The Experts below are selected from a list of 9804 Experts worldwide ranked by ideXlab platform
R B Figueira - One of the best experts on this subject based on the ideXlab platform.
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hot dip galvanized steel dip coated with ureasilicate hybrid in simulated concrete pore solution assessment of coating morphology and Corrosion protection efficiency
Progress in Organic Coatings, 2015Co-Authors: R B Figueira, Carlos Silva, E V PereiraAbstract:Abstract The barrier effect and the performance of an organic–inorganic hybrid (OIH) sol–gel coating are highly dependent on the coating deposition method as well as processing conditions. In this work, studies on the influence of experimental parameters using the dip coating method were performed. Factors such as residence time (Rt), a curing step between each dip step and the number of layers of sol–gel OIH films deposited on HDGS to Prevent Corrosion in highly alkaline environments were studied. These OIH coatings were obtained using a functionalized siloxane, 3-isociantepropyltriethoxysilane that reacted with a diamino-functionalized oligopolymer (Jeffamine ® D-230). The barrier efficiency of OIH coatings in simulated concrete pore solutions (SCPS) was assessed in the first moments of contact, by electrochemical impedance spectroscopy and potentiodynamic methods. The durability and stability of the OIH coatings in SCPS was monitored during eight days by macrocell current density. The morphological characterization of the surface was performed by scanning electronic microscopy before and after exposure to SCPS. Glow discharge optical emission spectroscopy was used to obtain quantitative composition profiles to investigate the thickness of the OIH coatings as a function of the number of layers deposited and the influence of the Rt in the coating thickness.
Iris De Graeve - One of the best experts on this subject based on the ideXlab platform.
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inhibitor evaluation in different simulated concrete pore solution for the protection of steel rebars
Construction and Building Materials, 2016Co-Authors: Hilke Verbruggen, H Terryn, Iris De GraeveAbstract:Abstract Corrosion of reinforcement steel forms a huge problem worldwide. A possible remedy for this problem is the application of Corrosion inhibitors. The purpose of this research is to evaluate different inhibitors for both types of Corrosion that can occur in reinforced concrete: pitting Corrosion (by chloride attack), and uniform Corrosion (by a drop in pH). Potentiodynamic polarization measurements in realistic concrete pore solutions (CPS) revealed three critical situations — representing pitting and uniform Corrosion, and the combination — in which the inhibitor needs to act. According to polarization experiments and micrographs Na 2 MoO 4 is the best performing inhibitor for the three cases. Our XPS measurements are in line with the proposed inhibitor mechanism by Vukasovich (1986), which is very complex and depends on whether the surface is active or passive to start with. In conclusion Na 2 MoO 4 is a possible — and environmental-friendly — candidate to Prevent Corrosion of reinforcement steel.
Longjiang Deng - One of the best experts on this subject based on the ideXlab platform.
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plasma induced fesial al2o3 sio2 core shell structure for exceptional microwave absorption and anti oxidation at high temperature
Chemical Engineering Journal, 2020Co-Authors: Xian Jian, Li Zhang, Chunhong Mu, Nasir Mahmood, Longjiang DengAbstract:Abstract Structural and chemical stability is the key factors of microwave absorbers for their applications in case of high-temperature oxidation. In this study, a plasma-induced method is developed to get a multistrata core-shell structure of FeSiAl@Al2O3@SiO2 with bifunctional performances of microwave absorption and anti-oxidation. Within a dense microstructure, the Al2O3 and SiO2 ceramic shell layers mitigate oxygen transport to Prevent Corrosion at high temperature. Consequently, the magnetic FeSiAl core is well-protected against oxidation up to 1279 °C in air and exhibits excellent microwave absorption property. In particular, dense ceramic layers effectively reduce the permittivity of FeSiAl without losing permeability. Furthermore, the novel FSA@GCLs microstructures are enriched with multiple interfaces to favor the interfacial polarization and vast internal scattering probabilities. Because of the strong synergistic magnetic-dielectric effects, the multistrata core-shell structure of FeSiAl@Al2O3@SiO2 owns a minimum reflection loss of −46.29 dB at 16.93 GHz and its wide bandwidth (with an RL value of −10 dB) particularly acquire 7.33 GHz in the frequency range of 10.14–17.45 GHz. The highly stable multistrata core-shell opens up the opportunities of extending the microwave absorption as well as anti-oxidation applications.
E V Pereira - One of the best experts on this subject based on the ideXlab platform.
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hot dip galvanized steel dip coated with ureasilicate hybrid in simulated concrete pore solution assessment of coating morphology and Corrosion protection efficiency
Progress in Organic Coatings, 2015Co-Authors: R B Figueira, Carlos Silva, E V PereiraAbstract:Abstract The barrier effect and the performance of an organic–inorganic hybrid (OIH) sol–gel coating are highly dependent on the coating deposition method as well as processing conditions. In this work, studies on the influence of experimental parameters using the dip coating method were performed. Factors such as residence time (Rt), a curing step between each dip step and the number of layers of sol–gel OIH films deposited on HDGS to Prevent Corrosion in highly alkaline environments were studied. These OIH coatings were obtained using a functionalized siloxane, 3-isociantepropyltriethoxysilane that reacted with a diamino-functionalized oligopolymer (Jeffamine ® D-230). The barrier efficiency of OIH coatings in simulated concrete pore solutions (SCPS) was assessed in the first moments of contact, by electrochemical impedance spectroscopy and potentiodynamic methods. The durability and stability of the OIH coatings in SCPS was monitored during eight days by macrocell current density. The morphological characterization of the surface was performed by scanning electronic microscopy before and after exposure to SCPS. Glow discharge optical emission spectroscopy was used to obtain quantitative composition profiles to investigate the thickness of the OIH coatings as a function of the number of layers deposited and the influence of the Rt in the coating thickness.
Marie Pierre Gigandet - One of the best experts on this subject based on the ideXlab platform.
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Evolution of Corrosion protection for sol-gel coatings doped with inorganic inhibitors
Surface and Coatings Technology, 2008Co-Authors: Virginie Moutarlier, Bertrand Neveu, Marie Pierre GigandetAbstract:One the way to improve the self-repair properties of sol–gel films on aluminium alloy is the addition of Corrosion inhibitors which could be released from the coating, minimising the Corrosion of the unprotected area. Environmentally friendly Corrosion inhibitors are studied (chromium III, molybdate, permanganate and cerium III) and compared to the standard Corrosion inhibitor, i.e. hexavalent chromium. Corrosion performances are studied by polarisation resistance (Rp) in chloride medium. Evolution of composition of sol–gel coatings, during the Corrosion test, is examined by GDOES (glow discharge optical emission spectroscopy). The results show that the morphology of sol–gel and the solubility of the additive play a role in the effectiveness of Corrosion protection for a long term. Additives such as molybdate and permanganate ions decrease the sol–gel network stability and are too soluble (they are rapidly lost from the sol–gel films, in an aggressive medium), decreasing the power to Prevent Corrosion. Incorporation of Ce III is not efficient for a long time due to its high solubility. Sol–gel films containing Cr VI and Cr III provide adequate Corrosion protection, due to the sol–gel stability and their low solubility.