The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Zhong Lin Wang - One of the best experts on this subject based on the ideXlab platform.
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electrochemical cathodic protection powered by triboelectric nanogenerator
Advanced Functional Materials, 2014Co-Authors: Xiaoyi Li, Mengxiao Chen, Lu Xu, Lin Dong, Wei Tang, Zhong Lin WangAbstract:Metal Corrosion is universal in the nature and the Corrosion Prevention for metals plays an important role everywhere in national economic development and daily life. Here a disk triboelectric nanogenerator (TENG) with segmental structures is introduced as power source to achieve a special cathodic protection effect for steels. The output transferred charges and short-circuit current density of the TENG achieve 1.41 mC/min and 10.1 mA/m 2 , respectively, when the rotating speed is 1000 revolutions per minute (rpm). The cathodic protection potential, Tafel polarization curves and electrochemical impedance spectra (EIS) measurements are measured to evaluate the Corrosion protection effect for the 403 stainless steel (403SS). The cathodic protection potential range from –320 mV to –5320 mV is achieved by changing rotation speeds and external resistance when the steel is coupled in a 0.5 M NaCl solution to the negative pole of the disk TENG. The Corrosion tests results indicate that the TENG can produce 59.1% degree of protection for Q235 steels in 0.5 M NaCl solution. Furthermore, an application of marine Corrosion Prevention is presented by mounting the TENG onto a buoy. This work demonstrates a versatile, cost-effect and self-powered system to scavenging mechanical energy from environment, leading to effectively protect the metal Corrosion without additional power sources.
Tommaso Pastore - One of the best experts on this subject based on the ideXlab platform.
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cyclic voltammetry evaluation of inhibitors for localised Corrosion in alkaline solutions
Electrochimica Acta, 2014Co-Authors: Marina Cabrini, Sergio Lorenzi, Tommaso PastoreAbstract:Abstract The paper focuses on chloride Corrosion of steel rebar in alkaline solutions. The effect of chloride content on Corrosion initiation was assessed through cyclic voltammetry (CV) tests at pH values between 12.6 and 13.8. The potential value E 1 , 1st was derived by CV tests to define the pitting initiation condition. The effect of inhibitor addition on the critical chloride content was also assessed. The performances of two innovative organic-acid-based inhibitors were compared to that of sodium nitrite, which is the most used for chloride Corrosion Prevention in concrete; the parameter f * was proposed for comparison purposes; this parameter defines the efficiency of the substance compared to alkalinity to prevent pitting initiation. The results confirm the role of the chloride-alkalinity ratio in Corrosion initiation; when the value of the ratio exceeds 0.6, the probability increases, confirming the literature data. The addition of nitrites causes an increase in the critical chloride threshold, as expected. The efficiency of sodium nitrite is similar to the effect of alkalinity; the value of the coefficient f * is equal to 0.84. Sodium aspartate exhibited the highest effect at pH values approaching 13.7; lower pH values resulted in lower efficiencies, nearly reaching zero at pH 12.6. Sodium lactate showed the lowest efficiency ( f * = 0.01).
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Corrosion inhibitors for chlorides induced Corrosion in reinforced concrete structures
Cement and Concrete Research, 2006Co-Authors: Marco Ormellese, M Berra, Fabio Maria Bolzoni, Tommaso PastoreAbstract:Abstract Reinforcements Corrosion is the most important cause of premature failure on reinforced concrete structures. Phenomena promoting Corrosion are the ingress of chlorides and the reaction of atmospheric CO 2 with cement paste. Aim of this paper is the investigation on the effectiveness of three organic commercial inhibitors in preventing carbon steel chlorides induced Corrosion in concrete, since there is not yet a clear knowledge on the real effectiveness of these products. Inhibitors were added to the concrete mixture in dosage suggested by the manufacturers. Chlorides were added in the concrete mixture or penetrated from outside by “ponding” cycles with a 3.5% sodium chloride solution. The effectiveness of the inhibitors has been evaluated by long-term rebar Corrosion monitoring in reinforced concrete and by rebar visual inspection after three years tests. Also solution tests were performed in order to verify the effectiveness of inhibition. Results give information about Corrosion Prevention ability of analysed commercial inhibitors.
Cécile Georges - One of the best experts on this subject based on the ideXlab platform.
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laser treatment for Corrosion Prevention of electrical contact gold coating
Applied Surface Science, 2002Co-Authors: Chantal Boulmerleborgne, H. Sanchez, C Perrin, Cécile Georges, Nadjib Semmar, D. SimónAbstract:Abstract The materials used in electrical contact applications are constituted of a copper alloy (brass or bronze) electroplated with two coatings, a nickel layer (diffusion barrier) and a gold layer (Corrosion barrier). There are some pores in the nickel and gold layers leading to Corrosion of the underlying layers. To modify the gold coating microstructure, a laser surface treatment has been undertaken. An excimer laser is used firstly because the photon absorption coefficient is larger in UV range and secondly because the laser beam homogeneity is available for a surface treatment. The purpose of this surface treatment is to suppress the porosity of the gold layer, which is responsible of the Corrosion pits, and to smooth the surface as the roughness prevents a correct electrical contact. The effects of the laser treatment are studied according to different surface parameters (roughness of the substrate, thickness of the two successive coatings, a nickel layer and a gold layer). A numerical code is used to simulate the influence of the laser beam parameter on the surface melting. Tests of Corrosion are carried out in the humid synthetic air containing low contents of pollutants (NO 2 , SO 2 and Cl 2 ). The techniques used to control these effects are optical microscopy and scanning electron microscopy (SEM).
Erika Kalman - One of the best experts on this subject based on the ideXlab platform.
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novel zinc rich epoxy paint coatings with hydrated alumina and carbon nanotubes supported polypyrrole for Corrosion protection of low carbon steel part ii Corrosion Prevention behavior of the hybrid paint coatings
Materials and Corrosion-werkstoffe Und Korrosion, 2013Co-Authors: Andras Gergely, Zoltan Paszti, I Bertoti, Tamas I Torok, Judith Mihaly, Erika KalmanAbstract:Utilization of various typesof multi-walled carbon nanotubes (MWCNTs) in zincrich paints (ZRPs) is presented addressing percolation and porosity related phenomena of traditional ZRPs. Hybrid paint coatings were formulated with 3.21wt% polypyrrole (PPy) deposited alumina-MWCNT inhibitor particles (PDAMIPs) and 70wt% zinc contents. Corrosion protection behavior of the hybrid coatings was investigated by electrochemical impedance spectroscopy (EIS), glow-discharge optical emission spectroscopy (GD OES), X-ray photoelectron spectroscopy (XPS), and FT-Raman spectroscopy. Immersion and salt-spray chamber tests gave evidence of improved galvanic protection and barrier nature of the hybrid coatings over the conventional ZRPs, whereas inhibited zinc Corrosion and ignorable steel Corrosion took place besides lower degradation of the binder. Zinc-rich hybrid paints with either high relative amount of polyelectrolyte-modified or low proportion of functionalized MWCNTsaffordedenhancedCorrosionPrevention.Thisresultispartlyattributed to the nanotube volume fractions around the threshold of infinite cluster formation contributing to electrical percolation and galvanic action of the hybrids. Experimental results are discussed in a broader context on the basis of structure related findings of the PDAMIPs (described in Part I) and in the light of recent literature data. From the newly developed inhibitor particles, some of them are respected as worthy additives for application in hybrid coatings featuring high performance Corrosion Prevention functionality.
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Corrosion protection of cold rolled steel with alkyd paint coatings composited with submicron structure types polypyrrole modified nano size alumina and carbon nanotubes
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2012Co-Authors: Andras Gergely, Zoltan Paszti, Judith Mihaly, Orsolya Hakkel, Eszter Drotar, Erika KalmanAbstract:Abstract This paper is focused on studying Corrosion protection of cold-rolled steel with alkyd paint coatings comprising nano-size alumina and either polystyrene-sulphonate (PSS) modified or sulphonated multi-walled carbon nanotube (MWCNT) supported polypyrrole (PPy). Single layer coatings (in thickness of 40 ± 5 μm) comprising PPy deposited alumina and PSS modified MWCNT supported PPy afforded viable protection during the 1 M sodium chloride test. The coatings containing PSS modified and weakly sulphonated MWCNTs (at volume fractions of 9.9 × 10−4 and 2.5 × 10−4) with PPy volume fractions of 3.5 × 10−3 and 2.5 × 10−3 provided effective Corrosion Prevention during the 1 M sodium chloride and hydrochloric acid solution tests. While inhibitor particles were characterised by infrared spectroscopy, Corrosion products formed at the paint–steel interface were studied by X-ray photoelectron spectroscopy. Apart from the electron microscopy observations, rheology study of three-dimensional structure of the inhibitor particles was performed in dispersions at similar compositions to those used for the paint formulations. Thus, protection mechanism relating to both types of immersion tests is discussed in terms of properties of the inhibitor particles and their microstructure in the coatings.
Xiaoyi Li - One of the best experts on this subject based on the ideXlab platform.
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electrochemical cathodic protection powered by triboelectric nanogenerator
Advanced Functional Materials, 2014Co-Authors: Xiaoyi Li, Mengxiao Chen, Lu Xu, Lin Dong, Wei Tang, Zhong Lin WangAbstract:Metal Corrosion is universal in the nature and the Corrosion Prevention for metals plays an important role everywhere in national economic development and daily life. Here a disk triboelectric nanogenerator (TENG) with segmental structures is introduced as power source to achieve a special cathodic protection effect for steels. The output transferred charges and short-circuit current density of the TENG achieve 1.41 mC/min and 10.1 mA/m 2 , respectively, when the rotating speed is 1000 revolutions per minute (rpm). The cathodic protection potential, Tafel polarization curves and electrochemical impedance spectra (EIS) measurements are measured to evaluate the Corrosion protection effect for the 403 stainless steel (403SS). The cathodic protection potential range from –320 mV to –5320 mV is achieved by changing rotation speeds and external resistance when the steel is coupled in a 0.5 M NaCl solution to the negative pole of the disk TENG. The Corrosion tests results indicate that the TENG can produce 59.1% degree of protection for Q235 steels in 0.5 M NaCl solution. Furthermore, an application of marine Corrosion Prevention is presented by mounting the TENG onto a buoy. This work demonstrates a versatile, cost-effect and self-powered system to scavenging mechanical energy from environment, leading to effectively protect the metal Corrosion without additional power sources.
