WO1998012548A1 - Detecteur de gaz - Google Patents
Detecteur de gaz Download PDFInfo
- Publication number
- WO1998012548A1 WO1998012548A1 PCT/JP1997/003318 JP9703318W WO9812548A1 WO 1998012548 A1 WO1998012548 A1 WO 1998012548A1 JP 9703318 W JP9703318 W JP 9703318W WO 9812548 A1 WO9812548 A1 WO 9812548A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- gas
- carbon
- metal
- carbon mixture
- current
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/0004—Gaseous mixtures, e.g. polluted air
- G01N33/0009—General constructional details of gas analysers, e.g. portable test equipment
- G01N33/0027—General constructional details of gas analysers, e.g. portable test equipment concerning the detector
- G01N33/0036—Specially adapted to detect a particular component
- G01N33/0054—Specially adapted to detect a particular component for ammonia
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Definitions
- the present invention relates to a gas sensor material.
- a gas sensor responds to a specific gas contained in a gas such as air and emits an electric signal, an optical signal, and the like according to the concentration.
- gas sensors of various detection methods are known, and gas components are often recognized by using chemical properties of gas, such as adsorption, reaction, and luminescence.
- energy conversion type such as battery electromotive force, in which a sensor signal can be obtained directly by contact with a gas.However, in many cases, changes in material properties such as electric resistance and changes in the Depeise characteristics such as transistor characteristics are converted into sensor signals. Energy control type.
- Exemplary gas sensor material, S n O 2 system is relatively irreducible oxides, include the Z eta theta system, etc., S n 0 2
- Most current commercial devices are ri semiconductor It is a porous sintered body.
- Semiconductor gas sensors using such oxide semiconductors are classified into surface-control type sensors in which the interaction with the gas remains on the semiconductor surface and bulk-control type sensors in which the interaction with the gas extends to the semiconductor body. Many are surface controlled. In such a surface control type sensor, a chemical reaction occurs on the semiconductor surface, but pure semiconductors alone often do not have sufficient activity, and fine particles of noble metal / metal oxide are dispersed on the surface of semiconductor particles. The sensor function has been improved.
- a main object of the present invention is to provide a sensor material that can detect gas at room temperature and that is excellent in gas type selectivity.
- the carbon mixture containing fullerene obtained by the carbon electrode-arc method adsorbs a polar gas at room temperature and does not adsorb a reactive gas. It has been found that the gas sensor has a unique gas adsorption characteristic, and that it is composed of carbon and carbon, has a large surface area, has electrical conductivity, and can be electrically measured. After examining the usefulness of the material, we found that it would be a gas sensor material that could detect gas at room temperature and had excellent gas selectivity. Furthermore, a carbon mixture containing a metal obtained by causing a metal component to be included in carbon TO used for arc discharge and using the resultant as an alloy to improve arc detection ability and selectivity to gas is improved. The present invention was completed here.
- the present invention provides the following gas sensor materials:
- the current density for the discharge conductive surface of the electrode is 0. 8 ⁇ 3. 5 A / mm 2 to become a direct current Or a gas sensor material consisting of a carbon mixture obtained as an evaporant by arc discharge generated by passing an alternating current.
- the current density on the discharge surface of the electrode is reduced by using a metal-containing carbon electrode containing 0.01 to 30% by weight of a metal component.
- a gas sensor material comprising a metal-containing carbon mixture obtained as an evaporant by an arc discharge generated by applying a direct current or an alternating current of 0.8 to 3.5 A / mm 2 .
- FIG. 1 is a schematic diagram of the arc discharge device used in Example 1.
- FIG. 2 is a graph showing the results of an ammonia gas detection test using the carbon mixture obtained in Example 1.
- FIG. 3 is a graph showing the results of an ammonia gas detection test using the Ni-containing carbon mixture obtained in Example 2.
- FIG. 4 is a graph showing the results of a detection test of triethylamine using the Ni-containing carbon mixture obtained in Example 2.
