaCl (ranging from 0 to 7.5 g l−1). With higher concentrations (10 to 15 g l−1) significantly less growth occurred, corresponding to the shortening of cyanobacterial filaments, which nevertheless maintained their metabolic functions, as revealed by the high intensity of chlorophyll auto-fluorescence and persistent microcystin production. These findings showed that moderate to high salt levels do not inhibit microcystin production by P. agardhii, at least for several weeks. This raises questions concerning the persistence of harmful cyanobacteria in shallow water systems more exposed to evaporation and consequently to an increase in salinity in the future, as predicted by various climate models.

Rapid investigation expiry drug green corrosion inhibitor on mild steel in NaCl medium

The unused expired clinical drugs are a major environmental hazardous pollutant due to the pharmaceutically active organic compounds present in it. Until recently, a quantum of unused drugs is being disposed through sewers, drainage, sediment are a threat to the public health. Several researchers have already reported the potential use of expired drugs as corrosion inhibitors in both acidic and alkaline medium. In this paper, we have reported three different drug molecules which have crossed the expiry date but not beyond six months. The drugs considered are rabeprazolesodium, domperidone and benfotiamine. Mild steel (MS) specimens were immersed 5 days with and without drug molecule in 3.5 wt% medium film formed on MS surface. These films were then analysed for crystallinity, surface morphology, iron complex, DFT and functional groups by XRD, SEM, and 3D profilometer, FTIR, UV and EPR. The experimental and theoretical results are good agreement with each other.

Estresse salino e diferentes temperaturas alteram a fisiologia em sementes de <i>Clitoria fairchildiana</i> Howard

Clitoria fairchildiana Howard, conhecida popularmente como sombreiro, é uma árvore nativa muito utilizada no paisagismo urbano devido ao rápido crescimento e beleza das flores, além disso, fornece excelente sombra e sua madeira é utilizada para diversas finalidades. Dessa forma, o trabalho foi realizado com o objetivo de determinar a tolerância das sementes de Clitoria fairchildiana Howard ao estresse salino na germinação em diferentes temperaturas. O experimento foi conduzido no Laboratório de Análise de Sementes do Centro de Ciências Agrárias da Universidade Federal da Paraíba, em Areia - PB. Para simular o estresse salino utilizou-se como soluto o cloreto de sódio (NaCl) diluído em água destilada e deionizada para obtenção das concentrações de 0,0 (controle); 1,5; 3,0; 4,5; 6,0; 7,5; 9,0 e 10,5 dS m-1, nas temperaturas de 25 e 30°C constantes e 20-30°C alternada. Na avaliação dos efeitos dos tratamentos determinaram-se as seguintes características: porcentagem, primeira contagem e índice de velocidade de germinação (IVG), bem como comprimento e massa seca de plântulas (raiz e parte aérea). O delineamento experimental foi inteiramente ao acaso, com os tratamentos dispostos em esquema fatorial 3 x 8 (temperaturas e níveis de salinidade), em quatro repetições. A porcentagem de germinação e o vigor das sementes reduziram com o aumento dos níveis de salinidade, no entanto, para aquelas submetidas à temperatura constante de 25°C a porcentagem de germinação foi superior em relação às demais. O decréscimo nos níveis de potencial osmótico das soluções salinas (NaCl) no meio germinativo provoca redução na germinação e no vigor das sementes de Clitoria fairchildiana Howard, as quais são classificadas como glicófitas, com moderada tolerância ao sal NaCl.

Electrochemical behavior study of carbon steel and the inhibitory effect of titano-zinc phosphate glasses in 3% saline solution

Abstract To minimize the metal corrosion, a new glass system titano-zinc phosphate glasses have been synthesized the electrochemical and theoretical investigations were used to study their anticorrosive performance for the carbon steel in 3% NaCl medium. This inhibitor act as great inhibitor for carbon steel in 3% NaCl. In the other hand, the surface of the steel has been analyzed by the scanning electron microscopy SEM. In addition the inhibition efficiency was found to increase with the increase of the inhibitors concentration due to the formation of protective the film on the substrate surface.

