Anticorrosive Coatings Research Articles

Modification of Liquid Glasses Is a Key Factor in the Technology of Obtaining Hybrid Compositions and Coatings with Anticorrosive Properties

The aim of the work was to investigate the prospects of imparting valuable physical and chemical properties, such as corrosion resistance, impact and bending strength, adhesion and storage stability, to hybrid systems of potassium and sodium silicates by modification with organic compounds. Here, we present the results of worldwide activities of scientific teams studying the manufacturing technology of modified liquid glass anticorrosive coatings used in chemical, petrochemical industry and modern construction. The authors theoretically and economically justified and put into practice novel organic and inorganic compositions with increased viability. The durable and waterproof coatings with good adhesion to various substrates (non-ferrous metals, steel, plastered surface and wood) were obtained. The authors demonstrate the possibility of recycling of zinc-containing rongalite production wastes and sludge pastes of electrochemical productions containing alkali and alkaline-earth metal cations by including them into the composition instead of pigmenting solid-phase components. We propose a technological route for obtaining anticorrosion coatings to protect aluminum and its alloys operated in a zone of elevated (up to 673 K) temperatures.

Fabrication of organic/inorganic hybrid waterborne polyurethane coating based on CeNPs @mTi3C2Tx composites for anti-corrosion applications

Ti3C2Tx has been studied as a nano-filler in anti-corrosion coatings, but its poor dispersion, interfacial interaction in coatings and poor long-term anti-corrosion performance limit its application. A series of organic/inorganic hybrid waterborne polyurethane anti-corrosion coatings were designed and prepared based on the barrier effect of MXene and the passivation mechanism of CeNPs, providing a green, environmentally friendly, and long-term efficient organic/inorganic hybrid anti-corrosion method. FT-IR, zeta potential, XPS and EDX analysis showed that the nano ceria was successfully loaded in mTi3C2Tx. SEM testing showed that the synthesized CeNPs @MXene filler had good dispersion and compatibility in polyurethane. According to the results, CeNPs, mTi3C2Tx, and CeNPs @mTi3C2Tx could enhance the anti-corrosion efficiency of waterborne polyurethane and prolong the anti-corrosion time. At the same time, WPU/CeNPs @ mTi3C2Tx exhibited an order of magnitude higher low-frequency impedance modulus than pure waterborne polyurethane and shown superior corrosion resistance over WPU/mCeNPs and WPU/mTi3C2Tx. The best anti-corrosion performance was achieved when the content of CeNPs @mTi3C2Tx was 1.5 wt%. The |Z|0.01Hz value was still close to 108 Ω·cm2 after 120 days of immersion.

Electrophoretic deposition of polytetrafluoroethylene (PTFE) as anti-corrosion coatings

Polytetrafluoroethylene (PTFE) is known as the ‘king of plastics’ because of its excellent resistance for both acid and alkali medium, so the coatings composed of PTFE have an attractive application prospect in the field of corrosion protection. In this work, with a solvent of ethanol containing 0.05 g·L−1 PEI + 0.1 mM nitric acid as the dispersion system, the PTFE coatings were successfully prepared onto the Mg-3Al-1Zn (AZ31) alloy sheets by electrophoretic deposition (EPD) strategy. The morphology of the electrophoretic PTFE coating was further reshaped through a sintering post-treatment at 380 °C in argon atmosphere. In 3.5 wt% NaCl solution, the corrosion current density was remarkably reduced (3.92 × 10−6 A·cm−2 for the bare AZ31 vs 1.54 × 10−9 A·cm−2 for the sintered PTFE coating AZ31), and the charge transfer resistance was significant increased (299.92 Ω·cm2 for the bare AZ31 vs 2.79 × 106 Ω·cm2 for the sintered PTFE coating AZ31), which means the electrophoretic-sintered PTFE coating can significantly improve the corrosion resistance of AZ31 alloys. Moreover, it is also suggested that the electrophoretic-sintered PTFE coating may be a general anti-corrosion strategy for a series of metal materials.

