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1

Extraction of rubidium and cesium from brine solutions using a room temperature ionic liquid system containing 18-crown-6

Huang D., Zheng H., Liu Z., Bao A., Li B.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 2

40--46

EN

Application of 1-butyl-3-metyhlimidazaolium hexafl uorophosphate ([C4mim][PF6 ]), in the extraction of rubidium and cesium from brine solutions using 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) as extractant was investigated. Parameters that affect the extraction including pH of aqueous phase, equilibration time, dosage of the ionic liquid, phase ratio, concentration of 18C6 were studied. Under the optimal conditions, the single extraction effi ciency of rubidium ions and cesium ions were up 84.11% and 94.99%, respectively. The stripping of alkali metal ions from the loaded organic phase with different stripping agents and concentrations were also investigated. The initial value of the K/Cs and K/Rb ratios were 93.0 and 104.3, respectively, which have dropped 91.21% and 88.01%, respectively, after the extraction and stripping experiments. It was taken a big step in the separation and enrichment of cesium (rubidium) ion and potassium ion. The extraction mechanism was revealed most likely to be a cation exchange mode in this system.

2

Test for short-lived organopotassium and organosodium intermediates

Stolarzewicz A., Grobelny Z., Maercker A.

Chemia Analityczna

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2009

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Vol. 54, No. 3

321-327

EN

A simple test is proposed for short-lived organopotassium and organosodium intermediates formed during some organic processes. It is based on the use of 15-crown-5 or 18-crown-6 as the additional reagent and identification of its ring opening product, i.e. alkali metal tetraethylene glycoxide vinyl ether or alkali metal pentaethylene glycoxide vinyl ether, respectively.

PL

Zaproponowano prosty test na oznaczanie krótko żyjących przejściowych związków potasowe- i sodoworganicznych. Polega on na użyciu eteru 15-korona-5 lub 18-korona-6 jako dodatkowego odczynnika, a następnie identyfikacji produktu otwarcia jego pierścienia, to jest odpowiednio eteru winylowego tetraetylenowego glikolanu lub eteru winylowego pentaetylenowego glikolanu potasu względnie sodu.

3

Study of Complex Formation Between 18-Crown-6 with Cu2+, Zn2+, Cd2+ and Pb2+ Cations in Some Binary Mixed Non-aqueous Solvents Using the Conductometric Method

Rounaghi G., Khazaee N., Sanavi K.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 7

1143-1153

EN

The complexation reactions between Cu2+, Zn2+, Cd2+ and Pb2+ metal cations with 18-crown-6 (18C6) were studied in methanol (MeOH) - dimethylformamide (DMF) and ethylacetate (EtOAc) - dimethylformamide (DMF) binary mixtures at different temperatures using the conductometric method. The conductance data show that the stoichiometry of the complexes in all cases is 1:1 (ML). The values of thermodynamic parameters ( Hc 0, Sc 0) for 18C6-Cu2+, 18C6-Zn2+, 18C6-Cd2+ and 18C6-Pb2+ complexes in MeOH - DMF and EtOAc - DMF binary systems were obtained from temperature dependence of stability constants. The results show that the thermodynamics of complexation reactions is affected by the nature and composition of the mixed solvents and in most cases, the complexes are enthalpy stabilized but entropy destabilized. The stability constants Kf of all complexes increase with increasing the concentration of solvent with lower donicity (based on Gutmann donicity scale) in the binary mixed solvents. In most cases, a non-linear behaviour was observed for variation of logKf of the complexes with the composition of the mixed solvents. The selectivity order of 18C6 for these metal cations in all solvent systems used in this study is: Pb2+>Cd2+>Cu2+>Zn2+.

4

The modyfication of diane epoxy resin ED-20 with the tert-butyl-hydroperoxide in the presence of two-component catalytic system

Chervinskyy T., Bratychak M.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2003

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Vol. 52, nr 25

579-581

EN

Chemical modyfication process between diane epoxy resin ED-20 and tert-butylhydroperoxide in the presence of 18-Crown-6 and ZnCl2 has been studied. Dependence of the reaction upon nature of catalyst was shown.

PL

Badano proces chemicznej modyfikacji żywicy epoksydowej (dian) ED-20 wodorotlenkiem III rz. butylu wobec eteru koronowego 18-korona-6 i ZnCl2. Wykazano zależność reakcji od rodzju katalizatora.