Inversion der Calcium-Isotopenseparation an einem Ionenaustauscher durch Ver- änderung der LiCl-Elektrolytkonzentration / Inversion of the Calcium Isotope Separation at an Ion Exchanger Resin by Variation of the LiCl Electrolyte Concentration

1982 ◽  
Vol 37 (6) ◽  
pp. 786-787 ◽  
Author(s):  
Klaus G. Heumann ◽  
H. Klöppel ◽  
G. Sigl
Keyword(s):  
Electrolyte Concentration ◽  
Isotope Separation ◽  
Electrolyte Solutions ◽  
Solution Phase ◽  
Complexing Agent ◽  
Column Experiments ◽  
Calcium Isotope ◽  
Separation Effect ◽  
Calcium Isotopes ◽  
Inverse Effect

Abstract The calcium isotope separation at a strongly acidic exchanger resin as a function of the concentration of a LiCl solution is investigated in column experiments. Whereas an enrichment of the heavier calcium isotopes in the solution phase is found with a 3 M LiCl solution, an inverse effect is obtained with 8 M and 12 M LiCl solutions. The separation effect e for the 12 M solution is found to be the highest calcium enrichment in a system without a complexing agent. The results are compared with those for other electrolyte solutions and can be explained by the anion/cation interactions.

Abhängigkeit der Calcium-Isotopenseparation bei der Ionenaustauschchromatographie von der HNO3-Elutionsmittelkonzentration / Calcium Isotope Separation by Ion Exchange Chromatography in Dependence on the HNO3 Eluant Concentration

1979 ◽  
Vol 34 (7) ◽  
pp. 1044-1046 ◽  
Author(s):  
Klaus G. Heumann ◽  
Helmut Klöppel
Keyword(s):  
Cation Exchanger ◽  
Isotope Separation ◽  
Strong Dependence ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Calcium Isotope ◽  
Separation Effect ◽  
Acidic Cation Exchanger ◽  
Calcium Isotopes ◽  
Resin Phase

Abstract Using a strongly acidic cation exchanger resin, the dependence of the calcium isotope separation on the HNO3 eluant concentration is investigated on column experiments. The elementary separation effect of the isotope ratios 44Ca/40Ca and 48Ca/40Ca is determined. Up to HNO3 concentrations of about 1.5 M the lighter calcium isotopes are enriched in the resin phase, whereas, using more concentrated HNO3 solutions, the heavier isotopes are enriched in the ion exchanger. A comparison of these results with those using hydrochloric acid and perchloric acid show, that there is a strong dependence of the isotope separation on the concentration and the counter ion of the eluant solution

Calciumisotopenseparation mit Kryptanden als Komplexbildner / Separation of Calcium Isotopes with Cryptand Complexes

1981 ◽  
Vol 36 (5) ◽  
pp. 566-570 ◽  
Author(s):  
Klaus G. Heumann ◽  
Hans-Peter Schiefer
Keyword(s):  
Isotope Separation ◽  
Extraction Procedure ◽  
Extraction System ◽  
Complexing Agent ◽  
Chemical Systems ◽  
Calcium Isotopes ◽  
Liquid Liquid Extraction ◽  
Separation Factors ◽  
O Phase ◽  
High Distribution Coefficient

The calcium isotope separation in the liquid-liquid extraction system H2O/CHCl3 is investigated using [2.2.1] and [2.2.2] cryptands for complex formation as well as without complexing agent. An extraction procedure is used which allows the transfer of larger amounts of calcium into the CHCl3 phase although the high distribution coefficient favours calcium in the H2O phase. Without complexing agent in the extraction system, enrichment of the lighter calcium isotopes is already evident in the CHCl3 phase which is just the same as when using [2.2.1] cryptand. In the case of [2.2.2] cryptand as a complexing agent, the isotope separation is higher. The separation factor is calculated to be α = 1 + ε = 1.011 for 40Ca/ 48Ca without complexing agent or with [2.2.1] cryptand and α = 1.015 in the system with [2.2.2] cryptand. For 40Ca/44Ca the ε-value is smaller by nearly a factor of two. These separation factors are the highest which are determined in chemical systems for calcium isotopes

The Isotope Effect of a Direct Electric Current through Liquid and Solid Metals

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe
Keyword(s):  
Liquid Metal ◽  
Electric Current ◽  
Isotope Effect ◽  
Direct Current ◽  
Capillary Tube ◽  
Isotope Separation ◽  
Direct Electric Current ◽  
Separation Effect ◽  
A Current

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.

The effects of electrolyte concentration, ion species and pH on the zeta potential and electrokinetic charge density of montmorillonite

Clay Minerals ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 853-861 ◽  
Author(s):  
E. E. Saka ◽  
C. Güler
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Negative Charge ◽  
Electrolyte Concentration ◽  
Great Influence ◽  
Electrolyte Solutions ◽  
Ionic Species ◽  
Positive Sign ◽  
Ion Species ◽  
Influence Of Ph

AbstractIn this study, the influence of pH, electrolyte concentration and type of ionic species (such as LiCl, NaCl, KCl, RbCl, CsCl, CaCl2, AlCl3) on the electrokinetic properties (zeta potential and electrokinetic charge density) of montmorillonite has been quantified. The zeta potential of montmorillonite particles did not change significantly with change in pH. The valencies of the ions have proven to have a great influence on the electrokinetic behaviour of the suspension. There is a gradual decrease in the zeta potential (from —24 mV to —12 mV) with increase in monovalent electrolyte concentration (from 10-4 M to 10-1 M). At any monovalent electrolyte concentration, the magnitude of the zeta potential increased with the electrolytes in the order Li+ > Na+ > K+ > Rb+ > Cs+. The zeta potential of the montmorillonite minerals in CaCl2 solutions illustrated the same behaviour as the monovalent cations. Less negative values were obtained for the CaCl2 electrolyte (∼–10 mV) due to the greater valence of the ions. A sign reversal was observed at an AlCl3 concentration of 5 x 10-4 M, and, at greater concentrations, zeta potential values had a positive sign (∼20 mV).The electrokinetic charge density of montmorillonite showed similar trends of variation in mono and divalent electrolyte solutions. Up to concentrations of ∼10-3 M, it remained practically constant at ∼0.5 x 10-3Cm-2, while for greater electrolyte concentrations the negative charge produced more negative values (–16 x 10-3Cm-2). The electrokinetic charge density of montmorillonite particles was constant at low AlCl3 concentrations, but at certain concentrations it increased rapidly and changed sign to positive.

scholarly journals Promoting solution phase discharge in Li–O2 batteries containing weakly solvating electrolyte solutions

2016 ◽  
Vol 15 (8) ◽  
pp. 882-888 ◽  
Author(s):  
Xiangwen Gao ◽  
Yuhui Chen ◽  
Lee Johnson ◽  
Peter G. Bruce
Keyword(s):  
Electrolyte Solutions ◽  
Solution Phase

Drastic change of the intrusion–extrusion behavior of electrolyte solutions in pure silica *BEA-type zeolite

2014 ◽  
Vol 16 (33) ◽  
pp. 17893-17899 ◽  
Author(s):  
A. Ryzhikov ◽  
I. Khay ◽  
H. Nouali ◽  
T. J. Daou ◽  
J. Patarin
Keyword(s):  
High Pressure ◽  
Electrolyte Concentration ◽  
Electrolyte Solutions ◽  
Drastic Change ◽  
Pure Silica ◽  
Type Zeolite ◽  
Zeolite P

A behavior of high pressure intrusion–extrusion of electrolyte solutions in pure silica *BEA-type zeolite depends drastically on electrolyte concentration.

Abhängigkeit der Chlor-Isotopenseparation vom Vernetzungsgrad eines stark basischen Anionenaustauschers / Dependence of Chlorine Isotope Separation on the Degree of Cross Linkage of a Strongly Basic Anion Exchange Resin

1979 ◽  
Vol 34 (3) ◽  
pp. 406-411 ◽  
Author(s):  
Klaus G. Heumann ◽  
Paul Roßmann ◽  
Anni Schwarz ◽  
Alfred Windfelder
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Isotope Separation ◽  
Exchange Reactions ◽  
Separation Effect ◽  
Chlorine Isotope ◽  
Cross Linkage ◽  
Basic Anion Exchange Resin ◽  
Basic Anion

Abstract Using ion exchange chromatography, the dependence of the chlorine isotope separation on the degree of cross linkage of a strongly basic anion exchange resin was investigated. With increasing degree of cross linkage the elementary separation effect for the two stable isotopes 35Cl and 37Cl increases. In all experiments 35Cl- is enriched in the resin phase, whereas 37Cl- is enriched in the solution, using 0.1 M NaNO3 as an eluant. Within the degree of cross linkage of 2 to 10 per cent investigated, there is a linear correlation of the elementary separation effect of the chlorine isotopes with the selectivity coefficient between the ions NO3- and Cl-. The results show that the electrolyte behavior of anionic isotope exchange reactions is comparable with that of cations. The 35Cl/37Cl isotope ratio is determined using thermal ionization mass spectrometry.

