Adsorption Of Corrosion Inhibitors Research Articles

Inspired corrosion resistance of copper mediated by multiple ethoxy units linker included indazole based bis-Schiff base dyes in NaCl solution

In this study, hydrophilic multiple ethoxy units linkage chain included bis-Schiff base dyes (SBs 1–3) were designed and synthesized for strengthening corrosion resistance of copper in NaCl solution. The corrosion resistance and corrosion inhibition mechanism of the target dyes for copper were investigated in 3.0 wt% NaCl solution. The adsorption of these dyes on copper surface was revealed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) revealed the adsorption of these dyes containing CN double bonds on copper surface, achieving excellent corrosion inhibition efficiency. The electrochemistry shows that the dyes were able to inhibit the corrosion of copper in sodium chloride solution, and the corrosion inhibition efficiency reached the peak value at a concentration of 1.00 mM. It is noted that the corrosion inhibition efficiency increased with the number increase of ethoxy units. The kinetic potential polarization curves indicate that the dyes were anodic corrosion inhibitors, which could inhibit the anodic reaction process of corrosion. The adsorption of corrosion inhibitor these dyes on copper surface followed Langmuir isothermal adsorption model.

Ultra-stable metal-organic framework-derived carbon nanocontainers with defect-induced pore enlargement for anti-corrosive epoxy coatings

Zeolitic imidazolate frameworks-8 (ZIF-8) have recently gained attention as nanocontainers for encapsulating corrosion inhibitors. However, two main challenges remain unsolved, casting doubt on their suitability as nanocontainers. The first challenge is their instability in acidic and basic environments, leading to structural decomposition and the second challenge is their mass diffusion limitation caused by micropore dominance and a small aperture size of 0.34–0.42 nm, limiting the efficient adsorption of corrosion inhibitors. To address both challenges, in this work, ZIF-8 nanostructures were transformed into nitrogen-doped ZIF-derived carbon-based nanocontainers (CZIF) via carbonization. This transformation not only stabilized the structure but also produced larger pore sizes (micro and mesopores), due to defects formed during carbonization. Benzotriazole (BTA) corrosion inhibitors were then encapsulated in CZIF structures to produce CZIF-BTA. Electrochemical impedance spectroscopy (EIS) demonstrated that the saline solution containing CZIF-BTA extract reduced the corrosion rate of steel by 50 % compared to a blank solution. The scratched epoxy (EP) coating containing 0.2 wt% of CZIF-BTA revealed an active inhibition performance with ∼100 % enhancement in the total resistance value compared to blank EP. Finally, the coating showed superior barrier properties with the impedance at the lowest frequency value of ∼2 × 1010 Ω cm2 after 71 days of immersion.

Diphenyl disulfide derivatives as high-efficiency corrosion inhibitors for copper in sulfuric acid: Experimental and theoretical studies

Three organic small molecules, namely Diphenyl disulfide (PDS), 4,4′-Dithiodianiline (DDA), and 4-Methylphenyl disulfide (MDS), were subjected to corrosion screening on copper substrates. Electrochemical testing revealed their corrosion efficacy, with MDS exhibiting the highest efficiency at 98.9 %. Investigation into MDS's corrosion mechanism attributed its superior performance to the presence of hydrophobic methyl groups, facilitating the formation of a denser molecular protective film on the copper surface. The adsorption of corrosion inhibitors on copper surfaces was investigated by Langmuir monolayer adsorption model and X-ray photoelectron spectroscopy. Theoretical calculations further elucidated the inhibitory mechanisms of these sulfurized compounds and the influence of different functional groups on corrosion efficiency. Specifically, the introduction of methyl groups enhanced MDS's ability to displace water molecules on the copper surface, thereby augmenting its corrosion inhibition potential. These findings align with the observations from electrochemical and surface analyses, affirming the efficacy of MDS in mitigating copper corrosion.

