Eco-friendly Silane Research Articles

Eco-friendly silane as corrosion inhibitor for dual self-healing anticorrosion coatings

Eco-friendly silane as corrosion inhibitor for dual self-healing anticorrosion coatings

Enhancement of corrosion resistance of mild steel in NaCl solution with an eco-friendly silane coating containing nanoclay and zinc acetylacetonate

PurposeThis paper aims to enhance the barrier properties and active protection of a water-based silane coating on mild steel through nanoclay and zinc acetylacetonate simultaneously included into the formulation.Design/methodology/approachThe corrosion protection performance of the silane sol-gel coatings with no additive, zinc acetylacetonate, nanoclay and nanoclay + zinc acetylacetonate was monitored using electrochemical impedance spectroscopy during 5 h of immersion in a sodium chloride solution. Moreover, the surface of coatings was analyzed using a field emission scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (FESEM-EDX) and water contact angle measurements.FindingsIn electrochemical impedance spectroscopy analysis, the impedance at low frequencies, coating resistance and charge transfer resistance were the parameters considered which indicated the superiority of silane coating formulated with both nanoclay and zinc acetylacetonate. According to the results of FESEM/EDX and water contact angle measurements, the superiority was linked with the enhancement in the barrier properties in the presence of nanoclay, as well as function of the corrosion inhibitor at coating–substrate interface.Originality/valueAccording to the literature, there is no research conducted to study the impact of the simultaneous use of nanoclay and zinc acetylacetonate on the barrier properties and active protection of an eco-friendly silane sol-gel coating including glycidyloxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane on mild steel in a sodium chloride solution.

Electrochemical noise assessment of effect of sol parameters on the performance of an eco-friendly silane sol-gel coating on 304L stainless steel

ProposeThis paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane with different pH values during various immersion periods.Design/methodology/approachThe 304L stainless steels coated through 10 and 30 s of immersion in the silane solutions with pH values of 2.1 and 2.8 were exposed to NaCl solution. The corrosion resistance of the coated substrates was studied through taking advantage of electrochemical noise method as well as atomic force microscopy (AFM), water contact angle and field emission-type scanning electron microscopy (FESEM) surface analysis.FindingsThe electrochemical current noise, PSD (I) plot, noise resistance and characteristic charge as parameters extracted from electrochemical noise method indicated the superiority of eco-friendly silane coating deposited on the substrate surface during 10 s exposure to the solution, due to the film uniformity and homogeneity as confirmed by FESEM and AFM. Moreover, immersion of the stainless steel in the silane solution with pH 2.1, characterized by higher hydrolysis ratio, led to more effective corrosion control in the NaCl electrolyte according to the results of electrochemical noise and FTIR measurements.Research limitations/implicationsThe noise resistance and characteristic charge as electrochemical noise parameters were only used in this research to evaluate the protective behavior of the water-based silane sol-gel coatings. Future studies should examine the correlation between electrochemical noise data and the parameters extracted from other electrochemical methods, e.g. electrochemical impedance spectroscopy.Practical implicationsThe data obtained in this research may provide an effective approach based on electrochemical noise method to screen the silane sol-gel coatings for protection of metallic substrates against corrosion.Originality/valueAccording to the literature, no report can be found studying the effect of immersion time on a silane solution, including glycidyloxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane, as well as the silane solution pH on the corrosion resistance of 304L stainless steel in NaCl solution through electrochemical noise method.

Synthesis and characterization of phosphorized polyaniline doped with phytic acid and its anticorrosion properties for Mg-Li alloy

ABSTRACTA phosphorized polyaniline (PANI) doped with phytic acid (PhA) was synthesized by the chemical oxide method with PhA as a dopant and applied to improve the anticorrosion properties of magnesium-lithium (Mg-Li) alloys after blending with eco-friendly silane sol. The chemical structures and morphologies of PANI samples were evaluated by FTIR spectroscopy, UV-Vis-NIR spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and scanning electron microscopy (SEM). All characterizations indicate that the as-synthesized phosphorized PANI (PANI-PhA) exists in doped emeraldine salt state with net-like structures crosslinked by phosphate carboxyl groups. The conductivity and thermostability of PANI-PhA were better than those of PANI doped with phosphoric acid (PANI-H3PO4) and undoped PANI. The anticorrosion properties of PANI/silane sol composite coatings for Mg-Li alloy were tested by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The results prove that the anticorrosion ability of PANI-PhA is the best among the three PANI samples, as shown by a low corrosion current (1.28 × 10−7 A·cm−2) and high impedance (5.62 × 106 Ω·cm2). The possible anticorrosion mechanism was proposed based on procedure analysis.

