Corrosion Protection Efficiency Research Articles

Anti‐corrosion property of superhydrophobic copper mesh with one‐step self‐assembled perfluorothiolate monolayers

Copper mesh (CM) is one of the most commonly used engineering materials due to its remarkable mechanical and electromagnetic properties. However, CMs are generally susceptible to chemical corrosion in harsh environments, which greatly limits their long‐term usage. In this paper, we come up with a one‐step perfluorodecanethiol self‐assembly means to manufacture superhydrophobic CM with significantly improved anti‐corrosion property. The self‐assembly reaction between copper and 1H,1H,2H,2H‐perfluorodecanethiol created nanoscale rough structures and lowered the surface energy of the CM surface, which was account for the excellent repellence towards various aqueous solutions. The electrochemical tests demonstrated that, compared with original CM, the icorr value of the self‐assembled monolayers (SAMs) functionalized CM decreases about one order of magnitude, whereas the corrosion protection efficiency of the treated CM in NaCl, NaOH, and HCl aqueous solutions were all obviously increased. Therefore, the proposed simple method could be an alternative candidate for the creation of functional CM with anti‐corrosion properties that could be used under complex conditions.

Corrosion resistance improvement of the Ti6Al4V/UHMWPE systems by the assembly of ODPA molecules by dip coating technique

Living with degenerative diseases, such as arthritis and osteoporosis, is challenging if orthopedic devices manifest adverse effects caused by corrosion processes. Ti6Al4V alloy is used to manufacture orthopedic implants due to its excellent mechanical and osseointegration properties. Nonetheless, it has poor resistance to wear and corrosion by biological fluids and mechanical activity. This degradation process generates the need to improve the corrosion resistance of metallic biomaterials used as biomedical implants. Dip-coating technique is a wet coating method used to lessen wear damage on the metal surface and can produce coatings using a wide variety of molecules at a low cost. In this work, Ti6Al4V alloys were coated with ultra-high molecular weight polyethylene (UHMWPE) and Octadecylphosphonic Acid (ODPA) films forming a UHMWPE/ODPA bilayer coating by dip-coating method to improve protection efficiency against corrosion in phosphate-buffered isotonic saline solutions and proposed it as alternative coatings to delay the failure of medical implants. The optimization of individual coated systems were obtained with an immersion time of 40 s (Ti6Al4V/UHMWPE) and 30 h (Ti6Al4V/ODPA) with corrosion current densities of 1.51 × 10−9 A cm−2 and 6.8 × 10−8 A cm−2, respectively. The formation of bilayer coatings reduces the average roughness from 19.34 nm (Ti6Al4V/UHMWPE) to 12.67 nm (Ti6Al4V/UHMWPE/ODPA). ODPA deposition on UHMWPE films changes the corrosion rate by interfering with the anodic and cathodic reactions, reducing the corrosion rate to 7.46 × 10−4 μm y−1 and an estimated corrosion protection efficiency of about 99.99 %. The results show a superior performance as a protective barrier over the individual films (1.19 μm y−1 with 97.2 %, and 0.026 μm y−1 with 99.9 %, ODPA, and UHMWPE, respectively), improving the corrosion resistance of the Ti6Al4V alloys.

A rapid two-step method for fabrication of superhydrophobic-superoleophobic nickel/copper alloy coating with self-cleaning and anticorrosion properties