- FIG. 5 is a graph showing the results of a nitric oxide gas detection test using the Ni-containing carbon mixture obtained in Example 2.
- FIG. 6 is a graph showing a detection test result of nitrogen trifluoride gas using the Ni-containing carbon mixture obtained in Example 2.
- the carbon mixture used as a gas sensor material in the present invention is obtained by an arc discharge method using carbon in an inert gas.
- a vacuum device for ordinary arc discharge can be used as a device for discharging the carbon mixture.
- the inert gas for example, helium, argon, neon, krypton, xenon and the like can be used.
- the pressure of the inert gas is about 0.1 to 600 Torr, preferably about 10 to 400 Torr.
- the arc discharge can be performed by applying a direct current or an alternating current, and the current density on the discharge surface of carbon, that is, the current on the surface of the cathode and the anode facing each other at a certain interval. density, and 0. 8 ⁇ 3. 5 a / mm 2 approximately.
- a carbon mixture obtained by such a method is used as a gas sensor material.
- This carbon mixture is what is called carbon soot, and is usually obtained by adhering to a device in the form of powder.
- the carbon mixture is usually ultrafine carbon particles having a diameter of about 1 nm to about 100 / m, and is mainly composed of graphite carbon, amorphous carbon, and fullerenes. 15% by weight included ⁇
- a metal component is contained in the carbon mixture, and this can be used as a gas sensor material.
- the detection sensitivity to gas is improved, and depending on the type of metal to be contained, specific characteristics are exhibited, and the selectivity to gas is also improved.
- the output of DC current is replaced (Rule 26).
- the format becomes extremely unique, making it easier to identify gas types.
- a typical elemental metal and a transition metal can be used as the metal component, and specific examples thereof include B, Mg, Al, S i, and In And transition metals such as La, Ni, Co, Fe, Cr, Ta, Mn, Mo, Ti, Au, Pd, Pt, and Ag. be able to.
- the metal component can be used singly or as a mixture of two or more types, and its content is suitably about 0.01 to 30% by weight in the sensor material.
- a carbon mixture containing a metal can be obtained by performing arc discharge in an inert gas using a carbon electrode containing a metal in the same manner as in the above-described method for producing a carbon mixture.
- the shape of the carbon electrode is not particularly limited, and may be the same as that used for normal arc discharge.
- the content of the metal component in the TO is evaporated by the arc discharge. It suffices that the metal content of the electrode portion that disappears be the same as the metal content in the carbon mixture generated by arc discharge, which is the target.
- ® can be made to contain metal by the method of uniformly mixing carbon and metal powder to make ⁇ 1, the carbon ⁇ ⁇ 1 with voids, and the powder ⁇ , linear, and block Although there is a method of filling a metal such as the above, any method may be used.
- the conditions of the arc discharge may be the same as those of the above-described arc discharge for obtaining the carbon mixture.
- the product obtained by the arc discharge using carbon containing metal is similar to the above-described carbon mixture.
- a mixture of ultrafine carbon particles having a diameter of about 1 nm to about 100 m and ultrafine metal particles of the same size is obtained.
- the ultrafine carbon particles are composed of graphite carbon, amorphous carbon, and fullerenes, and generally about 0.1 to 15% by weight of the fullerenes are contained in the ultrafine carbon particles.
- the metal content of the gold-containing carbon mixture is the same as the metal content of the portion that has been emitted and lost by the arc discharge.
- a gas sensor can be obtained by using a carbon mixture or a metal-containing carbon mixture obtained by the above method as a sensor material.
- the shape of the gas sensor is not particularly limited, and may be the same as various known gas sensors.
- a carbon mixture or a metal-containing carbon mixture formed into pellets, spheres, etc., replacement paper (Rule 26) Paste-shaped carbon mixture or metal-containing carbon mixture printed on ceramic substrate, MOS-structured transistor, FET type with carbon mixture or metal-containing carbon mixture instead of metal it can.
- There is no particular limitation on the method of forming the isomer and it can be formed by pressing a carbon mixture or a metal-containing carbon mixture at a high pressure.
