Analysis of graphene oxide as an anticorrosive film in metallic materials

2021 ◽  
Author(s):  
Thaisa Ribeiro ◽  
Mylena Rangel da Silva ◽  
Geanni B. da Silveira e Silva Pessanha ◽  
Elisangela Pimentel da Silva

Corrosion is an electrochemical or chemical process that causes the deterioration of materials, especially metallic ones, thereby leading to unpredictable negative consequences. The application of anti-corrosive coatings constitutes a means of minimizing such corrosive effects once these coatings act as barriers between the substrate and the corrosive medium. Graphene oxide is a material that has gained notoriety due to its properties, abundance and to the fact that it is environmental friendly. The work we developed aimed to apply a graphene oxide solution on a metallic substrate in order to verify its applicability as an anticorrosive film. For this purpose, the production of the precursor solution was carried out; the application of the solution was accomplished by the dip-coating technique; then, the immersion test in aqueous corrosive medium followed and the characterization by confocal microscopy was performed. The results showed that there was adhesion of the film to the substrate and that it remained insoluble. As a protective layer for anticorrosion coating, the film responded partially well to this study’s proposed objectives because, though it did not manage to slow down the corrosive process, it did minimize the formation of spot corrosion, a more aggressive form of corrosion.

2010 ◽  
Vol 644 ◽  
pp. 113-116
Author(s):  
L.A. García-Cerda ◽  
Bertha A. Puente Urbina ◽  
M.A. Quevedo-López ◽  
B.E. Gnade ◽  
Leo A. Baldenegro-Perez ◽  
...  

In this study, HfxZr1-xO2 (0 < x < 1) thin films were deposited on silicon wafers using a dip-coating technique and by using a precursor solution prepared by the Pechini route. The effects of annealing temperature on the structure and morphological properties of the proposed films were investigated. HfxZr1-xO2 thin films with 1, 3 and 5 layers were annealed in air for 2 h at 600 and 800 °C and the structural and morphological properties studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that the films have monoclinic and tetragonal structure depending of the Hf and Zr concentration. SEM photographs show that all films consist of nanocrystalline grains with sizes in the range of 6 - 13 nm. The total film thickness is about 90 nm.


2006 ◽  
Vol 317-318 ◽  
pp. 173-176 ◽  
Author(s):  
Hae Jin Hwang ◽  
Ji Woong Moon ◽  
Yong Ho Lim ◽  
Seung Hun Lee ◽  
Eun A Lee

Lanthanum strontium chromite (LSC) thin films were prepared from the solution of La, Sr, Cr nitrates, acetylacetone and 2-methoxyethanol. Dip-coating technique was used to decompose La0.8Sr0.2CrO3, LSC thin films. The obtained precursor solution was sufficiently spinable and dried gel films were crystallized after heat-treating above 500°C for 2 h. The oxidation at 800°C for 40 hr resulted in no Fe3O4 surface-insulating phase, which means that the LSC thin film would be an effective oxidation-protecting layer of SUS430 substrate. The carbon deposited on an uncoated SUS430 substrate was amorphous with spherical morphology. The obtained LSC thin film was found to be very effective on preventing carbon deposition under dry hydrocarbon atmosphere.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1554
Author(s):  
Justinas Januskevicius ◽  
Zivile Stankeviciute ◽  
Dalis Baltrunas ◽  
Kęstutis Mažeika ◽  
Aldona Beganskiene ◽  
...  

In this study, an aqueous sol-gel synthesis method and subsequent dip-coating technique were applied for the preparation of yttrium iron garnet (YIG), yttrium iron perovskite (YIP), and terbium iron perovskite (TIP) bulk and thin films. The monophasic highly crystalline different iron ferrite powders have been synthesized using this simple aqueous sol-gel process displaying the suitability of the method. In the next step, the same sol-gel solution was used for the fabrication of coatings on monocrystalline silicon (100) using a dip-coating procedure. This resulted, likely due to substrate surface influence, in all coatings having mixed phases of both garnet and perovskite. Thermogravimetric (TG) analysis of the precursor gels was carried out. All the samples were investigated by X-ray powder diffraction (XRD) analysis. The coatings were also investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Mössbauer spectroscopy. Magnetic measurements were also carried out.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 243
Author(s):  
Diana Horkavcová ◽  
Quentin Doubet ◽  
Gisèle Laure Lecomte-Nana ◽  
Eva Jablonská ◽  
Aleš Helebrant

