INTERFACE IN IMMISCIBLE IONIC MELTS

V. P. Stepanov; Степанов В. П.

doi:10.31857/S0235010623030106

INTERFACE IN IMMISCIBLE IONIC MELTS

Authors: Stepanov V.P.¹
Affiliations:
1. Institute of High-Temperature Electrochemistry, Ural Branch of the RAS
Issue: No 3 (2023)
Pages: 223-240
Section: Articles
URL: https://journals.rcsi.science/0235-0106/article/view/138671
DOI: https://doi.org/10.31857/S0235010623030106
EDN: https://elibrary.ru/PSIJXS
ID: 138671

Cite item

Full Text

Open Access
Restricted Access

Access granted
Restricted Access

Subscription Access

Abstract
About the authors
References
Supplementary files
Statistics

Abstract

The results of the study of the interface properties for immiscible mixtures LiF + KBr, LiF + CsCl, LiF + RbBr, LiF + KI, LiF + CsBr, LiF + RbI, LiF + CsI, LiCl + AgBr, LiCl + AgI и NaCl+AgI are summarized. It is established that the thickness of the interface increases when the temperature grows, tending to infinity near the critical mixing temperature. At equal temperature and the ratio of ion sizes, the layer thickness for melts containing silver halides turned out to be less than in mixtures of alkali metal halides. The surface energy for mixtures of alkali metal halides decreases as the temperature increases, obeying a power equation with a critical exponent equal to 1.5 in the vicinity of the critical mixing temperature. The critical exponent for the galvanic potential for mixtures containing silver halide turned out to be 18% less than the critical exponent for interfacial tension, which is due to the peculiarities of the chemical bond of silver halides. It is shown that at the same temperature, an increase in the size difference of the mixed ions leads to an increase in the energy and a decrease in the diffusivity of the transition layer due to a decrease in the mutual solubility of the components in this direction.

Keywords

ionic melt, immiscibility, criticality, interface

About the authors

V. P. Stepanov

Institute of High-Temperature Electrochemistry, Ural Branch of the RAS

Author for correspondence.
Email: v.stepanov@ihte.uran.ru
Russia, Yekaterinburg

References

Fisher M.E. The story of coulombic criticality // J. Stat. Phys. 1994. 75. P. 1–36.
Stell S. Criticality and phase transitions in ionic fluids // J. Stat. Phys. 1995. 78. P. 197–238.
Schröer W. Criticality of ionic liquids in solution // In: D. Henderson (Ed.), Ionic Soft Matter: Modern Trends in Theory and Applications. Berlin: Springer-Verlag. 2005. P. 143–180.
Domańska U., Marciniak A. Liquid phase behaviour of 1-hexyloxymethyl-3-methyl-imidazolium-based ionic liquids with hydrocarbons: The influence of anion // J. Chem. Thermodyn. 2005. 37. P. 523–625.
Stepanov V.P. Ultrasound velocity in stratified salt melts on the saturation curve // High Temperature. 2020. 58. P. 324–332.
Stepanov V.P. Adiabatic compressibility of biphasic salt melts // Z. Naturforschung A. 2021. 76. P. 723–730.
Stepanov V.P. Density of separating salt melts in the two-phase region // Russian Metallurgy. 2022. 8. P. 830–836.
Koryta J. Electrochemical polarization phenomena at the interface of two immiscible electrolyte solutions // Electrochim. Acta. 1988. 12. P. 189–192.
Murtomäki L., Kontturi K., Schiffrin D.J. Some remarks on the double layer correction to the kinetics of ion transfer at the interface of immiscible electrolytes // J. Electroanalyt. Chem. 1999. 474. P. 89–93.
Huber T., Pecina O., Schmickler W. The influence of the ions on the capacity of liquid/liquid interfaces // J. Elecrtoanalyt. Chem. 1999. 467. P. 203–206.
Reymond F., Fermin D., Lee H.J., Girault H.H. Electrochemistry at liquid/liquid interfaces: methodology and potential applications // Electrochim. Acta. 2000. 45. P. 2647–2662.
Laforge F.O., Sun P., Mirkin M.V. Shutting mechanism of ion transfer at the interface between two immiscible liquids // J. Am. Chem. Soc. 2006. 128. Р. 15019–15025.
Lockett V., Sedev R., Harmer S., Ralston J., Horn M., Rodopoulos T. Orientation and mutual location of ions at the surface of ionic liquids. Phys. Chem. Chem. Phys. 2010. 12. Р. 13816–13827.
Mareček V., Samec Z. Ion transfer kinetics at the interface between two immiscible electrolyte solutions supported on a thick-wall micro-capillary // Current Opinion in Electrochemistry. 2017. 1. P. 133–139.
Margheritis Ch., Flor G., Sinistri C. Miscibility gaps in fused salts // Z. Naturforsch. 1973. 28A. P. 1329–1334.
Flor G., Margheritis Ch., Vigano G.C., Sinistri C. Miscibility gар in fused salts. XI. Sуstems formed with silver halides and lithium or sodium halides // Z. Naturforsch. 1982. 37A. S. 1068–1072.
Mecham, N.J., Jonke, A.A. Commertial aspects of fuel processing // Reactor Fuel Proc. 1966. 9. P. 137–146.
Ignatiev V.V., Feinberg O.S., Zagnitko A.V., Merzlyakov A.V., Surenkov A.I., Panov A.V., Subbotin V.G., Afonichkin V.K., Khokhlov V.A., Kormilitsyn M.V. Liquid salt reactors: new opportunities, problems and solutions // Atomic energy. 2012. 112. P. 157–154.
Volkovich V.A., Maltsev D.S., Melchakov S.Yu., Yamshchikov L.F., Novoselova A.V., Smolenski V.V. Separation of Lanthanides and Actinides in a Chloride Melt-Liquid Metal System: The Effect of Phase Composition // ECS Transactions. 2016. 75. P. 397–408.
Kennedy J.H. Distribution of thallium chloride between KNO3 and AgCl and between K2S2O7 and AgCl // J. Phys. Chem. 1961 65. P. 1030–1033.
Kennedy J.H. Distribution of TlBr between KNO3 and AgBr // J. Chem. Eng. Data. 1964. 9. P. 95–98.
Moore R.H. Distribution coefficients for certain actinide and fission product chlorides in the immiscible salt system LiCl–KAlCl4 // J. Chem. Eng. Data. 1964. 9. P. 502–505.
Kojima T., Nomura K., Kageyama H. Molten salt liquid-liquid immiscibility, KNO3–(Li0.435Na0.315K0.25)2CO3 at 773 K and cation distribution between two liquids // J. Electrochem. Soc. 2016. 163. P. H584–H587.
Stepanov V.P., Babushkina L.M., Dokashenko S.I, Peshkin D.S. The effect of KCl and CsCl on the electrical conductivity of molten LiF–KBr at the critical composition // J. Chem. Eng. Data 2012. 57. Р. 2309–2312.
Janz G.J., Dampier F.W., Lakshminarayan G.R., Lorenz P.K., Tomkins R.P.T. Molten salts. National Standard Reference Data, NBS. 1968. 15. P. 1–168.
Schinke H., Sauervald F. Über die Volumenänderung beim Schmelzen und den Schmelzprozess bei Salzen // Z. Anorg. Allg. Chem. 1956. 287. P. 313–324.
Gagliardi L., Bonella S. Charge transport in superionic and melted AgI under a magnetic field studied via molecular dynamics // Phys. Rev. B. 2016. 94. 134426.
Puddephatt R.J. The Chemistry of Gold. Amsterdam: Elsevier Scientific. 1978.
Wilson M., Madden P.A., Costa-Cabral B.J. Quadrupole polarization in simulations of ionic systems: application to AgCl // J. Phys. Chem. 1996. 100. P. 1227–1237.
Guggenheim E.A. Thermodynamics. Amsterdam: North-Holland Publishing Company. 1950.
Rusanov A.I. Fazovyye ravnovesiya i poverkhnostnyye yavleniya [Phase equilibria and surface phenomena]. L.: Khimiya. 1967. [In Russian].
Tkachev N.K., Kobelev M.A. Okolokriticheskaya poverkhnost' zhidkost'-par nesim-metrichnogo po razmeram debay-khyukkelevskogo elektrolita [The near-critical surface of a liquid-vapor of a Debay-Hükkel electrolyte that is asymmetrical in size] // Rasplavy. 2002. 2. Р. 70–81. [In Russian].
Stepanov V.P., Minchenko V.I. Ultrasound velocity in dissolving alkali halide melts // J. Chem. Thermodynamics. 2011. 43. P. 467–470.
Babushkina L.M., Dokashenko S.I., Stepanov V.P. Elektroprovodnost’ rasplavov ftorida litiya s bromidom kaliya v oblasti rasslaivaniya [Electrical conductivity of melts of lithium fluoride with potassium bromide in the delaminating region] // Rasplavy. 2008. 3. Р. 35–39. [In Russian].
Babushkina L.M., Dokashenko S.I., Stepanov V.P., Shcherbakov K.N. Elektropro-vodnost' rasslaivayushchikhsya rasplavov ftoridov i bromidov shchelochnykh metallov na li-nii nasyshcheniya [Electrical conductivity of delaminating melts of fluorides and alkali bromides at the saturation line] // Rasplavy. 2010. 1. P. 23–28. [In Russian].
Babushkina L.M., Shcherbakov K.N., Dokashenko S.I., Stepanov V.P. Conductivity of fused mixtures of lithium fluoride with cesium halides in the stratification region [Conductivity of fused mixtures of lithium fluoride with cesium halides in the stratification region] // Russian J. Electrochem. 2010. 46. P. 627–632. [In Russian].
Babushkina L.M., Dokashenko S.I., Stepanov V.P., Shcherbakov K.N. Elektropro-vodnost' zhidkikh faz na linii nasyshcheniya v sistemakh ftorida litiya s iodidami kaliya, rubidiya i tseziya [Electrical conductivity of liquid phases at the saturation line in lithium fluoride with potassium, rubidium and caesium iodides systems] // Rasplavy. 2010. 5. P. 62–67. [In Russian].
Stepanov V.P., Babushkina L.M., Dokashenko S.I. Liquid + liquid equilibrium in mixtures of lithium fluoride with potassium and rubidium halides // J. Chem. Thermodyn. 2012. 51. Р. 12–16.
Stepanov V.P. Electrical conductivity of biphasic mixtures of molten silver iodide and lithium fluoride, chloride, and bromide // Ionics. 2017. 23. Р. 2055–2060.
Stepanov V.P. Electric conductivity of delaminated AgI + NaCl mixture // Russian J. Electrochem. 2018. 54. Р. 101–105.
Fumi F.G., Tosi M.P. Ionic sizes and born repulsive parameters in the NaСl-type alkali halides // J. Phys. Chem. Solids. 1964. 25. P. 31–43.
Rukavishnikova I.V., Lockett V.N., Stepanov V.P. Metodika izmereniya mezhfazno-go natyazheniya v rasslaivayushchikhsya ionnykh rasplavakh [Method of measuring interfacial tension in delaminating ionic melts] // Rasplavy. 2005. 6. P. 61–68. [In Russian].
Rukavishnikova I.V., Lockett V.N., Burukhin A.S., Stepanov V.P. The density and surface tension of high-temperature stratifying mixtures of alkali metal bromides and lithium fluoride // Russian J. Phys. Chem. 2006. 80. P. 1902–1906.
Rukavishnikova I.V., Lockett V.N., Stepanov V.P. Interphase tension at the boundary of stratifying lithium fluoride-cesium halide melts // Russian J. Phys. Chem. 2009. 83. P. 1285–1288.
Lockett V.N., Rukavishnikova I.V., Stepanov V.P., Tkachev N.K. Interfacial tension in immiscible mixtures of alkali halides // Phys. Chem. Chem. Phys. 2010. 12. P. 1139–1144.
Smirnov M.V., Stepanov V.P. Density and surface tension of molten alkali halides and their binary mixtures // Electrochim. Acta. 1982. 27. P. 1551–1563.
Kobelev М. Molecular dynamics simulation of the reciprocal fused LiF–KBr mixture: local structure and self-diffusion coefficients // Molecular Simulation. 2013. 39. Р. 868–874.
Yasnow D. Renormalisation group theoryof interface // In Phase Transitions and Critical Phenomena, ed. C. Domb and J.L. Lebowitz, Academic Press, London and Orland. 1986. 10. P. 269–363.
Adamson A.W. Physical chemistry of surfaces. N.Y.: Wiley-Interscience Publication. 1976.
Tkachev N.K., Kobelev M.A., Stepanov V.P. Surface tension in molten alkali halides as a function of the ion size // Russian J. Electrochemistry. 2002. 38. Р. 571–575.
Markin V.S., Volkov A.G. Potentials at the interface between two immiscible electrolyte solutions // Adv. Colloid Interface Sci. 1990. 31. P. 111–152.
Jensen H., Devaud V., Josserand J., Girault H.H. Contact Galvani potential differences at liquid | liquid interfaces: Part I: Experimental studies on single salt distribution at liquid | liquid interfaces using a streaming technique // J. Electroanalytical Chem. 2002. 537. P. 77–84.
Wandlowski T., Mareček V., Samec Z. Galvani potential scales for water-nitrobenzene and water-1,2-dichloroethane interfaces // Electrochim. Acta. 1990. 35. P. 1173–1175.
Reid J.D., Melroy O.R., Buck R.P. Double layer charge and potential profiles at immiscible liquid/liquid electrolyte interfaces // J. Electroanalytical Chem. 1983. 147. P. 71–82.
Lesnykh D.S., Kokarovtseva I.G. Elektroprovodnost’ i EDS rasplavlennykh solevykh sistem s rassloyeniyem [Electrical conductivity and EMF of molten salt systems with stratification] // V sb. Fiziko-khimicheskiy analiz solevykh sistem. 1962. P. 175–182. [In Russian].
Stepanov V.P., Kulik N.P. Phase-boundary potential in the two-liquid-phase (AgI + NaCl) system // J. Chem. Thermodyn. 2015. 90. P. 24–27.
Stepanov V.P., Kulik N.P. Galvani potential at liquid | liquid interfaces for dissolving AgBr + LiCl and AgI + LiCl melts // Ionics. 2018. 24. P. 2851–2856.
Tkachev N.K. Ogranichennaya rastvorimost' solevykh rasplavov i razlichiya v razme-rakh ionov [Limited solubility of salt melts and differences in ion sizes] // Rasplavy. 1999. 5. P. 90–94. [In Russian].