Characterization of Saccharomyces cerevisiae Strains from Palm Wine for Baking Leaven Production in Republic of Congo

This study was carried out to select the autochthon yeast strains from the palm wine. The work aims to wildly isolate, characterize and identify Saccharomyces cerevisiae in order to locally and safely produce a bio-leaven and to assess their ability to ferment wheat flour dough used for the bread making and other products. Palm wine samples have been bought in the village around Brazzaville. Samples have been collected in sterile glass bottles then stored under refrigeration condition at 4°C until they were processed. Yeasts were enumerated and isolated on Dichloran Rose Bengal Chloramphenicol agar medium at 37°C. Molecular identification was carried out by a PCR-based method using species-specific primer pairs to Saccharomyces genus without sequencing stage. The results showed that palm wine contains about 3.3106 CFUmL-1. Fifty-one isolates were obtained with a percentage of 13% corresponding to Saccharomyces cerevisiae. This identity was confirmed by the molecular characterization. Five yeast strains showed high ability to ferment wheat flour dough analogous of the control. The better growth of isolates was between 28 and 37°C. However, the near neutral pH gives the higher growth. High concentration of NaCl and glucose in medium has a strong negative impact on the growth of isolates.

Influence of the complexing agent sodium citrate on the chemical composition, surface morphology and corrosion resistance of Ni–Fe electrodeposits

ABSTRACTA comparative study has been made of the influence of the complexing agent, sodium citrate, on the characteristics of Ni–Fe alloys obtained by electrodeposition. The alloys were synthesised from modified Watts electrolytes with different proportions of Ni2+ and Fe3+ ions. Energy-dispersive X-ray spectroscopy (EDS) analyses showed that the coatings obtained from electrolytes without sodium citrate (CWOCs) had higher Fe values than Ni and those obtained with electrolytes containing complexing agent (CWCs) presented an inverse behaviour. Micrographs obtained by scanning electron microscopy (SEM) showed the formation of uniform, homogeneous and nodular deposits, typical of Ni coatings. However, the presence of microcracks and porosity in the CWCs was verified. Potentiodynamic linear polarisation (PLP) and electrochemical impedance spectroscopy (EIS) analysis identified corrosion processes with active dissolution in 0.1 mol L−1 NaCl medium in all the analysed deposits, with the CWOCs being more resistant than the CWCs.

Aging time effect of Ammi visnaga (L.) lam essential oil on the chemical composition and corrosion inhibition of brass in 3% NaCl medium. Experimental and theoretical studies

Abstract The objectives of this work are to study the essential oil (EO) of Ammi visnaga (L.) Lam which belongs to the family of Apiaceae, to investigate whether the aging factor over time has any effect on its chemical composition, as well as to assess its prospective corrosion inhibition of brass in 3% NaCl medium. The two corresponding plant samples were harvested in northern Morocco in 2016 and 2018during the same period of the year and under the same conditions. The essential oils (EO16, EO18) chemical composition was analyzed by gas chromatography-mass spectrometry (GC–MS). The electrochemical study was performed using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurement, in the presence of different concentrations of the two extracted essential oils. The GC–MS experimental results show that the major compounds of the two oils were linalool (25.79% in EO16 and 13.47% in EO18) and croweacin (31.11% in EO16 and 42.47% in EO18). The calculated inhibition efficiencies were 86% for EO16 and 96.36%for EO18 in the presence of 3% NaCl and 2 g/l concentration of EO. The computational studies, using the quantum chemical calculation in gas phase using (DFT) at B3LYP/6-31G (d,p) method showed that the studied major compounds especially croweacin is a good corrosion inhibitor.