In this study, the nickel/copper (Ni/Cu) alloy coating with layered micro/nanostructures was prepared on a brass substrate by the controlled generation of particles during the electrochemical co-deposition of nickel and copper ions. Subsequently, the surface of Ni/Cu alloy (NCA) coating was modified by 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane (PFDS), so that the prepared PFDS/NCA composite (PNCA) coating had excellent super-amphiphobicity. The structures and properties of PNCA coating evaluated and described used a range of methods. The wettability tests shown that the water and oil contact angles of the optimal coating sample with current density of 0.08 A/cm2 are 163 ± 1.3° and 155 ± 1.5°, respectively, and the sliding angle (SA) is no longer than 10°, indicating the high degree of super-amphiphobicity. Gratifyingly, the optimal PNCA coating exhibited good mechanical and chemical stabilities after knife scratching, tape peeling, sandpaper wear and chemical corrosion. The self-cleaning test shows that PNCA coatings have also outstanding self-cleaning ability, and the contaminants spread on their surfaces can be easily carried away by sealed droplets within 20 s. In addition, the corrosion resistances of PNCA coatings are greatly improved to compare with NCA coating, especially the corrosion rate of the optimal sample coating is the lowest, and the corrosion protection efficiency reaches to 91.73 %. Therefore, the conclusion can be depicted that the super-amphiphobic PNCA composite coatings prepared by electrochemical co-deposition combined with modification of low surface energy materials have a wide range of industrial prospects for applications in the fields of oil, fouling and corrosion resistances.

Large-scale prepared superhydrophobic HDTMS-modified diatomite/epoxy resin composite coatings for high-performance corrosion protection of magnesium alloys

Superhydrophobic coatings have great potential applications in protecting metallic substrates due to their excellent water-repellency and high corrosion resistance, however, most of their preparation processes are complicated, expensive and difficult to scale up for practical applications. Herein, we reported a facile, low-cost and large-scale-preparation method to fabricate superhydrophobic coatings on the magnesium alloy, of which superhydrophobic hexadecyltrimethoxysilane (HDTMS)-modified diatomite powder was first synthesized by electrochemical deposition method, and subsequent spray coating of the epoxy resin and superhydrophobic diatomite mixture was performed to form superhydrophobic composite coatings on the alloy substrates. The influencing factors of surface wettability of the modified diatomite were comprehensively investigated. Under the optimized synthesis condition of a current density of 0.033 A·cm−2 and electrodeposition time of 2.5 h, the superhydrophobic diatomite powder had an approximately 260 % (in mass fraction) production yield. The spray-coated composite coating delivered superior superhydrophobicity with water contact angle of circa 157° and self-cleaning ability. Such superhydrophobic coating also exhibited a high corrosion protection efficiency of circa 99.8 % and excellent anti-icing performance, and was demonstrated to own ISO grade 1 adhesion and good chemical stability to bear 90 days of immersion in a 3.5 wt% NaCl solution and 20 days of salt spray testing without corrosion. In addition, the superhydrophobic composite coating exhibited great robustness against water impact and sand impact. Therefore, this diatomite/epoxy resin-based superhydrophobic coating can be effectively used for Mg alloy anti-corrosion and has the potential in large-scale production for practical applications.

Robust Self-Healing Graphene Oxide-Based Superhydrophobic Coatings for Efficient Corrosion Protection of Magnesium Alloys

A self-healing coating possesses a broad application prospect in the metal corrosion protection area due to its pleasurable performance. By far, despite a great deal of research studies that have been reported in this field, it is still a challenge to construct an intrinsic self-healing surface that can repair a damaged structure and restore superhydrophobicity simultaneously. Herein, a self-healing superhydrophobic coating was fabricated by combining polydopamine (PDA)-functionalized Cu2+-doped graphene oxide (GO), octadecylamine (ODA), and polydimethylsiloxane (PDMS), which can recover the superhydrophobicity and microstructure of the coating after chemical/physical damage. The as-prepared self-healing coating displayed excellent liquid repellency with a water contact angle of 158.2 ± 2° and a sliding angle of 4 ± 1°, which endowed the Mg alloy with excellent anticorrosion performance. Once the coating is scratched, the local damaged structure will be automatically repaired through the chelation of catechol and Cu2+. Also, the superhydrophobicity of the coating can be rapidly restored under 1-sun irradiation even after being etched by O2 plasma. Furthermore, the as-fabricated self-healing coating still exhibited excellent corrosion protection against a magnesium alloy after immersion in 3.5 wt % NaCl solution for 30 days, which was attributed to the efficient repair of defects in GO by PDA through π-π interactions and the inherent chemical inertia of PDMS. Moreover, the as-fabricated self-healing coating also exhibited favorable mechanical stability, chemical durability, and weather resistance. This study paves a fresh insight into the design of robust self-healing coatings with huge application potential.

Designing attapulgite-based self-healing superhydrophobic coatings for efficient corrosion protection of magnesium alloys

Magnesium (Mg) and its alloys are susceptible to corrosion, which affects their large-scale applications. The traditional superhydrophobic coatings for corrosion protection of Mg substrates are particularly fragile and easily damaged after prolonged exposure to harsh conditions. Herein, a superhydrophobic ODA/PDA/APT-Ce3+ (OPA-Ce3+) coating with corrosion inhibition and self-healing properties was proposed to prevent corrosion of Mg alloy via combining the cerium nitrate loaded attapulgite (APT), polydopamine (PDA) and octadecylamine (ODA). Once the OPA-Ce3+ coating was corroded, the Ce3+ adsorbed by the APT were released to form insoluble cerium oxide and hydroxides, thereby inhibiting the penetration of the corrosive substance and preventing further occurrence of corrosion. Furthermore, the OPA-Ce3+ coating exhibited favorable self-healing ability against chemical damage, which could recover its superhydrophobicity under solar exposure after O2 plasma etching. The impedance modulus (|Z|0.01 Hz) of OPA-Ce3+ coating was about 3 orders of magnitude higher than that of Mg substrate after being exposed to 3.5 wt% NaCl solution for 15 days, showing outstanding long-lasting anticorrosion performance. Moreover, the abrasion resistance and chemical stability of the as-fabricated coating were also excellent. This work is expected to provide a new perspective for preparing cost-effective and durable anticorrosion coating on metal substrates.

CoNiWReP high entropy alloy coatings prepared by pulse current electrodeposition from aqueous solution

CoNiWReP high entropy alloy (HEA) coatings have been prepared in aqueous solution using direct current (DC) and pulse current (PC) electrodeposition technologies. The prepared amorphous HEA coatings are silver-white in appearance and have good adhesion to the substrate. The coatings prepared by PC are dense and suitable for engineering purpose. The HEA coatings have a cathodic protection effect for Cu substrate, providing a corrosion protection efficiency up to 73.8%. Importantly, this work provides a low cost and realizable industrial solution for the preparation of HEA coatings, which will be an innovation potential for HEA coatings by electrodeposition.

Corrosion protection efficiency of the electrochemically synthesized polypyrrole-azo dye composite coating on stainless steel

The polypyrrole-azo dye (Lanaset-Red-2B) composite coatings were electrochemically deposited on stainless steel 430 by means of repetitive cyclic voltammetry. The composite coatings were synthesized by addition of the dye in 10−6–10−3 M range to 0.1 M oxalic acid solution containing 0.1 M pyrrole monomer. All polypyrrole/Lanaset-Red-2B composite coatings are more protective with respect to the pristine polypyrrole in NaCl (3.5%) medium. The best protective coating synthesized in the presence of 10−5 M dye using optimized potential range, scan-rate and cycle number were characterized by infrared-reflection-absorption-spectroscopy, scanning-electron-microscopy and energy-dispersive-spectroscopy analyses. The electrochemical characterizations were performed by using potentiodynamic polarization and electrochemical-impedance-spectroscopy techniques. The steel coated with the polypyrrole/Lanaset-Red-2B composite is more resistant in 0.1 M H2SO4 solution comparing to NaCl (3.5%) during long-term immersion until 432 h. The corrosion protection efficiency of the coating is higher than that of its initial value at the end of 432 h immersion in both media due to controlled release of the Lanaset-Red-2B deposited as inhibitor in the polypyrrole structure.

