Patent US5234594A successfully refreshed from Google Patents.
US5234594A
Expired / Lapsed
US
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Nanochannel filter
Assignee: United States Department of the Navy
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Filing: 1992-06-12
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Granted: 1993-08-10
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Expires: 2012-06-12
Abstract
Abstract The present invention provides a wafer-like glass filter having channels therethrough having an average diameter of less than 1 micron, and further provides methods of making the filter.
Inventors
- 👤 Ronald J. Tonucci
- 👤 Brian L. Justus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:37
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/06; B01D63/061; B01D39/00; B01D39/14; B01D39/20; B01D39/2003; B01D63/066; B01D67/00; B01D67/0039; B01D67/0053; B01D67/0058; B01D69/00; B01D69/02; B01D69/04; B01D71/00; B01D71/02; B01D71/04; G; G01; G01N; G01N30/00; G01N30/02; G01N30/60; G01N30/6052; G01N30/6069; G01N30/50; G01N30/52; G01N2030/524; G01N2030/528; G01N30/6034; G01N30/6043
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
A method for forming a filter comprising the steps of: inserting acid etchable glass rods into respective inert hollow glass tubes; heating said rods and tubes to fuse each respective rod to a respective tube; drawing each of said fused rods and tubes to reduce the diameter of the rods and tubes to thereby form a filament; stacking a plurality of said filaments together to form a stack of filaments; heating the stack of filaments to fuse the filaments together to form an elongated bar having a plurality of channels filled with etchable glass; drawing said bar until each of the channels has a diameter of less than 1 micron; cutting the elongated bar to form a wafer-like filter; annealing the filter at an elevated temperature; and acid etching the etchable glass in the wafer-like filter to form channels therethrough having an average diameter of less than about 1 micron.
Claim 2
Independent Claim
150 words
A method for forming a filter comprising the steps of: inserting acid etchable glass rods into respective inert hollow glass tubes; heating said rods and tubes to fuse each respective rod to a respective tube; drawing each of said fused rods and tubes to reduce the diameter of the rods and tubes to thereby form a filament; stacking a plurality of said filaments together to form a stack of filaments; heating the stack of filaments to fuse the filaments together to form an elongated bar having a plurality of channels filled with etchable glass; drawing said bar until each of the channels has a diameter of less than 1 micron; cutting the elongated bar to form a wafer-like filter; annealing the filter at an elevated temperature; and acid etching the etchable glass in the wafer-like filter to form channels therethrough having an average diameter of less than about 1 micron.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein the tubes are hexagonal in cross-section and the matrix has a hexagonal close-packed configuration.
Claim 4
Dependent Claim
31 words
A method according to claim 1, wherein the etchable glass has a rate of etching 10 5 to 10 7 as great as the rate of etching of the inert glass.
Claim 5
Dependent Claim
11 words
A glass filter made according to the method of claim 1.
Claim 6
Independent Claim
115 words
A method for forming a filter comprising the steps of: stacking acid etchable glass filaments with acid inert glass filaments to form a stack of filaments having an oriented array of acid etchable glass filaments; heating the stack of filaments to fuse the filaments together to form an elongated bar having a plurality of channels filled with etchable glass; drawing said bar until each of the channels has a diameter of less than 1 micron; cutting the elongated bar to form a wafer-like filter; annealing the filter at an elevated temperature; and acid etching the etchable glass in the wafer-like filter to form channels therethrough having an average diameter of less than about 1 micron.
Claim 7
Independent Claim
115 words
A method for forming a filter comprising the steps of: stacking acid etchable glass filaments with acid inert glass filaments to form a stack of filaments having an oriented array of acid etchable glass filaments; heating the stack of filaments to fuse the filaments together to form an elongated bar having a plurality of channels filled with etchable glass; drawing said bar until each of the channels has a diameter of less than 1 micron; cutting the elongated bar to form a wafer-like filter; annealing the filter at an elevated temperature; and acid etching the etchable glass in the wafer-like filter to form channels therethrough having an average diameter of less than about 1 micron.
Claim 8
Dependent Claim
21 words
A method according to claim 5, wherein said filaments are hexagonal in cross-section and the filter has a hexagonal close-packed configuration.
Claim 9
Dependent Claim
31 words
A method according to claim 5, wherein the etchable glass has a rate of etching 10 5 to 10 7 as great as the rate of etching of the inert glass.
Claim 10
Dependent Claim
11 words
A glass filter made according to the method of claim 1.
Claim 11
Dependent Claim
32 words
A method according to claim 5, wherein said filaments are selected from round, aquare, and semicircular cross-sectional shapes and said filter has a configuration selected from hexagonal and aquare close packed configurations.
Claim 12
Dependent Claim
31 words
A method according to claim 5, wherein the etchable glass has a rate of etching 10 5 to 10 7 as great as the rate of etching of the inert glass.
Claim 13
Dependent Claim
11 words
A glass filter made according to the method of claim 5.
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) | 1996-08-09 | 1997-02-08 | 1997-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-09 | 2001-02-08 | 2001-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-09 | 2005-02-08 | 2005-08-10 | $7700.00 | Window Closed / Lapsed |