SYNTHESIS OF METAL AND METAL OXIDE NANOPARTICLES IN THE NANOSPACE OF ULTRATHIN TiO2-Gel FILMS: ROLE OF THE ION-EXCHANGE SITE

2002 ◽  
Vol 01 (05n06) ◽  
pp. 507-513
Author(s):  
JUNHUI HE ◽  
IZUMI ICHINOSE ◽  
SHIGENORI FUJIKAWA ◽  
TOYOKI KUNITAKE
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Metal Oxide Nanoparticles ◽  
Current Approach ◽  
Metal Salts ◽  
Lanthanide Elements ◽  
Exchange Site ◽  
Probable Distribution ◽  
Tio2 Gel

In this work, we showed that metal salts were easily deposited as aggregates (e.g., ultrathin planar microcrystals) on the surface of TiO 2- gel films in the absence of ion-exchange sites. In contrast, metal ions were efficiently incorporated into ultrathin TiO 2- gel films, when ion-exchange sites were created using Mg ( O - Et )2 as template. A variety of metal ions, including those of main group, transition, and lanthanide elements were successfully doped into TiO 2 thin films by the current approach. Probable distribution of the ion-exchange site in the film interior was discussed.

The Role of Metal Salts in a Solid Phase β-Selective Epoxidation of Δ5-steroids with Potassium Permanganate

2002 ◽  
Vol 2002 (11) ◽  
pp. 576-578 ◽  
Author(s):  
Jorge A.R. Salvador ◽  
James R. Hanson
Keyword(s):  
Metal Ions ◽  
Potassium Permanganate ◽  
Solid Phase ◽  
Metal Salts ◽  
Epoxide Formation

Epoxidation of Δ5-steroids with a potassium permanganate and a range of metal salts in the solid phase gives the 5β, 6β-epoxides. The results have been rationalised in terms of the oxophilic metal ions favouring epoxide formation in the collapse of a manganate intermediate.

Adaptive Role of Lipids in Algae under Metal Ions Impact (a Review)

2018 ◽  
Vol 54 (6) ◽  
pp. 78-93
Author(s):  
V. V. Grubinko ◽  
O. I. Bodnar ◽  
A. I. Lutsiv ◽  
G. B. Viniarska
Keyword(s):  
Metal Ions ◽  
Adaptive Role

Synergistic Methodology Based on Ion Exchange and Biodegradation Mechanisms Applied for Metal Complex Dye Removal from Waste Waters

2018 ◽  
Vol 69 (1) ◽  
pp. 38-44
Author(s):  
Nicoleta Mirela Marin ◽  
Olga Tiron ◽  
Luoana Florentina Pascu ◽  
Mihaela Costache ◽  
Mihai Nita Lazar ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Synergistic Effects ◽  
Freundlich Isotherm ◽  
White Rot ◽  
White Rot Fungus ◽  
Basic Anion Exchange Resin ◽  
Km Value ◽  
Points Of View ◽  
Basic Anion

This study investigates the synergistic effects of ion exchange and biodegradation methods to remove the Acid Blue 193 also called Gryfalan Navy Blue RL (GNB) dye from wastewater. Ion exchange studies were performed using a strongly basic anion exchange resin Amberlite IRA 400. The equilibrium was characterized by a kinetic and thermodynamic points of view, establishing that the sorption of the GNB dye was subject to the Freundlich isotherm model with R2 = 0.8710. Experimental results showed that the activated resin can removed up to 93.4% when the concentration of dye solution is 5.62�10-2 mM. The biodegradation of the GNB was induced by laccase, an enzyme isolated from white-rot fungus. It was also analyzed the role of pH and dye concentration on GNB biodegradation, so 5�10-2 mM dye had a maximum discoloration efficiency of 82.9% at pH of 4. The laccase showed a very fast and robust activity reaching in a few minutes a Km value of 2.2�10-1mM. In addition, increasing the GNB concentration up to 8�10-1 mM did not triggered a substrat inhibition effect on the laccase activity. Overall, in this study we proposed a mixt physicochemical and biological approach to enhance the GNB removal and biodegradability from the wastewaters and subsequently the environment.

The role of ion exchange membrane in vanadium oxygen fuel cell

2021 ◽  
Vol 629 ◽  
pp. 119271
Author(s):  
Jiří Charvát ◽  
Petr Mazúr ◽  
Martin Paidar ◽  
Jaromír Pocedič ◽  
Jiří Vrána ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Ion Exchange ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Oxygen Fuel

scholarly journals The Role of the Disulfide Bridge in the Copper (II) Binding by the Cyclic His4-Peptide

2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń
Keyword(s):  
Metal Ions ◽  
Coordination Mode ◽  
Transition Metal Ions ◽  
Disulfide Bridge ◽  
Chain Flexibility ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Cd Studies ◽  
Metal Ratios

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.

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