scholarly journals Graphene-Based Reinforcing Filler for Double-Layer Acrylic Coatings

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4499
Author(s):  
Massimo Calovi ◽  
Stefano Rossi ◽  
Flavio Deflorian ◽  
Sandra Dirè ◽  
Riccardo Ceccato
Keyword(s):  
Corrosion Protection ◽  
Double Layer ◽  
Abrasion Resistance ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
High Conductivity ◽  
Functionalized Graphene Oxide ◽  
Electron Microscopies ◽  
Joint Application ◽  
Acrylic Coatings

This study aims to demonstrate the remarkable features of graphene-based fillers, which are able to improve the protective performance of acrylic coatings. Furthermore, the joint application of a cataphoretic primer and a spray top coat, containing graphene and functionalized graphene oxide flakes, respectively, enables the deposition of a double-layer coating with high conductivity and abrasion resistance properties, capable of offering excellent corrosion resistance to the metal substrate. The surface morphology of the single- and double-layer coatings was investigated by optical and electron microscopies, analysing the defectiveness introduced in the polymer matrix due to the filler agglomeration. The behavior in aggressive environments was assessed by exposure of the samples in the salt spray chamber, evaluating the blister formation and the adhesion level of the coatings. Electrochemical impedance spectroscopy measurements were employed to study the corrosion protection properties of the coatings, whose conductivity and abrasion resistance features were analysed by conductivity assessment and scrub tests, respectively. The incorporation of graphene-based fillers in the cataphoretic primer improves the corrosion protection properties of the system, while the graphene flakes provide the top coat spray layer with high conductivity and excellent abrasion resistance features. Thus, this work demonstrates the possibility of employing different types of graphene-based fillers and deposition methods for the creation of multifunctional coatings.

scholarly journals Degradation of Sol-Gel Acrylic Coatings Based on Si and Zr Investigated Using Electrochemical Impedance, Infrared and X-Ray Photoelectron Spectroscopies

2021 ◽  
Vol 8 ◽  
Author(s):  
Peter Rodič ◽  
Sandrine Zanna ◽  
Ingrid Milošev ◽  
Philippe Marcus
Keyword(s):  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Salt Spray ◽  
Sol Gel ◽  
Synthesis Process ◽  
Corrosion Properties ◽  
X Ray ◽  
Acrylic Coatings

This study aimed to synthesise and characterise two types of sol-gel acrylic coatings: one based on Si and the other based on Si and Zr. These coatings, which served as a barrier for corrosion protection of aluminium, were synthesised by sol-gel methodology using silicon precursors tetraethyl orthosilicate and organically modified silicon precursor 3-methacryloxypropyltrimethoxysilane, without and with the addition of zirconium(IV) n-propoxide chelated with methacrylic acid. The synthesis process was followed using real-time Fourier transform infrared spectroscopy, which confirmed the condensation reactions of Si–O–Si and Si–O–Zr networks, depending on the sol type. This was reflected in the composition of the coating as well, as shown by X-ray photoelectron spectroscopy. The coating topography, thickness and morphology were analysed using focused ion beam scanning electron microscopy. X-ray photoelectron spectroscopy was employed to follow the degradation of acrylic coatings upon immersion in sodium chloride solution. Corrosion properties, evaluated using electrochemical impedance spectroscopy in 0.1 M NaCl, confirmed high barrier protection of coated aluminium with acrylic coatings based on Si and even better for coating based on Si with Zr. The more durable corrosion protection of the latter was also confirmed by salt spray testing.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

The study of the effectiveness of corrosion protection of zinc-rich coating on the base of water sodium silicate

2020 ◽  
Vol 25 (4) ◽  
Keyword(s):  
Corrosion Protection ◽  
Sodium Silicate ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Test Method ◽  
Liquid Sodium ◽  
Research Station ◽  
Marine Research