Shielding against erosion: Exploring the effectiveness of pre-erosion surface corrosion inhibitors

This study investigates the corrosion inhibition effect and adsorption process of two imidazoline corrosion inhibitors, HEIE and TDEI, on pre-eroded X65 steel surfaces. Analysis of weight loss and electrochemical measurements suggests that the irregular structure of pre-eroded surfaces may impede the uniform adsorption of corrosion inhibitors, resulting in reduced effectiveness pre-erosion. Particularly, at a 30° angle of pre-erosion, corrosion inhibition efficacy is observed to be at its lowest. The corrosion inhibition rates of HEIE and TDEI on X65 steel surfaces are found to be 11.9 % lower under pre-eroded conditions at a 30° angle compared to non-eroded surfaces at the same angle. Molecular dynamics (MD) simulations support these findings, indicating that TDEI exhibits lower energy bandgap values and more negative adsorption energies (Eads) compared to HEIE, aligning with experimental results. Moreover, TDEI demonstrates a smaller diffusion coefficient for corrosive agents than HEIE, suggesting stronger adsorption efficiency and a more pronounced protective effect. Study of the corrosion inhibition effect on pre-eroded surfaces provides new ideas and methods for improving protective measures.

Dopamine functionalized graphene oxide (DGO) as a corrosion inhibitor against X60 carbon steel corrosion in a simulated acidizing environment; An electrochemical, weight loss, SERS, and computational study

This study examines the effectiveness of dopamine-functionalized graphene oxide (DGO) as a corrosion inhibitor for carbon steel in a 15 % HCl solution simulating an oilfield acidizing corrosive environment. Experimental electrochemical and weight loss techniques were used for the evaluation, complemented by surface analytical methods such as FTIR, SEM/EDS, and AFM. The influence of temperature on the performance of the inhibitor was also studied. The adsorption behavior of DGO at different concentrations was studied using surface-enhanced Raman scattering (SERS). Computational tools were also used to understand the mode of adsorption of the inhibitor molecules on the steel surface and the nature of the interaction between the silver nanoparticles used in the SERS study and the inhibitor molecules. DGO showed a maximum inhibition efficiency of over 85 % at room temperature at the optimum concentration of 5 ppm as observed in the weight loss and electrochemical studies. The inhibitor behaved like a mixed-type according to the PDP measurement and obeyed the Langmuir adsorption theory. SEM/EDS, AFM, and FTIR analyses of the steel surface after 24 h of immersion in the test solution confirmed the adsorption of the inhibitor on the steel surface to form a protective layer that protects the steel from aggressive attack by corrosive media. The intensity of SERS showed a strong correlation with the electrochemical and weight loss results. Computational analysis revealed that the primary adsorption mechanism of DGO molecules on the carbon steel surface involves the bonding between the steel surface and the aromatic rings of the GO component. This research is significant as it addresses two major environmental issues: corrosion and waste disposal using GO derived from waste graphite powder. The SERS technique used in this study has the potential to serve as a sensor to monitor the dynamic adsorption of corrosion inhibitors irrespective of the type of metal.

Application of ellipsometry to study the adsorption of corrosion inhibitors on metals from aqueous solutions and vapor phase

Application of ellipsometry to study the adsorption of corrosion inhibitors on metals from aqueous solutions and vapor phase

Amino acid imidazole ionic liquids as green corrosion inhibitors for mild steel in neutral media: Synthesis, electrochemistry, surface analysis and theoretical calculations

The corrosion inhibition properties of three amino acid imidazole ionic liquids ([CyVIm][AA]) as corrosion inhibitors for mild steel in a 3.5 wt% NaCl corrosion medium were evaluated by electrochemical measurements. The polarization experiments show that [CyVIm][AA] influences anode reaction processes, demonstrating that [CyVIm][AA] is an anodic inhibitor type corrosion inhibitor. [CyVIm]Try outperforms [CyVIm]His and [CyVIm]Pro in terms of corrosion inhibition. The results of surface analysis and quantum chemical calculations show that [CyVIm]Try can form a protective film on the surface of mild steel and inhibit surface corrosion. Furthermore, by applying molecular dynamics simulations, after investigating the corrosion inhibitor adsorption trends on the Fe (110) surface, the interaction order between the molecular framework of the Fe corrosion inhibitor and the Fe (110) surface for entanglement was determined. According to the radial distribution function, the corrosion inhibitor adsorption mode on the metal surface is composite adsorption with chemisorption as the major mode and physical adsorption as the secondary mode.

Preparation of Bis-Thiophene Schiff Alkali-Copper Metal Complex for Metal Corrosion Inhibition.