The sol-gel method provides a wide variety of applications in the medical field. One of these applications is the formation of coatings on the metal implants. The coatings containing specific additive can enhance or improve the existing surface properties of the substrate. In this work, titania sol-gel coatings were doped with two forms of silver (AgNO3, Ag3PO4) and synthetic hydroxyapatite and applied on the titanium samples by dip-coating technique. After drying and slow firing, all coatings were characterized with scanning electron microscopy. Thin coatings were successfully prepared with excellent adhesion to the substrate (measured by ASTM D 3359-2), despite cracks. Coatings containing silver and hydroxyapatite demonstrated a 100% antibacterial effect against Escherichia coli after 24 h. The bioactivity of the coatings containing hydroxyapatite tested in modified simulated body fluid under static-dynamic conditions was confirmed by bone-like hydroxyapatite precipitation. To better understand the interaction of the coatings with simulated body fluid (SBF), changes of Ca2+ and (PO4)3− ions concentrations and pH values were studied.


2021 ◽  
Vol 11 (7) ◽  
pp. 3123
Author(s):  
Haroon Mahmood ◽  
Laura Simonini ◽  
Andrea Dorigato ◽  
Alessandro Pegoretti

In this work, a novel nanomaterial deposition technique involving the triboelectrification (TE) of glass fibers (GF) to create attractive charges on their surface was investigated. Through TE, continuous GF were positively charged thus, attracting negatively charged graphene oxide (GO) nanoparticles dispersed in a solution. The electrical charges on the glass fibers surface increased with the intensity of the TE process. The deposited GO coating was then chemically treated to obtain reduced graphene oxide (rGO) on the surface of GFs. The amount of coating obtained increased with the GO solution concentration used during the deposition process, as revealed by FESEM analysis. However, the same increment could not be noticed as a function of the intensity of the process. Both uncoated and coated GF were used to obtain single fiber microcomposites by using a bicomponent epoxy matrix. The fiber/matrix interfacial shear strength was evaluated through micro debonding tests, which revealed an increment of fiber/matrix adhesion up to 45% for rGO coated GF in comparison to the uncoated ones. A slight improvement in the electrical conductivity of rGO coated fibers through TE compared to conventional dip coating was also observed in terms of volumetric resistivity by a four-point probe setup.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 386
Author(s):  
Hakan Kaleli ◽  
Selman Demirtaş ◽  
Veli Uysal ◽  
Ioannis Karnis ◽  
Minas M. Stylianakis ◽  
...  

We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P were detected on the rubbing surfaces of both the ball and the block through energy-dispersive X-ray spectroscopy. Finally, it was shown that the wear scar diameter on the surface of the steel ball was lower by 3%, upon testing the engine oil sample containing reduced graphene oxide at concentration 0.02 wt %, compared to the control sample.


1992 ◽  
Vol 271 ◽  
Author(s):  
Shoji Kaneko ◽  
Naoto Mazuka ◽  
Tamotsu Yamada

ABSTRACTMn-Co-Ni-O thin films of metal atomic ratio 3.0 : 1.9 : 1.0 were prepared on glass substrates from methanol solutions of the corresponding metal β-diketonates by dip-coating. As-prepared films were heated at 900°C for 1 h mostly after being calcined at 450°C for 5 min. The film thickness increased with increasing concentration of the solution as well as the number of lifting times. However, the effect was not apparent with the sample prepared without calcination. The prepared films were observed to crystallize into a complicated spinel phase by the heating process at 900°C for 1 h. The surface of the dense film composed of particles of about 0.2 μm diameter, was almost even. The thermal and aging responses of electric resistance showed the film to be a good material as a thermistor.


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