scholarly journals Influence of Vitamin B3 Intercalated Layered Double Hydroxides (VB3-LDHs) on the Corrosion of Steel Bars in Cement Mortar

2021 ◽  
pp. 210362
Author(s):  
Heng Yang ◽  
Keyword(s):  
Layered Double Hydroxides ◽  
Cement Mortar ◽  
Vitamin B3 ◽  
Steel Bars ◽  
Corrosion Of Steel ◽  
Double Hydroxides

Hexacyanoferrate-Intercalated Layered Double Hydroxides as Nanoadditives for the Detection of Early-Stage Corrosion of Steel: The Revival of Prussian blue

2020 ◽  
Vol 2020 (21) ◽  
pp. 2063-2073
Author(s):  
Manon Wilhelm ◽  
Marcela C. Quevedo ◽  
Alesia Sushkova ◽  
Tiago L. P. Galvão ◽  
Alexandre Bastos ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Layered Double Hydroxides ◽  
Early Stage ◽  
Corrosion Of Steel ◽  
Double Hydroxides

scholarly journals Electrochemical Study of Clean and Pre-Corroded Reinforcements Embedded in Mortar Samples with Variable Amounts of Chloride Ions

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6883
Author(s):  
María de las Nieves González ◽  
María Isabel Prieto ◽  
Alfonso Cobo ◽  
Fernando Israel Olmedo
Keyword(s):  
Corrosion Potential ◽  
Cement Mortar ◽  
Electrochemical Techniques ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Corrosion Products ◽  
The Other ◽  
Steel Bars ◽  
One Year ◽  
Corrosion Of Steel

The present study investigates the possibility of re-surfacing previously corroded reinforcements and the suitability of the two electrochemical techniques that are widely used to determine the state of corrosion of steel (the corrosion potential Ecorr and the corrosion rate icorr). In order to test this, 32 pre-corroded B500SD reinforcing steel bars have been used for one year, where half of the bars have been cleaned to eliminate corrosion products. The other half have been maintained with the generated corrosion products. Subsequently, the bars have been embedded in cement mortar samples with variable amounts of chloride ion, and Ecorr and icorr have been measured for 250 days. The results showed that it is not possible to rework the reinforcement without removing corrosion products and that it is not possible to predict the passive or active state of steel by measuring Ecorr only.

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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