CN201000441Y - Low temperature plasma discharge generating transient state free radical trapping device - Google Patents
Low temperature plasma discharge generating transient state free radical trapping device Download PDFInfo
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- CN201000441Y CN201000441Y CNU2006201091704U CN200620109170U CN201000441Y CN 201000441 Y CN201000441 Y CN 201000441Y CN U2006201091704 U CNU2006201091704 U CN U2006201091704U CN 200620109170 U CN200620109170 U CN 200620109170U CN 201000441 Y CN201000441 Y CN 201000441Y
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Abstract
The utility model discloses a trapping device of a transient free radical generated by low temperature plasma electric discharging. When the average electric field intensity is 10 kV per cm, the transient free radical in gas phase generated by the corona discharge of the low temperature plasma reacts with an auto rotating collecting agent in the solution, to form an auto rotating adduct, the strength of the auto rotating collecting agent solution is between 0. 001 mol/L to 0. 01 mol/L, the reacting time is 1 second to 100 seconds, when the reaction is over, 0.1 to 0.2 m L rotating collecting agent is put into a quartz flat sample tube, and tested with an electron spinning and resonance apparatus, and the category of the free radical is measured through the ESR spectral line morphology character generated by the auto rotating adduct, and the content is measured by the spectral line signal. The utility model utilizes the electron spinning trapping technology, a plurality kinds of transient free radical in gas phase generated by the reaction of the low temperature plasma can be trapped quickly through the auto rotating adduct reaction of the free radical in gas phase and the auto rotating collecting agent, and the character and the content are measured accurately through the scanning of the electron spinning and resonance apparatus. The utility model can realize the test of the free radical, and establish foundation for the mechanism research of the electric discharging of the low temperature plasma.
Description
Technical field
The utility model relates to the capturing device that a kind of discharge of plasma in low temperature produces free radicals in transient state.
Background technology
Free radical is the intermediate of many chemical reaction processes, and the separation of these active organic reaction fragments or reaction intermediate and evaluation are extremely important for understanding and proved response mechanism.But because its character is very active, life-span and of short duration (ns level) thereof may the further redox reactions of very fast experience and generate diamagnetic substance, and therefore effectively capturing free radical is main research work and difficult point.
The process that discharge of plasma in low temperature is administered waste gas or chemosynthesis mainly is that high-voltage corona energizing gas molecule produces strong oxidizing property material such as free radical and acts on the compound of administering in waste gas or the chemosynthesis.Therefore, capture the free radicals in transient state that produces in the plasma reaction accurately and play crucial effects for the mechanism of studying reaction of low temperature plasma.
At present, the capture method of free radical mainly utilizes its strong oxidizing property and other characteristic (as complex reaction, induced luminescence reaction etc.), can make some materials produce the change of structure, character and color, these changes can utilize certain analytical approach, detect as high performance liquid chromatography, spectrophotometer, laser-induced fluorescence (LIF) meter etc., utilize this principle can carry out the indirect determination of free radical.For example: salicylic acid is as trapping agent, and OH attacks salicylic acid and generates 2,3 one dihydroxy-benzoic acids (2,3-DHBA) with 2,5 one dihydroxy-benzoic acids (2,5 one DHBA) utilize high performance liquid chromatography (HPLC) to separate, utilization UV or electrochemical method are analyzed, can directly detect 2,3 one DHBA and 2,5-DHBA, thereby infer the content of OH indirectly, utilize the trapping agent of similar principles to also have isopropyl alcohol, benzoic acid, dimethyl sulfoxide (DMSO), phenol etc.; Electronics transition between energy level on the molecular orbit can take place with free radical reaction as trapping agent in serge blue (MB), bromopyrogallol red (BPR), alizarin violet, Phen-Fe, Fe-phenanthroline complex compound and NPG etc., produce molecular absorption spectrum, utilize spectrophotometer to detect; Utilizing yeast is luminous trapping agent, and luminol is the light intensity amplification agent, can calculate the amount of free radical by the luminous intensity variations of measuring trapping agent capture free radical reaction front and back.
Above-mentioned several method has all used certain free radical and trapping agent generation chemical reaction, thereby reaches the purpose of indirect measurement free radical.Because its course of reaction more complicated, a lot of intermediate products and branch line product are arranged, can not accurate qualitative free radical under a lot of situations, measurement result also often is subjected to a lot of interference, for example, can have multiplely with the material that trapping agent reacts sometimes, whether the testing result that above method obtains is that free radical and its reaction product are still waiting to determine, still is being apparent not enough aspect the accurate qualitative and quantitative of free radical.
