Patent DE605262C successfully refreshed from Google Patents.
US3847652A
Expired / Lapsed
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Method of preparing water purification membranes
Assignee: National Aeronautics and Space Administration
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Filing: 1972-12-08
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Granted: 1974-11-12
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Expires: 1992-12-08
Abstract
Abstract Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.
Inventors
- 👤 J Fletcher
- 👤 J Hollahan
- 👤 T Wydeven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:01
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/12; B01D69/125; B01D69/127; B01J; B01J12/00; B01J12/002; B01J19/00; B01J19/08; C; C08; C08F; C08F2/00; C08F2/46; C08F2/52
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
107 words
A PROCESS FOR MAKING A REVERSE OSMOSIS MEMBRANE FOR DESALINATION OF WATER COMPRISING THE STEPS OF: A. DISPOSING A MICROPOROUS SUBSTRATE IN AN ENCLOSED SPACE, B. GENERATING A PLASMA OF AN INERT GAS WITHIN SAID ENCLOSED SPACE, C. DIRECTING SYMMETRICALLY A GASEOUS STREAM OF AN UNSATURATED ORGANIC COMPOUND INCLUDING AT LEAST ONE ALLYL GROUP TOWARD AND AROUND SAID SUBSTRATE, AND D. DIRECTING THE SAID PLASMA SYMMERTICALLY AND COUNTERCURRENTLY TOWARD SAID GASEOUS STREAM AND SAID SUBSTRATE, WHEREBY WITH THE SAID UNSATURATED ORGANIC COMPOUND IS POLYMERIZED WITH THE AID OF THE PLASMA AND DEPOSITED ON THE SAID SUBSTRATE AS A UNIFORM POLYMER FILM TO FORM THE REVERSE OSMOSIS MEMBRANE.
Claim 2
Dependent Claim
107 words
A PROCESS FOR MAKING A REVERSE OSMOSIS MEMBRANE FOR DESALINATION OF WATER COMPRISING THE STEPS OF: A. DISPOSING A MICROPOROUS SUBSTRATE IN AN ENCLOSED SPACE, B. GENERATING A PLASMA OF AN INERT GAS WITHIN SAID ENCLOSED SPACE, C. DIRECTING SYMMETRICALLY A GASEOUS STREAM OF AN UNSATURATED ORGANIC COMPOUND INCLUDING AT LEAST ONE ALLYL GROUP TOWARD AND AROUND SAID SUBSTRATE, AND D. DIRECTING THE SAID PLASMA SYMMERTICALLY AND COUNTERCURRENTLY TOWARD SAID GASEOUS STREAM AND SAID SUBSTRATE, WHEREBY WITH THE SAID UNSATURATED ORGANIC COMPOUND IS POLYMERIZED WITH THE AID OF THE PLASMA AND DEPOSITED ON THE SAID SUBSTRATE AS A UNIFORM POLYMER FILM TO FORM THE REVERSE OSMOSIS MEMBRANE.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said plasma is created by an electrodeless discharge at a radio frequency.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the plasma is generated with a microwave generator.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein the unsaturated organic compound is allyl amine.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the unsaturated organic compound is diallylamine.
Claim 7
Dependent Claim
21 words
The process of claim 1 wherein the total gaseous pressure within the enclosed space is maintained between 0.05 and 0.6 torr.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein the distance separating the zone of plasma generation and the substrate is no greater than 6 centimeters.
Claim 9
Dependent Claim
21 words
The process of claim 1 wherein the substrate is oriented perpendicular to the flow of gases and the generation of plasma.
Claim 10
Dependent Claim
73 words
A process for making a reverse osmosis membrane for desalination of water comprising the steps of: a. disposing a microporous substrate in an enclosed space, b. generating within said enclosed space a plasma of an unsaturated organic compound including at least one allyl group, and c. allowing said plasma to diffuse and surround said substrate and to polymerize and deposit on said substrate as a uniform film to form the reverse osmosis membrane.
Claim 11
Dependent Claim
73 words
A process for making a reverse osmosis membrane for desalination of water comprising the steps of: a. disposing a microporous substrate in an enclosed space, b. generating within said enclosed space a plasma of an unsaturated organic compound including at least one allyl group, and c. allowing said plasma to diffuse and surround said substrate and to polymerize and deposit on said substrate as a uniform film to form the reverse osmosis membrane.
Claim 12
Dependent Claim
18 words
The process of claim 9 wherein said plasma is created by an electrodeless discharge at a radio frequency.
Claim 13
Dependent Claim
13 words
The process of claim 9 wherEin the unsaturated organic compound is allyl amine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |