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Patent US4755192A successfully refreshed from Google Patents.
US4755192A
Expired / Lapsed
US
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Processes to condition gas permeable membranes
Assignee: The University of Texas System
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Filing: 1987-04-15
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Granted: 1988-07-05
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Expires: 2007-04-15
Abstract
Abstract Glassy-type gas separating membranes are conditioned to a state of enhanced permeability through controlled sorption of a selected conditioning gas such as CO 2 . Membranes are swelled to a state of plasticity without being rubberized and maintained in this state to allow their permeabilities to settle to a new, higher steady-state value. Upon depressurization, conditioned membranes exhibit enhanced permeability over untreated membranes, without serious loss of permselectivity. Membranes so conditioned must be maintained with a minimum sorption level of a conditioning or maintaining gas pending use to retain their improved characteristics.
Inventors
- 👤 William J. Koros
- 👤 Susan M. Jordan
- 👤 Greg K. Fleming
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:30
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
102 words
A process for conditioning a glassy-type polymeric gas permeable membrane to improve the flux of a gas penetrant therethrough, the process comprising the steps of: (a) swelling the membrane by dissolving therein a gaseous conditioning agent to a level that will plasticize the membrane without plasticizing the polymer to a rubbery state; (b) maintaining the membrane in a plasticized state for a period of time sufficient to stabilize the gas flux characteristics of the membrane; and (c) reducing the amount of dissolved conditioning agent in the stabilized membrane to a level that will maintain the membrane in the conditioned state pending use.
Claim 2
Dependent Claim
102 words
A process for conditioning a glassy-type polymeric gas permeable membrane to improve the flux of a gas penetrant therethrough, the process comprising the steps of: (a) swelling the membrane by dissolving therein a gaseous conditioning agent to a level that will plasticize the membrane without plasticizing the polymer to a rubbery state; (b) maintaining the membrane in a plasticized state for a period of time sufficient to stabilize the gas flux characteristics of the membrane; and (c) reducing the amount of dissolved conditioning agent in the stabilized membrane to a level that will maintain the membrane in the conditioned state pending use.
Claim 3
Dependent Claim
38 words
A process according to claim 1 wherein the conditioning agent is dissolved in the membrane to a sorption level of between about 0.1 and about 1.0 mmoles of the conditioning agent for every cubic centimeter of the membrane.
Claim 4
Dependent Claim
38 words
A process according to claim 1 wherein the conditioning agent is dissolved in the membrane to a sorption level of between about 0.2 and about 0.4 mmoles of the conditioning agent for every cubic centimeter of the membrane.
Claim 5
Dependent Claim
34 words
A process according to claim 1 wherein the conditioning agent is dissolved in the membrane to a sorption level of approximately 0.4 mmoles of the conditioning agent for every cubic centimeter of the membrane.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the conditioning agent comprises a gas having a boiling point of between about 90° and about 270° K.
Claim 7
Dependent Claim
58 words
A process according to claim 5 wherein the conditioning agent comprises CO 2 , C 2 H 2 , N 2 O, SO 2 , C 2 H 6 , C 2 H 4 , C 3 H 8 , C 3 H 6 , H 2 S, CF 4 , SF 6 , or NH 3 .
Claim 8
Dependent Claim
25 words
A process according to claim 1 wherein the conditioning agent comprises a gas having a boiling point of between about 150° and about 270° K.
Claim 9
Dependent Claim
35 words
A process according to claim 7 wherein the conditioning agent comprises CO 2 , C 2 H 4 , C 2 H 6 , C 3 H 8 , or C 3 H 6 .
Claim 10
Dependent Claim
39 words
A process according to claim 1 further comprising dissolving in the swelled membrane a flux maintaining agent, said agent being solubilized in the membrane to a sorption level that is sufficient to maintain the membrane in a conditioned state.
Claim 11
Dependent Claim
34 words
A process according to claim 9 wherein the flux maintaining agent is dissolved in the membrane at a level of at least 0.03 mmoles of the agent for every cubic centimeter of the membrane.
Claim 12
Dependent Claim
17 words
A process according to claim 9 wherein the flux maintaining agent comprises a gas, liquid or vapor.
Claim 13
Dependent Claim
25 words
A process according to claim 11 wherein the flux maintaining agent comprises a gas having a boiling point between about 60° and about 270° K.
Claim 14
Dependent Claim
25 words
A process according to claim 11 wherein the flux maintaining agent comprises a gas having a boiling point between about 100° and about 270° K.
Claim 15
Dependent Claim
59 words
A process according to claim 11 wherein the flux maintaining agent comprises CO 2 , C 2 H 2 , N 2 O, SO 2 , C 2 H 6 , C 2 H 4 , C 3 H 8 , C 3 H 6 , H 2 S, CF 4 , SF 6 , or NH 3 .