Effect of inhibition synergism of zinc chloride and 2-mercaptobenzoxzole on protective performance of an ecofriendly silane coating on mild steel

Abstract This work aims to study the impact of zinc cation and 2-mercaptobenzoxzole (MBO) on the corrosion protection of a silane sol-gel coating on mild steel. First, effectiveness of the organic and inorganic inhibitors on the corrosion of bare mild steel in a NaCl solution was shown to be linked to formation of a surface film. Using electrochemical data as well as results of surface analysis, a sharp inhibition synergism was found when an equal mole percentage of ZnCl 2 and MBO was added to the NaCl solution. Finally, electrochemical data indicated superior performance of the coating with the combination of inhibitors.

Development of an ecofriendly silane sol-gel coating with zinc acetylacetonate corrosion inhibitor for active protection of mild steel in sodium chloride solution

This work intends to develop an ecofriendly silane sol-gel coating with zinc acetylacetonate for active protection of mild steel. This water-based silane coating was composed of γ-glycidoxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane. The optimum inhibitor concentration was determined using electrochemical impedance spectroscopy. The electrochemical impedance spectroscopy data indicated no effect of zinc acetylacetonate on the coating barrier properties, which was confirmed by field emission scanning electron microscope (field emission scanning electron microscope), energy dispersive X-ray spectroscopy and fourier transform infrared spectroscopy surface analysis. From the charge transfer resistance, the superiority of inhibitor-doped films was associated with the function of zinc acetylacetonate at the interface. The electrochemical measurements showed an increase in the corrosion resistance of bare metal in sodium chloride solution with zinc acetylacetonate. From the results of field emission scanning electron microscope, energy dispersive X-ray spectroscopy, and atomic-force microscopy surface analysis, the corrosion control was suggested to be attributed to formation of a protective layer on the surface with contribution of zinc acetylacetonate.

The effect of zinc cation on the anticorrosion behavior of an eco-friendly silane sol–gel coating applied on mild steel

To provide active protection of mild steel, an eco-friendly silane sol-gel coating with ZnCl2 as zinc cation source was used. The optimal concentration of zinc cation was found using electrochemical impedance spectroscopy (EIS) and surface analysis. Evaluation of EIS data indicated that the superiority of doped-silane is mainly attributed to the corrosion inhibitive function of zinc cation at interface. Zinc cation showed no effect on the thickness and hydrophobicity of coatings which were evaluated by FESEM and water contact angle, indicating no influence on condensation reactions. Using electrochemical techniques and surface analysis, an insight into the zinc cation inhibition mechanism was obtained in the absence of silane coating. In the presence of zinc cation, FESEM/EDS indicated precipitation of a layer composed of zinc hydroxide and/or oxide on the mild steel surface.

Effect of synthesized NiFe 2 O 4 -silica nanocomposite on the performance of an ecofriendly silane sol–gel coating

Abstract In this research, nickel ferrite nanoparticles dispersed in a silica matrix (NiFe 2 O 4 -SiO 2 ) were prepared by sol–gel method. In addition to characterizing the particles using XRD and FTIR, TEM observations indicated that the silica matrix network provides an ideal nucleation environment to uniformly disperse NiFe 2 O 4 nanoparticles and thus to confine them to aggregate. The synthesized particles were then incorporated into an ecofriendly silane sol–gel coating applied on mild steel. The data extracted from electrochemical impedance spectroscopy indicated superior corrosion resistance of mild steel covered by the silane coating with 1000 ppm of NiFe 2 O 4 -SiO 2 particles compared to the substrate coated with neat silane. As shown by FESEM and AFM, a uniform, smooth and crack-free coating was formed in the presence of NiFe 2 O 4 -silica nanocomposite. According to FTIR and water contact angle measurements, the superiority of the nanoparticles inserted coating was suggested to be associated with stronger network reticulation providing more efficient barrier between the substrate and the sodium chloride solution.

Improvement in the corrosion resistance of stainless steel 304L in sodium chloride solution by a nanoclay incorporated silane coating

An eco-friendly silane sol–gel coating incorporating nanoclay was formulated to provide an effective corrosion protection for stainless steel 304L in a NaCl solution.

Effect of coating composition on the anticorrosion performance of a silane sol–gel layer on mild steel

In this study, the effect of coating composition on the protective performance of an eco-friendly silane sol–gel film applied on a mild steel substrate was investigated using electrochemical impedance spectroscopy and surface analysis methods.

Impact of curing on the corrosion performance of an eco-friendly silane sol–gel coating on 304L stainless steel

In this study, the effect of curing on the structure and protective performance of an eco-friendly silane sol–gel coating on stainless steel 304L was investigated using electrochemical methods as well as surface analysis.

