Corrosion Protection Applications Research Articles

Highly hydrophobic polyaniline nanoparticles for anti-corrosion epoxy coatings

Perfluorooctanoic acid doped polyaniline (PFOA/PANI) nanoparticles were successfully prepared through ultrasonication-assisted oxidation polymerization. The prepared PFOA/PANI nanoparticles exhibited high hydrophobicity and good dispersibility in ethanol, which could uniformly distribute in epoxy resin (EP) coatings to enhance their anti-penetrant efficiency towards corrosive media. The corrosion protection properties of PANI-contained coatings on Q215 steel were evaluated and compared through electrochemical impedance spectroscopy measurements in brine. The experimental results demonstrated the PFOA/PANI/EP coatings possessed higher corrosion performance than the EP coatings and HCl-doped PANI-contained EP coatings. Besides, dedoped PFOA molecules from PFOA/PANI nanoparticles can be adsorbed on the surface of steel to form a hydrophobic corrosion inhibition layer, which further improves the corrosion resistance. The impedance of PFOA/PANI/EP coatings continuously increased after the coatings were immersed in brine for more than 2 days, and the impedance modulus at 0.01 Hz was higher than 6 × 108 Ω·cm2 after 9 days. The novel method for the preparation of hydrophobic PANI nanoparticles proposed in this work may provide new ideas and methods for developing more high-performance anti-corrosion materials and promoting their applications in corrosion protection.

Durable and Regenerable Superhydrophobic Coating on Steel Surface for Corrosion Protection

Corrosion limits the usage of steel and leads to the tremendous loss of the economy. Superhydrophobic coating is proven an effective way to prevent corrosion due to its excellent water repellent nature. Herein, we describe the successful preparation of superhydrophobic coating on steel surface which is synthesized by using chemical etching technique with mixture of hydrochloric and nitric acid followed by treatment with lauric acid. By optimizing the etching process parameters, superhydrophobicity with water static contact angle of 170° and tilt angle of 5° is successfully achieved. Coated steel is found to be thermal, chemical, and mechanical stable. Besides, coating has also good regenerability. Furthermore, coating exhibits the excellent self-cleaning and anti-fogging properties. The electrochemical study is revealed the enhancement of corrosion resistance of steel after coating. This facile strategy inspires the large-scale fabrication of multifunctional steel surfaces for practical applications in self-cleaning, anti-fogging, and corrosion protection.

Preparation of Polycrystalline‐Mixed Graphene Film with Benzene Solution by Electromagnetic Induction for Application in Metal Corrosion Protection

AbstractMetals used in the electronics, machinery manufacturing, and construction industry are often chemically reactive and corrosion‐prone, while barriers on a metal as a conventional method for anticorrosion always have negative effects including a toxic nature, thickness increase over time, and changes of electrical and optical properties after surface coating. This study employs a benzene solution to induce a rapid formation of a polycrystalline graphene film on copper foils or iron sheet substrates under atmospheric conditions by electromagnetic induction, which is non‐toxic and environment‐friendly and produces favorable anticorrosive effects. The microscopic analysis shows that the as‐grown film is a polycrystalline graphene complex of graphene crystallites. It is revealed that the copper foils or iron sheets with the graphene film is significantly resistant to strong corrosion, with the corrosion current density is one order of magnitude lower when compared with samples without the graphene films. The polycrystalline structure of the graphene film can prevent the electronic conduction of the surface, thereby reducing corrosion and local over‐corrosion phenomena when metals are situated in a long‐term exposure to corrosive environments.

Effect of choline chloride on electrodeposited superhydrophobic nickel film and the corrosion protection application

Superhydrophobic nickel films constructed of micro-nano hierarchical structure were prepared on copper foil through one-step electrodeposition process with choline chloride as crystal modifier. The effects of electrodeposition parameters on surface morphology was observed by scanning electron microscopy (SEM). The results demonstrated that the hierarchical nickel films consist of alternate flower-like and leaf-like structure. Under the optimal parameters, the nickel film has a static contact angle of 162 ± 1°, exhibiting excellent superhydrophobic property without organic surface modification. The superhydrophobic properties of the superhydrophobic nickel surface was analyzing via SEM, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, the potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS) of the superhydrophobic films in 3.5 wt% NaCl solution demonstrates that the fabricated superhydrophobic films have superior corrosion resistance. Furthermore, the superhydrophobicity of films shows good self-recovery performance through atmospheric exposure.

Synthesis of a novel Ce(iii)/melamine coordination polymer and its application for corrosion protection of AA2024 in NaCl solution.

