Method of preparing a semipermeable membrame
Abstract
Abstract A METHOD OF PREPARING A SEMIPERMEABLE MEMBRANE ADAPTED TO PERMIT SUBSTANTIALLY SELECTIVE DIFUSION THERETHROUGH OF A COMPONENT O A SOLUTION. THE MEMBRANE IS PRPARED FROM A SOLUTION CONTAINING A CELLULOSIC ESTER OR ETHER DERIVATIVE AND A WATER-SOLUBLE LIQUID AMIDE HAVING THE FORMULA R6CONR7R8 WHEREIN R6 IS FROM THE CLASS CONSISTING OF HYDROGEN, LMETHYL AND ETHYL GROUPS AND R7 AND R8 ARE FROM THE CLASS CONSISTING OF HYDROGEN, ETHYL AND PROPYL GROUPS WITHOUT BOTH R7 AND R8 BEING HYDROGEN. THE SOLUTION IS CAST ON A SUPPORT. A PORTION OF THE LIQUID ANIDE IS EVAPORATD TO TRANSFORM THE CAST SOLUTION INTO A MEMBRANE. THE CAST MEMBRANE IS THEN IMMERSED IN WATER AND HEATED TO REDUCE ITS POROSITY.
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