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1.
The effect of counter anions on corrosion resistance of steel covered by bi-layered polypyrrole film
The bi-layered polypyrrole (PPy) coatings were investigated for corrosion prevention of a carbon steel. The inner layer was doped with the Keggin structure anions of (PMo12) and anions for stabilization of the passive oxide film at the metal-polymer interface, and the outer layer was doped with four organic anions of dihydroxynaphthalenedisulfonate (DHNDS), naphthalenedisulfonate (NDS), anthraquinonedisulfonate (AnqDS) or dodecylsulfate (DoS) for inhibition of the decomposition and release of PMo12. The corrosion tests were performed in 3.5 wt.% NaCl aqueous solution. The corrosion resistance of the steels covered by the bi-layered PPy films was found in the following order: PPy-PMo12/PPy-DHNDS < PPy-PMo12/PPy-NDS < PPy-PMo12/AnqDS < PPy-PMo12/PPy-DoS. The performance of corrosion protection related to the oxidized state of the polymer was discussed. 相似文献
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利用高能离子注入机和直线等离子体模拟装置,本文研究了高能氦离子预注入对氘等离子体辐照后钨中氘滞留行为的影响。采用FIB-SEM、TEM、GD-OES和TDS等分析方法,分析了氦离子预注入对钨中氘滞留行为的影响。结果表明:氦离子预注入在辐照损伤区域形成大量氦泡,钨经过氘等离子体辐照后,表面的氘泡数量明显低于未经过氦离子预注入的样品。GD-OES分析中可以看到在氦捕获位处氘滞留浓度明显升高,同时氦离子预注入增加了氘在钨中的扩散深度,结合TDS分析可知氦离子预注入增加了氘在钨中的滞留总量,这是由于氦离子预注入后,形成的缺陷又为钨中氘的俘获提供大量新的位点,从而导致钨中的氘滞留量明显提高。 相似文献
3.
Ultrasonic irradiation was imposed during electropolymerization of polypyrrole (PPy) in acid phosphate solution containing molybdophosphate () ions and pyrrole monomer. Corrosion of the steel coated by the PPy film prepared under ultrasonic irradiation was tested in 3.5 wt.% NaCl solution and compared with corrosion of the steel coated by the PPy film without ultrasonic irradiation. The PPy film prepared under ultrasonic irradiation kept the steel in the passive state one and a half times as long as that prepared without ultrasonic irradiation. Imposition of ultrasound enhanced the doping of and decreased the doping of . The surface morphology of the PPy film was changed with imposition of ultrasound in electropolymerization process. Under imposition of ultrasound, a dense and compact PPy layer was formed. The structure of the PPy film obtained under ultrasonic irradiation was assumed to result from change in nucleation-growth mechanism. 相似文献
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《International Journal of Hydrogen Energy》2020,45(2):1313-1324
Low-temperature anion-exchange membrane fuel cells (AEMFCs) are gathering increased attention because they facilitate the use of non-precious metal catalysts, which might drastically reduce costs compared to low-temperature proton exchange membrane fuel cells (PEMFCs). Metallic, e.g., stainless steel, bipolar plates (BPPs) present a cost-efficient solution for this type of cell. However, anodic film formation at high positive potentials (approx. +1.5 V vs. RHE) on uncoated metals/stainless steels leads to high interfacial contact resistance (ICR) of the BPP once exposed to such a potential. A potential of +1.5 V vs. RHE is commonly reached under local and global hydrogen starvation, which rules out the use of uncoated metals in AEMFCs. We have investigated the ICR change and oxide film formation of several materials under simulated fuel cell operating conditions and found that suppression of anodic film formation and, in turn, low ICRs can be achieved by carbon coating of stainless steels. 相似文献
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《Journal of Adhesion Science and Technology》2013,27(4):583-600
By using three different skin pass reductions, 0%, 0.75%, and 1.5%, the influence of skin pass rolling on the primer adhesion and corrosion resistance of primed hot-dip galvanized (HDG) steel has been studied. The corrosion resistance of primed panels was determined by a cyclic prohesion test, and the primer adhesion was examined with a combined cross-cut and impact test. Surface roughness was determined for untreated and pretreated skin passed panels and the samples were also studied using an optical microscope and a scanning electron microscope. Electron spectroscopy for chemical analysis (ESCA) and glow discharge optical emission spectroscopy (GD-OES) were used to characterize the chemical surface composition of the panels. According to the prohesion test results, the roughest samples showed the best corrosion resistance and also slightly improved adhesion test results. The ESCA and GD-OES results showed that the outermost surface was enriched by aluminium in the zinc coating. During skin pass rolling, the aluminium oxide-rich surface is broken and zinc is revealed to the surface. An increase in the skin pass reduction resulted in an almost linear increase in the surface roughness. Mechanical removal of the surface aluminium also affected the amount of aluminium dissolved during the chemical pretreatment. The best results obtained for the roughest samples are mainly due to the most homogeneous skin pass pattern obtained with the highest skin pass reduction. 相似文献