We present the synthesis of a new cerium(iii)–melamine coordination polymer (CMCP) by a mixed-solvothermal method and its characterization. Characterization techniques included Raman, Fourier Transformation Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), in which the change in the electronic environment and the crystallinity were tracked. The characterization results confirm the coordination of cerium(iii) with melamine through –NH2 groups, instead of the N atoms of the triazine ring, for which we propose a mechanism of interaction. In addition, Biovia Materials Studio package was applied to determine and investigate the molecular structure of the CMCP. All simulations were done using COMPASS force-field theory and atom-based method for summation of electrostatic and van de Waals forces. The application of the CMCP for the corrosion inhibition of AA2024 in 3.5% NaCl solution was tested using the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results point out that the presence of cerium as cerium(iii) in the CMCP structure plays the fundamental role of inhibition, whereby the inhibition mechanism occurs by cathodic oxidation of Ce(iii) to Ce(iv) and cyclic reduction of Ce(iv) to Ce(iii) by melamine part of CMCP.

Dynamic self-propelling condensed microdroplets over super-hydrophobic surface: An exceptional atmospheric corrosion inhibition strategy

Superhydrophobic surfaces (SHS) have potential application prospects in many fields for the lotus effect. The microdroplet self-propelling effect is a newly discovered mechanism of SHS phenomena, which provides more possibilities for SHS applications. In this study, the ZnO-nanoneedle array was designed and constructed by an electrodeposition method. Based on surface characterization and analysis, the nucleation, growth, and merging process of SHS surface droplets under simulated condensation conditions were studied. The correlation between the surface microstructure and the jumping behavior was established, and the self-propelling mechanism was analyzed from an energy perspective. Based on electrochemical data, the contribution of self-propelling behavior to the atmospheric corrosion protection performance of SHS was analyzed, which confirms that the droplet self-propelling behavior, as a new SHS atmospheric corrosion protection mechanism, has potential applications in atmospheric corrosion protection in the future.

Two birds with one stone: Graphene oxide@sulfonated polyaniline nanocomposites towards high-performance electromagnetic wave absorption and corrosion protection

Conventional electromagnetic wave (EMW) absorbing materials can exhibit excellent microwave absorption property. However, their susceptibility to corrosion and high density restrict them used in the harsh marine environments with high humidity conditions. Here, we report graphene oxide@camphorsulfonic acid-doped polyaniline (GO@CSA-PANi) nanocomposites prepared by an in-situ polymerization approach as promising materials for application in both EMW absorption and corrosion protection. Impressively, when applied as EMW absorbers, the as-obtained GO@CSA-PANi nanocomposites show excellent EMW absorbing capacity with broad bandwidth due to the remarkable impedance matching and EMW attenuation characteristics caused by the introduction of chiral CSA-PANi. The reflection loss (RL) and effective bandwidth of the GO@CSA-PANi can reach −48.1 dB and 5.3 GHz with a 2.4 mm matching thickness, respectively. Furthermore, owing to the synergistic effects of GO and CSA-PANi, the water borne epoxy composite coatings with GO@CSA-PANi nanocomposites exhibit long term corrosion resistance. The as-obtained composite coatings at optimized content exhibit a remarkable corrosion protection capability (97.43%) after 168 h of immersion in corrosive medium. The bifunctional nanocomposites could open new avenues towards high-performance electromagnetic wave absorption with corrosion protection.

Corrosion protection application of liquid-infused surface with self-healing via regional growth of layered double hydroxide films on aluminum alloy

Corrosion of aluminum and its alloys in marine system severely restricts their development and application. Therefore, the development of anti-corrosion ability of aluminum and its alloys is a subject of great importance. In this work, the liquid-infused surface (denoted as sample LR) with self-healing property is proposed. The porous structure prepared by laser ablation can store the lubricant oil. The regional growth of layered double hydroxide (LDH) films can lock in place the lubricant oil. Lubricant film is the key to self-healing ability of sample LR. The anti-corrosion and self-healing properties of sample LR were evaluated by electrochemical tests after immersed in 3.5 wt.% NaCl for different time. For the anti-corrosion ability, the corrosion current density of sample LR is 0.02 μA/cm2 after immersed for 48 h, which is ca.1 orders of magnitude lower than that of untreated AA1060 alloy (0.25 μA/ cm2). Correspondingly, the low-frequency impedance modulus of sample LR is 318 kΩ⋅ cm2, which is bigger than AA 1060 alloy (3.3 kΩ⋅cm2). For the self-healing property, low-frequency impedance modulus of sample LR immersed for 1 day (358 kΩ· cm2) is basically equal to that of sample LR immersed for 9 days (349 kΩ·cm2). Therefore, the fabricated sample LR shows the outstanding anti-corrosion and self-healing ability thus it has a widespread application prospect in industry.