Effect of Curing Conditions on the Protective Performance of an Ecofriendly Hybrid Silane Sol–Gel Coating with Clay Nanoparticles Applied on Mild Steel

An ecofriendly silane coating incorporating nanoclay was applied on mild steel through the sol–gel method. The concentration of nanoclay in which the hybrid coating consisting of glycidyloxypropyltrimethoxysilane, tetraethoxysilane, and methyltriethoxysilane revealed the most effective protection was determined through taking advantage of a combination of electrochemical noise method and surface analysis as well. Confirming the characteristic charge data obtained from shot noise theory, FTIR spectra and FESEM images indicated that the clay nanoparticles dispersed in the silane film might improve the barrier properties. The optimum curing characterization of the hybrid coating with nanoclay at the concentration ensuring the most effective protection was then determined using electrochemical measurements and surface analysis. Consistent with results of electrochemical impedance spectroscopy, electrochemical noise data revealed the significant impact of curing time and temperature on the protective function of the silane layer. Moreover, water contact angles showed the film structure is affected by the curing conditions.

Determination of optimum concentration of cloisite in an eco-friendly silane sol-gel film to improve corrosion resistance of mild steel

In this study, the effect of cloisite concentration on the protective performance of an eco-friendly silane sol-gel coating consisting of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and glycidyloxypropyltrimethoxysilane (GPS) applied on mild steel substrate was investigated using electrochemical techniques and surface analysis. Through taking advantage of electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical noise measurements, the optimum concentration of nanoparticles was determined. In the presence of the cloisite content, superiority of the hybrid silane film was connected to the enhanced barrier properties, confirmed by FE-SEM, FTIR and water contact angle studies. Moreover, a good trend correlation was observed between the noise resistance and low-frequency impedance modulus data.

Study of corrosion protection of mild steel by eco-friendly silane sol–gel coating

The effects of dipping duration in the silane solution and the sol pH on the protective performance of an eco-friendly silane sol–gel coating consisting a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane applied on mild steel substrate were studied in this paper using electrochemical techniques and surface analysis. In consistency with the data obtained from electrochemical impedance spectroscopy and polarization curves, electrochemical current noise fluctuation analysis, appearance of the power spectral density plots and noise resistance indicated the most efficient sol pH and immersion time in the silane solution. In this regard, field emission type scanning electron microscopy images and water contact angle values revealed impact of the sol pH on the film structure. The enhancement in protective performance of the hybrid coating resulting from optimum immersion in the silane solution with appropriate pH was connected to the film homogeneity and higher cross linking and thickness as well. Moreover, a good trend correlation was observed between the noise resistance and low-frequency impedance modulus data.

Synergistic effect of clay nanoparticles and cerium component on the corrosion behavior of eco-friendly silane sol–gel layer applied on pure aluminum

The synergistic effect of incorporation of nanoclay along with cerium nitrate as a corrosion inhibitor into an eco-friendly silane layer consisting of glycidyl–oxypropyl–trimethoxysilane (GPS), tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) applied on pure Al was studied in the present work. At first, the most effective concentration of cerium nitrate and the mechanism in which the cerium component could improve performance of silane layer were determined through a combination of electrochemical techniques and surface analysis methods as well. Based on the impedance spectra as well as polarization curves the superiority of silane film in the presence of cerium could be linked to deposition of a film on the cathodic zones, restricting access of the aggressive species to the surface. Moreover, FTIR spectra revealed impact of the inhibitor on the film structure. Furthermore, EIS data revealed that the nanoparticles enriched silane coating in the presence of cerium nitrate could provide superior corrosion protection compared to the sol–gel film which is solely incorporated with nanoclay.

Anticorrosion performance of eco-friendly silane primer for coil coating applications

In this paper, corrosion resistance and adhesion of environmental friendly silane primer on coil substrate was studied. Primer was formulated by using methyltrimethoxysilane and 3-glycidoxypropyltrimethoxysilane via acid hydrolysis and condensation reaction. Three different formulations (5%, 15% and 30%) were developed on the basis of sol/water ratio. Aluminium coils was dipped into primer and cured at 120°C for 20min. Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope was used to analyse the structural and morphological behaviour of the coating. Corrosion resistance of the coating was evaluated by salt-spray test and potentiodynamic polarization measurement. The adhesion behaviour of the coating was investigated by cross hatch test, before and after salt-spray immersion. Results showed that 15wt% sol content showed significant improvement in the corrosion resistance, adhesion of the coating and its UV resistance. Silane primers have excellent adhesion with substrate and commercial grade polyester, polyurethane and polyvinyldiene fluoride top coats.