Anticorrosive performance of lanthanum ions intercalated Stevensite clay on brass in 3% NaCl medium

Abstract New environmentally, friendly, inorganic rare earth elements are now being offered as possible alternatives to chromate and lead compounds for metals protection and were evaluated as corrosion inhibitors of brass in 3% NaCl medium. The purpose of this research is to study the corrosion inhibition performance of a beforehand swelling clay, Stevensite labeled ST, intercalated by lanthanum ions. XRD and ICP-AES technics were used to confirm the Stevensite exchange by Na+ and La3+. The basal spacing d001 of Na+-ST (14.2 A) increases to 16.2 A (La3+-ST). The inhibition efficiency of La3+-ST was carried out by the polarization and the electrochemical impedance spectroscopy (EIS) measurements. The performance of the smart inhibitor La3+-ST is due to the progressive release of lanthanum ions in the corrosive medium. Corrosion products were analyzed by SEM-EDS technique.

Application of modified graphene oxide – Polycaprolactone nanocomposite coating for corrosion control of mild steel in saline medium

Polycaprolactone (PCL), a non toxic biodegradable polymer has limited application in the field of corrosion. In this study graphene based nanoparticles are incorporated into PCL matrix in order to enhance its anti-corrosion performance. The influence of graphene oxide (GO) and functionalized graphene oxide (FGO) nanosheets on the corrosion protection performance of PCL coating have been investigated. GO was functionalized with 8-bromo-[1,2,4]triazolo[1,5-a]pyridin-2-amine (BTP), and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and Energy Dispersive X-ray spectroscopy (EDX). The composite coating mixture consisted of GO/FGO-PCL matrix was applied on mild steel and surface of the coated samples were examined using Contact Angle technique, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Barrier and corrosion protection performance of the coated samples were studied using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods in 3.5% NaCl medium. The results showed that FGO-PCL coating exhibit superior barrier and anti-corrosion properties by improving the dispersion and exfoliation of FGO in the PCL matrix. It is found that the incorporation of FGO nanosheets make PCL more hydrophobic and also provides additional adhesion strength to the polymer.

Anticorrosion Behaviour ofRhizophora mangleL. Bark-Extract on Concrete Steel-Rebar in Saline/Marine Simulating-Environment

This paper investigates anticorrosion behaviour of the bark-extract from Rhizophora mangle L. on steel-rebar in concrete slabs in 3.5% NaCl medium of immersion (for simulating saline/marine environment). Corrosion-rate, corrosion-current, and corrosion-potential were measured from the NaCl-immersed steel-reinforced concrete cast with admixture of different plant-extract concentrations and from positive control concrete immersed in distilled water. Analyses indicate excellent mathematical-correlation between the corrosion-rate, concentration of the bark-extract admixture, and electrochemical noise-resistance (ratio of the corrosion-potential standard deviation to that of corrosion-current). The 0.4667% Rhizophora mangle L. bark-extract admixture exhibited optimal corrosion-inhibition performance, η = 99.08±0.11% (experimental) or η = 97.89±0.24% (correlation), which outperformed the positive control specimens, experimentally. Both experimental and correlated results followed Langmuir adsorption isotherm which suggests prevalent physisorption mechanism by the plant-extract on the reinforcing-steel corrosion-protection. These findings support Rhizophora mangle L. bark-extract suitability for corrosion-protection of steel-rebar in concrete structure designed for immersion in the saline/marine environmental medium.

DGEBA‐polyaminoamide as effective anti‐corrosive material for 15CDV6 steel in NaCl medium: Computational and experimental studies

ABSTRACTThe present study is focusing on evaluating theoretically and experimentally stability and type of interactions between the epoxy resin bisphenol A diglycidyl ether (DGEBA)‐polyaminoamide anticorrosive coating and high strength low alloy steel surface 15CDV6. The coated steel samples were subjected to a harsh environment of an electrolyte solution of 3 wt % NaCl to simulate the corrosive marine environment. The performance of the epoxy coating was investigated using electrochemical impedance spectroscopy (EIS). The EIS results revealed the occurrence of some deterioration in the film after subjecting it to a harsh environment for 4392 h, because the impedance of the coating dropped by about 1.4 kΩ.cm2. Surface morphological study of metallic specimens before and after exposing to the simulated marine environment (3 wt % NaCl) was carried out using scanning electron microscopy, energy dispersive spectroscopy (EDS), and optical microscope (OM) methods. The interactions between DGEBA‐polyaminoamide and the metallic surface were further carried out using computation modeling such as density functional theory (DFT)‐based quantum chemical calculations, Monte Carlo (MC), and molecular dynamics (MD) simulations. Results showed that DGEBA‐polyaminoamide possesses a strong tendency to adhere and inhibits the corrosive dissolution of 15CDV6 steel surface in the stimulated marine environment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48402.

