A Study of the Anion Exchange in Layered Double Hydroxides with the Use of a Tritium Label

2004 ◽  
Vol 396 (1-3) ◽  
pp. 95-98
Author(s):  
A. V. Lukashin ◽  
E. V. Lukashina ◽  
A. A. Eliseev ◽  
G. A. Badun ◽  
Yu. D. Tret'yakov
1990 ◽  
Vol 29 (26) ◽  
pp. 5201-5207 ◽  
Author(s):  
Martina Meyn ◽  
Klaus Beneke ◽  
Gerhard Lagaly

2019 ◽  
Vol 55 (23) ◽  
pp. 3315-3318 ◽  
Author(s):  
Jose A. Carrasco ◽  
Andrew Harvey ◽  
Damien Hanlon ◽  
Vicent Lloret ◽  
Dave McAteer ◽  
...  

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.


2002 ◽  
Vol 14 (1) ◽  
pp. 232-234 ◽  
Author(s):  
Andrew M. Fogg ◽  
Amal J. Freij ◽  
Gordon M. Parkinson

2011 ◽  
Vol 185 (2-3) ◽  
pp. 1435-1439 ◽  
Author(s):  
Ramesh Chitrakar ◽  
Yoji Makita ◽  
Akinari Sonoda ◽  
Takahiro Hirotsu

2010 ◽  
Vol 43 (3) ◽  
pp. 434-447 ◽  
Author(s):  
Rune E. Johnsen ◽  
Frank Krumeich ◽  
Poul Norby

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.


2010 ◽  
Vol 195 (19) ◽  
pp. 6500-6503 ◽  
Author(s):  
Kohei Miyazaki ◽  
Takeshi Abe ◽  
Koji Nishio ◽  
Haruyuki Nakanishi ◽  
Zempachi Ogumi

2019 ◽  
Vol 98 ◽  
pp. 09005
Author(s):  
Elisabetta Dore ◽  
Franco Frau

Carbonate Layered Double Hydroxides (LDHs) with different cationic composition and M2+/M3+ molar ratio were tested, both untreated and calcined, for water defluoridation. The defluoridation capacity of calcined LDHs, produced by intercalation during the reconstruction of lamellar structure, is more effective than the anion exchange of untreated LDHs. Among the calcined LDHs tested, that with 3Mg/(0.5Al+0.5Fe) molar ratio yields a maximum fluoride sorption capacity up to 92.3 mg/g, in spite of the high pH value (up to 12) of the experiments. After four cycles of regeneration by calcination and subsequent water defluoridation, this LDH composition maintains more than 80% of its fluoride removal capacity.


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