Aqueous cellulose solution assisted direct exfoliation of graphite to high concentration graphene dispersion

In the present work, high concentration graphene dispersion was prepared by sonication-assisted liquid-phase exfoliation (LPE) using inexpensive and environment-friendly aqueous cellulose solution. The highly efficient exfoliation of starting graphite into graphene was achieved by the noncovalent affinity of cellulose towards graphene. The obtained aqueous graphene sheets exhibited remarkably high concentration of 8.54 mg mL−1 with fewer defects (ID/IG ~ 0.53) and multi-layers structures, which promised a potential ideal candidate for applications in antistatic, corrosion protection, and electromagnetic compatibility.

Role of oxygen functionalities of GO in corrosion protection of metallic Fe

We demonstrated the mechanism that makes Graphene Oxide (GO) a superior material for corrosion protection over reduced graphene oxide (rGO) and nitrogen doped reduced graphene oxide (N-rGO). According to the results of our electrochemical study, supported by a host of characterization methods and density functional theory (DFT) based calculations, reduction of GO to synthesize rGO or doping of foreign heteroatoms like nitrogen to synthesize N-rGO, exposes and/or creates the defects/pores on the basal carbon plane of GO. Through these defects/pores of rGO and N-rGO, the corrodants react with the metal-surface and corrode it. A subnanometric layer of GO adhered to carbonyl iron (CI) surface through grafting by a thin Glycine (Gly) layer, repels the corrodants and shows robust corrosion protection performance in 1 M KCl solution, over a similar layer of rGO or N-rGO. Hence, our work demonstrate that a coating of GO on metallic Fe surface, grafted via a thin glycine layer, is the economical solution and has the robust performance for its direct industrial application for corrosion protection.

Electrophoresis Deposition of Tungsten oxide Nanoparticles for Corrosion Inhibition

In the present research, electrophoretic deposition technique (EPD) was used to deposit tungsten oxide (WO3) nanoparticles onto galvanized steel from a tungsten oxide ethanol suspension at various concentrations of (1.7×10−2, 2.5×10−2 and 3.4×10−2 M) for corrosion protection application. The (WO3) nano coating was used as a barrier layer for the corrosion protection of galvanized steel in saline solution. (WO3) nanoparticles were characterized by measuring the Fourier transform infrared spectroscopy, UV-Visible and X-ray diffraction techniques. The morphology of the (WO3) nanoparticles was investigated using Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Results indicated that (WO3) nanoparticles layer was efficiently deposited onto galvanized steel using (EPD), also, the deposited nanoparticles film was found to be homogenous and smooth. (EPD) and the partial reduction of the (WO3) nanoparticles occurred simultaneously under the applied electrical fields. Moreover, the anti-corrosion performance of the (WO3) nanoparticles –EPD layers was characterized using Tafel polarization method. Polarization studies identified the coated (WO3) nanoparticles behave as a mixed type inhibitor. Protection efficiencies data were increased as the (WO3) nanoparticles concentrations and temperature increased, indicating chemisorption protection mechanism.

Preparation of a superhydrophobic TiN/PTFE composite film toward self-cleaning and corrosion protection applications

A titanium nitride-polytetrafluoroethylene (TiN-PTFE) composite film was developed on Q235 steel surface to achieve the superhydrophobic property. The morphology and wettability of TiN-PTFE films were regulated by changing the deposition thickness during electron beam deposition, resulting in the optimized hydrophobicity with a water contact angle of ~ 157.8° and a sliding angle down to ~ 3.6°. The superhydrophobic TiN-PTFE film could easily clean the surface contaminations by water dropping, given the excellent self-cleaning performance. Electrochemical measurement results showed that the TiN-PTFE surface could efficiently strengthen the corrosion resistance of carbon steel in 3.5 wt% NaCl solution through the protective barrier and the air cushion trapped inside the coating. Besides, the superhydrophobic film exhibited good chemical stability in acid and alkaline solutions as well as remarkable mechanical durability against abrasion. This work offers an efficient and cost-effective strategy for the large-scale fabrication of superhydrophobic films. It is expected that the superhydrophobic TiN-PTFE film has promising prospects for self-cleaning and corrosion protection applications.

