Cerium oxide loaded with Gum Arabic as environmentally friendly anti-corrosion additive for protection of coated steel

The depreciation of assets and safety threats because of corrosion has forced to develop eco-friendly and smarter corrosion protection strategies. In this study, natural Gum Arabic (GA) was used as a corrosion inhibitor and loaded into cerium oxide nanoparticles (CONPs) to develop an environment-friendly additive for corrosion protection of coated steel in the marine environment. This additive was uniformly dispersed into an epoxy formulation that was used to protect steel plates. Epoxy coatings containing CONPs, without GA, were also prepared as reference. High-Resolution Transmission Electron Microscopy (HR-TEM) and Fourier Transform infrared spectroscopy (FTIR) revealed the successful loading of GA into the CONPs. Thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) techniques confirmed approximately ⁓30.0 wt% loading of GA into the CONPs. Electrochemical impedance spectroscopy (EIS) demonstrated the anticorrosion properties of the epoxy coatings modified with the GA loaded CONPs when compared to reference coatings. The corrosion protection mechanism postulates that GA loaded CONPs act as a filler material for epoxy coating and it can also aid the recovery of the protective properties of the epoxy coating leading to the formation of a stable protective layer.This publication was made possible by NPRP11S-1226-170132 from Qatar National Research Fund (a member of the Qatar Foundation). Statements made herein are solely the responsibility of the authors. The authors would like to thanks to the Central Laboratories Unit (CLU), Qatar University, 2713, Doha, Qatar for FE-SEM, and HR-TEM analyses. Authors from Portugal acknowledge FCT for the additional funding under the project UIDB/00100/2020 and UIDP/00100/2020. Open Access funding provided by the Qatar National Library. The raw data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.Scopu

Synthesis and properties of polyelectrolyte multilayered microcapsules reinforced smart coatings

The present research work focuses on the synthesis, characterization and properties of novel polyelectrolyte multilayered microcapsules used as smart additives in organic coatings for corrosion protection of steel parts. Urea formaldehyde microcapsules encapsulated with linalyl acetate (UFMCs), sensitive to mechanical stimulus, were synthesized by in situ emulsion polymerization technique. In the next step, dodecylamine, working as a pH stimulus corrosion inhibitor, was loaded into layers of polyelectrolyte molecules, polyethylenimine (PEI) and sulfonated polyether ether ketone (SPEEK). These were applied layer-by-layer over the microcapsules to form inhibitor containing multilayered urea formaldehyde microcapsules (MLUFMCs). In the next step, MLUFMCs (5.0 wt%) and UFMCs (5.0 wt%) were thoroughly dispersed into the epoxy resin and coated on cleaned steel. A comparison of the structural, thermal and anticorrosive properties indicates that coatings modified with multilayered capsules (PMLSCs) demonstrate good thermal stability, improved self-healing characteristics and higher corrosion resistance compared to the coating modified with urea formaldehyde microcapsules. The improved properties of PMLSCs can be attributed to efficient release of the encapsulated self-healing agent and corrosion inhibitor from the MLUFMCs. Therefore, epoxy coatings modified with the novel multilayered capsules may be attractive for corrosion protection of steel parts used in oil and gas and related industries. - 2019, The Author(s).Open Access funding provided by the Qatar National Library. This publication was made possible by NPRP Grant 9–080-2-039 from Qatar National Research Fund (a member of the Qatar Foundation). Statements made herein are solely the responsibility of the authors. R. A. Shakoor would like to acknowledge the financial support of QU internal grant-QUCG-CAM-2018/2019-3 and the Core Labs, QEERI for their SEM and TEM imaging. M.F. Mon-temor thanks Fundac¸ão para a Ciência e a Tecnologia (FCT, Portugal) for financial support under the projects PEst-OE/QUI/UI0100/2013.Scopu

Electrodeposition of metallic foams and their application as catalyst for hydrogen production: Preliminary results

International audienc

Electrodeposited manganese oxide on tailored 3D bimetallic nanofoams for energy storage applications

Three-dimensional (3D) electrode design has great advantages over its two-dimensional (2D) counterparts, including higher mass loading of active material, enhanced ion diffusion, and electron charge transfer. Commercial 3D porous structures (i.e., Ni foams) do not fit the purpose of the ideal 3D electrode for supercapacitors, in which surface area (per cm(2)) is more important than large pore volume. These characteristics, however, can be tuned by the dynamic hydrogen bubble template (DHBT) electrodeposition, a route that is used to tailor 3D nanostructured (multi-) metallic porous surfaces. In addition to the higher surface area and tailored porosity, these 3D nanostructures can be subsequently functionalized with different species such as metal oxides or other compounds. Therefore, a facile two-step electrochemical fabrication of 3D composite electrode composed of a bimetallic foam functionalized with manganese (Mn) oxide is proposed. The effect of applied current densities on the distribution and structure of Mn oxide (MnOx) electrodeposited over the bare foam is discussed. The results demonstrate that this route paves the way to design high-surface-area architectures for charge storage electrodes with enhanced electrochemical performance (194Fg(-1) mg(-1) of electrodeposited MnOx at 0.5Ag(-1)) and high charge-discharge rate capabilities (91% capacitance retention at 20Ag(-1)) for supercapacitor applications.info:eu-repo/semantics/publishedVersio

From manganese oxide to manganese sulphide: Synthesis and its effect on electrochemical energy storage performance

High power pseudocapacitors are extremely relevant to answer specific needs in the current energy transition arena and to implement an efficient renewable energy society. However, literature shows that are still open gaps concerning improvement of their energy density at high power, conversion efficiency, cost and cycle life. Electrodes based on active transition metal compounds, and in particular metal sulphides, evidence high potential to meet these objectives. This work discusses the dependence on the synthesis route of the charge storage mechanism of manganese sulphide-based materials and relates the pseudocapacitive response of these electrodes with their polycrystalline nature. Results reveal that a manganese oxy-sulphide mixture can achieve a high specific capacitance of 231 F.g−1 at 0.5 A/g in a 0.65 V active window. These values represent a 31.5 % increase compared to pure rambergite, γ-MnS, and 436 % compared to pure hausmannite Mn3O4 prepared under the same conditions. Moreover, the results show that manganese oxy-sulphide electrodes are characterized by good charge retention (73%), and superior long term capacity retention (above 86%) after 5000 cycles, evidencing potential for high power energy storage applications.info:eu-repo/semantics/publishedVersio

On the synergistic corrosion inhibition and polymer healing effects of polyolefin coatings modified with Ce-loaded hydroxyapatite particles applied on steel

pH-sensitive hydroxyapatite particles were loaded with cerium ions (Ce-HAP) and incorporated into polyolefin coatings applied on carbon steel. The Ce-modified hydroxyapatite particles were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The protective performance of modified and reference polyolefin coatings applied on carbon steel was studied by electrochemical impedance spectroscopy (EIS), and the self-healing capability was evidenced by combining the scanning vibrating electrode technique (SVET) and pH micro-potentiometry with video-imaging, SEM and Raman. The modified coatings showed significantly improved long-term corrosion protection compared to reference coatings. The effect was attributed to the synergistic combination of the corrosion inhibition effect of cerium ions loaded in the HAP particles and polyolefin healing capability.This publication was made possible by NPRP11S-1226–170132 from Qatar National Research Fund (a member of the Qatar Foundation). The authors from Centro de Química Estrutural acknowledge the financial support of Fundação para a Ciência e Tecnologia (UIDB/00100/2020 and UIDP/00100/2020). Statements made herein are solely the responsibility of the authors. The authors acknowledge Dow Chemical Company (Dr. Bernhard Kainz, Global Application Development Leader Metal Packaging Coatings, Dow Coating Materials) for providing polyolefin CANVERA 1110 coating formulation; Voestalpine AG for providing carbon steel; Dr. Marta Alves (Instituto Superior Técnico) for conducting the XRD tests; Prof. Ana Clara Marques for valuable discussions; Mário Vale (Instituto Superior Técnico) for performing TG/DTG studies; Ana Mafalda Macatrão for helping with RAMAN characterization. Pedro Prazeres (PARALAB) for help with SEM visualization of self-healing; Mario Dias (LAIST, Técnico Lisboa) for determination of cerium, nitrate and total nitrogen contents in Ce-HAP particles.Scopu

Synthesis and characterisation of Ni–B/Ni–P–CeO2 duplex composite coatings

Abstract: Binary (Ni–B, Ni–P) and duplex coatings (Ni–B/Ni–P, Ni–B/Ni–P–CeO2) with an inner Ni–B layer were electrodeposited on mild steel substrates. A comparison of the structural, surface, mechanical, and electrochemical properties of the coatings is presented to demonstrate the mechanical behaviour and corrosion protection performance. Scanning electron microscope and atomic force microscope images showed that Ni–B/Ni–P–CeO2 duplex coatings had a well-defined nodular structure compared to Ni–P coatings, and fewer surface defects compared to Ni–B and Ni–B/Ni–P duplex coatings. However, these coatings had high surface roughness owing to the presence of CeO2 ceramic particles. X-ray diffraction analysis revealed that Ni–B coatings were crystalline but Ni–P and Ni–B/Ni–P–CeO2 coatings exhibited an amorphous structure. Ni–B/Ni–P–CeO2 coatings exhibited superior hardness (15%) compared to Ni–P and Ni–B/Ni–P duplex coatings. Potentiodynamic polarisation results confirmed that Ni–B/Ni–P–CeO2 duplex coatings had superior corrosion protection efficiency (91%) compared to Ni–B (30%) and duplex Ni–B/Ni–P coatings (77%). The novel Ni–B/Ni–P–CeO2 duplex coatings demonstrated superior mechanical and promising anti-corrosion properties, which render them attractive for various applications. Graphical Abstract: [Figure not available: see fulltext.]. © 2018, Springer Science+Business Media B.V., part of Springer Nature.Acknowledgements This publication was made possible by NPRP Grant # 9-080-2-039 from the Qatar National Research Fund (a member of the Qatar Foundation). Statements made herein are solely the responsibility of the authors. M.F. Montemor acknowledges Fundaç?o para a Ciência e Tecnologia (FCT) for the funding under the contract UID/QUI/00100/2013.Scopu

Inhibitor loaded calcium carbonate microparticles for corrosion protection of epoxy-coated carbon steel

pH-sensitive calcium carbonate microparticles were loaded with polyethyleneimine (PEI), a corrosion inhibitor, and used as anti-corrosion additive in epoxy coatings applied on carbon steel. The presence of PEI in the CaCO3 particles was confirmed by Fourier-Transform Infra-Red Spectroscopy (FTIR) and the loading was quantified by Thermal Gravimetric Analysis (TGA). The protective performance of the modified coatings applied on carbon steel was investigated by Electrochemical Impedance Spectroscopy (EIS) and the results evidenced that the modified coatings provided high corrosion protection and very stable barrier properties over time. The self-healing ability was investigated by Localized Electrochemical Impedance Spectroscopy (LEIS) and by the Scanning Vibrating Electrode Technique (SVET) on coated samples artificially damaged and immersed in NaCl solutions. The results revealed an important corrosion inhibition effect, stable over time, in the coatings modified with the PEI loaded particles. The corrosion inhibition effect involves the dissolution of the calcium carbonate microparticles in the local acid media formed at the anodic sites and subsequent release of the corrosion inhibitor that forms a protective film on the steel surface. - 2019 Elsevier LtdThis publication was made possible by NPRP Grant NPRP-9-080-2-039 from Qatar National Research Fund (a member of the Qatar Foundation). L. M. Calado acknowledges Fundação para a Ciência e Tecnologia ( FCT ) for Ph.D. grant SFRH/BD/127341/2016 . Authors from Portugal acknowledge FCT for the additional funding under the projects UID/QUI/00100/2013 and UID/QUI/00100/2019 ; Sherwin-Williams for providing the coating formulations; Voestalpine AG for providing carbon steel; Dr. Marta Alves (Instituto Superior Técnico) for conducting the XRD tests; Dr. Sónia Eugénio (Universidade Atlântica) and Mário Vale (Instituto Superior Técnico) for performing FTIR and TG/DTG studies; Dr. Nick Laycock and Dr. Abitha Ramesh (Qatar Shell Research and Technology Centre) for the helpful technical guidance. Statements made herein are solely the responsibility of the authors.Scopu