Adsorption of Cu(II), Pb(II) by Mg^|^#8211;Al Layered Double Hydroxides (LDHs): Intercalated with the Chelating Agents EDTA and EDDS

2014 ◽  
Vol 47 (4) ◽  
pp. 324-328 ◽  
Author(s):  
Shuang Zhang ◽  
Naoki Kano ◽  
Hiroshi Imaizumi
Keyword(s):  
Layered Double Hydroxides ◽  
Chelating Agents ◽  
Double Hydroxides

scholarly journals Layered Double Hydroxides as Effective Adsorbents for U(VI) and Toxic Heavy Metals Removal from Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
G. N. Pshinko
Keyword(s):  
Heavy Metals ◽  
Layered Double Hydroxides ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Aqueous Media ◽  
Water Soluble ◽  
Toxic Heavy Metals ◽  
Metals Removal ◽  
The Stability ◽  
Double Hydroxides

Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH)12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and hexamethylenediaminetetraacetic acid (HMDTA)) and heat-treated form Zn4Al2O7, to adsorb uranium(VI) and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to correlate with the stability of their complexes with the mentioned chelating agents in a solution. The synthesized layered double hydroxides (LDHs) containing chelating agents in the interlayer space are rather efficient for sorption purification of aqueous media free from U(VI) irrespective of its forms of natural abundance (including water-soluble bi- and tricarbonate forms) and from heavy metal ions. [Zn4Al2(OH)12]·EDTA·nH2O is recommended for practical application as one of the most efficient and inexpensive synthetic adsorbents designed for recovery of both cationic and particularly important anionic forms of U(VI) and other heavy metals from aqueous media. Carbonate forms of LDHs turned out to be most efficient for recovery of Cu(II) from aqueous media withpH0≥7owing to precipitation of Cu(II) basic carbonates and Cu(II) hydroxides. Chromate ions are efficiently adsorbed from water only by calcinated forms of LDHs.

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

Antibiotic-anionic Clay Matrix Used for Drug Controlled Release

2018 ◽  
Vol 69 (2) ◽  
pp. 321-323
Author(s):  
Georgeta Zegan ◽  
Elena Mihaela Carausu ◽  
Loredana Golovcencu ◽  
Alina Sodor Botezatu ◽  
Eduard Radu Cernei ◽  
...  
Keyword(s):  
Controlled Release ◽  
Layered Double Hydroxides ◽  
Bioactive Molecules ◽  
Drug Controlled Release ◽  
Anionic Clays ◽  
Anionic Clay ◽  
Toxicological Studies ◽  
High Efficient ◽  
Clay Matrix ◽  
Double Hydroxides

Anionic clay matrix acting as drug controlled release system have shown in last years a great potential for delivery of bioactive molecules and chemical therapeutics. This organic-inorganic nanohybrid system is high efficient offering an excellent protection of intercalated compounds from degradation. Compared to other nanoparticles used in medical area, anionic clays type layered double hydroxides have found to be biocompatible according to toxicological studies. Ampicillin containing MgAlLDHs and ZnAlLDH samples have been prepared following two routes: anion-exchange procedure and reconstruction from calcined layered double hydroxides. Solid samples have been characterized by FTIR and SEM-EDX highlighting the alteration of pristine LDHs structure when the antibiotic is introduced in the interlayer gallery.

Nanohybrid Enzymes - Layered Double Hydroxides: Potential Applications

2006 ◽  
Vol 2 (3) ◽  
pp. 283-294 ◽  
Author(s):  
Claude Forano ◽  
Stephanie Vial ◽  
Christine Mousty
Keyword(s):  
Layered Double Hydroxides ◽  
Potential Applications ◽  
Double Hydroxides
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