Comparison of selected inhibitor doped sol–gel coating systems for protection of mild steel (original) (raw)
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Materials Research, 2015
This study proposes a new pretreatment method that uses alkoxide precursors with a plasticizing agent; the purpose of this study is to improve the electrochemical and mechanical properties of a galvanized steel surface. Galvanized steel was covered with a hybrid film obtained from a sol that consisted of two alkoxide precursors, 3-(trimethoxysilylpropyl) methacrylate (TMSM) and tetraethoxysilane (TEOS), with nitrate cerium in a concentration of 0.01 M and a polyethylene glycol (PEG) plasticizer. The hybrid coatings were obtained by dip-coating method with various concentrations of plasticizer (0, 20, 40 and 60 g.L-1). The hybrid films were analyzed by scanning electron microscopy (SEM), profilometry, contact angle measurements, a tribometer with the type-setting ball on the plate and electrochemical tests. The addition of the plasticizer into the hybrid films improves the corrosion resistance behavior compared to the sample without the plasticizer. The addition of 20 g.L-1 of plasticizer showed the best performance in the electrochemical tests. The mechanical behavior results indicated that higher PEG concentrations resulted in films with enhanced durability.
Journal of Sol-Gel Science and Technology, 2018
Sol-gel coating material with enhanced corrosion protection for zinc-coated steel has been obtained through the incorporation of mono-phenol and bi-phenol organic precursors in an epoxide functionalised-silica-zirconia matrix. The effect of the presence of the organic precursors in the baseline formulation has been studied; sol stability has been examined by viscosity evolution; gel densification stage has been studied by differential scanning calorimetry (DSC); material composition has been analysed by Fourier transform infrared spectroscopy (FTIR) and X-ray spectroscopy (XPS); coating thickness and roughness has been measured by profilometry. Corrosion performance in three artificial weathering tests showed outstanding performance in the delay of zinc and steel corrosion products emergence, and electrochemical impedance spectroscopy (EIS) measurement permitted the identification of the coating presenting the most promising properties in terms of corrosion protection. Developed coatings have shown outstanding contribution to service life extension of zinc-coated parts.
Applied Surface Science, 2018
In this study the corrosion resistance, active protection, and cathodic disbonding performance of an epoxy coating were improved through surface modification of steel by a hybrid sol-gel system filled with green corrosion inhibitors loaded nanocontainer as intermediate layer on mild steel substrate. The green inhibitor loaded nanocontainers (GIN) were used to induce active inhibition performance in the protective coating system. The corrosion protection performance of the coated panels was investigated by electrochemical impedance spectroscopy (EIS), salt spray, and cathodic disbonding tests. It was observed that the corrosion inhibition performance of the coated mild steel panels was significantly improved by utilization of active multilayer coating system. The inhibitor release from nanocontainers at the epoxysilane film/steel interface resulted in the anodic and cathodic reactions restriction, leading to the lower coating delamination from the substrate and corrosion products progress. Also, the active inhibition performance of the coating system was approved by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDS) analysis on the panels with artificial defects. The inhibitive agents were released to the scratch region and blocked the active sites on the metal surface.
Sol–gel coatings on metals for corrosion protection
Sol-gel protective coatings have shown excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates. Further, the sol-gel method is an environmentally friendly technique of surface protection and had showed the potential for the replacement of toxic pretreatments and coatings which have traditionally been used for increasing corrosion resistance of metals. This review covers the recent developments and applications of sol-gel protective coatings on different metal substrates, such as steel, aluminum, copper, magnesium and their alloys. The challenges for industrial productions and future research on sol-gel corrosion protective coatings are also briefly discussed.
Protective Properties of a Sol-Gel Coating on Zinc Coated Steel
Journal of Sol-Gel Science and Technology, 2006
Galvanised and galvannealed steels are widely used due to their good corrosion resistance in aqueous solutions. However, when additional protection is required, organic coatings, corrosion inhibitors or conversion coatings are used to improve their corrosion protection. In this work, sol-gel coating was used to improve the corrosion behaviour of these two materials. This paper analyses the final protective properties of a sol-gel coating prepared by basic catalysis and its dependence on the sintering temperature and time of treatment. The influence of the sintering conditions on the galvanised and galvannealed substrates is a decisive factor for the coating quality and for the barrier affect against the aggressive media. While heat treatment time is the controlling factor for the galvannealed steels, the temperature is determining in the case of the galvanised. Corrosion mechanisms for sol-gel galvanised steels did not changed with respect to the uncoated steel. However for galvannealed steel, after coating the mechanism is not purely cathodic.
