One-electron redox kinetics of aqueous transition metal couples Zn2+/+, Co2+/+, and Ni2+/+ using pulse radiolysis

2020 ◽  
Vol 22 (34) ◽  
pp. 19046-19058 ◽  
Author(s):  
Alexandra Lisovskaya ◽  
Kotchaphan Kanjana ◽  
David M. Bartels

The one-electron redox potentials for aqueous metal couples Co2+/+ and Ni2+/+ have been investigated by pulse radiolysis using their reactions with a series of reference compounds to establish the most positive upper limits of E0.

1973 ◽  
Vol 26 (11) ◽  
pp. 2533 ◽  
Author(s):  
R Chant ◽  
AR Hendrickson ◽  
RL Martin ◽  
NM Rohde

The one-electron oxidation and reduction processes for some 80 dithiocarbamates of Cr, Mn, Fe, Co, Ni, and Cu reveal a marked dependence of redox potential on the metal 3dn electron configuration. For all the complexes examined, the relative ordering of the redox potentials with the dithiocarbamate substituents is remarkably consistent for both oxidation and reduction processes.


2001 ◽  
Vol 105 (25) ◽  
pp. 6102-6108 ◽  
Author(s):  
Mona Treguer ◽  
Hynd Remita ◽  
Pascal Pernot ◽  
Jamal Khatouri ◽  
Jacqueline Belloni

1979 ◽  
Author(s):  
Jan Hermans

Measurements of light scattering have given much information about formation and properties of fibrin. These studies have determined mass-length ratio of linear polymers (protofibrils) and of fibers, kinetics of polymerization and of lateral association and volume-mass ratio of thick fibers. This ratio is 5 to 1. On the one hand, this high value suggests that the fiber contains channels that allow the diffusion of enzymes such as Factor XHIa and plasmin; on the other hand, the high value appears paradoxical for a stiff fiber made up of elongated units (fibrin monomers) arranged in parallel. Such a high fiber volume is a property of only a small set out of many high-symmetry models of fibrin, which may be constructed from overlapping three-domain monomers which are arranged into strands, are aligned nearly parallel to the fiber axis and make adequate longitudinal and lateral contacts. These models contain helical protofibrils related to each other by rotation axes parallel to the fiber axis. The protofibrils may contain 2, 3 or 4 monomers per helical turn and there are four possible symmetries. A large specific volume is achieved if the ends of each monomer are slightly displaced from the protofibril axis, either by a shift or by a tilt of the monomer. The fiber containing tilted monomers is more highly interconnected; the two ends of a tilted monomer form lateral contacts with different adjacent protofibrils, whereas the two ends of a non-tilted monomer contact the same adjacent protofibril(s).


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.


2021 ◽  
Author(s):  
Wei Zhang ◽  
Qiang Wu ◽  
Ziqi Zeng ◽  
Chuang Yu ◽  
Shijie Cheng ◽  
...  

A soluble organoselenide compound, phenyl diselenide (PDSe), is employed as a soluble electrolyte additive to enhance the kinetics of sulfurized polyacrylonitrile cathode, in which radical exchange in the solid-liquid interface...


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 723
Author(s):  
Mahesh Muraleedharan Nair ◽  
Stéphane Abanades

The CeO2/CeO2−δ redox system occupies a unique position as an oxygen carrier in chemical looping processes for producing solar fuels, using concentrated solar energy. The two-step thermochemical ceria-based cycle for the production of synthesis gas from methane and solar energy, followed by CO2 splitting, was considered in this work. This topic concerns one of the emerging and most promising processes for the recycling and valorization of anthropogenic greenhouse gas emissions. The development of redox-active catalysts with enhanced efficiency for solar thermochemical fuel production and CO2 conversion is a highly demanding and challenging topic. The determination of redox reaction kinetics is crucial for process design and optimization. In this study, the solid-state redox kinetics of CeO2 in the two-step process with CH4 as the reducing agent and CO2 as the oxidizing agent was investigated in an original prototype solar thermogravimetric reactor equipped with a parabolic dish solar concentrator. In particular, the ceria reduction and re-oxidation reactions were carried out under isothermal conditions. Several solid-state kinetic models based on reaction order, nucleation, shrinking core, and diffusion were utilized for deducing the reaction mechanisms. It was observed that both ceria reduction with CH4 and re-oxidation with CO2 were best represented by a 2D nucleation and nuclei growth model under the applied conditions. The kinetic models exhibiting the best agreement with the experimental reaction data were used to estimate the kinetic parameters. The values of apparent activation energies (~80 kJ·mol−1 for reduction and ~10 kJ·mol−1 for re-oxidation) and pre-exponential factors (~2–9 s−1 for reduction and ~123–253 s−1 for re-oxidation) were obtained from the Arrhenius plots.


2014 ◽  
Vol 16 (6) ◽  
pp. 2297-2304 ◽  
Author(s):  
Koffi P. C. Yao ◽  
Yi-Chun Lu ◽  
Chibueze V. Amanchukwu ◽  
David G. Kwabi ◽  
Marcel Risch ◽  
...  

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