The study is examines the assessment of the corrosion-protective properties of zinc-rich coating based on water sodium silicate (ZRC) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl reference electrode in 3 M solution of KCl, auxiliary electrode – Pt (8x8 mm) and working electrodes for determination potential (Ecorr) and impedance measurement, salt spray test method and natural teszzt method at Dam Bay Marine Research Station, Nha Trang, Khanh Hoa, Viet Nam. ZSC can provide good cathodic protection when zinc content is 70% by weight or more. ZSC with a mixing ratio of High Modulus Liquid Sodium Glass / Zinc Powde : 25/75 by weight (working title – TTL-VN) has good corrosion protection after 16 cycles salt spray test and after 18 months natural test in seawater. The paint film has basic parameters as adhesion – 4,41 MPa, flexural strength – 2 mm, pendulum hardness – 0,62 conventional units and initial coating potentia l – 0,96 V Ag/AgCl.

scholarly journals Corrosion protection and antifouling properties of varnish-coated steel containing natural additive

2017 ◽  
Vol 23 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Besheir Abd-El-Nabey ◽  
Sherif El-Housseiny ◽  
Essam Khamis ◽  
Ashraf Abdel-Gaber
Keyword(s):  
Corrosion Protection ◽  
Visual Inspection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Coated Steel ◽  
Nacl Solution ◽  
Cannabis Extract ◽  
Steel Panels ◽  
Natural Additive ◽  
Peeling Off

The corrosion protection and antifouling properties of varnish-coated steel panels containing different amounts of cannabis extracts were investigated using electrochemical impedance spectroscopy (EIS), salt spray and immersion tests in 0.5 M NaCl solution and subjected to a field test in seawater. Analysis of the experimental data showed that the presence of cannabis extract resisted the deterioration (peeling off) tendency of the varnish-coated steel panels exposed to aggressive environments. Visual inspection showed that the cannabis extract also provided good antifouling properties.

scholarly journals SiO2-GO nanofillers enhance the corrosion resistance of waterborne polyurethane acrylic coatings

2020 ◽  
Vol 29 ◽  
pp. 2633366X2094152
Author(s):  
Liqi Liu ◽  
Xiaofeng Guo ◽  
Lei Shi ◽  
Liquan Chen ◽  
Fangzhou Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electron Microscope ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Waterborne Polyurethane ◽  
Metal Corrosion ◽  
X Ray Diffraction ◽  
Functionalized Graphene Oxide ◽  
Transmission Electron ◽  
Acrylic Coatings

Corrosion to metal is a great challenge to major industries. Anticorrosive coatings can effectively prevent metal corrosion. In this study, we propose a novel method to prepare silica nanoparticles-covered graphene oxide (SiO2-GO) nanohybrids and anticorrosion SiO2-GO/waterborne polyurethane acrylic (WPUA) coatings. Firstly, we obtained silane-functionalized graphene oxide (A-GO) via a simple covalent functionalization of graphene oxide (GO) with 3-aminopropyltriethoxysilane. Secondly, SiO2-GO was synthesized by a simple sol–gel method with tetraethoxysilane in water–alcohol solution. Finally, the obtained SiO2-GO nanofillers were added into WPUA to prepare SiO2-GO/WPUA coatings. GO, A-GO, and SiO2-GO nanohybrids could be confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectra, and transmission electron microscope. SiO2-GO nanohybrids showed small size compared with the unfunctionalized GO. Meanwhile, GO, A-GO, and SiO2-GO nanofillers were added into WPUA. The electrochemical impedance spectroscopy and field emission scanning electron microscope indicate that SiO2-GO nanohybrids can be homogeneously dispersed in the WPUA coatings at 0.4% loading level and the SiO2-GO/WPUA film exhibits excellent anticorrosion performance. SiO2-GO nanoparticles can effectively utilize in the area of anticorrosive nanofiller industry. This study provides a convenient method of anticorrosive coating production.

scholarly journals Study on a Novel Recyclable Anticorrosion Gel Coating Based on Ethyl Cellulose and Thermoplastic Polyurethane

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 618 ◽  
Author(s):  
Hailong Zhang ◽  
Junlei Tang ◽  
Hongchang Han ◽  
Shengwei Zhang ◽  
Hu Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Corrosion Protection ◽  
Ethyl Cellulose ◽  
Electrochemical Impedance ◽  
Raw Materials ◽  
Thermoplastic Polyurethane ◽  
Salt Spray ◽  
Mineral Oil ◽  
Mechanical Analysis ◽  
Salt Spray Test