Membrane Potentials across the Cation Exchange Membrane in Aqueous Mixed Electrolyte Solutions

2012 ◽  
Vol 476-478 ◽  
pp. 1825-1828 ◽  
Author(s):  
De Chun Liu ◽  
Ya Ping Zhang
Keyword(s):  
Membrane Potential ◽  
Cation Exchange ◽  
Electrolyte Concentration ◽  
Electrolyte Solutions ◽  
Membrane Potentials ◽  
Cation Exchange Membrane ◽  
Mixed Solution ◽  
Mixed Electrolyte ◽  
High Concentrations ◽  
Exchange Membrane

Membrane Potentials across the Cation Exchange Membrane in Aqueous Mixed Solutions Made of Two Kinds of Electrolytes Were Experimentally Studied. Effects of both the Concentration and the Species of Electrolytes on Membrane Potentials Were Presented. for any Mixed Solution Made of Two Kinds of Electrolytes, when the Total Electrolyte Concentration at Right Side of the Membrane Is Fixed, the Membrane Potential Increases with the Total Electrolyte Concentration at Left Side of the Membrane. however, such Increase Is Rather Slight at both Low and High Concentrations. when the Concentrations at each Side of the Membrane Are Equivalent for Three Mixed Solution Systems, the Membrane Potential Decreases with such Order: ΦKCl+NaCl>ΦKCl+MgCl2>ΦKCl+AlCl3.

Electrolytes in narrow pores / Electrolyten in engen Poren

2000 ◽  
Vol 6 (1) ◽  
pp. 87-102
Author(s):  
N.V. Churaev ◽  
Μ.J. Setzer ◽  
О. Wowra ◽  
Μ. Reick
Keyword(s):  
Electrolyte Concentration ◽  
Electrolyte Solutions ◽  
Solution Concentration ◽  
Chloride Ions ◽  
Double Layers ◽  
Bulk Solution ◽  
Surface Potentials ◽  
Structural Forces ◽  
Slit Pores ◽  
Repulsive Forces

Abstract Mean electrolyte concentration Cm in narrow charged pores decreases as a result of repulsion of co-ions from charged walls. The theory of electrical double layers (EDL) was used for calculation of this effect in dependence on surface potential values Φ1 and concentration C0 of bulk electrolyte solutions. The calculations were limited to the case of 1-1 electrolytes and low values of surface potentials Φ1 when simple analytical solutions may be used. Mean concentration of chloride ions and neutral solution in narrow negatively charged slit pores of different thickness h was calculated in dependence on Φ1 and Debye radius values. It was shown that the effect is more pronounced in narrow pores at relatively high absolute values of surface potentials and at low concentration of a bulk solution. In narrow hydrophilic pores, a decrease in mean electrolyte concentration results from the effect of dielectric exclusion caused by decreasing values of dielectric constant of water ef. The calculations were performed using Born equation that relates the self-energy of ions W with the 8f values and ion radii. Comparing the results obtained with measured values of rejection coefficients of electrolyte solutions in reverse osmosis membranes, the dependence of £f values on pore sizes was calculated. Repulsive forces arising in narrow pores as a result of overlapping of EDL are calculated in dependence on slit thickness, bulk solution concentration and surface potentials in the framework of the theory of electrostatic component of disjoining pressure. In the case of hydrophilic silica systems molecular attraction forces and repulsive structural forces were also taken into account. The arising structural forces are caused by overlapping of boundary layers of water with modified structure

Multiplication methods analysis of the elementary separation effect for laser isotope separation

1985 ◽  
Author(s):  
O. N. AVATKOV ◽  
A. B. BAKHTADZE ◽  
V. M. VETSKO ◽  
I. G. GVERDTSITELI ◽  
O. A. DEVDARIANI ◽  
...  
Keyword(s):  
Isotope Separation ◽  
Separation Effect ◽  
Laser Isotope Separation
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