Electrochemical impedance biosensor for detection of saxitoxin in aqueous solution

Author(s):  
Pablo C. Serrano ◽  
Gisele E. Nunes ◽  
Lindiomar B. Avila ◽  
Carleane P.S. Reis ◽  
Aldo M.C. Gomes ◽  
...  
2011 ◽  
Vol 239-242 ◽  
pp. 1771-1774 ◽  
Author(s):  
Meng Qiu Jia ◽  
Yu Hong Jin

Reflective topcoat and thermal insulation mid-coat composite coatings system was used in this work. The effect of the content of the hollow glass micro-beads and rutile titanium dioxide on the heat insulation performance and the reflectivity of the coatings were investigated, respectively. The heat insulation performance and the reflectivity of the thermal insulation reflective composite coatings (TIRCCs) were characterized by self-prepared experimental device. The results showed the good heat insulation property, and the insulated temperature reached 12-15°C, and the reflectivity was up to 95%. The anti-corrosion and anti-penetration of the TIRCCs were studied by electrochemical impedance spectroscopy (EIS) technique. The results showed that the resistance of the TIRCCs still be maintained at 108Ω·cm2 after 30 days in the 3.5% aqueous solution of sodium chloride. So The TIRCCs can be used on the surface of the steal structure for decreasing the temperature and enhancing anti-corrosion properties.


2012 ◽  
Vol 706-709 ◽  
pp. 2008-2013
Author(s):  
Satoshi Sunada ◽  
Norio Nunomura ◽  
Kazuhiko Majima

In this experiment two kinds of 410L stainless steel, i.e., the first one is prepared by the I/M process and the second one is prepared by MIM process were used, and their corrosion behavior under stress in deionized water and the aqueous solution of 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33) has been investigated by Electrochemical Impedance Spectroscopy (hereafter shortened as EIS) under Slow Strain Rate Tensile (hereafter shortened as SSRT) test. The charge transfer resistance (Rct) of the I/M specimen is larger than that of the MIM specimen irrespective of under stress or non-stress, which means that the I/M specimen has the better corrosion resistance than the MIM specimen in the 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33) solution. It was also confirmed from the fracture surface observation that hydrogen embrittlement occurred on the MIM specimen in the aqueous solution of 0.01kmol·m-3HCl+1.72mol·m-3MgCl2 (pH=2.33). This result would be confirmed to be due to the existing impurities and defects in the MIM specimen.


2011 ◽  
Vol 335-336 ◽  
pp. 779-782
Author(s):  
Shi Quan He ◽  
Hui Zhong

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.


2020 ◽  
Vol 67 (4) ◽  
pp. 357-366
Author(s):  
Gang Wang ◽  
Yue Zhang ◽  
Chen Gao ◽  
GuangTao Xu ◽  
MingHao Zhao

Purpose The purpose of this paper is to investigate, the effects of residual stress and microstructure on the corrosion behaviour of carburised 18CrNiMo7-6 steel in a 3.5% NaCl aqueous solution. Design/methodology/approach The electrochemical tests were conducted using an electrochemical workstation with a three-electrode system in a 3.5% NaCl aqueous solution, the residual stress of each working face was measured by a high-speed residual stress analyser, and microstructure of different carburised layers were observed scanning electron microscopy. Finally, the effect of carbon content, microstructure and residual stress on the corrosion behaviour of the steel was discussed. Findings The results showed that the residual compressive stress in the carburised layer initially increased and subsequently decreased with increasing depth of the carburised layer, reaching stability in the matrix layer. The electrochemical tests before and after stress reduction showed that the electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. Originality/value The residual compressive stress in the carburised layer initially increases and subsequently decreases with increasing carburised layer depth. The electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. The general relationship between electrochemical potential and residual stress was established.


Author(s):  
Mauro Andres Cerra Florez ◽  
Jorge Luiz Cardoso ◽  
Hamilton Ferreira Gomes de Abreu ◽  
Walney Silva Araújo ◽  
Marcelo José Gomes da Silva

Abstract The present study aims to establish a comparison of corrosion resistance between four (non-commercial) high manganese steel models in relation to 9% nickel steel in an aqueous solution of H2SO4. High manganese steels have emerged as an alternative material for the manufacture of equipment for the storage and transportation of liquefied petroleum gas due to their mechanical properties and mainly for the lower cost compared to 9% nickel steel. The electrochemical techniques used were open circuit potential, linear polarization and electrochemical impedance spectroscopy. The results obtained by these techniques have helped to understand the phenomena that produce a lower corrosion resistance of high manganese steels when compared to 9% nickel steel in aqueous solutions.


2013 ◽  
Vol 734-737 ◽  
pp. 1367-1373
Author(s):  
Guan Fa Lin ◽  
Xun Chang Dong ◽  
Shi Dong Zhu ◽  
Zhen Quan Bai

As an attempt to contribute to the understanding of the corrosion processes of anti-sulfur steel in CO2and H2S containing environment with different species, the corrosion behavior of SM 80SS tubing steel immersed in CO2and H2S containing solution was analyzed in this work. To determine the corrosion behavior of SM80SS steel, the linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) techniques were used, as well as weight loss test and surface analysis. The results showed that the presence of Cl-quickened the anodic dissolution processes and rapidly increased the corrosion rate of SM 80SS steel, and that the addition of Ca2+and Mg2+reduced corrosion rate. The corrosion processes of SM 80SS steel were controlled by the electrochemical reaction in the initial period and then converted to be controlled by electrochemical and activation reaction with increasing Cl-. Keywords: SM 80SS tubing steel; CO2/H2S corrosion; EIS; Chloride; Ca2++ Mg2+


2019 ◽  
Vol 28 (6) ◽  
pp. 1060-1067
Author(s):  
Alex Baldwin ◽  
Eugene Yoon ◽  
Trevor Hudson ◽  
Ellis Meng

CORROSION ◽  
10.5006/3230 ◽  
2020 ◽  
Vol 76 (9) ◽  
pp. 884-890
Author(s):  
Renata B. Soares ◽  
Wagner R.C. Campos ◽  
Pedro L. Gastelois ◽  
Waldemar A.A. Macedo ◽  
Luís F.P. Dick ◽  
...  

The electrochemical behavior and the electronic properties of passive films formed on a super martensitic stainless steel (SMSS) used in oil and gas industries were investigated in aqueous 0.6 M and 2.1 M NaCl solutions with additions of sodium acetate and acetic acid (pH 4.5). Open-circuit potential transients, electrochemical impedance spectroscopy, cyclic voltammetry, and x-ray photoelectron spectroscopy were measured to characterize the passive film formed on SMSS. The electrochemical behavior of the steel in an aqueous solution of 0.6 M NaCl presented the highest pitting potential and the highest polarization resistance in relation to the NaCl/NaAc solution. The passive film of SMSS in an aqueous solution of NaCl presented a thickness of 18.40 nm, three times the thickness of the oxide film in NaCl/NaAc, and consisted of FeO, Cr2O3, MoO2, and spinels such as FeCr2O4 species that are a p-type semiconductor, but may also contain a small fraction of the Fe2O3 and MoO3 oxides. Additionally, it was shown that the passive layer after immersion in a saline solution also contains hydroxides such as FeOOH and Cr(OH)3.


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