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US5076980A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making sol-gel monoliths

Assignee: GRYPHON VENTURES II LP
•
Filing: 1990-08-01
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Granted: 1991-12-31
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Expires: 2010-08-01
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Abstract

Abstract A method of making a sol-gel monolith, comprising the steps of: (a) hydrolyzing and polycondensing one or more oxide precursors to form a sol comprising a plurality of oxide particles suspended in a liquid; (b) casting said sol into a mold; (c) gelling said sol by cross-linking said oxide particles to form a gel; (d) aging said gel to form an aged gel; (e) subjecting said aged gel to a drying treatment comprising the steps of: (i) heating said aged gel in a high humidity environment; and then (ii) heating said aged gel in a low humidity environment to remove liquid from the pores of the aged gel to form a dried, aged gel; and (f) densifying said dried, aged gel to form a sol-gel monolith.

Inventors

  • 👤 Jean-Luc Nogues
  • 👤 Canan Balaban
  • 👤 William V. Moreshead

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 09:50
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/14; C04B35/622; C04B35/624; C03; C03B; C03B19/00; C03B19/12

Claims Analysis

Total Claims: 63
Claim 1
Independent Claim 126 words
A method of making a sol-gel monolith, comprising the steps of: (a) hydrolyzing and polycondensing one or more oxide precursors to form a sol comprising a plurality of oxide particles suspended in a liquid; (b) casting said sol into a mold; (c) gelling said sol by cross-linking said oxide particles to form a gel; (d) aging said gel to form an aged gel; (e) subjecting said aged gel to a drying treatment comprising the steps of: (i) heating said aged gel in a high humidity environment; and then (ii) heating said aged gel in a low humidity environment to remove liquid from the pores of the aged gel to form a dried, aged gel; and (f) densifying said dried, aged gel to form a solgel monolith.
Claim 2
Independent Claim 126 words
A method of making a sol-gel monolith, comprising the steps of: (a) hydrolyzing and polycondensing one or more oxide precursors to form a sol comprising a plurality of oxide particles suspended in a liquid; (b) casting said sol into a mold; (c) gelling said sol by cross-linking said oxide particles to form a gel; (d) aging said gel to form an aged gel; (e) subjecting said aged gel to a drying treatment comprising the steps of: (i) heating said aged gel in a high humidity environment; and then (ii) heating said aged gel in a low humidity environment to remove liquid from the pores of the aged gel to form a dried, aged gel; and (f) densifying said dried, aged gel to form a solgel monolith.
Claim 3
Dependent Claim 20 words
A method of making a sol-gel monolith according to claim 1, wherein said oxide precursor is a metal oxide precursor.
Claim 4
Dependent Claim 21 words
A method of making a sol-gel monolith according to claim 2, wherein said metal oxide precursor is a silicon oxide precursor.
Claim 5
Dependent Claim 29 words
A method of making a sol-gel monolith according to claim 1, wherein said drying treatment is carried out at a temperature between about room temperature and about 200° C.
Claim 6
Dependent Claim 28 words
A method of making a sol-gel monolith according to claim 4, wherein said drying treatment is carried out at a temperature between about 40° and about 160° C.
Claim 7
Dependent Claim 23 words
A method of making a sol-gel monolith according to claim 1, wherein said drying treatment is carried out for at least two hours.
Claim 8
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 6, wherein said drying treatment is carried out for from about two hours to about fifteen days.
Claim 9
Dependent Claim 26 words
A method of making a sol-gel monolith according to claim 7, wherein said drying treatment is carried out for from about two to about seventy hours.
Claim 10
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 1, wherein the relative humidity of said high humidity environment is from about 50% to about 100%.
Claim 11
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 9, wherein the relative humidity of said high humidity environment is from about 80% to about 100%.
Claim 12
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 10, wherein the relative humidity of said high humidity environment is from about 95% to about 100%.
Claim 13
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 1, wherein said heating in a high humidity environment is carried out at a temperature between about 40° C. and about 200° C.
Claim 14
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 1, wherein said heating in a high humidity environment is carried out for at least two hours.
Claim 15
Dependent Claim 31 words
A method of making a sol-gel monolith according to claim 13, wherein said heating in a high humidity environment is carried out for from about two hours to about fifteen days.