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Today, material analysis in industry and research centres is very often performed by the glow-discharge optical emission spectrometry (GD-OES), which allows an extraordinarily quick material analysis (average time of analysis: 2-5 min) and a determination mainly by the pumping time of the glow discharge source. The reliability of the analysis is, especially in the case of thin films (film thickness <100 nm), determined by the purity of the discharge gas and of the surface of the source and sample.We could reduce the ultimate pressure and increase the purity of the gas at the place of analysis by improving the dimensions and construction of the pumping set, and the conduction of the pumping and venting process of a given commercial spectrometer device.Moreover, an automatic and computer-aided evaluation of the pressure vs. time run in the source chamber can inform the user about possible leaks or contamination of inner surfaces. For this purpose, it is possible to use the control computer of commercial equipment and the data acquisition system of the GD-OES instrument. Thus, one can receive important hints from the p-t plot regarding the equipment and can start leak detection, cleaning of the source chamber or replacing of components in time. 相似文献
8.
Helium and hydrogen interaction in tungsten simultaneously irradiated by He+-H2+ at high temperature
《International Journal of Hydrogen Energy》2020,45(16):9959-9968
Tungsten (W) is one of the most promising candidates for plasma facing materials in the fusion reactor. Helium (He) in W can influence the retention of hydrogen isotopes. In the present study, W targets were simultaneously irradiated by He+-H2+ or He+-D2+ ion beams with the energies of 1 keV or 3 keV, at fixed temperatures in a range of room temperature (R.T.) to 1073 K. Mechanisms of He and hydrogen interaction in W were discussed, especially from the point of He retention, which was characterized by the high-temperature thermal desorption spectroscopy (TDS) and glow-discharge optical emission spectroscopy (GD-OES) measurements. It is found that He desorption shifts to a lower temperature range for the W simultaneously irradiated by 3 keV He+-1 keV H2+ at 573 K, under He+ fluence up to 1 × 1022 He+m−2. Transmission electron microscope (TEM) observation and annealing treatment at the temperature of 873–1073 K show that the increased He uptake is caused by the formation of dislocation. Enhanced retention amounts for the hydrogen isotopes were also confirmed. Amounts of the dislocation loops introduced by the H2+-only irradiation can be reduced by annealing treatment at 873 K, while that introduced by He+ irradiation are quite stable, which grows larger at elevated temperatures. With an increase of H2+ energy, Helium uptakes at both weak trapping sites and bubbles are increased, while the amounts of hydrogen retention are decreased. It suggests that hydrogen ion has a significant influence on the He trapping sites at the irradiation temperature up to 573 K, while the hydrogen retention is determined by the distribution of He bubbles and dislocation loops. 相似文献
9.
An SUS316L stainless steel separator was coated with amorphous carbon by using an electron cyclotron resonance (ECR) plasma sputtering technique, and used in a polymer electrolyte fuel cell (PEFC). Characteristics of this carbon film were investigated with Raman spectroscopy and XPS. Quantitative depth profiles and chemical depth profiles of the deposited carbon layer were measured with GD-OES and XPS, respectively. The contact resistivity between a carbon paper and the carbon coated SUS316L steel was also measured. The performance of PEFC single cells assembled with carbon coated SUS316L separators, uncoated SUS316L separators, and conventional carbon separators were compared. The results revealed that an assembled PEFC having carbon coated SUS316L separators provided better performance than one having uncoated SUS316L, and the PEFC showed comparable performance to one having conventional carbon separators. 相似文献
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