Method for modifying asymmetric membranes by endo-treating
AssigneeAlbany International Corp.
InventorsMyron J. Coplan, R. Douglas Burchesky, Salvatore Giglia
Life of this patent
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Abstract
A method of upgrading the selectively of a dry asymmetric permselective membrane comprising a porous barrier layer adjacent to a porous main body, where the barrier layer has an external obverse surface. The method comprises maintaining the barrier layer surface in a drying atmosphere while applying a wetting liquid which is not a solvent for the bulk of the membrane to the obverse surface to wet interstices of the bulk of the membrane, and drying the membrane by continuing the exposure of the external surface of the barrier layer to the drying atmosphere as the wetting liquid moves from the obverse surface through the membrane main body and the barrier layer.
Claims12
The method of upgrading the selectivity of a dry asymmetric permselective membrane comprising a porous barrier layer adjacent to a porous main body, the barrier layer having an external surface and the main body having an external obverse surface, comprising:
- (a) a wetting liquid which is not a solvent for the bulk of the membrane to said obverse surface to wet interstices of the bulk of the membrane;
- and
- (b) drying the membrane by continuing the exposure of the external surface of the barrier layer to a drying atmosphere, the wetting liquid moving from said obverse surface through the membrane main body and the barrier layer.
Dependencies are inferred from the claim text.