Due to the obvious numerous economic and technical consequences of the corrosion process, its inhibition is one of the most critical aspects of current research. A corrosion inhibitor for the bis-thiophene Schiff base copper-metal complex Cu(II)@Thy-2 was investigated here, which was synthesized via a coordination reaction with a bis-thiophene Schiff base (Thy-2) as a ligand and copper chloride (CuCl2-2H2O) as a ligand metal salt. When the corrosion inhibitor concentration was increased to 100 ppm, the self-corrosion current density Icoor reached a minimum of 2.207 × 10-5 A/cm2, the charge transfer resistance reached a maximum of 932.5 Ω·cm2, and the corrosion inhibition efficiency reached a maximum of 95.2%, with the corrosion inhibition efficiency showing a trend of increasing first and then decreasing with concentration increase. After adding Cu(II)@Thy-2 corrosion inhibitor, a uniformly distributed dense corrosion inhibitor adsorption film formed on the surface of the Q235 metal substrate, significantly improving the corrosion profile compared to both before and after the addition of the corrosion inhibitor. Before and after the addition of corrosion inhibitor, the metal surface's contact angle CA increased from 54.54° to 68.37°, showing that the adsorbed corrosion inhibitor film decreased the metal surface's hydrophilicity and increased its hydrophobicity.

(Corrosion Division Rusty Award for Mid-Career Excellence) Rust At a Glance: Electrochemical Thermodynamics and Kinetics of Porous Corroding Interfaces

The development of a rust layer is governed by physico-chemical processes at the electrode/electrolyte porous interface, including electrochemical thermodynamics and kinetics, as well as transport and reaction processes. While rust can be protective under passive and inert regions found on the Pourbaix diagram, it becomes interesting to see whether its stability is compromised under harsh conditions that lead to active dissolution of this porous interface.Thermodynamics calculations can predict phase transformation, which nucleation and growth is governed by the chemical activity of the porous interfaces as well as by the saturation of the electrolyte solution. Understanding the electrochemical interface is a major challenge to unravel the corrosion mechanism of porous systems. The heterogeneous nature of the oxide structure as well as the development of amorphous gel regions influences the formation of active sites and point defects with a high lability for reacting with gas phases dissolved, entrapped, or occluded within interfacial substructures.The stabilization and corrosion protection of the rust interface requires to understand the adsorption of corrosion inhibitors on the surface of the active site on the electrode ‒ creating a stable protective passive film. Enthalpy and entropy of the dissolution process can explain the spontaneous formation of a rust layer as well as the displacement of water molecules, which ultimately will result in the effective physico-chemical adsorption of the inhibitor molecules.In summary, this communication is aimed to present the role of rust at a glance, and its implications on the electrochemical corrosion mechanisms on porous interfaces. The application of electrochemical fundamentals and first principles combined with state of the art electrochemical, chemical and surface characterization techniques provides a comprehensive vision and mission on current trends in corrosion and protection of steel in porous media.

Investigation of Corrosion Inhibitor Adsorption on Mica and Mild Steel Using Electrochemical Atomic Force Microscopy and Molecular Simulations

Electrochemical atomic force microscopy (EC-AFM) experiments, including simultaneous linear polarization resistance (LPR) tests and in situ AFM imaging, under a CO2 atmosphere, were performed to investigate the adsorption characteristics and inhibition effects of a tetradecyldimethylbenzylammonium corrosion inhibitor model compound. When the inhibitor bulk concentration was at 0.5 critical micelle concentration (CMC), in situ AFM results indicated nonuniform tilted monolayer formation on the mica surface and EC-AFM results indicated partial corrosion of the UNS G10180 steel surface. At 2 CMC, a uniform tilted bilayer or perpendicular monolayer was detected on mica, and corrosion with UNS G10180 steel was uniformly retarded. Consistently, simultaneous LPR tests showed that corrosion rates decreased as the inhibitor concentration increased until it reached the surface saturation value (1 and 2 CMC). Molecular simulations have been performed to study the formation of the inhibitor layer and its molecular-level structure. Simulation results showed that at the initiation of the adsorption process, islands of adsorbed inhibitor molecules appear on the surface. These islands grow and coalesce to become a complete self-assembled layer.

Inhibition Effect and Mechanism Explanation of Perilla Seed Extract as a Green Corrosion Inhibitor on Q235 Carbon Steel.

The development of environmentally friendly corrosion inhibitors has become a research hotspot. Aiming at the potential corrosion inhibition effect of perilla seed extract on Q235 carbon steel, the corrosion inhibition effect was quantitatively evaluated by various research methods, and the effective corrosion inhibition composition and mechanism were discussed. The research methods include potentiodynamic polarization curve method, HPLC-MS, FT-IR, XPS and chemical calculation. The experimental results show that the inhibitor prepared from perilla seed extract is a mixed inhibitor, and its adsorption behavior accords with Langmuir adsorption theory and its adsorption free energy is −22.70 kJ/mol. Combined with the experimental results and theoretical calculation, the effective corrosion inhibiting components are luteolin and apigenin. Theoretical calculation shows that both of them are adsorbed parallel to the surface of carbon steel to form thin films. The adsorption mechanism is that carbonyl O atoms in luteolin and apigenin hybridize with the 3 d empty orbit of Fe. From the point of view of quantum chemistry, the smaller the HOMO value and the energy gap value, the better the adsorption of corrosion inhibitor on the surface of carbon steel. From the point of view of molecular dynamics simulation, the greater the absolute value of adsorption energy, the better the adsorption of corrosion inhibitor on carbon steel surface.

Защита металлов ингибиторами коррозии в растворах различных кислот

The current state of research in the field of inhibitor protection of metals and alloys in solutions of mineral and organic acids has been summarized and analysed. Acid solutions in modern industry are widely used at oil-and-gas facilities, metallurgy, housing-and-communal services, where they can be in contact with metal parts of industrial equipment for a long time, without the use of additional protection measures, causing its destruction. The specificity of the corrosive effect of acid solutions on metallic materials is analysed. Various groups of metal corrosion inhibitors (CIs) for these media and the features of the mechanism of their protective action were discussed. Among the various groups of CIs that protect metals in acidic media, various azole derivatives deserve the most attention. The industrial use of azoles is promising in the form of mixtures with other compounds. Promising lines of research in the field of inhibitory protection of metals in acidic media are associated with the wider application of the possibilities of electrochemical methods (voltammetry and electrochemical impedance spectroscopy). When determining the thermodynamic parameters of CIs adsorption, one should be guided by determining their true values, and not effective values. In the development of mixed CIs, a thorough theoretical study of these issues is required, taking into account prospects of such developments for the industrial use. Prospects for the industrial application of environmentally friendly («green») CIs for the protection of metals in acidic environments are considered. At present, the practical application of such products is limited by the lack of data on their compliance with the tight requirements of modern industries for CIs. The bibliography includes 129 references.

Corrosion Inhibition and Adsorption Process of 3-Amino-5-Mercapto-1,2,4-Triazole on Aluminium Alloy: Experimental and Theoretical Studies

The corrosion inhibition effect of 3-amino-5-mercapto-1,2,4-triazole (AMT) on AA2024 aluminium alloy in 3.5 wt.% NaCl solution was investigated, and the corrosion inhibition mechanism was revealed. The influence of AMT concentration on the corrosion inhibition performance was evaluated by potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS). Surface analysis and surface-enhanced Raman scattering (SERS) spectra were used to study the adsorption process and corrosion inhibition mechanism of AMT on the alloy surface. Polarization curve and EIS results showed that when the AMT concentration was 1.5 g/L, the corrosion current density (icorr) was the lowest and the resistance of adsorption film (Rf) was the largest, illustrating the highest corrosion inhibition efficiency. Moreover, the adsorption kinetics process of AMT was revealed by SERS measurement, and a positive correlation between the SERS intensity and Rf values of AMT after different immersion time was achieved. It indicated that the efficient adsorption of corrosion inhibitors significantly enhanced the corrosion inhibition performance. Density functional theory (DFT) and molecular dynamics simulations were used to give further insight into the adsorption and inhibition mechanism of AMT on the aluminium alloy surface.

Computational molecular-level prediction of heterocyclic compound–metal surface interfacial behavior