- hydrocarbons such as paraffin, polyvinyl acetate, and the like.
- Polyvinyl alcohol, carboxymethylcellulose, petroleum pitch, coal beach, etc. are used as a binder in an amount of about 5 to 10% by weight of the total amount, and the carbon mixture or the metal-containing carbon mixture and the binder are dispersed in water, alcohols, methylcellosolve, etc. After dispersing in a medium, it is molded into a desired shape, solidified and dried, heated at about 200 to 300 ° C, and, if necessary, baked at about 400 to 900 ° C. It can be a body. Alternatively, about 1 to 20% by weight of colloidal silica is added to a carbon mixture or a metal-containing carbon mixture, and the mixture is dried at room temperature to 200 ° C.
- a metal alkoxide solution for example, Si
- gas sensors can detect gas because the output voltage or output current changes in response to changes in gas concentration.
- a carbon mixture or a metal-containing carbon mixture can be fixed to a hydrogen oscillator, and gas can be detected by a frequency change of the hydrogen oscillator due to a weight change due to gas adsorption.
- the gas can be detected at room temperature, but the detection sensitivity may be low depending on the type of the detection gas. It may be heated to about 50 to 200 ° C.
- the heating method may be a method of continuously heating to a constant temperature.However, since the sensor material of the present invention has a property of adsorbing a gas at room temperature and releasing an adsorbed gas when heated, pulse heating is performed. The gas can be detected while forcibly releasing the adsorbed gas.
- the gas sensor material of the present invention has a unique characteristic that it is sensitive to polar gases and hardly sensitive to nonpolar gases such as methane, butane, and isobutane. In addition, even for polar gases, the form of current or voltage output differs depending on the gas type. However, since the gas type can be easily specified based on these characteristics, the sensor material has excellent selectivity.
- polar gases that can be detected using the sensor material of the present invention include amines such as ammonia and methylamine, which are gases containing an amino group; and sulfur, such as methylmercaptan, which is a gas containing a thiol group.
- oxides such as NOx and SOx, which are oxygen-containing gases
- fluorocarbons and trifluorinated gases such as methane tribromide and dichloromethane, which are fluorine-containing gases
- Nitrogen chloride (NF 3 ) chlorinated compounds such as dichlorosilane and trichlorosilane, which are gases containing chlorine atoms
- water such as arsine (A s H 3 ) and phosphine (PH 3 ), which are gases containing hydrogen atoms Fluorinated compounds and the like.
- a carbon mixture was produced using the carbon electrode arc discharge device shown in FIG.
- the direct current power source 4 is used to apply a discharge surface (electrode) to the carbon electrodes 1 and 2.
- a current was applied so that the current density on the surfaces facing each other was about 2 A / mm 2 , arc discharge was performed, and the carbon mixture was evaporated.
- industrial nitrogen gas was introduced into the vacuum chamber 3 to make the inside of the chamber large, and the carbon mixture adhered to the inside of the vacuum chamber 3 was taken out.
- the obtained pellets were tested for ammonia gas detection at room temperature by the four-terminal method described below.
- a cylindrical hole with a diameter of 3.2 mm and a depth of 15 mm was drilled at the center of one bottom surface of a cylindrical carbon rod with a diameter of 2 O mm and a length of 50 O mm. (200 mesh) was filled with 0.9 g to prepare a carbon electrode containing nickel. These were used as anode 1 and cathode 2 and the surfaces filled with nickel were opposed to each other at regular intervals to form a discharge surface.
- the same carbon arc discharge device as in Example 1 the same conditions as in Example 1 were used. An arc discharge was performed at, and was evaporated to obtain a carbon mixture containing nickel as a deposit inside the vacuum chamber. The resulting mixture contained 2.95% by weight of nickel having a particle size of about 200 angstroms.
- a gas detection test was performed using the nickel-containing carbon mixture thus obtained as a gas sensor material.
