US4169790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid surface texture suitable for a stationary phase for chromatography
Assignee: South African Inventions Development Corp
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Filing: 1978-02-03
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Granted: 1979-10-02
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Expires: 1998-02-03
Abstract
Abstract A body having a siliceous surface provided with a surface texture comprising predominantly a plurality of siliceous microvilli or whiskers projecting from and grown onto the surface is useful as a solid stationary phase for chromatography.
Inventors
- 👤 Victor Pretorius
- 👤 Jacobus D. Schieke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:53
CPC Classifications
C; C03; C03C; C03C23/00; B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/28; B01J20/28014; B01J20/281; B01J20/282; B01J20/283; B01J20/292; B01J20/30; B01J20/32; B01J20/3202; B01J20/3204; B01J20/3231; B01J20/3287; B01J2220/00; B01J2220/50; B01J2220/54
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
36 words
A body having a siliceous surface provided with a surface texture comprising siliceous microvilli projecting from and grown onto the surface, the density of microvilli being not less than 1.7×10 3 microvilli per cm 2 .
Claim 2
Dependent Claim
36 words
A body having a siliceous surface provided with a surface texture comprising siliceous microvilli projecting from and grown onto the surface, the density of microvilli being not less than 1.7×10 3 microvilli per cm 2 .
Claim 3
Dependent Claim
18 words
The body of claim 1, wherein the microvilli are between 10 -4 and 10 -2 cm in length.
Claim 4
Dependent Claim
20 words
The body of claim 2, wherein the ratio of length to diameter of said microvilli is between 3:1 and 100:1.
Claim 5
Dependent Claim
18 words
The body of claim 1, wherein the microvilli are between 10 -4 and 5×10 -3 cm in length.
Claim 6
Dependent Claim
20 words
The body of claim 4, wherein the ratio of length to diameter of said microvilli is between 6:1 and 50:1.
Claim 7
Dependent Claim
20 words
The body of claim 5, wherein the ratio of length to diameter of said microvilli is between 8:1 and 25:1.
Claim 8
Dependent Claim
13 words
The body of claim 1, wherein the microvilli have a dendritically-branched micro structure.
Claim 9
Dependent Claim
14 words
The body of claim 1, wherein the siliceous surface is silica, silicate or glass.
Claim 10
Dependent Claim
15 words
The body of claim 8, wherein said microvilli are composed wholly or predominantly of silica.
Claim 11
Dependent Claim
84 words
A process for making a body of claim 1 which comprises subjecting a siliceous surface to the action of the vapor of a silica-dissolving medium at a concentration higher than that required for achieving an etching effect and below that at which a coarse crystal growth predominates and recovering a body as defined in claim 1, wherein the silica-dissolving substance is a fluorine-containing substance and wherein a temperature between 240° and 500° C. is maintained for at least 1 hour in a non-oxidizing atmosphere.
Claim 12
Dependent Claim
22 words
The process of claim 10, wherein the fluorine-containing substance is hydrofluoric acid or a fluorocarbon ether which liberates hydrofluoric acid on heating.
Claim 13
Dependent Claim
13 words
The process of claim 10, wherein the fluorine-containing substance is methyltrifluorochloroethyl ether (MTFEE).
Claim 14
Dependent Claim
43 words
The process of claim 12, wherein methyltrifluorochloroethyl ether is employed at a concentration of 20 to 150 ml of liquid per liter of vapor space in which the siliceous surface being treated is contained and the temperature is between 240° and 500° C.
Claim 15
Dependent Claim
24 words
The process of claim 13, wherein the concentration is between 25 and 120 ml per liter and said temperature between 250° and 450° C.
Claim 16
Dependent Claim
28 words
The process of claim 14, wherein said concentration is between 25 and 100 ml per liter of vapor space and said temperature is between 350° and 420° C.
Claim 17
Dependent Claim
15 words
The process of claim 10, wherein the temperature is maintained for 1 to 6 hours.
Claim 18
Dependent Claim
15 words
The process of claim 16, wherein said temperature is maintained for 2 to 5 hours.
Claim 19
Dependent Claim
26 words
The process of claim 10, wherein the surface of the microvilli is flushed thoroughly with a dry, inert gas immediately after the completion of formation thereof.
