resumo
The dissimilarities and features of the crystal structure of ZnAl LDH-NO3 conversion layers grown directly on pure zinc and aluminum alloy 2024 were investigated in the present paper. Although the nature of the cations in the double hydroxides are the same in both cases (Al3+ and Zn2+), their sources differ according to the substrate. This leads to a difference in the cationic layers and interlayer structure, which consequently influences the anionic exchange reaction. In the frame of this work, the kinetics of the anion-exchange of nitrate by chloride was investigated as well as the crystal structure of the resulting ZnAl LDH-Cl on both substrates. Synchrotron high-resolution X-ray diffraction was the main method to obtain structural information and was supported by additional calculations and scanning electron microscopy. The current study revealed noticeable changes on the positioning of the interlayer atoms for the ZnAl-LDH-Cl on zinc in comparison with the ones on AA2024 substrate.
palavras-chave
LAYERED DOUBLE HYDROXIDES; CORROSION PROTECTION; CONVERSION COATINGS; MAGNESIUM ALLOY; ALUMINUM-ALLOYS; SMART COATINGS; FILMS; DIFFRACTION; RESISTANCE; PROGRAM
categoria
Chemistry; Materials Science; Physics
autores
Bouali, AC; Iuzviuk, MH; Serdechnova, M; Yasakau, KA; Wieland, DCF; Dovzhenko, G; Maltanava, H; Zobkalo, IA; Ferreira, MGS; Zheludkevich, ML
nossos autores
Kiryl Yasakau
Investigador Auxiliar
Maria Serdechnova
Bolseiro de pós-Doutoramento
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)Projectos
Projeto de Investigação Exploratória: Kyril Yasakao (IF/01284/2015)
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
MULTI-functional metallic SURFaces via active Layered Double Hydroxide treatments (MULTISURF)
agradecimentos
We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III under the proposal number I-20170366. We would like to thank Dr. Sergey Volkov for assistance in using the diffractometer in P08 high-resolution diffraction beamline.; A.C.B and M.H.I are grateful for the financial support of the German-Russian Interdisciplinary Science Center (G-RISC) in form of a travel grant (T-2018b-1 and T-2018a-3 respectively) that enables them to perform a scientific exchange and complete this work.; K.Y. thanks financial support of a researcher grant (IF/01284/2015) and the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES, and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.; M.S. and M.L.Z. are thankful to I2B fond for financial support of this work in frame of MUFfin project as well as the ACTICOAT project (Era.Net RUS Plus Call 2017, Project 477). This research was also partially supported by the European project MULTISURF MULTIfunctional metallic SURFaces via active Layered Double Hydroxide treatments (REA-Horizon2020-RISE-645676).