Hierarchically self-reporting and self-healing photothermal responsive coatings towards smart corrosion protection

For conventional anticorrosion coatings, it is challenging to simultaneously report and repair two failure stages involving coating damage and interfacial metal corrosion. Thus, it leads to difficulties for continuous detection of coating service status, and may result in premature failure of metal-based equipment. Herein, we present a novel photothermal responsive composite epoxy system with hierarchical damage reporting and healing capabilities, which is enabled by mesoporous polydopamine nano-spheres loaded with crystal violet lactone (CVL) and phenanthroline (Phen). In our design, the coating damage is indicated by the immediately intensified fluorescent and can be rapidly closed in 90 s of NIR irradiation. Furthermore, the on-demand released corrosion probes (Phen) are able to chelate with Fe2+ ions generated from localized corrosion, producing distinct visual red color to report corrosion pits and resisting corrosion developing process. The proposed smart coatings provide a concept for achieving hierarchically self-reporting and self-repairing function of general coating defects and substrate corrosion, thus having certain potential to be applied in smart anticorrosion applications.

Characterization and Superhydrophobic Anticorrosive Coating of AA-7475/ZrO2/Polymer Nanocomposites

An AA-7475 is coated with superhydrophobic (SH) polymer nanocomposites (PNCs), emphasizing the coating’s manufacturing, characterization, and anticorrosive qualities. Coating AA-7475 alloy with polyvinyl chloride (PVC), copper stearate (CS), and zirconium oxide (ZrO2) nanoparticles produces the desired superhydrophobic. Using an X-ray diffractometer, field-emission scanning electron microscopy, Fourier-transform infrared spectrometer, ZrO2 nanoparticles, CS, and PVC PNCs are analyzed structurally and molecularly. The atomic force microscope picture was analyzed to determine how the surface roughness affected the SH behavior reached by changing the weight percentage of ZrO2 nanoparticles from 0.6 to 3.0 wt%. PNC-5 with 3.0 wt% ZrO2 nanoparticles is used as resistance to corrosion coating for AA-7475 due to its water contact angle of 154°. In a 3.5% NaCl solution, uncoated and PNC-5-coated AA-7475 are examined using potentiodynamic polarization and electrochemical spectroscopy. PNC-5 coating reduces AA-7475 corrosion rate from 23.75 to 0.2253 mpy. In this study, we use polarization resistance, corrosion resistance efficiency, double layer capacitance, corrosion current density, and charge transfer resistance to demonstrate that the SH surface air trapping phenomena are responsible for effective corrosion resistance.

Hybrid Zinc Coatings with Chitosan/Alginate Encapsulated CuO-Nanoparticles for Anticorrosion and Antifouling Protection of Mild Steel

The construction of anticorrosion coatings containing antifouling agents is an effective way to ensure the long-term durability of marine steel infrastructures. In this work, an innovative hybrid coating was prepared by introducing biocide CuO nanoparticles in ordinary zinc coating to improve its protective ability for steel in aggressive salt water environments. The CuO nanoparticles were embedded inside the matrix of chitosan/alginate complexes to prevent spontaneous copper leaching during corrosive attacks. Two procedures were applied for the electrodeposition of hybrid/composite zinc-based coatings on low-carbon steel substrates (DC current): first—the co-electrodeposition of encapsulated CuO nanoparticles with zinc on a cathode (steel) electrode from a sulfate electrolyte with a relatively low pH value of about 4.5–5.0 and second—the encapsulated CuO nanoparticles were electrodeposited from aqueous solution as an intermediate layer between two zinc deposits. The particles size and stability of suspensions were evaluated using dynamic light scattering. Both hybrid coatings were compared in terms of surface morphology and hydrophilicity (SEM and AFM analysis, contact angle measurement) and corrosion resistance (potentiodynamic polarization curves, polarization resistance). The protective characteristics of the coatings were compared in a 3.5% NaCl solution and artificial sea water. The hybrid coating showed 2–4 times higher polarization resistance than the bare zinc coating during a 30 day immersion in artificial sea water, indicating that this coating has the necessary characteristics to be used in a marine environment.

HD-SiO2/SiO2 Sol@PDMS Superhydrophobic Coating with Good Durability and Anti-Corrosion for Protection of Al Sheets.

Superhydrophobic coatings with excellent water-repellent properties imply a wide range of application areas. However, improvements are needed in terms of stability and complex processing procedures. In the present study, a superhydrophobic coating on Al sheets was prepared by mixing hexadecyltrimethoxysilane (HDTMS)-modified SiO2 nanoparticles and acid-catalyzed silica sols (HD-SiO2/SiO2 Sol) with polydimethylsiloxane (PDMS) binder. The HD-SiO2 nanoparticles and acid-catalyzed silica sol (SiO2 sol) form a binary graded micro-nanostructure, providing excellent superhydrophobicity (Water Contact Angle = 158.5°, Sliding angle = 0°). Superhydrophobic coatings with excellent water-repellent properties have potential for corrosion prevention. However the commonly used organic resins have poor chemical and mechanical properties. In the present study, the results of outdoor exposure for 30 days, immersion in acid and alkaline solutions for 24 h, grit abrasion, and water impact experiments, respectively, showed that the prepared superhydrophobic coating has good wear resistance. The integrated superhydrophobic coating on the Al sheets exhibited good corrosion inhibition with an efficiency (η) of 98.9%, which is much higher than that of the uncoated sheets. The present study provides a promising approach for producing stable superhydrophobic coatings at a low cost, with the potential to supplant conventional organic resin anti-corrosion coatings.

Engineering Active-Site-Induced Homogeneous Growth of Polydopamine Nanocontainers on Loading-Enhanced Ultrathin Graphene for Smart Self-Healing Anticorrosion Coatings

Engineering nanocontainers with encapsulated inhibitors onto graphene has been an emerging technology for developing self-healing anticorrosion coatings. However, the loading contents of inhibitors are commonly limited by inhomogeneous nanostructures of graphene platforms. Here, we propose an activation-induced ultrathin graphene platform (UG-BP) with the homogeneous growth of polydopamine (PDA) nanocontainers encapsulated with benzotriazole (BTA). Ultrathin graphene prepared by catalytic exfoliation and etching activation provides an ideal platform with an ultrahigh specific surface area (1646.8 m2/g) and homogeneous active sites for the growth of PDA nanocontainers, which achieves a high loading content of inhibitors (40 wt %). The obtained UG-BP platform exhibits pH-sensitive corrosion inhibition effects due to its charged groups. The epoxy/UG-BP coating possesses integrated properties of enhanced mechanical properties (>94%), efficient pH-sensitive self-healing behaviors (98.5% healing efficiency over 7 days), and excellent anticorrosion performance (4.21 × 109 Ω·cm2 over 60 days), which stands out from previous related works. Moreover, the interfacial anticorrosion mechanism of UG-BP is revealed in detail, which can inhibit the oxidation of Fe2+ and promote the passivation of corrosion products by a dehydration process. This work provides a universal activation-induced strategy for developing loading-enhanced and tailor-made graphene platforms in extended smart systems and demonstrates a promising smart self-healing coating for advanced anticorrosion applications.

Preparation of new surface coating based on modified oil-based polymers blended with ZnO and CuZnO NPs for steel protection

In our paper, we have synthesized modified PEA and alkyd resin by replacing the new source of polyol (SDEA) which was confirmed by different analyses such as IR, and 1HNMR spectra. A series of conformal, novel, low-cost, and eco-friendly hyperbranched modified alkyd and PEA resins were fabricated with bio ZnO, CuO/ZnO) NPs through an ex-situ method for mechanical and anticorrosive coatings. The synthesized biometal oxides NPs and its composite modified alkyd and PEA were confirmed by FTIR, SEM with EDEX, TEM, and TGA, and can be stably dispersed into modified alkyd and PEA resins at a low weight fraction of 1%. The nanocomposite coating was also subjected to various tests to determine their surface adhesion, which ranged from (4B-5B), physico-mechanical characteristics such as scratch hardness, which improved from < 1.5 to > 2 kg, gloss (100–135) Specific gravity (0.92–0.96) and also chemical resistance test which passed for water, acid, and solvent except alkali, was poor because of the hydrolyzable ester group in the alkyd and PEA resins. The anti-corrosive features of the nanocomposites were investigated through salt spray tests in 5 wt % NaCl. The results indicate that well-dispersed bio ZnO and CuO/ZnO) NPs (1.0%) in the interior of the hyperbranched alkyd and PEA matrix improve the durability and anticorrosive attributes of the composites, such as degree of rusting, which ranged from 5 to 9, blistering size ranged from 6 to 9, and finally, scribe failure, which ranged from 6 to 9 mm. Thus, they exhibit potential applications in eco- friendly surface coatings. The anticorrosion mechanisms of the nanocomposite alkyd and PEA coating were attributed to the synergistic effect of bio ZnO and (CuO/ZnO) NPs and the prepared modified resins are highly rich in nitrogen elements, which might be regarded as a physical barrier layer for steel substrates.

Corrosion resistance of graphene/basalt flake modified waterborne epoxy zinc-rich primer

Purpose The purpose of this study is to evaluate the effect of graphene, basalt flakes and their synergy on the corrosion resistance of zinc-rich coatings. As the important heavy-duty anticorrosion coatings, zinc-rich coatings provided cathodic protection for the substrate. However, to ensure cathodic protection, a large number of zinc powder made the penetration resistance known as the weakness of zinc-rich coatings. Therefore, graphene and basalt flakes were introduced into zinc-rich coatings to coordinate its cathodic protection and shielding performance. Design/methodology/approach Three kinds of coatings were prepared; they were graphene modified zinc-rich coatings, basalt flakes modified zinc-rich coatings and graphene-basalt flakes modified zinc-rich coatings. The anticorrosion behavior of painted steel was studied by using the electrochemical impedance spectroscopy (EIS) technique in chloride solutions. The equivalent circuit methods were used for EIS analysis to obtain the electrode process structure of the coated steel system. Simultaneously, the corrosion resistance of the three coatings was evaluated by water resistance test, salt water resistance test and salt spray test. Findings The study found that the addition of a small amount of graphene and basalt flakes significantly improved the anticorrosion performance of coatings by enhancing their shielding ability against corrosive media and increasing the resistance of the electrochemical reaction. The modified coatings exhibited higher water resistance, salt water resistance and salt spray resistance. The graphene-basalt flakes modified zinc-rich coatings demonstrated the best anticorrosion effect. The presence of basalt scales and graphene oxide in the coatings significantly reduced the water content and slowed down the water penetration rate in the coatings, thus prolonging the coating life and improving anticorrosion effects. The modification of zinc-rich coatings with graphene and basalt flakes improved the utilization rate of zinc powder and the shielding property of coatings against corrosive media, thus strengthening the protective effect on steel structures and prolonging the service life of anticorrosion coatings. Originality/value The significance of developing graphene-basalt flakes modified zinc-rich coatings lies in their potential to offer superior performance in corrosive environments, leading to prolonged service life of metallic structures, reduced maintenance costs and a safer working environment. Furthermore, such coatings can be used in various industrial applications, including bridges, pipelines and offshore structures, among others.

Recent progress of zeolitic imidazolate frameworks (ZIFs) in superhydrophobic and anticorrosive coatings for metals and their alloys

Recent progress of zeolitic imidazolate frameworks (ZIFs) in superhydrophobic and anticorrosive coatings for metals and their alloys

Self-assembly of exfoliated graphene flakes as anticorrosive coatings for additive manufactured steels

This study demonstrates the feasibility of using liquid exfoliation of expandable graphite into multilayer exfoliated graphene flakes (EGFs) to form a self-assembled thin film on an air–water interface. The film can coat the surface of additive manufactured (AM) steel substrates to enhance surface properties, specifically AM 316 stainless-steel (AM316), AM 8620 steel (AM8620), and samples of the same alloys made by conventional manufacturing (CM) processes. Liquid exfoliation offers a high yield route for an EGF coating that can cover up to 95% of the sample surface with a single application. The thin, flexible EGFs can coat a rough AM metal surface, while the highly intact crystal lattice protects covered areas against diffusing ions and prevents localized corrosion compared to similar coatings made with graphene oxide (GO) or reduced GO (rGO). The EGF coating exploits a unique self-assembly process without surfactants or stabilizers, wherein the hydrophobicity and hydrophilicity of EGFs arrange the flakes, then van der Waals (vdW) forces bond them together and to the substrate for a coherent anti-corrosive coating. Electrochemical measurements indicate lower corrosion potential for coated samples, nanoindentation measurements show surface hardness protection against corrosive attack, and weight loss measurements demonstrate long-term protective capabilities. Density functional theory calculations, using the optB88-vdW exchange functional of the graphene and iron (111) interface demonstrated stronger binding and shorter interface distance compared to the well-studied graphene/nickel (111) interface. These calculations and experimental results can further elucidate the superior performance of EGF thin film coatings on high iron content steels, especially AM steels.

An Overview of the Current State and the Advantages of using acrylic resins as anticorrosive coatings

Corrosion protection coating is one of the most common ways of protecting structures against all kinds of negative external influences. Various types of anti-corrosion coatings can be used to successfully extend the service life of products. However, conventional paints are not water-resistant coatings, and small cracks always appear over time due to temperature fluctuations. Compared to other types of coatings, acrylic coatings are less expensive and just as durable. Acrylic resins have high anti-corrosion properties as well as water resistance, impact resistance, good adhesion to the substrate and overall durability. This powerful combination of cost and performance makes acrylic coatings such a popular and sensible solution for protecting structures against corrosion. The main purpose of this review is to describe the different types of acrylic resins and compare their properties, synthesis and drawbacks. It is expected that this work will be the cornerstone for the future development of acrylic resins.

Multi-layer organic-inorganic hybrid anticorrosive coatings for protection of medium carbon steel

In the current study, sol-gel technology was used to produce organic-inorganic hybrid coatings onto AISI 1045 carbon steel as a means of corrosion protection. The organic-inorganic hybrid coatings were prepared using tetraethylorthosilicate (TEOS) and 3-(trimethoxysilyl)propyl methacrylate precursors. The coatings were thermally treated and the effect of temperature and time was studied. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated that the coatings possess homogeneous morphologies and that their thickness decreases with increasing heat treatment temperatures. At the highest treatment the coating was 20% thinner and more than 25% more scratch resistant compared with the untreated coating. According to thermalgravimetric analysis the coating mass loss was approximately 15% up to 150 °C and 2.7% between 150 and 400 °C. The electrochemical measurements, in 3.5% NaCl aqueous solution, determined that the coatings treated at 100 °C have polarization resistance values on the order of 60 kΩ cm2 after 72 h of exposure time in saline solution. The phase angle at high frequency (close to −90° at 103-105 Hz) demonstrated that the coating presented capacitive behavior related to less aggressive corrosion in this electrolyte. Further increasing the temperature beyong 100 °C reduced the performance of the coatings as demonstrated by a decrease of the polarization resistance by about one order of magnitude and the shift of the corrosion potential to more negative values.

New Epoxy and Hardener System Based on an Imidazolium Ionic Liquid as an Anticorrosive Coating for Steel in the Marine Environment.

The large sizes of cations and anions of organic salts are the driving force for the application of ionic liquids (organic salts) in harsh salty conditions. Moreover, the formation of crosslinked ionic liquid networks as anti-rust and anticorrosion protective films on the substrate surfaces repels seawater salt and water vapor from their surface to prevent corrosion. In this respect, an imidazolium epoxy resin and polyamine hardener as ionic liquids were prepared by the condensation of either pentaethylenehexamine or ethanolamine with glyoxal and p-hydroxybenzaldehyde or formalin in acetic acid as a catalyst. The hydroxyl and phenol groups of the imidazolium ionic liquid were reacted with epichlorohydrine in the presence of NaOH as a catalyst to prepare polyfunctional epoxy resins. The chemical structure, nitrogen content, amine value, epoxy equivalent weight, thermal characteristics, and stability of the imidazolium epoxy resin and polyamine hardener were evaluated. Moreover, their curing and thermomechanical properties were investigated to confirm the formation of homogeneous, elastic, and thermally stable cured epoxy networks. The corrosion inhibition and salt spray resistance of the uncured and cured imidazolium epoxy resin and polyamine as coatings for steel in seawater were evaluated.

Catalysis Research of PDMSUr-PWA Films: Aspects to be Considered

PU/PDMS based co-polymers present as drawbacks low hardness and tenacity. By this reason, they are reinforced with silicate structure like ormosil, which is acting as a reinforcement agent. In turn, these ormosil can act as a suitable matrix to host polyoxometalates like phosphotungstic acid (H3PW12O40/ PWA). Thus, PDMSUr-PWA films (containing PDMS, Urethanes, Polyurethanes, Silicates and PWA), which constitute hybrid materials exhibit interesting mechanical and chemical properties, looking to satisfy part of the demand of thermal and electrical insulators and anticorrosive coatings also. For the applications of these materials are necessary the correlation among structure, composition, and properties. From results of XPS and ATR FT-MIR analysis constitute evidence of the presence of molecular ([PW12O40]3–) and atomic (W) Tungsten at top Surface (10 nm of depth) of these materials. Furthermore, considering features that PDMSUr-PWA films exhibit e.g. elasticity and hardness, one can infer that these materials could constitute a structural support for PWA in applications of heterogeneous catalysis in many chemical reactions. PDMSUr-PWA film containing 35 w/w% of PWA approximately (content at which the W concentration is maxima), the Tungsten segregation at surface of these films is predominant. Additionally, if it is taken in consideration the significant Bromine presence at surface at the concentration of PWA mentioned above, one could deduct that this sample is candidate for application as anticorrosive coatings. Finally, taking advantage of the Proton conductivity of PWA, this sample also could be considered as a mixed conductor (of protons and electrons), which in the form of membranes fulfill the requirements in order to be used as fuel cells.

Electrochemical Polymerization of New Schiff Base Monomer as an Anti-corrosion Coating on Carbon Steel in Saline Water: Experimental and Theoretical Studies

Electrochemical Polymerization of New Schiff Base Monomer as an Anti-corrosion Coating on Carbon Steel in Saline Water: Experimental and Theoretical Studies

Temporary Anti-Corrosive Double Layer on Zinc Substrate Based on Chitosan Hydrogel and Epoxy Resin.

In practice, metal structures are frequently transported or stored before being used. Even in such circumstances, the corrosion process caused by environmental factors (moisture, salty air, etc.) can occur quite easily. To avoid this, metal surfaces can be protected with temporary coatings. The objective of this research was to develop coatings that exhibit effective protective characteristics while also allowing for easy removal, if required. Novel, chitosan/epoxy double layers were prepared on zinc by dip-coating to obtain temporary tailor-made and peelable-on-demand, anti-corrosive coatings. Chitosan hydrogel fulfills the role of a primer that acts as an intermediary between the zinc substrate and the epoxy film to obtain better adhesion and specialization. The resulting coatings were characterized using electrochemical impedance spectroscopy, contact angle measurements, Raman spectroscopy, and scanning electron microscopy. The impedance of the bare zinc was increased by three orders of magnitude when the protective coatings were applied, proving efficient anti-corrosive protection. The chitosan sublayer improved the adhesion of the protective epoxy coating. The structural integrity and absolute impedance of the protective layers were conserved in both basic and neutral environments. However, after fulfilling its lifespan, the chitosan/epoxy double-layered coating could be removed after treatment with a mild acid without damaging the substrate. This was because of the hydrophilic properties of the epoxy layer, as well as the tendency of chitosan to swell in acidic conditions.

A bifunctional epoxy coating doped by cerium (III)-8-hydroxyquinoline: Early self-reporting and stimuli-responsive inhibition on corrosion of Al substrate

Recently, anti-corrosion coatings with auto-inhibition and self-reporting on their premature flaws are becoming more and more attractive. In this work, we engineered a cerium nitrate/8-hydroxyquinoline (Ce-HQ) hybrid pigment to endow epoxy coatings with corrosion self-inhibiting and fluorescent self-reporting performances via molecule design. The Ce-HQ pigments were synthesized by physical mixture and then dispersed into the commercial epoxy coating. Once the epoxy coating gets degraded, the underneath aluminum alloy matrix may corrode to produce Al3+ ions, which can compete with Ce3+ ions in the Ce-HQ complex, and then chelate with dissociative 8-HQ to form fluorescent Al-HQ complex, due to the higher bonding strength of Al3+ with 8-HQ than Ce3+ ions. Thus, not only the responsive releasing of Ce3+ ions and 8-HQ can inhibit the underlying Al alloy, but the newly formed Al-HQ complex could indicate the location and severity of coating flaws through fluorescent emission under UV light. Electrochemical impedance evidenced that the composite epoxy coating containing 1 % mass Ce-HQ presents high corrosion resistance even after 504 h of salt spray test, showing 90 % corrosion refraining efficiency. This work may enlighten an approach to developing self-healing and self-diagnosis coating for premature corroded Al alloy beneath coatings via reactive release and fluorescent visualization.

Adhesion of Various Geopolymers Coatings on Metal Substrates

This article deals with adhesion of various alkali-activated metakaolin-based geopolymer coatings on structural steel 1.0038 (according to EN 10025-2). This steel alloy was chosen in order to analysis ad-hesion of prepared geopolymer coatings. Our samples were characterized by laser and SEM micros-copy and grid test was performed. Microscopy was performed to get knowledge about visible charac-terization and overall quality of prepared coatings. Based on previous research SEM results corre-spond with properties changes in coatings and their classification of grid test. Grid test was per-formed and results was evaluated. These results show potential of our prepared GP and could be used as base for further research and possible application as anti corrosion coatings in construction or fire-resistant barriers. The aim of the research was to prepare alkali-activated metakaolin-based geopoly-mer on a structural steel substrate, to evaluate the visual quality of the coatings and to evaluate the results of the grid test.