- Example 3 As the test device, the same test device as in Example 1 was used, and the nickel-containing carbon mixture was pelletized in the same manner as in Example 1. Four terminals were taken out from this as in Example 1, and 0 was connected to the two terminals at both ends. After a current of lmmA was passed, ammonia gas was injected into the container at 5 ppm using a micro syringe, and after a certain period of time, the output change of the DC current when the lid of the container was opened was determined. The results are shown in Figure 3.
- Fig. 5 shows the test results for nitric oxide gas
- Fig. 6 shows the test and test results for nitrogen trifluoride gas.
- the nickel-containing carbon mixture shows excellent sensitivity to various polar gases, and the output type specific to each type of gas is changed depending on the gas type. ) As shown, it is excellent in selectivity of gas type. In particular, since the nitrogen trifluoride gas has a special output power type different from other gases, it is easy to specify the gas type. Industrial applicability
- a carbon mixture or a metal-containing carbon mixture obtained by arc discharge was used as it was without purification, and no operation such as purification was required. There is no adverse effect such as the generation of materials and the increase in cost.
- the sensor material is very useful because it can detect gas at room temperature and is excellent in gas type selectivity.
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/101,106 US6105417A (en) | 1996-09-20 | 1997-09-19 | Gas sensor |
EP97941203A EP0869355A4 (en) | 1996-09-20 | 1997-09-19 | GAS SENSOR |
KR1019980703888A KR19990071612A (ko) | 1996-09-20 | 1997-09-19 | 가스센서 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8249412A JP3047062B2 (ja) | 1996-09-20 | 1996-09-20 | ガスセンサ |
JP8/249412 | 1996-09-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998012548A1 true WO1998012548A1 (fr) | 1998-03-26 |
Family
ID=17192596
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1997/003318 WO1998012548A1 (fr) | 1996-09-20 | 1997-09-19 | Detecteur de gaz |
Country Status (5)
Country | Link |
---|---|
US (1) | US6105417A (ja) |
EP (1) | EP0869355A4 (ja) |
JP (1) | JP3047062B2 (ja) |
KR (1) | KR19990071612A (ja) |
WO (1) | WO1998012548A1 (ja) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6346189B1 (en) * | 1998-08-14 | 2002-02-12 | The Board Of Trustees Of The Leland Stanford Junior University | Carbon nanotube structures made using catalyst islands |
US7416699B2 (en) * | 1998-08-14 | 2008-08-26 | The Board Of Trustees Of The Leland Stanford Junior University | Carbon nanotube devices |
US6245280B1 (en) * | 1999-06-21 | 2001-06-12 | Energy Conversion Devices, Inc. | Method and apparatus for forming polycrystalline particles |
US6321587B1 (en) * | 1999-10-15 | 2001-11-27 | Radian International Llc | Solid state fluorine sensor system and method |
DE69925317D1 (de) * | 1999-11-23 | 2005-06-16 | Mat & Electrochem Res Corp | Lagerung von gasen mit hilfe von auf fulleren basierten sorbentien |
TW523960B (en) * | 2000-09-29 | 2003-03-11 | Sony Corp | Method of producing fuel cell |
US7183228B1 (en) | 2001-11-01 | 2007-02-27 | The Board Of Trustees Of The Leland Stanford Junior University | Carbon nanotube growth |