Claim 20
Dependent Claim
15 words
The process of claim 18, wherein flushing is carried out at 100° to 300° C.
Claim 21
Dependent Claim
21 words
The process of claim 19, wherein said process is repeated after flushing to produce on said microvilli a dendritically-branched micro texture.
Claim 22
Dependent Claim
46 words
The process of claim 10, wherein the silica-dissolving medium is a carbonaceous substance which during said process decomposes resulting in light deposits of finely dispersed carbon on the surface and wherein such deposits are removed by exposure of the surface to hot oxygen for several hours.
Claim 23
Dependent Claim
26 words
The process of claim 21, wherein the treated surface is exposed to a stream of oxygen at 400° to 450° C. for 6 to 12 hours.
Claim 24
Dependent Claim
20 words
The body of claim 1, wherein the density of microvilli is 1.7×10 3 to 2.5×10 8 per cm 2 .
Claim 25
Dependent Claim
46 words
A body having a siliceous surface provided with a surface texture comprising siliceous microvilli projecting from and grown onto the surface, said body being in the form of a tube, the inner surface of which is the siliceous surface provided with the surface texture comprising microvilli.
Claim 26
Dependent Claim
46 words
A body having a siliceous surface provided with a surface texture comprising siliceous microvilli projecting from and grown onto the surface, said body being in the form of a tube, the inner surface of which is the siliceous surface provided with the surface texture comprising microvilli.
Claim 27
Dependent Claim
11 words
The body of claim 24, in the form of chromatographic column.
Claim 28
Dependent Claim
17 words
The body of claim 24 which comprises not less than 1.7×10 +3 microvilli per cm 2 .
Claim 29
Dependent Claim
42 words
In an apparatus for chromatography comprising a column containing a solid surface bearing stationary phase exchange sites exposed to a moving phase, said surfaces having a surface configuration of a plurality of microvilli projecting into a flow path of the moving phase.
Claim 30
Dependent Claim
42 words
In an apparatus for chromatography comprising a column containing a solid surface bearing stationary phase exchange sites exposed to a moving phase, said surfaces having a surface configuration of a plurality of microvilli projecting into a flow path of the moving phase.
Claim 31
Dependent Claim
13 words
The apparatus of claim 27, wherein the substrate and the microvilli are siliceous.
Claim 32
Dependent Claim
14 words
The apparatus of claim 28, wherein the microvilli are partially deactivated prior to use.
Claim 33
Dependent Claim
16 words
The apparatus of claim 28, wherein the microvilli are a support for an applied stationary phase.
Claim 34
Dependent Claim
31 words
The apparatus of claim 29, wherein the stationary phase is a physically applied thin film of liquid stationary phase or a stationary phase chemically bonded to the surface of said microvilli.
Claim 35
Dependent Claim
20 words
The apparatus of claim 30, wherein said microvilli are enveloped or coated individually with retention of said microvilli surface configuration.
Claim 36
Dependent Claim
16 words
The apparatus of claim 27, wherein the surface is the inner periphery of a capillary column.
Claim 37
Dependent Claim
15 words
The apparatus of claim 27, wherein the surface is the surface of a column packing.
Claim 38
Dependent Claim
58 words
In a process for chromatographic separation which comprises subjecting a phase to chromatographic separation between a stationary phase and a moving gas or liquid mixture to effect separation of components, the improvement which comprises using as the stationary phase a surface provided with a plurality of microvilli projecting into the moving phase from and grown onto the surface.
Claim 39
Dependent Claim
58 words
In a process for chromatographic separation which comprises subjecting a phase to chromatographic separation between a stationary phase and a moving gas or liquid mixture to effect separation of components, the improvement which comprises using as the stationary phase a surface provided with a plurality of microvilli projecting into the moving phase from and grown onto the surface.
Claim 40
Dependent Claim
13 words
The process of claim 35, wherein the surface and the microvilli are siliceous.
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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) | 1982-10-01 | 1983-04-02 | 1983-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-01 | 1987-04-02 | 1987-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-01 | 1991-04-02 | 1991-10-02 | $7700.00 | Window Closed / Lapsed |