scholarly journals Effects of direct stray current on the performance of cathodic disbonding epoxy powder coatings

2019 ◽  
Vol 16 (6) ◽  
pp. 1417-1429
Author(s):  
Yan-Yu Cui ◽  
Rui-Tao Bu ◽  
De-You Wang ◽  
Yu-Jun Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Powder Coating ◽  
Powder Coatings ◽  
Stray Current ◽  
Epoxy Powder Coating ◽  
Scanning Electron

Abstract The influence of the direction and magnitude of direct (DC) stray current on the disbonding performance of epoxy powder coating was studied by using electrochemical impedance spectroscopy and scanning electron microscopy technology. The results show that the application of DC stray current could accelerate the anodic dissolution. The peeling degree of the coating increases as the magnitude of positive DC stray current interference increases in the range of 2–8 V. With 16 V positive stray current disturbance, the degree of coating disbonding decreases. With the application of negative stray current, the coating peeling becomes more serious, and the degree of peeling increases as the DC stray current increases.

Effect of KI on the Corrosion Resistance of Ni-P Electroless Plating Coating

2014 ◽  
Vol 633-634 ◽  
pp. 817-820
Author(s):  
Ping Liang ◽  
Yun Xia Zhang ◽  
Yan Hua Shi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Phosphorus Content ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Electroless Coating ◽  
Scanning Electron

To improve the corrosion resistance of Ni-P electroless coating, the KI was added in the electroless solution. The surface micrograph was observed using scanning electron microscopy (SEM), and the corrosion resistance of Ni-P coatings in 3.5%NaCl solution was examined by polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that KI reduced the amount of defects and the size of crystal grain of Ni-P coating, and the surface of Ni-P coating became more homogenous, smoother and compact by KI. In addition, the phosphorus content of Ni-P coating was increased by KI. These factors increased the ability to corrosion protection of Ni-P coating.

Long-Term SOFCs Button Cell Testing

2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Gianfranco DiGiuseppe ◽  
Li Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Electrochemical Impedance ◽  
X Ray ◽  
Total Polarization ◽  
Scanning Electron

This paper reports a new study where relatively long-term tests of about a 1000 h are performed on several planar anode-supported solid oxide fuel cells. The cell electrochemical behaviors are studied by using voltage-current density measurement, electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The cell total polarization obtained from electrochemical impedance spectroscopy results is shown to be consistent with the area-specific resistance calculated from the voltage-current density curve over the course of the test. In addition, a four-constant phase element model is used to analyze the cell components resistances at different intervals over the lifetime of the test. Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used postmortem to determine if any damages occurred to the cells and to determine if any change in composition occurred to the lanthanum strontium cobalt ferrite cathode. This study shows that the tested cells remain stable with a relatively small increase in the cell total polarization but with no increase in ohmic resistance.

Supramolecular p-sulfonated calix[4,6,8]arene for tryptophan detection

2014 ◽  
Vol 92 (12) ◽  
pp. 1139-1144 ◽  
Author(s):  
Tao-Tao Pang ◽  
Li-Ming Du ◽  
Hai-Long Liu ◽  
Yun-Long Fu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Spectroscopy Analysis ◽  
Modeling Calculation ◽  
Potential Complex ◽  
Scanning Electron

Numerous techniques have focused on the ability of p-sulfonated calix[n]arene to form complexes with tryptophan. Scanning electron microscopy and Fourier transform infrared spectroscopy were utilized to study the organization and molecular structure of different layers of the electrode surface. Scanning electron microscopy results showed that SC4A displayed a cubic structure whereas SC6A and SC8A displayed dendrite structures. The electrochemical properties and potential complex formation between SCnA and tryptophan were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetry experiments showed that the gold electrode was successfully functionalized by self-assembled cysteamine and SC4A. Electrochemical impedance spectroscopy results showed the observation of the tryptophan–SCnA interaction and indicated that SC4A had the highest sensitivity to tryptophan and allowed 2.04 μg L−1 tryptophan to be detected. Electrochemical impedance spectroscopy analysis and molecular modeling calculation confirmed that SC4A has higher tryptophan sensitivity than SC6A and SC8A.

The Improvement of Anticorrosive Technology for Pipeline in Panjin Oilfield

2012 ◽  
Vol 472-475 ◽  
pp. 2901-2904
Author(s):  
Li Ming Tang ◽  
Wen Jun Bi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Working Life ◽  
Anticorrosive Coating ◽  
Basic Work ◽  
Scanning Electron

The anticorrosive work for pipeline is a long-term basic work. It is significant for us to lengthen pipeline working life and enhance the operation reliability. In this article, the corrosive status in quo and reasons for pipeline in Panjin oilfield were narrated. In accordance with the corrosive characters, the new anticorrosive coating that epoxy heavy anticorrosive over-rust primer/IPN topcoat was opened up. In the lab, the anticorrosive coating by analyzed with electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The corrosion behavior of the new anticorrosive coating was compared with that of the traditional asphalt paint. The conclusion is that the epoxy heavy anticorrosive over-rust primer/IPN topcoat is superior to asphalt paint in anticorrosive properties.

scholarly journals Pelapisan Silika pada Stainless Steel secara Elektroforesis Disertai Anodisasi untuk Perlindungan Korosi

2019 ◽  
Vol 14 (1) ◽  
pp. 97-103
Author(s):  
Ni Made Intan Putri Suari ◽  
Delyana Ratnasari ◽  
Sahara Tulaini ◽  
Widiyastuti Widiyastuti ◽  
Heru Setyawan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Stainless Steel ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Duty Cycle ◽  
Electrochemical Impedance ◽  
Particle Size Analyzer ◽  
Scanning Electron

Penelitian ini mempelajari pengaruh anodisasi terhadap karakteristik perlindungan korosi lapisan silika pada permukaan stainless steel. Anodisasi dilakukan menggunakan larutan asam oksalat dengan memvariasikan waktu anodisasi dan beda tegangan. Elektroforesis dilakukan menggunakan campuran sol silika, isopropanol dan asam asetat dengan perbandingan mol 0,0028 : 0,5048 : 0,1938 selama 10 menit dengan amplitudo 0,5 V, frekuensi 80 Hz dan duty cycle 60%. Dilakukan uji Particle Size Analyzer (PSA) terhadap sol silika. Diperoleh distribusi ukuran partikel sebesar 3,19 nm dan zeta potensial -31,68 mV. Dilakukan analisa polarisasi linear dan Electrochemical Impedance Spectroscopy (EIS) dengan larutan NaCl 3,5% serta Scanning Electron Microscopy (SEM) terhadap lapisan yang terbentuk pada permukaan stainless steel. Dari hasil analisa diperoleh logam yang telah dianodisasi dan elektroforesis memiliki kemampuan perlindungan korosi lebih baik dibanding logam tanpa perlakuan. Waktu dan beda tegangan saat anodisasi berpengaruh terhadap karakteristik perlindungan korosi lapisan pada logam. Diperoleh waktu anodisasi optimum selama 20 menit dan voltase 10 volt dengan laju korosi sebesar 0,000659 mm/tahun. Untuk uji EIS, nilai admitan dan nilai tahanan pori masing-masing sebesar 1.824,7 ohm dan 0,0010226 Mho. Hasil SEM menunjukkan bahwa setelah dilakukan anodisasi terbentuk lapisan yang berpori yang nantinya menjadi tempat menempelnya silika pada proses elektroforesis.

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