US7022541B1 (en) | 2001-11-19 | 2006-04-04 | The Board Of Trustees Of The Leland Stanford Junior University | Patterned growth of single-walled carbon nanotubes from elevated wafer structures |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06118042A (ja) * | 1992-10-08 | 1994-04-28 | Kyocera Corp | ガスセンサ素子 |
JPH06213852A (ja) * | 1992-06-27 | 1994-08-05 | Draegerwerk Ag | 流体媒体中の被検体を検出するためのセンサ |
JPH0772108A (ja) * | 1993-08-31 | 1995-03-17 | Sony Corp | 水蒸気センサ |
JPH07237912A (ja) * | 1994-02-28 | 1995-09-12 | Univ Nagoya | フラーレン類の製造方法及びその製造装置 |
JPH07257916A (ja) * | 1994-03-22 | 1995-10-09 | Tokai Carbon Co Ltd | フラーレン類の製造方法および装置 |
JPH07315819A (ja) * | 1994-05-19 | 1995-12-05 | Toyo Tanso Kk | フラーレン類製造用原料及びフラーレン類の製造方法 |
JPH08165112A (ja) * | 1994-12-08 | 1996-06-25 | Tokai Carbon Co Ltd | フラーレン類の製造装置 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3422053C2 (de) * | 1984-06-14 | 1986-07-17 | Matter + Siegmann Ag, Wohlen | Verfahren zur quantitativen und/oder qualitativen Erfassung von Substanzen |
US5227038A (en) * | 1991-10-04 | 1993-07-13 | William Marsh Rice University | Electric arc process for making fullerenes |
US5413689A (en) * | 1992-06-12 | 1995-05-09 | Moltech Invent S.A. | Carbon containing body or mass useful as cell component |
US5876684A (en) * | 1992-08-14 | 1999-03-02 | Materials And Electrochemical Research (Mer) Corporation | Methods and apparati for producing fullerenes |
US5393955A (en) * | 1993-01-14 | 1995-02-28 | Simmons; Walter N. | Preparation of fullerenes and apparatus therefor |
US5470680A (en) * | 1993-03-19 | 1995-11-28 | Materials And Electrochemical Research Corp. | Electrochemical fullerene system |
US5350794A (en) * | 1993-07-22 | 1994-09-27 | E. I. Du Pont De Nemours And Company | Aliphatic polyamide compositions and fibers |
US5547748A (en) * | 1994-01-14 | 1996-08-20 | Sri International | Carbon nanoencapsulates |
JP2611179B2 (ja) * | 1994-02-25 | 1997-05-21 | 工業技術院長 | フラーレンの製造方法及び装置 |
CA2120682C (en) * | 1994-04-06 | 1999-02-23 | Sabatino Nacson | Improved apparatus for rapid and specific detection of organic vapours |
-
1996
- 1996-09-20 JP JP8249412A patent/JP3047062B2/ja not_active Expired - Lifetime
-
1997
- 1997-09-19 US US09/101,106 patent/US6105417A/en not_active Expired - Fee Related
- 1997-09-19 EP EP97941203A patent/EP0869355A4/en not_active Withdrawn
- 1997-09-19 WO PCT/JP1997/003318 patent/WO1998012548A1/ja not_active Application Discontinuation
- 1997-09-19 KR KR1019980703888A patent/KR19990071612A/ko not_active Application Discontinuation
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06213852A (ja) * | 1992-06-27 | 1994-08-05 | Draegerwerk Ag | 流体媒体中の被検体を検出するためのセンサ |
JPH06118042A (ja) * | 1992-10-08 | 1994-04-28 | Kyocera Corp | ガスセンサ素子 |
JPH0772108A (ja) * | 1993-08-31 | 1995-03-17 | Sony Corp | 水蒸気センサ |
JPH07237912A (ja) * | 1994-02-28 | 1995-09-12 | Univ Nagoya | フラーレン類の製造方法及びその製造装置 |
JPH07257916A (ja) * | 1994-03-22 | 1995-10-09 | Tokai Carbon Co Ltd | フラーレン類の製造方法および装置 |
JPH07315819A (ja) * | 1994-05-19 | 1995-12-05 | Toyo Tanso Kk | フラーレン類製造用原料及びフラーレン類の製造方法 |
JPH08165112A (ja) * | 1994-12-08 | 1996-06-25 | Tokai Carbon Co Ltd | フラーレン類の製造装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP0869355A4 * |
Also Published As
Publication number | Publication date |
---|---|
EP0869355A1 (en) | 1998-10-07 |
JPH1090209A (ja) | 1998-04-10 |
JP3047062B2 (ja) | 2000-05-29 |
EP0869355A4 (en) | 1999-05-19 |
KR19990071612A (ko) | 1999-09-27 |
US6105417A (en) | 2000-08-22 |
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