scholarly journals Investigation of Using Sol-Gel Technology for Corrosion Protection Coating Systems Incorporating Colours and Inhibitors

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 52 ◽  
Author(s):  
Wenjin Yan ◽  
Wee Kit Ong ◽  
Linda Yongling Wu ◽  
Sudesh L. Wijesinghe

Corrosion protection coatings need frequent developments to cater to different challenges arising from users. In addition to a long lasting corrosion protection, aesthetic requirements and multi-functional properties by the same coating system are prominent demands to be considered. Productivity is another vital factor to be considered, as there is a thriving demand from users to have more productive coating systems, such as a smaller number of layers in a system. Thus, attention to using different coating technologies is an essential step to fulfil these demands. This work investigates the use of sol-gel technology as a topcoat on a zinc rich primer to form a two-coat system. A colored sol-gel topcoat on a zinc primer was developed as a two-coat system to replace the current three or multi-coat systems to improve productivity while maintaining the sacrificial protective capability. The overall corrosion protection performance together with the color retaining capability was evaluated in this development. As another step forward, the development of sol-gel technology as a topcoat with additional inhibitive corrosion protection was investigated. Two corrosion inhibitors, namely molybdate and cerium(III), were loaded onto suitable inorganic oxide carriers and then incorporated into sol-gel coatings to provide an inhibitive protection other than the barrier protection. The corrosion performance of the coatings was evaluated using electrochemical impedance spectroscopy (EIS). Sol-gel coating with a cerium(III) system attained the highest impedance and proved to be the best candidate. The mechanical and physical properties of the coating systems are tested using international standard methods.

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
C. Menchaca ◽  
I. Castañeda ◽  
A. Soto-Quintero ◽  
R. Guardián ◽  
R. Cruz ◽  
...  

This work presents the electrochemical evaluation of a proposed copper corrosion protection hybrid coating acting as asmartcorrosion protection system. This consists of an alkyd varnish, painted over electrospun nylon fibers acting as a secondary diffusion barrier and also as a benzotriazole (BTAH) inhibitor nanocontainer. Submicron diameter electrospun nylon 6-6 fiber nanocontainers were prepared from a polymeric solution containing BTAH at different concentrations, and Cu samples were coated with the electrospun fibers and painted over with an alkyd varnish by the drop method. Functional groups in fibers were determined through FTIR spectroscopy. Optical and SEM microscopies were used to characterize the nanocontainer fibers. Samples were evaluated using electrochemical impedance and noise, during six weeks of immersion, in a chloride-ammonium sulfate solution. Excellent response was obtained for thesmartinhibitor coating system. For long periods of immersion good corrosion protection performance was observed. The results presented demonstrate the good barrier properties of the hybrid coating, obstructing the diffusion of aggressive species, through the electrospun structure. Furthermore the nanocontainer functionality to store and liberate the corrosion inhibitor, only when it is needed, was also proved.


2006 ◽  
Vol 519-521 ◽  
pp. 661-666 ◽  
Author(s):  
A.N. Khramov ◽  
V.N. Balbyshev ◽  
R.A. Mantz

Several heterocyclic organic corrosion inhibitors that contain ionazible functional group were encapsulated into nano-structural hybrid organo-silicate coating to improve its corrosion protection performance on aluminum alloy 2024-T3 substrate. When the coating is formed on the substrate surface, it serves simultaneously as protective barrier and as a reservoir for leachable corrosion inhibitor that is stored and released through the mechanism of reversible ionic interaction with the matrix material. The efficiency of active corrosion protection for these coating systems was examined by electrochemical methods including potentiodynamic polarization (PDS) and electrochemical impedance spectroscopy (EIS). The effects of chemical structure and the loading concentration of the inhibitor within the coating were determined.


2012 ◽  
Vol 05 ◽  
pp. 234-241 ◽  
Author(s):  
NAHID PIRHADY TAVANDASHTI ◽  
SOHRAB SANJABI

Nanostructured hybrid silica/epoxy films containing boehmite nanoparticles were investigated in the present work as pretreatments for AA2024 alloy. To produce the nanocomposite sol-gel films, boehmite nanoparticles prepared from hydrolysis/condensation of aluminum isopropoxide ( AlI ) were doped into another hybrid organosiloxane sol. The produced oxide nanoparticles have the capability to act as nanoreservoirs of corrosion inhibitors, releasing them controllably to protect the metallic substrate from corrosion. For this purpose the corrosion inhibitor, cerium nitrate, was introduced into the sol-gel system via loading the nanoparticles. The morphology and the structure of the hybrid sol-gel films were studied by Scanning Electron Microscopy (SEM). The corrosion protection properties of the films were investigated by Potentiodynamic Scanning (PDS) and Electrochemical Impedance Spectroscopy (EIS). The results show that the presence of boehmite nanoparticles highly improved the corrosion protection performance of the silica/epoxy coatings. Moreover, they can act as nanoreservoirs of corrosion inhibitors and provide prolonged release of cerium ions, offering a self-healing property to the film.


RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12553-12560 ◽  
Author(s):  
D. K. Ivanou ◽  
K. A. Yasakau ◽  
S. Kallip ◽  
A. D. Lisenkov ◽  
M. Starykevich ◽  
...  

A composite “self-healing” corrosion protection coating with high barrier properties was created on a Mg alloy by combining PEO and sol–gel techniques.


2015 ◽  
Vol 227 ◽  
pp. 515-518 ◽  
Author(s):  
Luigi Calabrese ◽  
Lucio Bonaccorsi ◽  
Chiara Borsellino ◽  
Angela Caprì ◽  
Francesca Fabiano ◽  
...  

In this work the assessment of the corrosion performances in saliva solution of NdFeB magnets coated with silane layers was studied for its application in orthodontic brackets. The silane film, deposited by dip coating technique, has been prepared with varying dipping steps, with the purpose to identify the number of layers able to achieve an optimal protective action. Corrosion protection performance, during immersion in Fusayama synthetic saliva solution, was evaluated by means electrochemical impedance spectroscopy (EIS). The silane coatings evidenced good barrier properties resulting in an improvement of the anti-corrosion performances of the magnets. Better results were observed for samples with at least 15 layers of silane, that evidenced still acceptable protective action after three days of immersion in a Fusayama synthetic saliva solution.


Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 385 ◽  
Author(s):  
Ana Karen Acero-Gutiérrez ◽  
Ana Lilia Pérez-Flores ◽  
Jesús Gilberto Godínez-Salcedo ◽  
Joel Moreno-Palmerin ◽  
Ángel de Jesús Morales-Ramírez

Tin oxide (SnO2) nanoparticles were successfully added to silicon oxide (SiO2) coatings deposited on A36 steel by the sol-gel and dip-coating methods. These coatings were developed to improve the performance of corrosion protection of steel in a 3 wt % NaCl solution. The effects of modifying the SnO2 particle concentration from 0–7.5 vol % were investigated by polarization resistance, Tafel linear polarization, and electrochemical impedance spectroscopy (EIS). The formation of protective barriers and their corrosion inhibition abilities were demonstrated. It was found by electrochemical studies that all of the coated samples presented higher corrosion resistances compared with an uncoated sample, indicating a generally beneficial effect from the incorporation of the nanoparticles. Furthermore, it was established that the relationship between the SnO2 content and the corrosion inhibition had parabolic behaviour, with an optimum SnO2 concentration of 2.5 vol %. EIS showed that the modified coatings improved barrier properties. The resistance for all of the samples was increased compared with the bare steel. The corrosion rate measurements highlighted the corrosion inhibition effect of SnO2 nanoparticles, and the Tafel polarization curves demonstrated a decrease in system dissolution reactions at the optimal nanoparticle concentration.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 948 ◽  
Author(s):  
Peter Rodič ◽  
Romana Cerc Korošec ◽  
Barbara Kapun ◽  
Alenka Mertelj ◽  
Ingrid Milošev

Pre-hydrolysed/condensed tetraethyl orthosilicate (TEOS) was added to a solution of methyl methacrylate (MMA) and 3-methacryloxypropyltrimethoxysilane (MAPTMS), and then copolymerised for various times to study the influence of the latter on the structure of hybrid sol-gel coatings as corrosion protection of aluminium alloy 7075-T6. The reactions taking place during preparation were characterised using real-time Fourier transform infrared spectroscopy, dynamic light scattering and gel permeation chromatography. The solution characteristics were evaluated, using viscosimetry, followed by measurements of thermal stability determined by thermogravimetric analysis. The optimal temperature for the condensation reaction was determined with the help of high-pressure differential scanning calorimetry. Once deposited on 7075-T6 substrates, the coatings were evaluated using a field emission scanning electron microscope coupled to an energy dispersive spectrometer to determine surface morphology, topography, composition and coating thickness. Corrosion properties were tested in dilute Harrison’s solution (3.5 g/L (NH4)2SO4 and 0.5 g/L NaCl) using electrochemical impedance spectroscopy. The copolymerization of MMA and MAPTMS over 4 h was optimal for obtaining 1.4 µm thick coating with superior barrier protection against corrosion attack (|Z10 mHz| ~ 1 GΩ cm2) during three months of exposure to the corrosive medium.


2008 ◽  
Vol 53 (5) ◽  
pp. 2087-2094 ◽  
Author(s):  
S. Sathiyanarayanan ◽  
S. Syed Azim ◽  
G. Venkatachari

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