| 摘要 |
Anisotropic membranes particularly useful in reverse osmosis because of their good salt rejection properties and high transmission rate are provided which consist essentially of a polymer comprising a plurality of units of the formula <IMAGE> (I) in which each of the symbols Q, Q' and Q'', which can be identical or different, represents a hydrogen atom, an alkyl radical with 1 to 4 carbon atoms or a -SO3H radical, the number of -SO3H radicals in the polymer being such that the ionic capacity of the polymer is from about 0.5 to about 5 meg/g, in the form of a layer which exhibits a degree of salt rejection, said layer having an equivalent thickness of from about 0.01 to about 5 mu , and a highly porous support layer, of thickness up to about 1 mm.
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