TY - JOUR

T1 - Solubility of rare earth chlorides in ternarywater-salt systems in the presence of a fullerenol-C60(OH)24 Nanoclusters at 25 °C. models of nonelectrolyte solubility in electrolyte solutions

AU - Charykov, Nikolay A.

AU - Keskinov, Viktor A.

AU - Tsvetkov, Kirill A.

AU - Kanbar, Ayat

AU - Semenov, Konstantin N.

AU - Gerasimova, Lubov’ V.

AU - Shaimardanov, Zhassulan K.

AU - Shaimardanova, Botagoz K.

AU - Kulenova, Natalia A.

N1 - Charykov, N.A.; Keskinov, V.A.; Tsvetkov, K.A.; Kanbar, A.; Semenov, K.N.; Gerasimova, L.V.; Shaimardanov, Z.K.; Shaimardanova, B.K.; Kulenova, N.A. Solubility of Rare Earth Chlorides in Ternary Water-Salt Systems in the Presence of a Fullerenol—C60(OH)24 Nanoclusters at 25 °C. Models of Nonelectrolyte Solubility in Electrolyte Solutions. Processes 2021, 9, 349. https://doi.org/10.3390/pr9020349

PY - 2021/2/14

Y1 - 2021/2/14

N2 - The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol-by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.

AB - The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol-by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.

KW - Atomic absorption spectroscopy

KW - Chlorides of rare earth elements

KW - Electron spectrophotometry

KW - Eutonics

KW - Fullerenol

KW - Isothermal saturation in ampoules

KW - Modified sechenov equation

KW - Salting-out

KW - Saltingin effects

KW - Solubility

KW - salting-in effects

KW - modified Sechenov equation

KW - eutonics

KW - salting-out

KW - atomic absorption spectroscopy

KW - chlorides of rare earth elements

KW - isothermal saturation in ampoules

KW - solubility

KW - fullerenol

KW - electron spectrophotometry

UR - http://www.scopus.com/inward/record.url?scp=85102249107&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/8da06259-a28c-37ec-b098-e3b2be4fc22e/

U2 - 10.3390/pr9020349

DO - 10.3390/pr9020349

M3 - Article

AN - SCOPUS:85102249107

VL - 9

JO - Processes

JF - Processes

SN - 2227-9717

IS - 2

M1 - 349

ER -