Freezing, drying, and/or vitrification of membrane- solute-water systems.

Membranes are often damaged by freezing and/or dehydration, and this damage may be reduced by solutes. In many cases, these phenomena can be explained by the physical behavior of membrane-solute-water systems. Both solutes and membranes reduce the freezing temperature of water, although their effects are not simply additive. The dehydration of membranes induces large mechanical stresses in the membranes. These stresses produce a range of physical deformations and changes in the phase behavior. These membrane stresses and strains are in general reduced by osmotic effects and possibly other effects of solutes-provided of course that the solutes can approach the membrane in question. Membrane stresses may also be affected by vitrification where this occurs between membranes. Many of the differences among the effects of different solutes can be explained by the differences in the crystallization, vitrification, volumetric, partitioning, and permeability properties of the solutes.