In recent years, there is a wide-spread interest towards aqueous solutions of polymers. Because of the increasing use of synthetic polymers in a great variety of applications and because of the prevalence of water and aqueous solutions in environment, the study of the interactions between water and polymer molecules has many practical aspects in technology. On the other hand, since water and macromolecules are essential constituents of biosystems, the knowledge of water/polymer interactions is also important for the understanding of molecular processes in living cells such as conformational changes of polypeptides. Moreover, there is an additional interest in polymer/water systems, since their hydration properties may cast some light upon the molecular structure and dynamics of aqueous solutions of organic molecules in general.