It is difficult to comprehensively understand the interfacial mechanism (IM) of the adsorption of corrosion inhibitors (CIs) on metal surfaces solely through experiments and electronic structure parameters of isolated molecules. To better understand the molecular-level IM of CIs, a combination of atomistic simulations and first-principles calculations was used to obtain reliable information on the adsorption nature and intermolecular interactions during the actual interfacial behavior. The IM and property changes of two synthesized heterocyclic sustainable-green CIs, namely 4-{[(5-nitrofuran-2-yl)methylene]amino}-5-propyl-4H-1,2,4-triazole-3-thiol (NFPT and 4-{[(5-nitrofuran-2-yl)methylene]amino}-4H-1,2,4-triazole-3-thiol (NFT), were investigated on the Fe(110) surface using first-principles density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The NFPT was preferentially adsorbed through a parallel configuration with a high interaction energy (–706.12 kJ·mol−1) compared to NFT, owing to stronger chemical bonds via S, N, and O atoms with the Fe surface. Additionally, the adsorbed NFPT film effectively inhibited Fe surface corrosion owing to the small diffusion coefficient of corrosive particles in the presence of NFPT. Subsequently, the anti-corrosion performance of both CIs was validated through electrochemical methods, surface analysis, and adsorption isotherm models. The observations suggest that the combination of modern computational perspectives could efficiently design and select the best CIs before their laboratory synthesis.

Anticorrosive reinforcement of waterborne epoxy coating on Q235 steel using NZ/BNNS nanocomposites

The 5-aminotetrazole@ZIF-7@zinc gluconate/boron nitride nanosheets (NZ/BNNS) nanocomposites were synthesized by a facile one-pot method for anticorrosive reinforcement of waterborne epoxy (WEP) coating. The electrochemical tests and scratch tests show that the incorporation of NZ/BNNS nanocomposite can significantly improve the corrosion protection performance of WEP coating by the synergetic effects of passive and active protection. The impedance modulus at 0.01 Hz of WEP NZ/BNNS coating is about 1–1.5 orders of magnitude higher than that of pure WEP coating during the 288 h immersion corrosion test. The enhanced passive protection mainly derives from the two-dimensional structure and impermeability of NZ/BNNS. NZ/BNNS nanocomposites can prolong the diffusion path of corrosive medium. UV–vis spectra indicate that 5-aminotetrazole inhibitor encapsulated in NZ is stimuli-responsively released under acidic conditions. After the intrusion of corrosive ions on Q235 carbon steel, the hydrolysis of iron ions induces local acidification. NZ nanocontainers dissociate under acidic condition and release the corrosion inhibitors. The adsorption of corrosion inhibitors on the substrate then provides the active protection. Relevant corrosion protection mechanism has been proposed.

Two common antihistamine drugs as high-efficiency corrosion inhibitors for copper in 0.5M H2SO4

Experiments and theoretical calculations to explore the potential of anti-corrosion performance corresponding dioxopromethaxine hydrochloride(DPZ) and promethazine hydrochloride(PZ) for copper in 0.5 M H2SO4 solution. The electrochemical test results and topography information indicated that corrosion inhibition ability of PZ outshines DPZ, the suppression efficiency was high to 96.98% and 93.43%, respectively. The results indicated that two corrosion inhibitor adsorption models follow the Langmuir. Combing XPS and FT-IR confirmed that the DPZ and PZ can adsorp on the copper surface. The molecular dynamics simulation(MD) calculation based on DFT theory verifies the DPZ and PZ successful adsorptionon Cu(1 1 1) surface.

Chromium-Free Conversion Protective Coatings on 1424 Aluminum Alloy

Abstract—It is known that lithium-containing aluminum alloys possess low pitting corrosion resistance. It has been previously shown that an IFKhANAL-3 alkaline chromate-free conversion composition gives the coatings on a series of aluminum alloys, such as AMg3, D-16, and V95, which are comparable to conventional chromate coatings in terms of protective properties. It should also be noted that inhomogeneous CCs that do not adhere to the substrate are formed in standard chromate conversion composition on lithium-containing alloys; therefore, development of the method for the fabrication of protective CC for 1424 alloy is a relevant task. In this work, the effect of various complexing agents on the oxidation and protective properties of the coatings based on 1424 alloy have been studied. The modifying additives under study have decreased the concentration of different oxides in the conversion compositions providing adsorption of corrosion inhibitors and increase in their protective properties. According to the results of accelerated corrosion tests, integrated use of Trilon B and BTA significantly increases the corrosion resistance of the coatings based on 1424 alloy.

