Liquid polymorphism, density anomaly and H-bond disruption in an associating lattice gases

Aline Balladares; Vera B. Henriques; Marcia C. Barbosa

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Liquid polymorphism, density anomaly and H-bond disruption in an associating lattice gases

Aline Balladares·Vera B. Henriques·Marcia C. Barbosa

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Abstract

We have investigated the effects of either distorting hydrogen bonds or removing proton degeneracy on the thermodynamic properties of a minimal model for associating liquids. The presence of two liquid phases and a density anomaly is unaffected in both cases. Increasing the degeneracy of bonded structures leads to lower temperature critical points and a steeper liquid-liquid coexistence line, implying a low density liquid of larger entropy. Analysis of the hydrogen bond net accross the phase diagram indicates that the density anomaly is accompanied by a steep reduction of hydrogen bond density, which introduces a restriction on a correlation which has been preconized long ago. This feature is present independent of bond distortion or of the presence of proton entropy.

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Aline Balladares, Vera B. Henriques, Marcia C. Barbosa. 2006-09-21. Liquid polymorphism, density anomaly and H-bond disruption in an associating lattice gases. https://arxiv.org/abs/cond-mat/0609542

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