UV resistance, anticorrosion and high toughness bio-based waterborne polyurethane enabled by a Sorbitan monooleate

Sorbitan monooleate (SP) is considered to be a promising renewable polyol with unique molecular structures for the development and design of bio-based waterborne polyurethane (WPU) with versatility and excellent mechanical properties. In this study, SP was used as a bio-based polyol in combination with castor oil to design and prepare a series of bio-based WPU with anti-ultraviolet, corrosion resistance and excellent mechanical properties. The influence of the hydroxyl ratios between SP and castor oil on the chemical structures and properties of bio-based WPU dispersions and the resulting WPU films was systematically studied. The resulting WPU films exhibited excellent mechanical properties and thermo-physical properties due to the presence of large amounts of hydrogen bonding and rigid furan ring, and high crosslinking densities. The bio-based WPU films could lift heavy objects 10,330 times their own weight. The resulting WPU coatings could resist ultraviolet radiation in the region (200–400 nm) and exhibited excellent UV resistance in outdoor practical application tests. In addition, these WPU coatings demonstrated effectively anticorrosive effect in which the anticorrosion period of the coating on the tinplate outdoors could be as long as 6 months in terms of corrosion potential, corrosion current and corrosion protection efficiency of the coating reached −0.507 V, 2.92 × 10−6 A, and 95.39%, respectively. This study provides a new and simple method for preparing bio-based WPU with excellent anti-ultraviolet performance, anti-corrosion performance and excellent mechanical properties.

Controlling Superhydrophobicity of Aluminum with Hierarchical Micro‐Nanostructure Film for Superb Self‐Cleaning and Anti‐Corrosion

AbstractIn this study, typical electrodeposition method was proposed to fabricate uniform CuO hierarchical micro‐nanostructure on aluminum (Al) substrate. The superhydrophobic protective film was then fabricated by modifying stearic acid (STA) on this hierarchical CuO film. The static water contact angle reached up to 163° by coating CuO/STA film on Al substrate, and the rolling‐off angle was as low as 3.7°. In addition, CuO/STA coated Al displayed wonderful non‐sticking performance when the free‐falling water droplets contact the surface. As expected, superb anti‐corrosion properties of Al were achieved by coating superhydrophobic CuO/STA film on Al. The corrosion current density of CuO/STA coated Al decreased 2 orders of magnitude comparing with that of pristine Al, and the corrosion protection efficiency of CuO/STA coated Al reached up to 98 % in comparison with pristine Al. Therefore, superhydrophobic CuO/STA film coated Al substrate greatly prolong the working life of Al materials in harsh working condition. The universal method used in this study also provides a potential route for coating superhydrophobic and anti‐corrosion protective film on other metallic substrates or conductive substrates.

Corrosion protection properties of poly((benzoyl phenyl) methacrylate-co-methoxy ethylmethacrylate) coating on mild steel

The copolymer, poly(BPM-CO-MOEMA) has been synthesized from different monomer feed ratios of benzoylphenyl methacrylate (BPM) and methoxyethyl methacrylate (MOEMA) was achieved using the free radical solution polymerization technique. The thermal stability of the synthesized copolymers was studied by using TGA and DSC. The molecular weight of the copolymer was determined by GPC. The corrosion protection efficiency of the mild steel specimens coated with different mole ratios of the copolymer has been investigated using electrochemical techniques like EIS and potentiodynamic polarization studies in 1 M H2SO4. The observation of electrochemical results confirmed that the copolymer coating shows good protection efficiency for mild steel in the corrosive media. The surface and morphological investigations also confirm the barrier effect of the copolymer film on the metal surface against the invasion of corrosive ions.