In this paper, ethyl cellulose, thermoplastic polyurethane, and mineral oil were used as the main raw materials to synthesize a recyclable thermoplastic gel for anticorrosion coatings by a hot melt method. In addition, the effect of thermoplastic polyurethane on the properties of the coating was discussed. The structure and corrosion protection properties of the coating were characterized and analyzed by a scanning electron microscope, transmission electron microscope, X-ray diffraction, infrared spectroscopy, dynamic mechanical analysis, salt spray test, and electrochemical measurements. The results show that the ethyl cellulose and oil in the coating can form a stable organic-gel structure by hydrogen bonding, and the mineral oil and castor oil are uniformly dispersed in the coating. The surface of the coating does not change after 3000 h of a salt spray test. During the repeated hot melting spraying and immersion in 3.5 wt.% NaCl solution for five times, the electrochemical impedance modulus of the coating was always above 109 Ω⋅cm2, the water absorption rate was always less than 1.5 wt.%, and the mechanical properties of the coating did not decrease. This novel coating could be used for the corrosion protection of flange and valve connections in pipeline and bolting connections in different industries. The disassembly and assembly operation of these connection structures during the regular maintenance will destroy the ordinary anticorrosion coating, and the irregular geometric shape of such places also make difficulties for the preparation of ordinary coatings onsite.

A Comparative Study of Neat Epoxy Coating and NanoZrO2/Epoxy Coating for Corrosion Protection on Carbon Steel

2014 ◽  
Vol 599-601 ◽  
pp. 3-6
Author(s):  
Xia Zhao ◽  
Shuan Liu ◽  
Bao Rong Hou
Keyword(s):  
Carbon Steel ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Epoxy Coating ◽  
Steel Plates ◽  
Neat Epoxy ◽  
Corrosive Media ◽  
Tafel Polarization ◽  
Q235 Carbon Steel

nanoZrO2 was modified by styrene coupling grafting method and then used as an additive to improve the protective performance of epoxy coating. Two kinds of coatings, neat epoxy coating and nanoZrO2/epoxy coating, were prepared and applied on Q235 carbon steel plates. The plates were submitted to salt spray chamber and seawater immersion for 1000 hours to evaluate the corrosion protection performance for these two kinds of coatings. Tafel polarization curves and electrochemical impedance spectroscopy (EIS) were determined to analyze the corrosion behavior of coating/metal system. Scanning electron microscopy (SEM) and photographs were carried out for morphology analysis of two kinds of coatings under different conditions. Results showed a superior stability and efficient corrosion protection by nanoZrO2 /epoxy coating. The modified nanoZrO2 could inhibit the penetration of corrosive media and then improve the corrosion protection of the epoxy coating on carbon steel.

Long-term corrosion protection of styrene acrylic coatings enhanced by fluorine and nitrogen co-doped graphene oxide

2021 ◽  
Author(s):  
Haoran An ◽  
Yanan Gao ◽  
Shengyuan Wang ◽  
Shuang Liang ◽  
Xin Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Hydrothermal Process ◽  
Polymer Coatings ◽  
Resin Matrix ◽  
Physical Barrier ◽  
Doped Graphene ◽  
Acrylic Coatings ◽  
Co Doped

Abstract Graphene materials are widely used as a physical barrier when applying anticorrosion polymer coatings due to their large surface area and layered structure. However, the electrical conductivity of intrinsic graphene can accelerate galvanic corrosion and shorten the protection period. In this work, fluorine and nitrogen co-doped graphene oxide (FNGO) was synthesized by a hydrothermal process and acted as an anticorrosion filler in waterborne styrene acrylic coatings. Styrene acrylic coatings with 0.4 wt% FNGO showed a corrosion current density that was two orders of magnitude lower than the other samples in the potential polarization test and the largest impedance modulus in the electrochemical impedance spectroscopy (EIS) results. The outstanding corrosion protection was attributed to the graphene acting as a physical barrier and the synergistic effect of the doped fluorine and nitrogen. In addition to the “labyrinth effect” of the graphene matrix, the nitrogen atoms inserted in the graphene plane and fluorine atoms grafted on the graphene simultaneously adjusted the electrical properties of graphene, prohibiting electron transport between it and the styrene acrylic resin matrix. This result indicates that doped graphene oxide has great potential to increase the corrosion resistance of waterborne coatings.