Claim 16
Dependent Claim 31 words
A method of making a sol-gel monolith according to claim 14, wherein said heating in a high humidity environment is carried out for from about two hours to about seventy hours.
Claim 17
Dependent Claim 28 words
A method of making a sol-gel monolith according to claim 1, wherein said heating in a high humidity environment is carried out while immersing said gel in water.
Claim 18
Dependent Claim 32 words
A method of making a sol-gel monolith according to claim 1, wherein the relative humidity of said low humidity environment is from about 50% to less than about 5 parts per million.
Claim 19
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 1, wherein said heating in a low humidity environment is carried out at a temperature between about 40° C and about 200° C.
Claim 20
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 1, wherein said heating in a low humidity environment is carried out for a time from about one hour to about seventy hours.
Claim 21
Dependent Claim 45 words
A method of making a sol-gel monolith according to claim 1, wherein, if any organic solvent is present in the liquid of step (a), the molar ratio of the organic solvent to the oxide precursor used in step (a) is between about 0 and 100.
Claim 22
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 20, wherein no organic solvent is supplied from an external source to the liquid of step (a).
Claim 23
Dependent Claim 26 words
A method of making a sol-gel monolith according to claim 1, wherein said sol is filtered to remove undesirable particulate inclusions during said casting step (b).
Claim 24
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 22, wherein said sol is filtered with a nonreactive membrane having a pore size of less than about 0.1 to about 5 microns.
Claim 25
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 1, wherein said gelling step (c) is carried out at a temperature between the freezing point and the boiling point of said sol.
Claim 26
Dependent Claim 29 words
A method of making a sol-gel monolith according to claim 24, wherein said gelling step (c) is carried out at a temperature between about 18° and about 25° C.
Claim 27
Dependent Claim 28 words
A method of making a sol-gel monolith according to claim 1, wherein said gelling step (c) is carried out for from about two hours to about one month.
Claim 28
Dependent Claim 28 words
A method of making a sol-gel monolith according to claim 26, wherein said gelling step (c) is carried out for from about two hours to about seven days.
Claim 29
Dependent Claim 37 words
A method of making a sol-gel monolith according to claim 1, wherein said aging step (d) is carried out at a temperature between the freezing point of the interstitial liquid of the gel and about 250° C.
Claim 30
Dependent Claim 30 words
A method of making a sol-gel monolith according to claim 28, wherein said aging step (d) is carried out at a temperature of from about 15° to about 80° C.
Claim 31
Dependent Claim 28 words
A method of making a sol-gel monolith according to claim 1, wherein said aging step (d) is carried out for from about two hours to about one month.
Claim 32
Dependent Claim 27 words
A method of making a sol-gel monolith according to claim 30, wherein said aging step (d) is carried out for from about two to about five days.
Claim 33
Dependent Claim 48 words
A method of making a sol-gel monolith according to claim 1, wherein, during said aging step (d), said gel is subjected to at least one treatment wherein said gel is held at a constant temperature for a period of time between about one hour and about 24 hours.
Claim 34
Dependent Claim 37 words
A method of making a sol-gel monolith according to claim 1, wherein said densifying step (f) is carried out at a temperature between about the maximum temperature of the drying step (e) up to about 1400° C.
Claim 35
Dependent Claim 32 words
A method of making a sol-gel monolith according to claim 1, wherein, during said densifying step (f), the temperature is increased at a rate of from about 10 to about 500° C./hour.
Claim 36
Dependent Claim 45 words
A method of making a sol-gel monolith according to claim 1, wherein, during said densifying step (f), said gel is subjected to at least one treatment wherein said gel is held at a constant temperature for a period of about 1 to about 6 hours.
Claim 37
Dependent Claim 49 words
A method of making a sol-gel monolith according to claim 1, wherein said densifying step (f) is carried out in a flow of dried atmospheric air or inert gas or in a flow of dried gas containing at least 1% oxygen, 1% chlorine, 1% fluorine or a combination thereof.
Claim 38
Dependent Claim 26 words
A method of making a sol-gel monolith according to claim 36, wherein said flow rate is between zero and several hundred standard cubic feet per hour.
Claim 39
Dependent Claim 24 words
A method of making a sol-gel monolith according to claim 1, wherein, during said densifying step (f), said sol-gel monolith is only partially densified.
Claim 40
Dependent Claim 23 words
A method of making a sol-gel monolith according to claim 1, wherein, during said densifying step (f), said sol-gel monolith is fully densified.
Claim 41
Dependent Claim 31 words
A method of making a sol-gel monolith according to claim 1, wherein, during said densifying step (f), an anitdiffusion system is used to prevent the retrodiffusion of impurities from the exhaust.
Claim 42
Dependent Claim 23 words
A method of making a sol-gel monolith according to claim 1, further comprising the step of sealing the surface of said sol-gel monolith.
Claim 43
Dependent Claim 29 words
A method of making a sol-gel monolith according to claim 41, wherein said sealing is carried out by subjecting the surface porosity of said sol-gel monolith to localized heating.
Claim 44
Dependent Claim 29 words
A method of making a sol-gel monolith according to claim 41, wherein said sealing is carried out by applying a polymer coating onto the surface of said sol-gel monolith.
Claim 45
Dependent Claim 33 words
A method of making a sol-gel monolith according to claim 41, wherein said sealing is carried out by subjecting said monolith to low temperature densification with surface doping of low valence fluxing additives.
Claim 46
Independent Claim 37 words
A method of drying a gel, which comprises: (i) heating said gel in a high humidity environment; and then (ii) heating said gel in a low humidity environment to remove liquid from the pores of said gel.
Claim 47
Independent Claim 37 words
A method of drying a gel, which comprises: (i) heating said gel in a high humidity environment; and then (ii) heating said gel in a low humidity environment to remove liquid from the pores of said gel.
Claim 48
Dependent Claim 27 words
A method of drying a gel according to claim 45, wherein said drying is carried out at a temperature between about room temperature and about 200° C.
Claim 49
Dependent Claim 26 words
A method of drying a gel according to claim 46, wherein said drying is carried out at a temperature between about 40° and about 160° C.
Claim 50
Dependent Claim 21 words
A method of drying a gel according to claim 45, wherein said drying is carried out for at least two hours.
Claim 51
Dependent Claim 25 words
A method of drying a gel according to claim 48, wherein said drying is carried out for from about two hours to about fifteen days.
Claim 52
Dependent Claim 24 words
A method of drying a gel according to claim 49, wherein said drying is carried out for from about two to about seventy hours.
Claim 53
Dependent Claim 26 words
A method of drying a gel according to claim 45, wherein the relative humidity of said high humidity environment is from abut 50% to about 100%.
Claim 54
Dependent Claim 26 words
A method of drying a gel according to claim 51, herein the relative humidity of said high humidity environment is from about 80% to about 100%.
Claim 55
Dependent Claim 26 words
A method of drying a gel according to claim 52, wherein the relative humidity of said high humidity environment is from about 95% to about 100%.
Claim 56
Dependent Claim 32 words
A method of drying a gel according to claim 45, wherein said heating in a high humidity environment is carried out at a temperature between about 40° C. and about 200° C.
Claim 57
Dependent Claim 26 words
A method of drying a gel according to claim 45, wherein said heating in a high humidity environment is carried out for at least two hours.
Claim 58
Dependent Claim 30 words
A method of drying a gel according to claim 55, wherein said heating in a high humidity environment is carried out for from about two hours to about fifteen days.
Claim 59
Dependent Claim 30 words
A method of drying a gel according to claim 56, wherein said heating in a high humidity environment is carried out for from about two hours to about seventy hours.
Claim 60
Dependent Claim 27 words
A method of drying a gel according to claim 45, wherein said heating in a high humidity environment is carried out while immersing said gel in water.
Claim 61
Dependent Claim 31 words
A method of drying a gel according to claim 45, wherein the relative humidity of said low humidity environment is from about 50% to less than about 5 parts per million.
Claim 62
Dependent Claim 32 words
A method of drying a gel according to claim 45, wherein said heating in a low humidity environment is carried out at a temperature between about 40° C. and about 200° C.
Claim 63
Dependent Claim 32 words
A method of drying a gel according to claim 45, wherein said heating in a low humidity environment is carried out for a time from about one hour to about seventy hours.

References Cited (Backward Citations)

US4272894A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-12-30 1995-07-01 1995-12-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-12-30 1999-07-01 1999-12-31 $3760.00 Window Closed / Lapsed
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