Corrosion Engineering Science and Technology, 2016
Pentaglycidyl ether pentabisphenol A of phosphorus (PGEPBAP) phosphorus polymer was investigated as corrosion inhibition for carbon steel in aggressive solution using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss (WL), scanning electron microscope (SEM), density functional theory (DFT), electrostatic potential (ESP), radial distribution function (RDF), molecular dynamics (MD) and Monte Carlo (MC) simulations. The higher inhibition efficiencies for PDP, EIS and WL studies at 10 −3 M concentration of PGEPBA phosphorus polymer are 94.18 %, 91.79 % and 91.3 %, respectively. E corr (23.7 mV) value of PGEPBAP phosphorus polymer is lower than 85 mV has been assigned to mixed type inhibitor. PGEPBAP formed protective film on carbon steel surface by adsorption according to Langmuir adsorption isotherm. SEM morphology suggested that PGEPBAP could effectively block acid attack by chemisorption on metal surface. To evaluate the polymer inhibitor and potential mechanism were especially realized DFT, ESP, RDF, MD and MC simulations.
Sol-Gel Process for Anti-Corrosion Coatings
Journal of Research Updates in Polymer Science
This review paper summarizes the current state of the art of sol-gel technology for formulating anti corrosive protective coating. A brief description of the mechanism of sol-gel reactions, various parameters that influence the property of the final product and the course of the sol-gel reaction has been given. Different types of metal precursors that are extensively used in sol preparation and the advantages and disadvantages have also been mentioned in brief. Surface chemistry of sol-gel matrix and various stabilizing and destabilizing forces that are active on the surface of colloidal particles have also been discussed. Problems related to obtaining good quality product with uniformly distributed concentrations have been outlined. Possible pathways for further improvement of anti-corrosive properties of the coating have been described, such as incorporation of various types of additives into the sol matrix prior to coating. As a whole the present study summarizes the superiority and benefits of organic-inorganic hybrid coatings using sol-gel technique and having good protective and anti-corrosive properties.
Corrosion Resistance Nano-hybrid Sol–Gel Coating on Steel Sheet
ISIJ International, 2011
Titania-containing organic-inorganic hybrid sol-gel film was developed to improve the corrosion resistance property of steel. Titania precursor was prepared from titanium-isopropoxide and methyl hydrogen silicone was used as a coupling agent to enhance the adhesion and hydrophobic nature of coating. The kinetics, thermal resistance and morphology of films were analyzed by, fourier transformed infrared spectroscopy, thermo-gravimetric and differential thermal analysis and scanning electron microscopy. The anticorrosion performance of the sol-gel coated sample was investigated by electrochemical impedance spectroscopy. The results demonstrated that coatings were dense, uniform and provided excellent corrosion resistance properties.
A Review of Preparation and Characterization of Sol-Gel coating for Corrosion Mitigation
International Journal of Engineering Technology and Management Sciences, 2024
Sol-gel technology has emerged as a powerful and versatile tool for synthesizing a wide range of materials such as catalyst, ceramics, coatings, composite, glasses, fibers.Many industries like Automotive, Biomedical , Communications, Construction and Electronics sectors benefit from the use of sol-gel chemistry due to its versatility in fabricating a wide range of materials with different properties. In the sol-gel process, a precursor solution (sol) is used, and the precursor molecules undergo controlled hydrolysis and polycondensation to become a solid substance (gel). This paper explores the application of the sol-gel synthesis method in coating technology for corrosion prevention. Corrosion presents a notable risk to infrastructure, machinery, and diverse industrial uses, resulting in considerable economic losses and safety hazards. Several methods exist for corrosion prevention using coatings such as chemical vapor deposition and physical vapor deposition but sol-gel stands out due to its low synthesis temperature ,cost-effectiveness, simplicity ,ability to incorporate and leverage corrosion inhibitors and adaptability to various substrates. Limitations exist in terms of process optimization, and long-term stability, ongoing research efforts are actively addressing these challenges to unlock its full potential. Additionally with our study of related journals we have found that these coatings can be further engineered to exhibit additional functionalities like hydrophobicity, conductivity, or biocompatibility, expanding their applicability across diverse industrial needs.
Sol-gel coatings for chemical protection of stainless steel
Journal of Sol-Gel Science and Technology, 1994
Sol-gel thin coatings of ZrO2, SiO2, 70SiO2-30TiO2 and 88SiO2-12A12Oa compositions (mole %) have been prepared from sonocatalyzed sols and deposited by dip-coating technique on 316L stainless steel foils. The influence of the coatings on the chemical corrosion of the substrate has been measured through potentiodynamic polarization curves in aqueous 15% H2SO4 solution between 25 and 50°C. The values of the corrosion potential, polarization resistance and corrosion rate have been determined. Analysis of the data combined with scanning electron microscopy studies indicate that the films act as a geometric blocking against exposure to the corrosive media and increase the lifetime of the substrate up to a factor 8.5.