Semipermeable membranes and the method for the preparation thereof
AssigneeThe United States of America as represented by the Secretary of the Interior
InventorWolfgang J. Wrasidlo
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Abstract
Semipermeable membranes which are useful in reverse osmosis processes are prepared by forming a polymeric ultra-thin film which possesses semipermeable properties on a microporous support. An example of the composite semipermeable membrane comprising an ultra-thin film formed by contacting an amine modified polyepihalohydrin with a polyfunctional agent and depositing this film on one surface of a microporous substrate.
Claims7
In a process for desalination of saline water by reverse osmosis comprising contacting the saline water under pressure with a reverse osmosis membrane, the improvement comprising using as the reverse osmosis membrane a composite semipermeable membrane prepared by a method comprising the steps of:
- a. treating a microporous substrate with an aqueous solution of an amine modified polyepihalohydrin,
- b. immersing the resultant coated microporous substrate in a solution of a polyfunctional agent capable of reacting with the amine groups of said amine modified polyepihalohydrin to form an ultra-thin film on one surface of said microporous support, and
- c. drying said composite semipermeable membrane at an elevated temperature.
Dependencies are inferred from the claim text.