Claim 16
Dependent Claim
24 words
A process according to claim 11 wherein the flux maintaining agent comprises CO 2 , CH 4 , O 2 or N 2 .
Claim 17
Dependent Claim
34 words
A process according to claim 1 wherein the amount of dissolved conditioning agent is reduced to a level of no less than 0.03 mmoles of conditioning agent for every cubic centimeter of the membrane.
Claim 18
Dependent Claim
14 words
A process according to claim 1 wherein the membrane comprises a gas separating membrane.
Claim 19
Dependent Claim
17 words
A process according to claim 1 wherein the membrane comprises a contact lens, pervaporation or barrier membrane.
Claim 20
Dependent Claim
48 words
A process according to claim 1 wherein the glassy-type polymeric membrane comprises a membrane formed of a homopolymer, heterochain polymer, polymer blend or copolymer which includes a polycarbonate, a polyester, a polyamide, a polyimide, a polysulfone aryl ether, a substituted acetylene, an alpha-substituted olefin or a modified cellulosic.
Claim 21
Dependent Claim
15 words
A membrane of the glassy polymeric type conditioned by a process according to claim 1.
Claim 22
Dependent Claim
12 words
The membrane of claim 20 further defined as a gas separating membrane.
Claim 23
Dependent Claim
15 words
The membrane of claim 20 further defined as a contact lens, pervaporation, or barrier membrane.
Claim 24
Dependent Claim
42 words
The membrane of claim 20 wherein the membrane is formed of a homopolymer, heterochain polymer, copolymer or heteropolymer which includes a polycarbonate, a polyester, a polyamide, a polyimide, a polysulfone aryl ether, a substituted acetylene, an alpha-substituted olefin or a modified cellulosic.
Claim 25
Dependent Claim
130 words
A process for conditioning a glassy-type polymeric membrane to improve the flux of a penetrant therethrough, the process comprising the steps of: (a) swelling the membrane by dissolving therein between about 0.1 and about 1.0 mmoles of a conditioning gas for every cubic centimeter of the membrane, the gas having a boiling point of between about 90° and about 270° K; and (b) maintaining the level of dissolved conditioning gas at between about 0.1 and about 1.0 mmoles of gas for every cubic centimeter of the membrane until the membrane obtains about a steady state level of permeability; and (c) reducing the level of dissolved conditioning gas in the membrane to a level of at least 0.03 mmoles of conditioning gas for every cubic centimeter of the membrane pending use.
Claim 26
Dependent Claim
130 words
A process for conditioning a glassy-type polymeric membrane to improve the flux of a penetrant therethrough, the process comprising the steps of: (a) swelling the membrane by dissolving therein between about 0.1 and about 1.0 mmoles of a conditioning gas for every cubic centimeter of the membrane, the gas having a boiling point of between about 90° and about 270° K; and (b) maintaining the level of dissolved conditioning gas at between about 0.1 and about 1.0 mmoles of gas for every cubic centimeter of the membrane until the membrane obtains about a steady state level of permeability; and (c) reducing the level of dissolved conditioning gas in the membrane to a level of at least 0.03 mmoles of conditioning gas for every cubic centimeter of the membrane pending use.
Claim 27
Dependent Claim
22 words
A process according to claim 1 or 24 wherein the membrane is maintained in a swelled state for at least 6 hours.
Claim 28
Dependent Claim
22 words
A process according to claim 1 or 24 wherein the membrane is maintained in a swelled state for at least 24 hours.
Claim 29
Dependent Claim
21 words
A process according to claim 1 or 24 wherein the membrane is maintained in a swelled state for at least 48
Claim 30
Dependent Claim
89 words
A process for enriching for a gas permeate from a mixture of gases comprising the steps of: (a) selecting a gas separating membrane of the polymeric glassy type, the membrane having a upstream side and a downstream side; (b) treating the membrane by a process according to claim 1 or 24; (c) contacting the upstream side of the membrane with the mixture of gases under sufficient pressure to achieve a flux of gas across the membrane; and (d) collecting the gas permeate from the downstream side of the membrane.
Claim 31
Dependent Claim
13 words
A process according to claim 28 wherein the permeate comprises a conditioning agent.
Claim 32
Dependent Claim
14 words
A process according to claim 28 wherein the permeate comprises a flux maintaining agent.
Claim 33
Dependent Claim
62 words
In a process for enriching for a gas permeate from a mixture of gases, which process includes subjecting a glassy-type polymeric gas separating membrane to a mixture of gases under sufficient pressure to achieve a flux of gas across the membrane and collecting the gas permeate, wherein the improvment comprises treating the membrane by a process according to claim 1 or 24.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |