The chemical stability of phosphonium-based ionic liquids under gamma irradiation

RSC Advances ◽  
2015 ◽  
Vol 5 (36) ◽  
pp. 28570-28581 ◽  
Author(s):  
Ryan P. Morco ◽  
Jiju M. Joseph ◽  
J. Clara Wren
Keyword(s):  
Ionic Liquids ◽  
Gamma Irradiation ◽  
Raman Spectra ◽  
Chemical Stability ◽  
Irradiation Time

Photographs of irradiated [P14666][dca] and the corresponding UV-vis and Raman spectra, and conductivities as a function of irradiation time. Black, blue and red lines are for 0, 96 and 192 h of irradiation, respectively.

Thermodynamics kinetics of boron carbide under gamma irradiation dose

2019 ◽  
Vol 33 (09) ◽  
pp. 1950073 ◽  
Author(s):  
Matlab Mirzayev ◽  
Ertugrul Demir ◽  
Khagani Mammadov ◽  
Ravan Mehdiyeva ◽  
Sakin Jabarov ◽  
...  
Keyword(s):  
Activation Energy ◽  
Boron Carbide ◽  
Gamma Irradiation ◽  
Irradiation Time ◽  
Energy Levels ◽  
Initial State ◽  
Scanning Calorimetry ◽  
Gas Atmosphere ◽  
Quantitative Changes ◽  
Kinetics Of

In this paper, high purity boron carbide samples were irradiated by [Formula: see text]Co gamma radioisotope source (0.27 Gy/s dose rate) with 50, 100, 150 and 200 irradiation hours at room-temperature. The unirradiated and irradiated boron carbide samples were heated from 30[Formula: see text]C to 1000[Formula: see text]C at a heating rate of 5[Formula: see text]C/min under the argon gas atmosphere of flow rate 20 ml/min. Thermogravimetric (TG) and Differential Scanning Calorimetry (DSC) were carried out in order to understand the thermodynamic kinetics of boron carbide samples. The weight kinetics, activation energy and specific heat capacity of the unirradiated and irradiated boron carbide samples were examined in two parts, T [Formula: see text] 650[Formula: see text]C and T [Formula: see text] 650[Formula: see text]C, according to the temperature. The dynamic of quantitative changes in both ranges is different depending on the irradiation time. While the phase transition of unirradiated boron carbide samples occurs at 902[Formula: see text]C, this value shifts upto 940[Formula: see text]C in irradiated samples depending on the irradiation time. The activation energy of the unirradiated boron carbide samples decreased from 214 to 46 J/mol in the result of 200[Formula: see text]h gamma irradiation. The reduction of the activation energy after the irradiation compared to the initial state shows that the dielectric properties of the irradiated boron carbide samples have been improved. After the gamma irradiation, two energy barrier states depending on the absorption dose of samples were formed in the irradiated samples. The first and second energy barriers occurred in 0.56–0.80 and 0.23–0.36 eV energy intervals, respectively. The existence of two energy levels in the irradiated boron carbide indicates that the point defects are at deep levels, close to the valence band.

Raman spectra of ionic liquids: Interpretation via computer simulation

2004 ◽  
Vol 120 (14) ◽  
pp. 6609-6620 ◽  
Author(s):  
Paul A. Madden ◽  
Mark Wilson ◽  
Francis Hutchinson
Keyword(s):  
Computer Simulation ◽  
Ionic Liquids ◽  
Raman Spectra

The Influence of Solvents on the Fluorescence Background in Raman Spectroscopy

1987 ◽  
Vol 41 (3) ◽  
pp. 413-416 ◽  
Author(s):  
Sciichiro Higuchi ◽  
Er Jie Yu ◽  
Shigeyuki Tanaka
Keyword(s):  
Laser Irradiation ◽  
Raman Spectra ◽  
Aromatic Compounds ◽  
Irradiation Time ◽  
Polycyclic Aromatic Compounds ◽  
Background Intensity ◽  
Solvent Influence ◽  
Polycyclic Aromatic ◽  
Influence Of Solvents ◽  
Large Background

For the purpose of reducing the fluorescence background induced by the laser irradiation in the measurements of Raman spectra, the influence of solvents on the background intensities for three polycyclic aromatic compounds was examined, where the experiments were conducted with typical solvents. It was demonstrated that the behaviors of the fluorescence background against the laser irradiation time were quite different according to the solvents, and that the behaviors could be classified roughly into the three categories. It was proved that when suitable solvents were used, the background intensities could be reduced sufficiently, even for the fluorescent samples such as those treated here; thus, the clear observation of Raman spectra is obtained. As an example of the solvent influence on the Raman spectra, the results of measurements for three separate cases were shown for 1-nitropyrene. The three cases are as follows: first, the Raman bands are masked almost completely by the strong background (solvent: 1,1,2,2-tetrachloroethane); second, though the spectrum can be obtained, its S/N ratio is low because of the relatively large background (solvent: acetonitrile); third, a clear spectrum with excellent S/N ratio can be obtained because the background intensity is low enough (solvent: carbon tetrachloride).

Chemical stability of choline-based ionic liquids supported on carbon materials

2012 ◽  
Vol 169 ◽  
pp. 37-42 ◽  
Author(s):  
Eduardo J. García-Suárez ◽  
Carmen Menéndez-Vázquez ◽  
Ana B. García
Keyword(s):  
Ionic Liquids ◽  
Chemical Stability ◽  
Carbon Materials

Study of High Precision of Low Absorbed Dose Determinations using Chemical Dosimetry

2008 ◽  
Vol 59 (1) ◽  
pp. 33-36
Author(s):  
Georgiana Madalina Nedelcu ◽  
Traian Zaharescu ◽  
Corneliu Podina ◽  
Ion Mihalcea
Keyword(s):  
Gamma Irradiation ◽  
High Precision ◽  
Spectrophotometric Method ◽  
Ferrous Sulfate ◽  
Irradiation Time ◽  
Absorbed Dose ◽  
Dose Determination ◽  
Precision Method ◽  
Straight Line ◽  
Chemical Dosimetry

A study on chemical dosimetry with the purpose of the elaboration of high precision method for low absorbed dose determination in the case of 137Cs gamma irradiation is presented. A dosimetric solution of ferrous sulfate was used and the dependence of Fe3+ ions concentration on the time irradiation was assessed by spectrophotometric method at 303 nm. From the slope of obtained straight line the dase rate was calculated. On this base the absorbed dose was estimated for each irradiation time. In order to evaluate the precision of dosimetric measurements the series of 12 dosimetric solutions were irradiated on the same conditions.

Li+ solvation in glyme–Li salt solvate ionic liquids

2015 ◽  
Vol 17 (12) ◽  
pp. 8248-8257 ◽  
Author(s):  
Kazuhide Ueno ◽  
Ryoichi Tatara ◽  
Seiji Tsuzuki ◽  
Soshi Saito ◽  
Hiroyuki Doi ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Crown Ether ◽  
Raman Spectra ◽  
Liquid State ◽  
Electrode Potentials

Raman spectra and electrode potentials corroborated that glyme–Li salt solvate ionic liquids consist of crown-ether like complex cations and counter anions with a few uncoordinated glyme molecules in the liquid state.

Raman spectra of a pseudo-oxocarbon anion in ionic liquids

2009 ◽  
Vol 41 (5) ◽  
pp. 524-528 ◽  
Author(s):  
Humberto C. Garcia ◽  
Luiz F. C. de Oliveira ◽  
Mauro C. C. Ribeiro
Keyword(s):  
Ionic Liquids ◽  
Raman Spectra

Raman spectra of acetonitrile in imidazolium ionic liquids

2010 ◽  
Vol 41 (12) ◽  
pp. 1720-1724 ◽  
Author(s):  
Humberto C. Garcia ◽  
Luiz F. C. de Oliveira ◽  
Bruno G. Nicolau ◽  
Mauro C. C. Ribeiro
Keyword(s):  
Ionic Liquids ◽  
Raman Spectra ◽  
Imidazolium Ionic Liquids

Long-Term Structural and Chemical Stability of DNA in Hydrated Ionic Liquids

2010 ◽  
Vol 49 (9) ◽  
pp. 1631-1633 ◽  
Author(s):  
Ranganathan Vijayaraghavan ◽  
Aleksey Izgorodin ◽  
Venkatraman Ganesh ◽  
Mahadevan Surianarayanan ◽  
Douglas R. MacFarlane
Keyword(s):  
Ionic Liquids ◽  
Chemical Stability
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