Corrosion behavior and mechanism of Cr–Mo alloyed steel: Role of ferrite/bainite duplex microstructure

This study presents a systematic investigation of the corrosion behavior and corrosion mechanism of a novel ultralow-carbon Cr–Mo alloyed ferrite/bainite duplex steel rebar. Electrochemical tests revealed the studied steel rebar to have satisfactory corrosion resistance in an NaCl medium, similar to 430 stainless steel and better than 403 stainless steel. The formation of a Cr-dominated bilayer-structured oxidation passive film endows the steel with excellent passivity. During long-term exposure, the Cr–Mo alloyed steel presented no tendency of pitting corrosion. Meanwhile, the formation of a Cr–Mo enriched rust layer inhibited penetration of the corrosive medium, efficiently delaying corrosion propagation in the steel matrix. Given its excellent anticorrosion performance, this novel alloyed steel rebar has great application potential in marine concrete structures. Electron probe microanalyzer, transmission electron microscope, and electron backscattered diffraction analysis of the rebar matrix revealed the bainite phase to have lower Cr–Mo content but more crystal defects than the ferrite phase, leading to the lower potential and higher corrosion tendency of the bainite phase. Microgalvanic corrosion between the bainite phase (anode) and ferrite phase (cathode) caused prior breakdown of the passive film on the bainite phase, stimulating corrosion initiation of this Cr–Mo alloyed duplex steel.

Epoxy-Based nanocomposite coating reinforced by a zeolite complex: Its anticorrosion properties on mild steel in 3.5 wt% NaCl media

Epoxy-based nanocomposite coatings have attracted attention in industrial and engineering applications. Good and high efficiency of the epoxy-based nanocomposite coatings are due to their outstanding attributes like high-stability, good adhesion, diminished H2O permeability, remarkable acid-alkali and solvent resistance, and enhanced mechanical properties. Epoxy coatings containing different weight fractions of encapsulated Ni (II) Complex-Zeolite Y ([Ni((Bu)2[14]aneN6)]-NaY) are prepared and used on mild steel. Their anticorrosion properties are explored by Tafel polarization and electrochemical impedance-spectroscopy (EIS) techniques under immersion in 3.5-wt. % NaCl solutions as a corrosive medium. According to the results, it can be understood that [Ni((Bu)2[14]aneN6)]-NaY can advance the ability of corrosion protection of the epoxy-coating and its best weight-fraction is 3 wt%. SEM results showed that the presence of [Ni((Bu)2[14]aneN6)]-NaY in epoxy coatings has a significant protective effect and showed the epoxy-based nanocomposite coatings are crack free and uniform. The immersion test studies show that the Rct values of the synthesized nanocomposite coating a little decrease during 43 days immersion and the coatings have very high protective properties because after 43 days immersion, the PE value of nanocomposite coating is 99.72%.

A detailed computational exploration and experimental surface/electrochemical analyses of mild steel functionalized by zinc-aminotris methylene phosphonic acid complex film

