The complexation reactions between Tl+ and Pb2+ ions and crown ethers 12-crown-4(12C4), 15-crown-5 (15C5), benzo-15-crown-5 (B15C5), 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and aza-18-crown-6 (A18C6) were studied in 90% acetonitrile and 90% ethanol solutions at 25 °C, using an a.c. polarographic technique. The stoichiometry and stability of the complexes we...

The continuous extraction of an amino acid from aqueous solution into ionic liquid phase was studied experimentally in small channels, demonstrating a double intensification the solvent used and overall process. Channels with 0.5, 1 2 mm internal diameter were for acid, L-tryptophan (0.005 mol L?1), hydrophobic liquid, 1-Butyl-3-methylimidazolium Bis (trifluoromethanesulfonyl)imide, [C4mim][Tf2...

A secondary nucleation model mainly based on the findings of Ottens (1973) and Evans (1974) considering both crystal-impeller collisions and crystal-crystal collisions was investigated using experimental data obtained from two crystallizers, a 22-liter Draft Tube (DT) crystallizer and an 1100-liter Draft Tube Baffled (DTB) crystallizer, which are both operated continuously in an evaporative mod...

Introduction: Dauphas et al. [1] and Yin et al. [2] reported molybdenum isotopic anomalies in bulk undifferentiated and differentiated meteorites and this was the first time that isotopic anomalies were found on the scale of a meteorite hand-specimen. Even more recently, Chen and Papanastassiou [3,4] identified ruthenium isotopic anomalies in meteorites. Dauphas et al. [5] used theoretical prod...

The interaction between hydronium ion and several crown ethers was studied via conductometry in nitromethane at 25 °C and 1H-NMR techniques. The stabilities of the resulting 1:1 complexes were determined from the conductance data and found to vary in the order DC18C6 > 18C6 > DB30C10 > DB24C8 > DB18C6 > ~B15C5 > DB21C7. For the first time, evidences for the formation of a 2:1 san...

The kinetics of the potassium thiocyanate transport mediated by dicyclohexyl-18-crown-6 (L) through a bulk liquid membrane is studied experimentally and theoretically. The proposed model is based on the assumption of a pure diffusion of the complex salt [K·L]+SCN¯ through the liquid membrane stagnant films at the interfaces. It illustrates the ...

Introduction: Recently, the classic theory of stable isotope fractionation of the Bigeleisen-Mayer equation [1] has been expanded by the original author to include the mass-independent term named the nuclear field shift effect [2]. The improved theory successfully explained the observed non-linear isotope effect on U in a chemical exchange system [2]. Since then, researchers have applied the ne...