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

scholarly journals Recent Advances on the Application of Layered Double Hydroxides in Concrete—A Review

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1426
Author(s):  
Zahid M. Mir ◽  
Alexandre Bastos ◽  
Daniel Höche ◽  
Mikhail L. Zheludkevich
Keyword(s):  
Layered Double Hydroxides ◽  
Economic Losses ◽  
Recent Past ◽  
New Class ◽  
Recent Advances ◽  
Chloride Resistance ◽  
Potential Applications ◽  
Balanced Structure ◽  
Double Hydroxides ◽  
Positively Charged

The issue of chloride induced corrosion of reinforced concrete is a serious problem affecting infrastructure globally and causing huge economic losses. As such this issue has gained a considerable attention in the scientific community in the recent past. Layered Double Hydroxides (LDHs) have recently emerged as a new class of concrete-additives with a potential to increase the chloride resistance of concrete and mitigate corrosion. LDHs are clay like structures consisting of positively charged layers of cations with associated hydroxides and exchangeable anions in between the layers. Due to this charge balanced structure, LDHs possess the property of encapsulating an anion from the environment and replacing it with an exchangeable anion present in its layers. Potential applications include chloride entrapment in concrete and delivery of corrosion inhibiting anions. However, many versatile compositions of LDHs can be easily synthesized and their application as cement additives reach far beyond corrosion mitigation in concrete. This review presents a summary of recent advances on the applications of LDH in concrete. An extensive set of recently published literature has been critically reviewed and trends have been identified.

Layered Double Hydroxides-Based Materials as Oxidation Catalysts

2017 ◽  
pp. 59-121 ◽  
Author(s):  
Ioan-Cezar Marcu ◽  
Adriana Urdă ◽  
Ionel Popescu ◽  
Vasile Hulea
Keyword(s):  
Volatile Organic Compounds ◽  
Transition Metal ◽  
Organic Compounds ◽  
Selective Oxidation ◽  
Layered Double Hydroxides ◽  
Complete Oxidation ◽  
Oxidation Catalysts ◽  
Volatile Organic ◽  
Potential Applications ◽  
Double Hydroxides

This chapter is focused on the transition-metal-containing LDHs-based materials having potential applications in both catalytic selective oxidation for obtaining chemicals and intermediates, and complete oxidation as a promising valuable technology for the destruction of Volatile Organic Compounds (VOCs).

scholarly journals Mg-Fe Layered Double Hydroxides Enhance Surfactin Production in Bacterial Cells

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 355 ◽  
Author(s):  
Pei-Hsin Chang ◽  
Si-Yu Li ◽  
Tzong-Yuan Juang ◽  
Yung-Chuan Liu
Keyword(s):  
Layered Double Hydroxides ◽  
Time Course ◽  
Effective Means ◽  
Scale Up ◽  
Molar Ratio ◽  
Bacterial Cells ◽  
High Productivity ◽  
Potential Applications ◽  
Surfactin Production ◽  
Double Hydroxides

In this study, four additives—montmorillonite, activated carbon, and the layered double hydroxides (LDHs), Mg2Fe–LDH and Mg2Al–LDH—were tested for their ability to promote surfactin production in a Bacillus subtilis ATCC 21332 culture. Among these tested materials, the addition of 4 g/L of the Mg-Fe LDH, which featured an Mg/Fe molar ratio of 2:1, produced the highest surfactin yield of 5280 mg/L. During the time course of B. subtilis cultivation with the added LDH, two phases of cell growth were evident: Growth and decay. In the growth phase, the cells grew slowly and secreted a high amount of surfactin; in the decay phase, the cells degraded rapidly. The production in the presence of the Mg2Fe–LDH had three characteristics: (i) High surfactin production at low biomass, indicating a high specific surfactin yield of 3.19 g/g DCW; (ii) rapid surfactin production within 24 h, inferring remarkably high productivity (4660 mg/L/d); and (iii) a lower carbon source flux to biomass, suggesting an efficient carbon flux to surfactin, giving a high carbon yield of 52.8%. The addition of Mg2Fe–LDH is an effective means of enhancing surfactin production, with many potential applications and future industrial scale-up.

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.

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