Understanding the relationship between the structural properties of three corrosion inhibitors and their surface protectiveness ability in different environments

All-atom molecular simulations and chemical quantum calculations were used to understand the effect of the environment on the surface adsorption of corrosion inhibitor (CI) molecules. Three CIs abbreviated: TEPA, iTEPA and HC-iTEPA studied in this work, were selected to systematically investigate the influence of the alkyl tail, N-pendant group, imidazoline and benzene rings, on the CIs adsorption behavior. A relationship is provided between their structural properties and their surface protectiveness ability in different environments. Chemical quantum calculations revealed the electron distribution in inhibitors structures, indicating their ability to accept/donate charges from the Fe atoms in vacuum and in water solvation. The quantum molecular parameters in water solvation anticipated higher electron transfer ability of iTEPA in aqueous conditions compared to TEPA and iTEPA, thus, leading to stronger adsorption on iron surface, corroborated by the molecular dynamics (MD) classical simulations. MD simulations showed that nearly 53%, 39%, 59% reduction in adsorption energies was detected for single inhibitor molecule of TEPA, iTEPA, and HC-iTEPA shifting from water to CO2-saline media, respectively. The formation of water double adsorption layer contributed to decreasing the CIs adsorption energies by the larger surface separation distances spotted in the density profiles. Nevertheless, the multi-inhibitors study revealed strong adsorption of TEPA and iTEPA on the iron surface, while HC-iTEPA neglected cooperative adsorption and aggregated as a spherical-like micelle with lower surface coverage propensity. Radial distribution functions g(r) explored the preferential interactions of inhibitor-H2O and inhibitor-CO2 that guided the CIs adsorption conformation. Self-diffusivity coefficients of competing adsorbates with the three CIs were found to be one to two orders of magnitude lower near the interface than in the bulk.

(Invited) Investigation of Corrosion Inhibitor Adsorption on Mild Steel By Electrochemical Atomic Force Microscopy

Mild steel has wide application in oil and gas industry due to its excellent mechanical properties and low costs. However, it is susceptible to corrosion attack in a typical water-containing service environment. Organic corrosion inhibitors can adsorb on steel surfaces to form protective layers even when added in a small amount. As conceptualized in the literature, the decrease in corrosion rates due to addition of inhibitor should be directly related to their surface coverage. However, studies have so far not provided any direct evidence of such a link, primarily due to limitations of conventional electrochemical analysis that have been used to investigate them. In the present work, a specially designed holder for electrochemical atomic force microscopy (EC-AFM) has been used to study the influence of a tetra-decyl-dimethyl-benzyl-ammonium inhibitor model compound on mitigation of corrosion. AFM results shows that when the bulk solution inhibitor concentration was at 0.5 CMC, partial coverage of the surface by the inhibitor film and patchy corrosion (which could lead to localized attack) of the UNS G1018 steel surface were observed by contact mode AFM imaging. When inhibitor bulk concentration was above the surface saturation value (1 CMC), full surface protection was indicated by the almost unchanged AFM topography images from 10 minutes to 4 hours exposure to the inhibited solution. The LPR results obtained with EC-AFM showed that the corrosion rates of this steel decreased as the bulk solution concentration of inhibitor in separate tests was increased from 0, 0.5 CMC to 1 CMC, while further increase of concentrations (from 1 CMC to 2 CMC) didn’t lead to any apparent reduction of general corrosion rate. Although the LPR corrosion rates at 1 CMC and 2 CMC were extremely low (0.05 - 0.1 mm/year), the values didn’t reduce to 0 under these full coverage conditions. Additional AFM tapping mode imaging results on mica indicated the formation of a porous film (a layer with ‘holes’) which is used to explain the types of adsorption layers possible and their probable influence on corrosion.

New atmospheric corrosion inhibitor of aluminum alloy D16

The application of mixed corrosion inhibitor (CI), which is an equimolar composition of oleoyl sarcosinate (SOS) and sodium flufenamate (SFF), for protection of D16 aluminum alloy from atmospheric corrosion has been studied. The polarization measurements used to assess the effectiveness of preliminary passivation of the alloy with solutions of SOS, SFF and their composition showed significant advantages of mixed CI. The XPS method was used to study features of CI adsorption on the surface of D16 alloy. It has been established that upon adsorption of SOS and SFF separately a monolayer is formed, firmly bonded to the alloy surface, thickness of which is not exceeding 2.6—3.2 nm. After the joint adsorption of these CI, the layer thickness reaches 12—20 nm. The composition of this layer includes a considerable amount of Al3+ ions (~20%) related to their compounds with SFF and SOS, as well as to aluminum hydroxides. A possible mechanism for the formation of such a protective layer is proposed. The results of corrosion tests in a humid atmosphere with daily water condensation on samples of D16 alloy confirmed the high protective ability of the mixed CI film.