US5262199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating porous materials with metal oxides and other ceramics by MOCVD
Assignee: Virginia Tech Intellectual Properties Inc
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Filing: 1992-04-17
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Granted: 1993-11-16
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Expires: 2012-04-17
Abstract
Abstract Metal organic chemical vapor deposition (MOCVD) is used to form a layer of a metal oxide on the surfaces and within the pores of a porous ceramic material. The metal oxide is formed from one or more inexpensive metal organic precursors which permeate the pores of the substrate as a vapor. Surface reactions on the heated substrate convert the metal organic precursors to their metal oxide. The technique has particular utility in creating catalysts with very large surface areas and in providing a protective coating on ceramic materials that prevents or reduces damage from hostile environments. In a preferred embodiment, aluminum isopropoxide, [(CH3)2CHO]3 Al, and titanium ethoxide, Ti(C2H5O)4, are used simultaneously or successively as precursors to generate a Al2TiO5 coating on a porous ceramic substrate such as SiC or porous refractory cement candle filters.
Inventors
- 👤 Seshu Desu
- 👤 Chien-Hsiung Peng
- 👤 Tian Shi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:55
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B01; B01J; B01J37/00; B01J37/02; B01J37/0215; B01J37/0238; B01J37/08; B01J37/082; B01J37/086; C04B41/45; C04B41/4505; C04B41/455; C04B41/4554; C04B41/50; C04B41/5025; C04B41/5041; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C23; C23C; C23C16/00; C23C16/04; C23C16/045; C23C16/22; C23C16/30; C23C16/40; C04B2111/00; C04B2111/00474; C04B2111/00793; C04B2111/0081
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
124 words
A method of coating Al 2 TiO 5 on a substrate, comprising the steps of: placing a substrate in an environment which can be heated and evacuated to subatmospheric pressures; introducing a vaporized aluminum organic compound into said environment and allowing said vaporized aluminum organic compound to contact said substrate; introducing a vaporized titanium organic compound into said environment and allowing said vaporized titanium organic compound to contact said substrate; converting said aluminum organic compound and said titanium organic compounds to Al 2 O 3 and TiO 2 , respectively, on said substrate; and heating said substrate with said Al 2 O 3 and said TiO 2 to a temperature and for a time sufficient to create Al 2 TiO 5 on said substrate.
Claim 2
Independent Claim
124 words
A method of coating Al 2 TiO 5 on a substrate, comprising the steps of: placing a substrate in an environment which can be heated and evacuated to subatmospheric pressures; introducing a vaporized aluminum organic compound into said environment and allowing said vaporized aluminum organic compound to contact said substrate; introducing a vaporized titanium organic compound into said environment and allowing said vaporized titanium organic compound to contact said substrate; converting said aluminum organic compound and said titanium organic compounds to Al 2 O 3 and TiO 2 , respectively, on said substrate; and heating said substrate with said Al 2 O 3 and said TiO 2 to a temperature and for a time sufficient to create Al 2 TiO 5 on said substrate.
Claim 3
Dependent Claim
24 words
A method as recited in claim 1 wherein said steps of introducing said aluminum organic compound and introducing said titanium organic compound occur sequentially.
Claim 4
Dependent Claim
24 words
A method as recited in claim 1 wherein said steps of introducing said aluminum organic compound and introducing said titanium organic compound occur simultaneously.
Claim 5
Dependent Claim
47 words
A method as recited in claim 1 wherein said step of converting includes the step of heating said substrate to a temperature and for a time sufficient to create a layer of Al 2 O 3 on a surface of said substrate from said aluminum organic compound.
Claim 6
Dependent Claim
15 words
A method as recited in claim 4 wherein said aluminum organic compound is aluminum isopropoxide.
Claim 7
Dependent Claim
45 words
A method as recited in claim 1 wherein said step of converting includes the step of heating said substrate to a temperature and for a time sufficient to create a layer of TiO 2 on a surface of said substrate from said titanium organic compound.
Claim 8
Dependent Claim
15 words
A method as recited in claim 6 wherein said titanium organic compound is titanium ethoxide
Claim 9
Dependent Claim
22 words
A method as recited in claim 1 wherein said step of heating is performed at approximately 1400° C. for approximately one hour.
Claim 10
Independent Claim
174 words
A method of coating Al 2 TiO 5 on a porous ceramic filter, comprising the steps of: placing a porous ceramic filter in an environment which can be heated and evacuated to subatmospheric pressures; introducing a vaporized aluminum organic compound into said environment and allowing said vaporized aluminum organic compound to permeate the pores of said porous ceramic filter and contact the interior and exterior surfaces of said porous ceramic filter; introducing a vaporized titanium organic compound into said environment and allowing said vaporized titanium organic compound to permeate the pores of said porous ceramic filter and contact the interior and exterior surfaces of said porous ceramic filter; converting said aluminum organic compound and said titanium organic compounds to Al 2 O 3 and TiO 2 , respectively, on said interior and exterior surfaces of said porous ceramic filter; and heating said porous ceramic filter with said Al 2 O 3 and said TiO 2 to a temperature and for a time sufficient to create Al 2 TiO 5 on said porous ceramic filter.
Claim 11
Independent Claim
174 words
A method of coating Al 2 TiO 5 on a porous ceramic filter, comprising the steps of: placing a porous ceramic filter in an environment which can be heated and evacuated to subatmospheric pressures; introducing a vaporized aluminum organic compound into said environment and allowing said vaporized aluminum organic compound to permeate the pores of said porous ceramic filter and contact the interior and exterior surfaces of said porous ceramic filter; introducing a vaporized titanium organic compound into said environment and allowing said vaporized titanium organic compound to permeate the pores of said porous ceramic filter and contact the interior and exterior surfaces of said porous ceramic filter; converting said aluminum organic compound and said titanium organic compounds to Al 2 O 3 and TiO 2 , respectively, on said interior and exterior surfaces of said porous ceramic filter; and heating said porous ceramic filter with said Al 2 O 3 and said TiO 2 to a temperature and for a time sufficient to create Al 2 TiO 5 on said porous ceramic filter.
Claim 12
Dependent Claim
24 words
A method as recited in claim 9 wherein said steps of introducing said aluminum organic compound and introducing said titanium organic compound occur sequentially.
Claim 13
Dependent Claim
24 words
A method as recited in claim 9 wherein said steps of introducing said aluminum organic compound and introducing said titanium organic compound occur simultaneously.
Claim 14
Dependent Claim
54 words
A method as recited in claim 9 wherein said step of converting includes the step of heating said porous ceramic filter to a temperature and for a time sufficient to create a layer of Al 2 O 3 on said interior and exterior surfaces of said porous ceramic filter from said aluminum organic compound.
Claim 15
Dependent Claim
15 words
A method as recited in claim 12 wherein said aluminum organic compound is aluminum isopropoxide.
Claim 16
Dependent Claim
52 words
A method as recited in claim 9 wherein said step of converting includes the step of heating said porous ceramic filter to a temperature and for a time sufficient to create a layer of TiO 2 on said interior and exterior surfaces of said porous ceramic filter from said titanium organic compound.
Claim 17
Dependent Claim
15 words
A method as recited in claim 14 wherein said titanium organic compound is titanium ethoxide.
Claim 18
Dependent Claim
22 words
A method as recited in claim 9 wherein said step of heating is performed at approximately 14000° C. for approximately one hour.
Claim 19
Independent Claim
74 words
A method for creating an Al 2 TiO 2 5 film, comprising the steps of: providing a sapphire substrate; vaporizing a titanium organic compound; depositing the vaporized titanium organic compound on said sapphire substrate; converting said titanium organic compound deposited on said substrate to TiO 2 ; and heating said sapphire substrate to a temperature and for a time sufficient to react said sapphire substrate with said TiO 2 to form AlTiO 5 .
Claim 20
Independent Claim
74 words
A method for creating an Al 2 TiO 2 5 film, comprising the steps of: providing a sapphire substrate; vaporizing a titanium organic compound; depositing the vaporized titanium organic compound on said sapphire substrate; converting said titanium organic compound deposited on said substrate to TiO 2 ; and heating said sapphire substrate to a temperature and for a time sufficient to react said sapphire substrate with said TiO 2 to form AlTiO 5 .
Claim 21
Dependent Claim
15 words
A method as recited in claim 17 wherein said titanium organic compound is titanium ethoxide.
Claim 22
Dependent Claim
21 words
A method as recited in claim 17 wherein said heating step is performed at approximately 1400° C. for approximately one hour.
Claim 23
Independent Claim
106 words
a method of coating a porous material with a metal oxide or ceramic layer, comprising the steps of: placing a porous material having a pore size on the order of 100 μm in an environment which can be heated and evacuated to subatmospheric pressures; introducing at least two different vaporized metal or ceramic organic precursor compounds into said environment using vacuum pressure; allowing said two different vaporized metal or ceramic organic precursor compounds to permeate into pores in said porous material; and converting said metal or ceramic organic precursor compounds into a combined metal oxide or ceramic on internal and external surfaces of said porous material.
Claim 24
Independent Claim
106 words
a method of coating a porous material with a metal oxide or ceramic layer, comprising the steps of: placing a porous material having a pore size on the order of 100 μm in an environment which can be heated and evacuated to subatmospheric pressures; introducing at least two different vaporized metal or ceramic organic precursor compounds into said environment using vacuum pressure; allowing said two different vaporized metal or ceramic organic precursor compounds to permeate into pores in said porous material; and converting said metal or ceramic organic precursor compounds into a combined metal oxide or ceramic on internal and external surfaces of said porous material.
Claim 25
Dependent Claim
40 words
A method as recited in claim 20 wherein said step of introducing includes the step of bubbling nitrogen gas through said metal or ceramic organic precursor compound when said metal or ceramic organic precursor compouond is in a liquid state.
Claim 26
Dependent Claim
147 words
A method as receited in claim 20 wherein said metal or ceramic organic precursor compound is selected from the group consisting of Al(C 3 H 7 O) 3 , [ZR(C 11 H 19 O 2 ) 4 ], [ZR(C 4 H 9 O) 4 ], [Ti(C 3 H 7 O) 4 ], [Y(C 11 H 19 O 2 ) 3 ], [SC(C 11 H 19 O 2 ) 3 ], [SR(C 11 H 19 O 2 ) 2 ], [Ta(C 2 H 5 O) 5 ], [Ca(C 11 H 19 O 2 ) 2 ], Si[N(CH 3 ) 2 ] 4 , Ti[N(CH 3 ) 2 ] 4 , Zr[N(C 2 H 5 ) 2 ] 4 , [(CH 3 ) 2 AlNH 2 ] 3 , CH 3 SiCl 3 , C 2 H 5 TiCl 3 , and C 5 H 5 ZrCl 3 .
Claim 27
Dependent Claim
24 words
A method as recited in claim 20 wherein said metal or ceramic organic precursor compounds primarily react by surface reaction on said porous material.
Claim 28
Dependent Claim
23 words
A method as recited in claim 23 wherein said metal or ceramic organic precursor compound is Ti(C 3 H 7 O) 4 .
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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) | 1996-11-15 | 1997-05-17 | 1997-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-15 | 2001-05-17 | 2001-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-15 | 2005-05-17 | 2005-11-16 | $7700.00 | Window Closed / Lapsed |