One-step electrochemical synthesis of poly(vinyl pyrrolidone) modified polyaniline coating on stainless steel for high corrosion protection performance

Composite coatings of poly(vinyl pyrrolidone) (PVP)-polyaniline (PANI) were prepared on 304 stainless steel (SS) for corrosion protection application by one-step electrodeposition. The composition and structure of the coatings were obtained by Fourier transform infrared spectra (FTIR), Raman spectroscopy, X-ray diffraction (XRD), UV–vis spectrum, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electropolymerization rate of aniline is decreased and large aggregation of polyaniline particles can be significantly inhibited in the presence of PVP. It is suggested that 1.0 wt% PVP-PANI coating provides enhanced corrosion protection for 304 SS in 1 M H2SO4 solution. The interaction between PANI and PVP favors the formation of the compact structure and consequent high corrosion performance.

Pehuén (Araucaria araucana) seed residues are a valuable source of natural antioxidants with nutraceutical, chemoprotective and metal corrosion-inhibiting properties

In the last decade, green chemistry has been attracting great interest in many contexts, including, among others, natural antioxidants. However, only a few works deal with natural residue extracts and biowaste, which could be an efficient, economical and environmentally friendly source for the production of useful compounds. In this study, we look for antioxidant activity in Araucaria araucana seeds, an iconic pine species of the Argentine and Chilean Patagonia commonly known as “pehuén”. Piñones are the edible pehuén seeds, and it is estimated that approximately 40 tons of piñones are harvested annually in Argentina and Chile. The chemical composition, antioxidants, metal corrosion-inhibiting properties and biological activity of edible and discarded piñón tissues were determined. Acute toxicity was discarded by in vitro testing and double fluorescent staining. Biological activity was evaluated in vivo by determining redox markers in salivary glands from rats treated with Cyclophosphamide (an oncological drug). All piñón tissues had antioxidants and antioxidant activity, with the coats showing the highest levels (up to 404 µg ascorbic acid equivalent per mg). The coats, in particular, had high gallic acid, catechin, quercetin and tannin contents, and more antioxidant activity, polyphenols and flavonoids than berries from the region. Results by X-ray fluorescence spectrometry showed that Na, Mg, P, S, Cl, K, and Ca were majority elements in the coat, embryo and endosperm. Furthermore, coat extract also showed significant anti-corrosion activity and in vivo protection against oxidative damage. The results indicate that piñón biowaste is a low-cost attractive source of natural antioxidants with potential nutraceutical, medical and metal corrosion protection applications.

Synthesis and characterization of gordaite, osakaite and simonkolleite by different methods: Comparison, phase interconversion, and potential corrosion protection applications

Gordaite (NaZn4(OH)6SO4Cl·6H2O) is a mineral from the layered hydroxide salts (LHS) family that presents both cation- and anion-exchange properties, which is rare in this class of materials, having then called much attention lately due to its interesting potential applications. Sharing similar layered structure and composition, gordaite’s non-cation-exchanger analogous such as osakaite (Zn4(OH)6SO4·5H2O) and simonkolleite (Zn5(OH)8Cl2·H2O) show the possibility of interconversion reactions, in dynamics that might be of interest in technological applications such as corrosion protection. The materials can act as stimuli-responsive nanocontainers for storing corrosion inhibitors between the layers that might then be released on demand and avoid corrosion reactions on metals and alloys. In this work, we study the different methodologies for obtaining these LHS by synthesizing them by the oxide hydrolysis, co-precipitation by increasing pH and electrochemical methods, and comparing the obtained results.

Nanosecond laser fabrication of superhydrophobic surface on 316L stainless steel and corrosion protection application

Herein, we developed an facile, cost-effective and efficient method to fabricate microstructures of different scales on 316 L stainless steel substrate surface by laser modification. By changing the laser parameters, such as various laser fluence (2.69, 3.96, 6.28, 8.14,9.55 J/cm2) during laser irradiation, different sizes of micro-cracks and brain-like microstructures can be obtained. The experimental results indicate that a static contact angle of 160 ± 5° and the sliding angle of 3 ± 0.5°, can be achieved at a scanning interval of 30.0 μm and laser fluence of 8.14 J/cm2, which has the best outstanding wettability. In addition, the microstructures and chemical compositions on the surface were examined by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The corresponding corrosion resistance properties was evaluated by the means of potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The laser textured superhydrophobic surface was found to enhance the corrosion resistance dramatically. Also, after the laser modification, excellent self-cleaning performance was demonstrated based on tests with quartz sand particles. Particularly, we extensively discussed how the structures on the 316 L stainless steel were formed after the ultraviolet nanosecond laser irradiation and the interaction mechanism of the laser and substrate. This study not only provides important insights into the formation mechanism of laser textured surfaces, but also guides practical industrial applications as this approach is simple, low-cost and convenient for fabrication of large-area superhydrophobic surfaces on various metal materials.