In the present integrated experimental/theoretical work, the synergistic inhibition effects of aminotris methylene phosphonic acid (ATMP) and Zn ions for steel corrosion mitigation in NaCl solution were examined. The inhibition property of ATMP:Zn mixture was evaluated by electrochemical approaches including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). In addition, the chelation between ATMP‑zinc ions and/or iron cations was investigated applying various morphological approaches. The ATMP and ATMP-Zn complex chemical structures were identified via UV–Vis and FT-IR spectra. According to EIS outcomes, the excellent inhibition efficiency of about 99% was achieved within 72 h steel subjection to 3.5% NaCl media containing 200:600 ppm ATMP:Zn mixture. The PDP plots disclosed that the complex inhibitors mainly retarded the steel corrosion cathodically. Furthermore, FE-SEM and AFM microstructures analyses clarified the emergence of a high-coverage ATMP:Zn complex inhibitive layer over metallic adsorbent, evidencing significant corrosion mitigation. The detailed results elucidated from EDS and XPS spectra ensured the successive chemical bonding of ATMP molecules with zinc and/or iron ions. Alongside experiments, fundamental theoretical studies at detailed microscopic levels (i.e., atomic and electronic) were conducted using molecular simulations and quantum mechanics (QM). Monte Carlo (MC) combined with molecular dynamics (MD) was applied for assessing the organic-inorganic inhibitor adsorption features. Additionally, electronic-structure QM calculation on the basis of density functional theory (DFT) was adopted so as to fundamentally analyze the reactive sites determining the inhibitor adsorption. The outcomes elucidated by MC/MD tools ensured the surface adsorption propensity of hybrid inhibitors. The DFT based observations proposed that the inhibitors adsorption likely occurs at interface through donor-acceptor interactions.

Photoinduced gold recovery mediated by isopolymolybdate in strongly acidic HCl/NaCl solutions

The laser-induced formation of gold nanoparticles (AuNPs) was studied in hydrochloric acid solutions containing isopolymolybdate. Aqueous solutions of HAuCl4 (0.5 mM) in HCl (0.1–1.0 M)/NaCl media containing ethanol (0.5% v/v) were irradiated with 355 nm laser pulses in the absence or presence of molybdate. The reaction progress was probed by UV–vis spectroscopy. Without molybdate, the formation of AuNPs is significantly hindered because a large excess of Cl− renders the AuCl4− precursor resistant to direct photoreduction with ethanol. The incorporation of molybdate into solution effectively mediates the photoinduced formation of AuNPs in 0.1–0.5 M HCl. For this range of acidity, photoirradiation generates the molybdenum blue (MB) species from the reaction of photoexcited Mo36O1128− (polyoxoanions) with ethanol, followed by the reduction of AuCl4− with the MB species. At a higher acidity, the formation of AuNPs is virtually undetectable because the MB species are no longer generated due to the absence of anionic molybdate precursors.

Effect of Polyethylene Glycol 12000 on Morphology and Corrosion Behavior of TiO(OH)2/MnO2/PEG12000 Composite Electrodeposited on Pure Copper

In this study, TiO(OH)2/MnO2/PEG12000 composite was elaborated on pure copper in a two-step deposition process in the presence of 1% w/v of polyethylene glycol 12000 (PEG12000). The influence of PEG12000 on the composite morphology, composition and surface roughness was studied by SEM–EDS and AFM techniques. The results show that a porous composite of a multilayer structure with PEG12000 dispersed spherical particles was synthesized. Though the roughness homogeneity of TiO(OH)2/MnO2/PEG12000 was slightly improved, carbon content ranges from 5 to 12 At% reflecting an adsorption process of PEG12000 during the composite deposition. Results were confirmed by XPS technique, which provides further evidence about the existence of PEG12000. High-resolution C1s and O1s signals affirm the presence of the characteristic C–O bond, resulting from the coupling of PEG12000 on the composite surface. The electrochemical corrosion was evaluated in chloride medium by OCP measurements and linear polarisation curves. It was found that the corrosion resistance of TiO(OH)2/MnO2 composite was improved markedly in the presence of PEG12000. The stability of TiO(OH)2/MnO2/PEG12000 composite was also studied by following the evolution of impedance parameters during immersion time in 0.05 M NaCl medium completed by a characterization of the composite morphology and composition at the end of immersion by SEM–EDS and XPS analysis. The composite indicates good stability due to the formation of PEG-CuCl complexes, capable of limiting the infiltration of Cl− ions in both the composite and the substrate surfaces.