Enhanced adhesion of anticorrosion ruthenium films deposited by RF sputtering on 304L stainless steel

Thin ruthenium films present an economical approach to corrosion protection of stainless steel alloys in reducing acidic environments. However, ruthenium films tend to spall and delaminate during corrosion exposure, thereby limiting their practical applicability. Herein, three strategies to enhance the adhesion of ruthenium films deposited on AISI 304 L by radio frequency (RF) magnetron sputtering, are investigated. These include roughening substrate surface, pulsing deposition pressure and using a 2 nm thick titanium seed layer. The ruthenium films produced by pulsing deposition pressure between 1.2 and 3.6 × 10−3 mbar exhibited the best performance, remaining mostly intact and adherent for 48 h of exposure to 1 M sulphuric acid. Resistance to electron transfer as measured by electrochemical impedance spectroscopy (EIS) was outstandingly high on these ruthenium films, giving corrosion protection efficiencies >500%. Scanning electron microscopy results show that pulsing deposition pressure significantly reduced tendency of film wrinkling, suggesting a considerable decrease in film stresses. A first of its kind, this study suggests two methods for improving the adhesion of ruthenium films on stainless steel substrates, thereby presenting an opportunity to expand the application spectrum of ruthenium.

Anodizing of aluminum 6061 alloy with incorporated nanoparticles to inhibits the aluminum corrosion

In this work, Aluminum alloy 6061 (A6061) was modified by Anodizing and incorporating with ZnO and Fe3O4 nanoparticles to improve its corrosion-resistant. The titanium sheet was used as a counter electrode and the DC voltage reach 20 mV while the anodizing solution was 20% H2SO4 while the H2SO4 was mixed with the two Oxide nanoparticle to incorporate the AA6061 surface. Anodizing and incorporation with (ZnO and Fe3O4) NPS were confirmed by X-ray diffraction. The surface morphology of anodized and incorporated surface was examined through scanning electron microscopy (SEM). Modified A6061 by Anodizing and nanoparticle incorporation revealed a good corrosion protection efficiency even at temperatures ranging (298-328) K in a saline medium. Where the corrosion current density increase with the increase in temperature. Activation energy and pre-exponential factor (kinetic parameters) were calculated and discussed. Also, thermodynamic values ?G* and ?H* were calculated.

Synthesis of self-healing inhibitor releasing nanocapsules blended phenol novolac resin for high performance anticorrosion coating

The present work intended to synthesize a composite material exhibiting self-healing and enhanced anticorrosion properties. In this context, MWCNT incorporated nanocapsule (NC) filler material was synthesized, then it is blended with phenol novolac resin (PNR). The surface characterization studies of MWCNT/NC-PNR composite material signify the nano-size, spherical, and multiwalled structures of NC and CNT. The composite materials consisting of different weight percentages of MWCNT inserted NC were coated on the mild steel (MS) surface by the doctor blade method. The 0.3 wt% MWCNT/NC blended PNR showed significantly enhanced hydrophobicity of the coating which is evidenced by the high value of water contact angle (98.2°) amongst the coating materials prepared. Further, electrochemical impedance spectroscopy (EIS) tests of the coating confirm a high impedance value of 3.039× 107 ohm cm2 at the low frequency region for 50 days of immersion in 3.5 wt% NaCl solution. Thus, it was found that 0.3 wt% MWCNT incorporated NC filler increased the corrosion protection efficiency of NC/PNR coating by 32.61%. Therefore, the results show that the MWCNT/NC-PNR composite coating exhibits significantly elevated corrosion resistance, and can be used as a self-healing inhibitor coating material for long-term anti-corrosion shield.

