Influence of pore geometry on the state of bulk pore water in the pressure-temperature phase space
Abstract
In recent years, the existence of a second critical point of the liquid-liquid transition of water has been proven. In the pressure-temperature phase space, this point is located in the temperature range –50 °С... –100 °C and at pressure ~ 100 MPa. The exact position of this point is not yet known due to experimental difficulties in achieving the deep supercooling of bulk water. The Widom line, the locus of increased fluctuations in entropy and density, is associated with the second critical point. When approaching the Widom line, a sharp increase in a number of physical quantities was established: heat capacity at constant pressure, isothermal compressibility, volume expansion coefficient. However, the practical significance of these features is not clear, since for pressures close to atmospheric, the temperature on it is –45 °C. At the same time, it
is known that at temperatures below – 41 °C (homogeneous nucleation temperature), chemically pure supercooled bulk water is unstable due to the very rapid formation of ice crystal nuclei. Nevertheless, supercooling of bulk water to –70 °C in nanometre-sized pores is known.
In the present study, we investigated the possibility of reaching the state on the Widom line at negative pressures, for which, theoretically, the temperature of such a state becomes higher than –45 °C and can reach it positive values at a pressure of –100 MPa. Such a state, in this study, is assumed in the cylindrical hydrophilic pores with a diameter of several nanometres. For the investigation of this possibility and the achievable values of negative pressure (and high temperatures on the Widom line), we measured the low-frequency impedance of a cooled capacitive cell filled with a moistened MCM-41 nanoporous material. In addition, the thermal characteristics were measured in the form of a temperature response of the
medium from a pulsed spot heater at a certain distance from it. The position of the Widom line, associated with the second critical point of water, was determined based on the anomalies of the measured physical values in the temperature range –50 °С…+10 °C. For MCM-41 with an average pore diameter of 3.5 nm, dielectric and thermal extrema were found near –18 °C, which corresponds to a pressure of about –65 MPa.
Thus, the performed experiments have shown the possibility of reaching the state on the Widom line at temperatures characteristic of ordinary conditions. Consequently, a significant change in the physicochemical characteristics of dispersed moistened media in various natural and artificial objects is possible. The study of other sorbents with cylindrical pores in order to achieve positive temperatures on the Widom line is of interest.
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References
Anisimov M. A. Cold and super-cooled water: a novel supercritical-fluid solvent. Russian Journal of Physical Chemistry B. 2012;6: 861–867. https://doi.org/10.1134/S199079311208009X
Shi R., Tanaka H. The anomalies and criticality of liquid water. Proceeding of National Academy of Science (USA). 2020;117: 26591–26599. https://doi:org/10.1073/pnas.2008426117
Pallares G., Gonzalez M., Abascal I. L. F., Valeriani C., Caupin F. Equation of state for water and its line of density maxima down to −120 MPa. Physical Chemistry Chemical Physics. 2016;18: 5896–5900. https://doi.org/10.1039/C5CP07580G
Biddle J. W., Singh R. S., Sparano E. M., Ricci F., Gonzalez M. A, Valeriany C., Abascal J. L. F., Debenedetti P. G., Anisimov M. A., Caupin F. Two-structure thermodynamics for the TIP4P/2005 model of water covering supercooled and deeply stretched regions. Journal of Chemical Physics. 2017;146(3): 034502. https://doi.org/10.1063/1.4973546
Abascal I. L. F., Vega C. Widom line and the liquid-liquid critical point for the TIP4P/2005 water model. Journal of Chemical Physics. 2010;133: 234502–234510. https:/doi.org/10.1063/1.3506860
Caupin F. Escaping the no man’s land: recent experiments on metastable liquid water. Journal of Non-Crystalline Solids. 2015;407: 441–448. https://doi.org/10.1016/j.jnoncrysol.2014.09.037
Bordonskiy G. S., Gurulev A. A. Regarding physical and chemical transformation with the involvement of water near – 45 °C. Condensed Matter and Interphases. 2019;21(4): 478–489. (In Russ.,abstract in Eng.). https://doi.org/10.17308/kcmf.2019.21/2359
Briggs L. G. Limiting negative pressure of water. Journal of Applied Physics. 1950;21: 721–722. https://doi.org/10.1063/1.1699741
Alvarenga A. D., Grimsditch M., Bondar R. J. Elastic properties of water under negative pressure. Journal of Chemical Physics. 1993;98(11): 8392–8396. https://doi.org/10.1063/1.464497
Shi K., Shen Y., Santiso E. E., Gibbins K. E. Microscopic pressure tensor in cylindrical geometry: pressure of water in a carbon nanotube. Journal of Chemical Theory and Computation. 2020;16: 5548–5561. https://doi.org/10.1021/acs.jctc.0c00607
Artyomenko L. V., Kozhevnicov N. O. Modelling the Maxwell-Wagner effect in frozen unconsolidated rocks. arth’s Cryoshere. 1999;3(1): 60–68. (In Russ., abstract in Eng.). Available at: http://earthcryosphere.ru//archive/1999_1/60-68.pdf
Cerveny S., Mallamace F., Swenson J., Vogel M., Xu L. Confined water as model of supercooled water. Chemical Reviews. 2016;116(13): 7608–7625. https://doi.org/10.1021/acs.chemrev.5b00609
Menshikov L. I., Menshikov P. L., Fedichev P. O. Fenomenological model of hydrophobic and hydrophilic interaction. Journal of Experimental and Theoretical Physics. 2017;152(6): 1173–1188. https://doi.org/10.1134/S1063776117120056
Barsukov E., Macdonald J. R. (eds). Impedance Spectroscopy. Theory, experiment and applications. New Jersey: Wiley; 2005. 595 p.
Carballo-Sanchez A. F., Gurevich Y. G., Logvinov G. N., Drogobitskii Y. V., Titov O. Y. Propagation of a heat pulse in a bounded conducting medium: thermoelectric detection. Physics of the Solid State. 1999; 41(4): 544–549. https://doi.org/10.1134/1.1130821
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