Inhibitor-self-gated stimuli-responsive anticorrosion system based on π-π stacking

Most of existing nanocontainers suffer from tedious, complicated and unsustainable assembly process which restricts their application in corrosion protection as smart inhibitor carriers. In this study, we adopted the framework-hybridization approach to prepare a smart anticorrosion system (MBT@Ph-HPMO), with MBT inhibitor as cargo and phenylene-bridged hollow periodic mesoporous organosilica (Ph-HPMO) as nanocontainer. Results reveal that the π-π stacking between MBT and framework of Ph-HPMO serves as nature valve, which is supplemented by the molecular dynamic simulation. The encapsulated inhibitor was loaded into Ph-HPMO at neutral pH, demonstrating fast release in acidic environment. On-demand release of inhibitors from MBT@Ph-HPMO contributed to achieving in situ active corrosion protection. Anticorrosion performance of MBT@Ph-HPMO for copper alloy was evaluated in 3.5 wt% NaCl solution for a period of 30 days. The alloy exhibited the slightest corrosion damage in the corrosion medium with the addition of 0.24 wt% MBT@Ph-HPMO. This facile and versatile strategy will have broad applications in new class of nanocontainers fabrication and open up a new prospect for active corrosion protection.

A two-step method fabricating a hierarchical leaf-like superamphiphobic PTFE/CuO coating on 6061Al

Aluminum-based materials are widely used, but they are easily corroded and contaminated in some harsh conditions. Now, fabricating anti-wetting coatings on aluminum-base materials is a promising way to solve the above problems. In this work, a two-step method is developed to fabricate a hierarchical leaf-like superamphiphobic PTFE/CuO coating on 6061Al substrate, and it is simple, economical and environmentally friendly. The resultant coating is repellent to many liquids, such as tap water, ink, tea water, milk, H2SO4 solution (pH 3), NaOH solution (pH 10), ethylene glycol and glycerol. All contact angles of these liquids on the PTFE/CuO coating are more than 150°, and water sliding angles are less than 10°. Importantly, the results of the self-cleaning, adhesion, chemical stability and corrosion resistance tests indicate that the PTFE/CuO coating could protect the 6061Al substrate from corrosion and pollution. Furthermore, after the UV, thermal stability and mechanical stability tests, the PTFE/CuO samples are still be superhydrophobic, which suggests that 6061Al substrate with the PTFE/CuO coating could be applied in harsh conditions. In sum, the method is especially suitable to large-scale industry production and promising for corrosion protection and functional applications of aluminum-based materials.

Nanoparticles influence miscibility in LCST polymer blends: from fundamental perspective to current applications.

Polymer blending is an effective method that can be used to fabricate new versatile materials with enhanced properties. The blending of two polymers can result in either a miscible or an immiscible polymer blend system. This present review provides an in-depth summary of the miscibility of LCST polymer blend systems, an area that has garnered much attention in the past few years. The initial discourse of the present review mainly focuses on process-induced changes in the miscibility of polymer blend systems, and how the preparation of polymer blends affects their final properties. This review further highlights how nanoparticles induce miscibility and describes the various methods that can be implemented to avoid nanoparticle aggregation. The concepts and different state-of-the-art experimental methods which can be used to determine miscibility in polymer blends are also highlighted. Lastly, the importance of studying miscible polymer blends is extensively explored by looking at their importance in barrier materials, EMI shielding, corrosion protection, light-emitting diodes, gas separation, and lithium battery applications. The primary goal of this review is to cover the journey from the fundamental aspects of miscible polymer blends to their applications.

