Temperature and temporal heterogeneities of water dynamics in the physiological temperature range

Abstract

We present a systematic study of the impact of temperature on the microscopic dynamics of water in the physiologically important temperature range. We also offer a detailed account of the diffusion model for water and discuss the time-dependent dynamics of water and the relaxation processes in the range of temperatures important from the physiological viewpoint. We report that the temperature dependence of α-relaxation time at T = (308 ÷ 315) К deviates from the linear behavior, indicating the change in the mechanisms of diffusion in water. Such change occurs as water molecules slow down due to the increase in the molecule’s jump time by an inter-particle distance from one equilibrium state into another. Two diffuse regimes of water molecules motion are identified at T = 308 K and T = 315 K, pointing at the existence of two diffusion regimes. These two regimes are paramount in determining the dynamics of water and the interaction of water with biomolecules in this physiologically important temperature range.