Viscosity and speed of sound of potassium nitrate and lithium nitrate in poly(ethylene glycol)

Densities, viscosities, and speeds of sound of 0.15[xKNO(3) + (1 - x)LiNO3] + 0.85[poly(ethylene glycol)] and 0.20[xKNO(3) + (1 - x)LiNO3] + 0.80[poly (ethylene glycol)] systems (molecular weight of poly(ethylene glycol) = 300 ) were measured as functions of composition (x = 0.0 to 1.0 mole fraction) and temperature (273.15 less than or equal to T/K less than or equal to 343 .15). The viscosity and the structural relaxation time were found to be non -Arrhenius temperature dependent and were analyzed by using the Vogel-Tamma n-Fulcher equation. The normalized viscosity isotherm exhibits a significan t mixed alkali effect for the 0.20[xKNO(3) + (1 - x)-LiNO3] + 0.80[poly(eth ylene glycol)] system at 273.15 K. The onset of the mixed alkali effect in this system has been explained by the competitive polarization model. The a bsence of the mixed alkali effect in the 0.15[xKNO(3) + (1 - x)LiNO3] + 0.8 5[poly(ethylene glycol)] system is attributed to the lesser amount of total alkali ion content in the system.