Diffusion−Viscosity Decoupling in Supercooled Aqueous Trehalose Solutions

Abstract

The diffusional mobility of disodium fluorescein has been measured in supercooled aqueous solutions of trehalose, a widely used cryoprotectant disaccharide. The results were analyzed on the basis of the classical continuum hydrodynamic theory (Stokes-Einstein relationship) and compared with results for the diffusion and electrical conductivity of other ionic and nonionic solutes in trehalose and sucrose aqueous solutions. Disodium fluorescein obeys the classical model over a restricted range of inverse reduced temperatures, T g/ T, scaled by the glass transition temperature. Decoupling in neutral solutes takes place at higher values of T g/ T, while in ionic solutes it occurs all over the range of T g/ T studied, as observed for the water mobility in supercooled sugar solutions.

Trehalose solution viscosity at low temperatures measured by dynamic light scattering method: Trehalose depresses molecular transportation for ice crystal growth

“…Open diamonds [26], open inverted triangles [23], Xs [24], and crosses [17] are plotted. predicted by extrapolating the temperature dependence of the viscosity in the liquid state, at least within our experimental validity (i.e, the temperature is not below T g /0.6 [19]). The variation of the temperature dependence parameter of trehalose solutions (Q treha ) with the solute concentration C indicates interesting properties: Q treha for dilute solutions with concentrations of less than 10 wt% is almost concentrationindependent, which is the same as that of pure water (Q w =17.371.4 kJ mol -1 ).…”

“…where T is the absolute temperature, k B Boltzmann's constant, and A a constant that depends on the type of friction between a material with radius R and its surrounding liquid [19]. This relation can be applied to disaccharide solutions when the conditions of the liquid are such that T g /T is less than about 0.6 [19].…”

“…This relation can be applied to disaccharide solutions when the conditions of the liquid are such that T g /T is less than about 0.6 [19]. The viscosity of sucrose has been thoroughly studied, but that of trehalose has seldom been investigated.…”

“…Several indirect methods have been proposed, such as the fluorescence recovery after photobleaching (FRAP) [19,27] and the laser-light-scattering method [15]. However, these indirect methods have been developed very recently, and their accuracies remain relatively low.…”

Viscous organic aerosol particles in the upper troposphere: diffusivity-controlled water uptake and ice nucleation?

“…Previous studies investigated the viscosity of atmospherically relevant model systems at around room temperature and used the StokesEinstein relation to derive diffusion coefficients (RenbaumWolff et al, 2013;Hosny et al, 2013;Power et al, 2013;Abramson et al, 2013;Booth et al, 2014;Zhang et al, 2015). However, diffusivity and viscosity decouple below approximately 1.2 T g or higher, where T g refers to the thermal glass transition temperature as measured by differential scanning calorimetry (Mapes et al, 2006;Corti et al, 2008). As a result of this decoupling, diffusion coefficients predicted with the Stokes-Einstein relation may be orders of magnitude smaller than observed (Molinero and Goddard, 2005;Power et al, 2013).…”