Fabrications of hybrid Polyurethane-Pd doped ZrO2 smart carriers for self-healing high corrosion protective coatings

The work demonstrates the effective utilization of hybrid Polyurethane - palladium doped zirconium oxide (Pd–ZrO2) as innovative carriers for corrosion protection coatings on steel materials. ZrO2 and Pd–ZrO2 nanoparticles were successfully synthesized using Photodeposition followed by the hydrothermal synthesis method. The synthesized nanoparticles were then incorporated into the polyurethane matrix and characterized using Fourier-transform infrared spectroscopy and scanning electron microscopy (SEM). The FTIR and SEM confirm the presence of ZrO2 and Pd–ZrO2 nanoparticles and their morphologies in polyurethane composites material. The thermogravimetric analysis (TGA) results indicated that the polyurethane matrix remained stable up to 250 °C. At 800 °C, >50% of residues are observed for Pd–ZrO2 – polyurethane in the TGA analysis, which confirms that the primer and nanoparticles addition enhances the thermal stability of the composite. The water contact angle measurement explains the hydrophobic behavior of nanocomposite modified coatings on a mild steel substrate. It indicates that Pd–ZrO2 and primer significantly increase the hydrophobicity of polyurethane. The major advantages of developing water-repellent or hydrophobic surfaces open up a world of possibilities for metals and alloys in terms of corrosion prevention. Electrochemical impedance spectroscopy (EIS) and a salt spray test were used to determine the anti-corrosion behavior of the prepared polymer nanocomposites. The polymer nanocomposite coatings have better anti-corrosive capabilities when compared to pure polyurethane. The corrosion protection efficiency increased from 76.63% to 97.57% upon incorporating 2 wt % of Pd–ZrO2 in the polyurethane matrix. The results confirmed that the modifications on the polyurethane enhanced the hydrophobicity and anti-corrosion properties of the polymer nanocomposite coatings.

Long-Term Durability of Robust Super-Hydrophobic Co–Ni-Based Coatings Produced by Electrochemical Deposition

The long-term durability for two kinds of Co–Ni-based robust coatings, the Co–Ni super-hydrophobic (Co–Ni SHPB) coating and Co–Ni/WC super-hydrophobic (Co–Ni/WC SHPB) coating, was analyzed through an immersion test in 3.5 wt.% NaCl solution. The evolution of their surface properties was characterized by scanning electron microscope (SEM) images, energy-dispersive spectrometry (EDS), a wettability measurement and X-ray photoelectron spectrometer (XPS), and the evolution of anti-corrosion mechanisms was evaluated with electrochemical measurements. The results show that as-prepared two kinds of robust coatings display a good long-term durability, with the Co–Ni SHPB coating and Co–Ni/WC SHPB coating losing their super-hydrophobicity after being immersed for more than 10 days. Additionally, both kinds of coatings present efficient corrosion protection even after long-term immersion.

Rational design of PDMS/paraffin infused surface with enhanced corrosion resistance and interface erosion mechanism

Metal corrosion is a headache in marine industry. The existing technologies can hardly provide an effective long-term corrosion protection. Biomimetic slippery lubricant infused porous surface (SLIPS) has been developed as a potential alternative technique to resolve this problem. Herein, a stable triple-layered slippery surface which consist of compact-nickel-underlayer/porous-nickel-midlayer/PDMS/paraffin infused toplayer was designed and developed for corrosion protection. This composite surface exhibited a low sliding angle with good stability and thermal assitant self-healing property. Simultaneously, it demonstrated good anti-corrosion property with an extremly low corrosion current density and a large impedance of 2.301 × 107 Ω·cm−2, the as-prepared sample even can provide efficient corrosion protection for a long-term immersion in NaCl solution. Furthermore, the interface erosion mechanism was studied via the assistance of electrochemical and surface analysis techniques. The results revealed that no corrosion products were generated which further proved the good anti-corrosion performance. We believe that this triple-layered slippery surface can broaden the application of metals in the field of marine and other industries.

