Effect of temperature and pressure on structural self-organization of aqueous sodium chloride solutions

The features of self-organization of aqueous NaCl solution structure are studied by the extended RISM integral equation method over a wide range of temperature (T = 313-633 K, p = 25 МPа), pressure (p = 0.1-1000 МPа, T = 298 K) and concentration (1.11-5.55 molal). Effects of external parameters (T, p) on the structural state of bulk water, ion hydration and ion association in solutions are analyzed. According to the obtained results, temperature and pressure exert the same destructive influence on bulk water structure but have opposite impact on ion hydration and ion association. The pressure-induced structure transformations discussed here are largest at p > 150 МPа and specific to moderate salt concentrations of NaCl(aq).