Corrosion Protection of Aluminum Alloy 2024-T3 by Vanadate Conversion Coatings

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 284-296 ◽  
Author(s):  
H. Guan ◽  
R. G. Buchheit
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Inductively Coupled Plasma ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Self Healing ◽  
Pitting Potential ◽  
X Ray ◽  
Aluminum Alloy 2024

Abstract In this paper, the formation, chemistry, morphology, and corrosion protection of a new type of inorganic conversion coating is described. This coating, referred to as a vanadate conversion coating (VCC), forms on aluminum alloy substrates in a matter of minutes during simple immersion in aqueous vanadate-based solutions at ambient temperatures. VCCs are yellow in color and conformal across the surface of aluminum alloy 2024-T3 (AA2024-T3 [UNS A92024]) substrates. Auger electron sputter depth profiles and x-ray absorption near-edge spectroscopy show that VCCs formed by a 3-min immersion are 300 nm to 500 nm thick and consist of a mixture of vanadium oxides and other components in the coating bath. In anodic polarization experiments conducted in aerated chloride solutions, VCCs increase the pitting potential and decrease the rate of oxygen reduction. When characterized by electrochemical impedance spectroscopy, VCCs demonstrate a low-frequency impedance between 1 MΩ-cm2 and 2 MΩ-cm2 after 24 h exposure to aerated 0.5 M sodium chloride (NaCl) solutions. In salt spray testing conducted according to ASTM B117, VCCs suppress formation of large pits for more than 168 h. VCCs also appear to be self-healing. Analysis of solution in contact with VCCs by inductively coupled plasma emission spectroscopy indicates that vanadate is released into solution upon exposure. Vanadium deposits were identified by x-ray microchemical analysis on a bare alloy substrate held in close proximity to a vanadate conversion-coated surface, and corrosion resistance of this bare surface was observed to increase during exposure. An important component of VCC formation appears to involve inorganic polymerization of V5+, which leads to the buildup of a film that passivates the surface and inhibits corrosion.

scholarly journals The Effect of the Methyl and Ethyl Group of the Acrylate Precursor in Hybrid Silane Coatings Used for Corrosion Protection of Aluminium Alloy 7075-T6

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 172 ◽  
Author(s):  
Damir Hamulić ◽  
Peter Rodič ◽  
Matic Poberžnik ◽  
Marjan Jereb ◽  
Janez Kovač ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Chemical Properties ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
Corrosion Properties ◽  
Ethyl Methacrylate

This study investigated polysiloxane hybrid sol-gel coatings synthesized from tetraethyl orthosilicate (TEOS), 3-(trimethoxysilyl)propyl methacrylate (MAPTMS) and two different precursors, i.e., methyl- or ethyl- methacrylate (MMA or EMA), as corrosion protection of aluminium alloy 7075-T6. The hypothesis was that the additional alkyl group might affect the chemical properties and, consequently, the corrosion properties. Synthesis of the sols proceeded in two steps, each involving either MMA or EMA in the same molar ratio. The resulting sols, siloxane-(poly(methyl methacrylate-co-MAPTMS)) or siloxane-(poly(ethyl methacrylate-co-MAPTMS)), were applied on aluminium alloy followed by characterization in terms of chemical structure and composition, topography, wettability, adhesion and corrosion resistance in 0.1 M sodium chloride solution. The chemical properties of sols, monoliths and coatings were investigated using Fourier transform infrared spectrometry, solid state nuclear magnetic resonance spectrometry, X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. Coatings were similar in terms of surface topography, while the wettability of the coating with EMA showed 6° greater water contact angle compared to the coating with MMA. Both coatings were shown, by electrochemical impedance spectroscopy in 0.1 M NaCl solution, to act as barriers to protect the underlying substrate in which coating with EMA exhibits better protection properties after 2 months of immersion. Adhesion tests confirmed the highest grade of adhesion to the substrate for both coatings. Testing in a salt-spray chamber demonstrated excellent corrosion protection, where coatings remaining intact after more than 600 h of exposure.

Sign in / Sign up

Export Citation Format

Share Document