Capabilities of X-ray methods in studies of processes of permeation through dense membranes

As follows from the review of recent publications information about the structural interaction membrane–penetrant is so far fragmentary. The capabilities of X-ray methods in this field have been described for the system: cellulose–water (light and heavy). Two methods were applied: WAX and SAXS. The following information has been obtained: WAX – existence of structural changes, different for H2O and D2O, at intermolecular level after water-vapor treatment of cellulose, and existence of bulk water after soaking cellulose into water. In order to obtain better presentation the structural changes, a method of measurement and calculation of interference function, F(k), in a limited range of k, has been elaborated. SAXS – existence of water clusters in cellulose soaked in water and calculation of their approximate sizes