Patent US4749487A successfully refreshed from Google Patents.
US4749487A
Expired / Lapsed
US
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High flux membrane
Assignee: Syrinx Research Pty Ltd
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Filing: 1985-04-10
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Granted: 1988-06-07
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Expires: 2005-04-10
Abstract
Abstract The instant invention provides a semipermeable membrane having a maximized porosity with surface properties providing enhanced flux, and good chemical resistance.
Inventors
- 👤 Michel S. M. Lefebvre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:30
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/02; B01D67/00; B01D67/0039; B01D67/0048; B01D71/0213; B01D2323/00; B01D2323/48; B01D2325/00; B01D2325/08; B01D2325/20; B01D2325/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A semi-permeable membrane for selective retention of molecules of greater than a pre-selected size, which comprises a macro-porous substrate having a micro-porous microskin permanently deposited thereon, the microskin having a surface of Fractal geometry including means for generating a dynamic layer which is reticulated at the molecular level, including an ordered arrangement of absorption/repulsion sites for said retained molecules of at least three different energy levels, the spacing between the absorption and repulsion sites being of the same order of magnitude as the mean free path of Brownian motion of said retained molecules, wherein the microskin is formed of a desolvated gel comprising a tribasic compound selected so as to provide said at least three different energy levels.
Claim 2
Dependent Claim
118 words
A semi-permeable membrane for selective retention of molecules of greater than a pre-selected size, which comprises a macro-porous substrate having a micro-porous microskin permanently deposited thereon, the microskin having a surface of Fractal geometry including means for generating a dynamic layer which is reticulated at the molecular level, including an ordered arrangement of absorption/repulsion sites for said retained molecules of at least three different energy levels, the spacing between the absorption and repulsion sites being of the same order of magnitude as the mean free path of Brownian motion of said retained molecules, wherein the microskin is formed of a desolvated gel comprising a tribasic compound selected so as to provide said at least three different energy levels.
Claim 3
Dependent Claim
18 words
A membrane according to claim 1 wherein the reticulation spacing is in the region 1 to 20 microns.
Claim 4
Dependent Claim
13 words
A membrane according to claim 1 wherein the microskin comprises a multivalent ion.
Claim 5
Dependent Claim
18 words
A membrane according to claim 3 wherein the multivalent ion is selected from calcium, aluminium, phosphorus and silicon.
Claim 6
Dependent Claim
12 words
A membrane according to claim 3 wherein the microskin comprises calcium apatite.
Claim 7
Dependent Claim
12 words
A membrane according to claim 3 wherein the microskin comprises calcium aconitate.
References Cited (Backward Citations)
US4414111A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |