Design and fabrication of enhanced corrosion resistance Zn-Al layered double hydroxides films based anion-exchange mechanism on magnesium alloys

2017 ◽  
Vol 404 ◽  
pp. 246-253 ◽  
Author(s):  
Meng Zhou ◽  
Luchun Yan ◽  
Hao Ling ◽  
Yupeng Diao ◽  
Xiaolu Pang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Anion Exchange ◽  
Magnesium Alloys ◽  
Layered Double Hydroxides ◽  
Exchange Mechanism ◽  
Double Hydroxides

scholarly journals Anticorrosion Performance of LDH Coating Prepared by CO2 Pressurization Method

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaochen Zhang ◽  
Peng Jiang ◽  
Chunyan Zhang ◽  
Bateer Buhe ◽  
Bin Liu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Layered Double Hydroxides ◽  
Atmospheric Pressure ◽  
Az91d Alloy ◽  
Cross Sectional ◽  
Anticorrosion Performance ◽  
Double Hydroxides ◽  
First Time

Many surface treatment methods are used to improve the corrosion resistance of magnesium alloys. LDH (layered double hydroxides) conversion coatings are currently found in the most environmentally friendly and pollution-free coatings of magnesium alloy. In this study, the CO2 pressurization method was applied to the preparation of LDH coating on magnesium alloy for the first time. The effect of CO2 pressurization on the formation and corrosion resistance of LDH coating on AZ91D alloy was investigated. The hardness and adhesion were significantly higher on LDH coating in the case of CO2 pressurization than it is in atmospheric pressure. The surface and cross-sectional morphologies show that LDH coating is more compact in the case of CO2 pressurization than with atmospheric pressure. The results of the polarization curve, hydrogen evolution, and immersion tests indicate that the corrosion resistance of the LDH coating prepared by the CO2 pressurization method was significantly improved.

Anion-exchange reactions of layered double hydroxides

1990 ◽  
Vol 29 (26) ◽  
pp. 5201-5207 ◽  
Author(s):  
Martina Meyn ◽  
Klaus Beneke ◽  
Gerhard Lagaly
Keyword(s):  
Anion Exchange ◽  
Layered Double Hydroxides ◽  
Exchange Reactions ◽  
Double Hydroxides

scholarly journals Liquid phase exfoliation of carbonate-intercalated layered double hydroxides

2019 ◽  
Vol 55 (23) ◽  
pp. 3315-3318 ◽  
Author(s):  
Jose A. Carrasco ◽  
Andrew Harvey ◽  
Damien Hanlon ◽  
Vicent Lloret ◽  
Dave McAteer ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Anion Exchange ◽  
Layered Double Hydroxides ◽  
Exchange Reactions ◽  
Liquid Phase Exfoliation ◽  
Double Hydroxides

Direct exfoliation of carbonate layered double hydroxides has been achieved by using a novel horn-probe sonic tip, avoiding the development of time-consuming anion-exchange reactions.

Synthesis and Anion Exchange Chemistry of Rhombohedral Li/Al Layered Double Hydroxides

2002 ◽  
Vol 14 (1) ◽  
pp. 232-234 ◽  
Author(s):  
Andrew M. Fogg ◽  
Amal J. Freij ◽  
Gordon M. Parkinson
Keyword(s):  
Anion Exchange ◽  
Layered Double Hydroxides ◽  
Double Hydroxides

Synthesis of a novel layered double hydroxides [MgAl4(OH)12](Cl)2·2.4H2O and its anion-exchange properties

2011 ◽  
Vol 185 (2-3) ◽  
pp. 1435-1439 ◽  
Author(s):  
Ramesh Chitrakar ◽  
Yoji Makita ◽  
Akinari Sonoda ◽  
Takahiro Hirotsu
Keyword(s):  
Anion Exchange ◽  
Layered Double Hydroxides ◽  
Double Hydroxides ◽  
Exchange Properties

Structural and microstructural changes during anion exchange of CoAl layered double hydroxides: anin situX-ray powder diffraction study

2010 ◽  
Vol 43 (3) ◽  
pp. 434-447 ◽  
Author(s):  
Rune E. Johnsen ◽  
Frank Krumeich ◽  
Poul Norby
Keyword(s):  
Phase Transformation ◽  
Exchange Reaction ◽  
Anion Exchange ◽  
Powder Diffraction ◽  
Layered Double Hydroxides ◽  
Two Phase ◽  
X Ray ◽  
Double Hydroxides ◽  
Anion Exchange Reaction

Anion-exchange processes in cobalt–aluminium layered double hydroxides (LDHs) were studied byin situsynchrotron X-ray powder diffraction (XRPD). The processes investigated were CoAl–CO3→ CoAl–Cl → CoAl–CO3, CoAl–Cl → CoAl–NO3and CoAl–CO3→ CoAl–SO4. The XRPD data show that the CoAl–CO3→ CoAl–Cl process is a two-phase transformation, where the amount of the CoAl–CO3phase decreases exponentially while that of the CoAl–Cl phase increases exponentially. Energy-dispersive X-ray spectroscopy (EDXS) studies of a partially chloride-exchanged CoAl–CO3LDH sample along within situXRPD data suggested that the individual particles in the CoAl–CO3sample are generally anion-exchanged with chloride one at a time. In contrast with the CoAl–CO3→ CoAl–Cl transformation, the XRPD data show that the reverse CoAl–Cl → CoAl–CO3process is a one-phase transformation. Rietveld refinements indicate that the occupancy factors of the carbon and oxygen sites of the carbonate group increase, while that of the chloride site decreases. In the CoAl–Cl → CoAl–NO3anion-exchange reaction, the XRPD patterns reveal the existence of two intermediate phases in addition to the initial CoAl–Cl and final CoAl–NO3phases. Thein situdata indicate that one of these intermediates is a mixed nitrate- and chloride-based LDH phase, where the disorder decreases as the nitrate content increases. The XRPD data of the partial CoAl–CO3→ CoAl–SO4anion-exchange reaction show that the process is a two-phase transformation involving a sulfate-containing LDH with a 1H polytype structure.

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