Synthesis of Ti3C2 MXene@PANI composites for excellent anticorrosion performance of waterborne epoxy coating

Ti3C2 MXene nanosheets have become a research hotspot in the anticorrosion field owing to their excellent barrier performance and mechanical properties. However, the utilization of different etching agents for the preparation of Ti3C2 MXene nanosheets has positive or negative influence on corrosion protection of waterborne epoxy coating (WEP) for metal owing to their quiet distinct electrical conductivity. In this study, we successfully synthesized multilayer Ti3C2 MXene nanosheets, and Ti3C2 MXene@PANI composites, such that PANI with high doping levels were uniformly anchored on the Ti3C2 MXene nanosheets' surface via in situ intercalation polymerization. Moreover, we verified the LiF and HCl treatment of Ti3C2 MXene accelerated the failure of WEP coating, which can be attributed to its higher electrical conductivity caused by the intercalation of Li+ than that of HF treatment. Ti3C2 MXene@PANI composites significantly improved the corrosion resistance of the WEP coating, thus greatly resolving the accelerating corrosion issue of Ti3C2 MXene. 0.3 wt% or more Ti3C2 MXene@PANI-1.0/WEP coatings' corrosion current density, impedance modulus, and charge transfer resistance increased by 1–2 orders of magnitude than that of pure WEP and Ti3C2 MXene/WEP in 3.5 wt% NaCl after 10 days of immersion. These results demonstrated that the synergistic effect of Ti3C2 MXene nanosheets' barrier effect and PANI's passivation effect enable Ti3C2 MXene@PANI composites with lower electrical conductivity to achieve long-term and efficient corrosion protection in WEP coating for Q235 steel.

CaCO3-derived from eggshell waste for improving the corrosion resistance of zinc composite coating on mild steel for biodiesel storage tank

Sustainability of energy does not end in the generation of biofuels, but as well encompasses proper mitigation of the metallic equipment used in the plant from corrosion degradation. Corrosion of metallic equipment in biodiesel plants limits the storage and distribution of biodiesel to the end-users. Carbon steel of Mild steel type/grade is one of the major metallic materials used in the construction of biodiesel storage tanks. The major setback of using mild steel for biodiesel storage is the high corrosion rate. This research aims to develop a novel coating of mild steel using CaCO3 derived from eggshell waste (ESP). The Codeposition method was used to develop Zn-10%CaCO3-ESP (single and double layer). The corrosion of the samples was tested in a Jatropha curcas biodiesel (JBD) environment. Microstructure, hardness values, viscosity, and density of the oil were determined. A corrosion protection efficiency of 68.87% was obtained using the Zn-10%CaCO3-ESP double layer. High corrosion damage as a result of localized pitting corrosion mechanism was observed for the mild steel without coating. This novel coating can be used in the industrial fabrication of storage tanks for biodiesel since the CaCO3-ESP is prepared by a simple method.

Superior barrier, hydrophobic and mechanical properties of multifunctional nanocomposite coatings on brass in marine environment

The influence of functionalized silicon carbide (SiC) nanoparticles on the electrochemical and mechanical properties of silicon carbide/epoxy nanocomposite was investigated. The reactive SiC nanoparticles were synthesized using 3-amino-5-mercapto-1,2,4-triazole (AMT) and 5-amino-2-methoxypyridine (AMP) and characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravitric analysis (TGA) techniques. The resultant novel nanocomposite coating on brass in seawater was investigated with the help of the Tafel polarization, electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) studies. Electrochemical studies revealed excellent corrosion protection efficiency and a decreased corrosion current density, with an optimum concentration of 2 wt% SiC nanoparticles. The results indicated that the reactive SiC nanoparticles dispersed uniformly and retarded the propagation of corrosive ions to the brass sample and coating interface through the deflected route and minimized the electron movement between the electrolyte and alloy surface. SECM observations confirmed the detection of least current at the scratched area of the coated alloy. SEM observations showed that reactive SiC nanofillers are dispersed uniformly. The changes in surface morphology, phase structure and composition were analyzed using SEM/EDX and XRD techniques. The strong attachment of the reactive SiC and epoxy resin resulted in an enhanced mechanical properties with a defectless compact film. It was found that the reinforcement of reactive SiC nanoparticles in the epoxy coatings exhibited a smooth microstructure surface producing superior corrosion protection and mechanical properties.