Use of electrochemical impedance spectroscopy to study corrosion of Ni/Al2O3/PTFE composite coatings in NaCl and CMA solutions

2020 ◽  
Vol 1 (6) ◽  
pp. 12-16
Author(s):  
BEATA KUCHARSKA
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Ptfe Composite

Effect of Doping of Nanoparticles on the Properties of Zn-Ni Composite Coatings

2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Corrosion Performance ◽  
X Ray ◽  
Ni Alloy

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.

scholarly journals Electrochemical Impedance Spectroscopy Investigation on the Corrosive Behaviour of Waterborne Silicate Micaceous Iron Oxide Coatings in Seawater

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 415 ◽  
Author(s):  
Zhao ◽  
Qi ◽  
Zhang ◽  
Li ◽  
Li
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Iron Oxide ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Impact Resistance ◽  
Zinc Powder ◽  
Corrosive Media ◽  
Pencil Hardness ◽  
Iron Oxide Coatings

The anticorrosive composite coatings based on waterborne silicate were prepared to replace existing solvent-based coatings suitable for ships. A series of composite coatings were prepared by adding zinc powder and micaceous iron oxide to the waterborne silicate resin. The adhesion, pencil hardness and impact resistance of the coatings were investigated and corrosion performance in seawater is characterized by electrochemical impedance spectroscopy (EIS). The results show that coatings have excellent adhesion and impact resistance and their pencil hardness can reach up to 4H. During the immersion of composite coatings in seawater for 8 h, only one time constant appears in the Bode plot, coating capacitance (Qc) gradually increases but dispersion coefficient (n) and coating resistance (Rc) gradually decrease. The breakpoint frequency formula was deduced, considering the dispersion effect. With the increase of micaceous iron oxide, the fluctuation of breakpoint frequency with immersion time is weakened. It can be used to evaluate the corrosion resistance of inorganic anticorrosive coatings in seawater. In addition, different penetration models of corrosive media were proposed for the coatings with low or high content of micaceous iron oxide.

Electrochemical impedance spectroscopy study of electron transfer at poly(3,4-ethylenedioxythiophene) containing gold nanoparticles coating

2011 ◽  
Vol 76 (12) ◽  
pp. 1433-1445
Author(s):  
Stelian Lupu
Keyword(s):  
Gold Nanoparticles ◽  
Electron Transfer ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Au Nanoparticles ◽  
Electrochemical Impedance ◽  
Electrochemical Polymerization ◽  
Composite Coatings ◽  
Supporting Electrolyte ◽  
Transfer Resistance

Electrochemical impedance spectroscopy (EIS) was used for characterization of electron transfer in various redox probes, such as the redox couple ferrocyanide-ferricyanide, ferrocene, ferrocenemethanol, and the poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer containing gold nanoparticles. The PEDOT coating was deposited onto platinum (Pt) and glassy carbon (GC) electrodes by galvanostatic electrochemical polymerization from an aqueous solution containing 10–2 M EDOT and 10–1 M LiClO4 as supporting electrolyte. The PEDOT-Au nanoparticles composite coating was prepared by droplet deposition of Au nanoparticles on top of the Pt/PEDOT and GC/PEDOT modified electrodes. The pure PEDOT and PEDOT-Au nanoparticles composite coatings were investigated using EIS and cyclic voltammetry (CV) in 10–1 M LiClO4 solution containing various redox probes. The impedance spectra were recorded at the formal redox potential of the redox probes. The charge transfer resistance (Rct), solution resistance (Rs), exchange current density (i0), standard rate constant (k0), and double-layer capacitance (Cdl) were calculated from the EIS data.

Electrochemical Characteristics of Various Ni-P Composite Coatings in 0.6M NaCl Solution

2020 ◽  
Author(s):  
Mahboobeh Azadi ◽  
Hossein Tavakolli ◽  
Saeid Haghighatkhah ◽  
Freshteh Amjadi Eranegh
Keyword(s):  
Heat Treatment ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Electrochemical Characteristics ◽  
Nacl Solution ◽  
Nano Sio2 ◽  
Tafel Polarization ◽  
Sio2 Particles

In this paper, various Ni-P composite coatings containing toner, MoS2, and nano-SiO2 particles were deposited on steel substrates by the electroless method. Then, the electrochemical properties of these coatings after a heat treatment process were compared. The microstructural evaluations were also done by using the optical and electron microscopy methods. Both Tafel polarization and electrochemical impedance spectroscopy techniques were utilized to survey the electrochemical behavior of such coatings. The surface morphology of all coatings contained cauliflower-like nodules. The X-ray diffraction patterns showed the crystalline phases of Ni and Ni3P for all coatings after the heat-treatment step. Obtained results showed that all composite coatings exhibited lower corrosion rates with respect to Ni-P coatings. Such a reduction was about 21.6-92.2%. This behavior was attributed to the presence of reinforcement as barriers for corrosive ion diffusion through the coating plus the changes in detected phases and thickness. Electrochemical impedance spectroscopy test results also demonstrated that the increase in the polarization resistance for composites coatings was about 18.4-85.3% after 1 h immersion in a 0.6M NaCl solution; however, when the immersion time increased to 24 h, such increased resistance changed to 18.1 to 73.1%. Totally, despite the lower deposition rate, the presence of MoS2 and nano-SiO2 particles were more effective than toner particles to raise the corrosion rate of the Ni-P coating.

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