Etude de la couche dense superficielle des membranes en acetate de cellulose destinees a l'osmose inverse

Swelling of LOEB-type membranes has been investigated using light-reflexion (for{qtλ} = 0.580 μ) differential refractometry and densitometry. These membranes are highly unsymmetrical and exhibit on the evaporated solvent side a face with a lower water content (38 per cent w/w) than the remaining (61.8 per cent). This zone is presumably made of a homogeneous non-porous gel. The water content increases continuously from the surface inwards, probably very quickly in the surface region, more slowly, but not negligeably, in the deeper regions.