The solubility behavior of NaCl in water at high pressure studied by neutron diffraction and Raman scattering

ABSTRACT

The solubility of NaCl in water is one of the most important thermo-physical properties. However, the solubility behavior of NaCl in water is poorly understood at high pressure and low temperature. Herein, we performed high pressure neutron diffraction and Raman scattering to investigate the solubility of NaCl in water and the corresponding structural change, respectively. With the pressure increasing, the solubility almost increases linearly below 0.2 GPa, beyond which it starts to level off and reaches its maximum at about 0.61 GPa. The Raman spectra suggested that the deformation of the hydrogen-bonded network in the NaCl aqueous solution promotes the formation of ions pairing and is responsible for the solubility increase of NaCl in water. Finally, we used a two-dimensional Mercedes-Benz model to descript the picture of solubility behavior of NaCl in water at high pressure.

KEYWORDS:

• Solubility of NaCl in water
• high pressure neutron diffraction
• Raman scattering
• deformation of the hydrogen-bonded network

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by National Key Research and Development Program of China (No. 2018YFA0305900) and the National Natural Science Foundation of China [grant number 51472171 and 11427810].