scholarly journals Electrochemical Behaviour Of Ferrocene/Ferricinium Redox System In Pure And CO2 Saturated [C6MIM][PF6]

2012 ◽  
Vol 11 (2) ◽  
pp. 53
Author(s):  
Sebastien Chanfreau ◽  
Liang-Nian He ◽  
Bing Yu

The electrochemical behaviour of ferrocene has been studied in green solvent combining pure ionic liquid and CO2. Experimental results were achieved for the Fc/Fc+ (ferrocene/ferricinium ion) oxidation/reduction in pure and CO2 saturated 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) over the temperature range from 298.15 K to 323.15 K. Peak shaped voltammograms were obtained and usual electrochemical parameters were calculated in order to classify electron process at the electrode. Diffusion coefficients of electroactive species were determined in the order of 10-11 m2 s-1 using the Randles–Ševcík relationship. Mass transport was also favoured by both increases in temperature and dilution of CO2 in the media.

Author(s):  
X.Q. Zhang ◽  
M.J. Chen ◽  
H.H. Wang ◽  
X.X. Wen ◽  
C.F. Liu ◽  
...  

Heterocycles ◽  
2009 ◽  
Vol 78 (8) ◽  
pp. 2013 ◽  
Author(s):  
Zhang-Gao Le ◽  
Tao Zhong ◽  
Zong-Bo Xie ◽  
Jian-Ping Xu

Holzforschung ◽  
2019 ◽  
Vol 73 (5) ◽  
pp. 509-516 ◽  
Author(s):  
Jenny Bengtsson ◽  
Kerstin Jedvert ◽  
Artur Hedlund ◽  
Tobias Köhnke ◽  
Hans Theliander

Abstract Lignin, a substance considered as a residue in biomass and ethanol production, has been identified as a renewable resource suitable for making inexpensive carbon fibers (CFs), which would widen the range of possible applications for light-weight CFs reinforced composites. Wet spinning of lignin-cellulose ionic liquid solutions is a promising method for producing lignin-based CFs precursors. However, wet-spinning solutions containing lignin pose technical challenges that have to be solved to enable industrialization. One of these issues is that a part of the lignin leaches into the coagulation liquid, which reduces yield and might complicate solvent recovery. In this work, the mass transport during coagulation is studied in depth using a model system and trends are confirmed with spinning trials. It was discovered that during coagulation, efflux of ionic liquid is not hindered by lignin concentration in solution and the formed cellulose network will enclose soluble lignin. Consequently, a high total concentration of lignin and cellulose in solution is advantageous to maximize yield. This work provides a fundamental understanding on mass transport during coagulation of lignin-cellulose solutions, crucial information when designing new solution-based fiber forming processes.


2020 ◽  
Vol 73 (11) ◽  
pp. 1080
Author(s):  
Laura Sanchez-Cupido ◽  
Jennifer M. Pringle ◽  
Amal Siriwardana ◽  
Cristina Pozo-Gonzalo ◽  
Maria Forsyth

Electrodeposition using ionic liquids has emerged as an environmentally friendly approach to recover critical metals, such a neodymium. The investigation of ionic liquid chemistries and compositions is an important part of the move towards efficient neodymium recovery from end-of-life products that needs further research. Thus, in this paper we have investigated a series of phosphonium ionic liquids as potential electrolytic media. Anions such as bis(trifluoromethylsulfonyl)imide (TFSI), dicyanamide (DCA), and triflate (TfO) have been investigated, in combination with short- and long-alkyl-chain phosphonium cations. The work here suggests that [TFSI]– is one of the most promising anions for successful deposition of Nd and that water plays an important role. In contrast, electrochemical behaviour was significantly hindered in the case of DCA ionic liquid, most likely owing to strong coordination between [DCA]– and Nd3+. Mixtures of anions, [TfO]– and [TFSI]–, have also been investigated in this work, resulting in two reduction processes that could be related to a different deposition mechanism involving two steps, as observed in the case of dysprosium or, alternatively, different coordination environments that have distinct deposition potentials. Additionally, we investigated the influence of electrode substrates – glassy carbon and copper. Cu electrodes resulted in the largest current densities and thus were used for subsequent electrodeposition at constant potential. These findings are valuable for optimising the deposition of Nd in order to develop more efficient and inexpensive recycling technologies for rare earth metals.


2000 ◽  
Vol 6 (4) ◽  
pp. 429-450
Author(s):  
R. Kriegel ◽  
A. Buchwald ◽  
Ch. Kaps

Abstract The diffusive mass transport in materials is above all determined by the material structure. The experimental determination of diffusion coefficients is based on diffusion models, which results from special mathematical solutions of Fick's second law and its corresponding boundary conditions. The general usefulness of these diffusion models will be described using some examples, e. g. the diffusion of deteriorating salts in masonry materials, the oxygen ion diffusion in mixed conducting ceramics and the cation exchange in single crystals. The measurement of the diffusion coefficients results in a better comprehension of the transport mechanism as well as of the "morphology" of the transport medium, which allows to optimize the conditions of the mass transport and the material structure and composition, respectively.


RSC Advances ◽  
2014 ◽  
Vol 4 (17) ◽  
pp. 8431-8438 ◽  
Author(s):  
Sadegh Khazalpour ◽  
Davood Nematollahi

Electrochemical behaviour of resazurin in aqueous buffered solutions and ionic liquid was studied. The orientation of adsorbed resazurin was estimated. It is found that, the orientation of the adsorbed resazurin at glassy carbon surface is edgewise.


2000 ◽  
Vol 78 (9) ◽  
pp. 1170-1177 ◽  
Author(s):  
Ibrahim S El-Hallag ◽  
Gad B El-Hefnawy ◽  
Youssef I Moharram ◽  
Enass M Ghoneim

The electrochemical behaviour of Schiff base compounds derived from an antipyrine nucleus was investigated in 30% (v/v) ethanolic buffer solutions (pH 3-11) using various electrochemical techniques at mercury electrode. The results showed that, the total limiting current of each of the studied compounds corresponds to 2-electron transfer process. The mechanistic pathway of the electrode reaction of the investigated compounds at mercury electrode, the effect of the medium, and the evaluation of the electrode reaction parameters were illustrated and discussed.Key words: Schiff base, antipyrine nucleus, electrode reaction, electrochemical parameters, cyclic voltammetry.


2015 ◽  
Vol 273 ◽  
pp. 668 ◽  
Author(s):  
Swapnil L. Fegade ◽  
Jason P. Trembly
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document