Chemical Imaging of Reactive Surfaces Using Microsensors As Tips in Scanning Electrochemical Microscopy: Applications in Corrosion Research and Protection

Chemical imaging of reactive surfaces with high spatial resolution has become available with the introduction of scanning electrochemical microscopy (SECM). In fact, this technique has become a powerful tool in the study of a wide range of corrosion processes. This presentation provides a brief review on the applications of scanning electrochemical microscopy (SECM) in measuring, characterising and evaluating corroding systems as developed in our research group at the University of La Laguna (Spain). Localized corrosion processes and electrochemical activity distributions in surfaces can thus be investigated in real time with high spatial resolution. The SECM is a unique near-field scanning technique that is electrochemically integrated as to detect chemical and electrochemical activities in electrochemical heterogeneous systems such as those operating in corrosion research. The SECM can be used in a variety of ways, which can be broadly classified into amperometric and potentiometric modes, depending on the type of the sensing probe, namely an ultramicroelectrode (UME) and an ion-selective microelectrode, respectively. Because the corroding metal usually involves local changes in ionic concentrations, as they produce Mz+ at the anodic sites transferred under diffusion control, the system can be studied by amperometric SECM. This feature has been exploited to image the generation of specific metal cations for the visualization of metastable pits on austenitic steel [1], and the detection of metal dissolution either from inclusions in alloys [2], or from defects in polymer-coated metals [3]. Additionally, in a neutral aqueous media, the reaction of dissolved oxygen from the electrolyte at the cathodic areas may be analyzed through the monitoring of the subsequent depletion of oxygen content in the solution volume adjacent to the cathodic sites [4]. However, for the detection of concentration distributions in certain corroding samples, especially for metals with sufficiently negative redox potentials in aqueous environments, the use of Pt microelectrodes is limited by the onset of oxygen reduction and hydrogen evolution reactions [5]. Though less employed, these physicochemical parameters may be studied using ion-selective electrodes (ISEs) as tips. In this case, the SECM is operated in the potentiometric mode, which gives greater chemical selectivity. In this respect, the applicability of Zn2+ [6] and Mg2+ ion-selective microelectrodes [7] with SECM has been established, although the onset of high electric fields in the electrolyte phase associated to galvanic corrosion [8] requires new tip assemblies for accurate monitoring [9]. In this contribution, the operation modes of the instrument are briefly described together with typical experiments selected to illustrate their application in sensing localized corrosion. Selected examples regarding the characterization of corrosion processes using scanning electrochemical microscopy are presented, including passivity breakdown and pit initiation, galvanic coupling, and blistering and delamination processes in coated metals. [1] Y. González-García, G.T. Burstein, S. González, R.M. Souto. Imaging metastable pits on austenitic stainless steel in situ at the open-circuit corrosion potential. Electrochemistry Communications 6, 637-642 (2004). [2] J. Izquierdo, S. González, R.M. Souto. Application of AC-SECM in corrosion science: Local visualization of heterogeneous chemical activity in AA2024 surfaces. International Journal of Electrochemical Science 7, 11377-11388 (2012). [3] R.M. Souto, Y. González-García, S. González. In situ monitoring of electroactive species by using the scanning electrochemical microscope. Application to the Investigation of degradation processes at defective coated metals. Corrosion Science 47, 3312-3323 (2005). [4] J.J. Santana, J. González-Guzmán, L. Fernández-Mérida, S. González, R.M. Souto. Visualization of local degradation processes in coated metals by means of scanning electrochemical microscopy in the redox competition mode. Electrochimica Acta 55, 4488-4494 (2010). [5] R.M. Souto, Y. González-García, D. Battistel, S. Daniele. In situ SECM detection of metal dissolution during zinc corrosion by means of mercury sphere-cap microelectrode tips. Chemistry, A European Journal 17, 230-236 (2011). [6] J. Izquierdo, L. Nagy, Á. Varga, I. Bitter, G. Nagy, R.M. Souto. Scanning electrochemical microscopy for the investigation of corrosion processes: measurement of Zn2+ spatial distribution with ion selective microelectrodes. Electrochimica Acta 59, 398-403 (2011). [7] J. Izquierdo, A. Kiss, J.J. Santana, L. Nagy, I. Bitter, H.S. Isaacs, G. Nagy, R.M. Souto. Development of Mg2+ ion-selective microelectrodes for potentiometric Scanning Electrochemical Microscopy monitoring of galvanic corrosion processes. Journal of The Electrochemical Society 160, C451-C459 (2013). [8] A. Kiss, D. Filotás, R.M. Souto, G. Nagy. The effect of electric field on potentiometric Scanning Electrochemical Microscopic imaging. Electrochemistry Communications 77, 138-141 (2017). [9] D. Filotás, B.M. Fernández-Pérez, A. Kiss, L. Nagy, G. Nagy, R.M. Souto. Double barrel microelectrode assembly to prevent electrical field effects in potentiometric SECM imaging of galvanic corrosion processes. Journal of The Electrochemical Society 165, C270-C277 (2018).