Hydration of ions-how does it influence water treeing?

Water treeing in polyethylene in contact with aqueous salt solutions is influenced by the diffusion constant of the salt in the polymer and especially by hydration effects around salt inclusions. Salt molecules accumulate in regions of locally increased electric fields and act as condensation nuclei for liquid water. An aqueous solution of the salt is formed and the reduction of the saturation pressure over this saturated solution attracts additional water by diffusion processes. Specific chemical properties of the salts seem not to be of any importance.