The sixties spin trapping technique of development is widely used in photochemistry, galvanochemistry, superpolymer and field of biology.Its principle is the free radical that produces a kind of available ESR detection of quite stable with a kind of diamagnetism compound (spin catching agent) and unsettled free radical reaction. generally be referred to as spin adduct.The structure that people can come the research freedom base from the ESR constant (as hyperfine coupling constant, the g factor) of spin adduct, the feature ESR spectral line form that produces by spin adduct is determined the kind of free radical, the intensity of spectral line signal is determined its content.The spin catching agent that is adopted has very strong selectivity, generates metastable feature spin adduct with the free radical of particular types, demonstrates characteristic spectral line.In addition, a kind of spin catching agent usually can with multiple free radical reaction, demonstrate difform characteristic spectral line in ESR instrument kind, be qualitative, quantitative one of the method the most quickly and accurately of multiple free radical.
But, more than various trapping techniques all be that free radical in the liquid phase is captured and detects, both at home and abroad the capture method for gaseous phase free radical rarely has report, the multiple transient state gaseous phase free radical that particularly produces in the reaction of low temperature plasma.In Atmospheric Chemistry, mainly adopt laser fluorescence spectrum and long light path absorption spectroscopy, these methods are had relatively high expectations to the coupling of free-radical generator and detecting instrument, complicated operation, complicated and the difficult identification of measured spectral line, quantitatively difficulty causes its application to be very limited.
Summary of the invention
The purpose of this utility model is to provide a kind of discharge of plasma in low temperature to produce the capturing device of free radicals in transient state, and this device can trap the multiple transient state gaseous phase free radical that produces in the reaction of low temperature plasma accurately.
The technical scheme that its technical matters that solves the utility model adopts is:
Comprise that high-voltage DC power supply, upper wall have the tubular insulation crust of gas outlet, rotating nozzle type hollow metal corona discharge electrode, cylindric wire netting earthing pole, the insulating vessel that fills free radical spin catching agent solution and tubular insulation crust loam cake and form.Tubular insulation crust inwall is equipped with cylindric wire netting earthing pole, rotating nozzle type metal corona discharge electrode is contained in metal net shaped earthing pole center, and be fixed on the tubular insulation crust and cover, the lower end of rotating nozzle type metal corona discharge electrode and metal net shaped earthing pole lower end are in same surface level, the insulating vessel that fills free radical spin catching agent solution is positioned over reactor bottom, the positive pole of high-voltage DC power supply connects rotating nozzle type metal corona discharge electrode, minus earth.
Described rotating nozzle type hollow metal corona discharge electrode, its periphery is evenly equipped with the metallic nozzle of hollow, the metallic nozzle of hollow is connected with rotating nozzle type hollow metal corona discharge electrode, the metallic nozzle of hollow rotating nozzle type hollow metal corona discharge electrode radially to be the circumference equal angles uniform, axially in the shape of a spiral or many helical structures.
Discharge of plasma in low temperature produces in the capturing device of free radicals in transient state, under average field intensity 4～10kV/cm, the low temperature plasma corona discharge produces gaseous phase free radical, gaseous phase free radical that plasma discharge produces and the reaction of the spin catching agent in the solution form spin adduct, spin catching agent solution concentration 0.001～0.1mol/L, reaction time 1～100s, after reaction finishes, getting 0.1～0.2mL trapping solution packs into and detects with electron spin resonanceapparatus in the quartzy flat sample hose, the feature ESR spectral line form that produces by spin adduct is determined the kind of free radical, and the intensity of spectral line signal is determined its content.Described spin catching agent solution is water, benzene or phenixin.
The beneficial effect that the utlity model has is: utilize the electron spin trapping technique, the spin addition reaction takes place by transient state gaseous phase free radical and spin catching agent, trap the multiple transient state gaseous phase free radical that produces in the reaction of low temperature plasma first fast and accurately, and by the scanning of electron spin resonance (ESR) instrument, accurately qualitative, quantitative.This law can realize the detection of gaseous phase free radical, for the mechanism research of discharge of plasma in low temperature lays the foundation.
Description of drawings
Fig. 1 is free-radical generating and capturing device structure front elevation;
Fig. 2 is corona discharge electrode structural drawing and cutaway view Amplified image;
Fig. 3 is the ESR simulation spectrogram that DMPO captures the OH free radical;
Fig. 4 is the ESR simulation spectrogram that DMPO captures H (or CnH2n+1) free radical;
Fig. 5 is the ESR simulation spectrogram that DMPO captures the OO free radical;
Fig. 6 is the ESR spectrogram of spin catching agent DMPO-aqueous solution;
Fig. 7 is the ESR spectrogram of the inferior plasma corona discharge of air atmosphere DMPO-aqueous solution.
Among the figure: 1. high-voltage DC power supply, 2. gas outlet, 3. tubular insulation crust, 4. rotating nozzle type metal corona discharge electrode, 5. cylindric wire netting earthing pole, 6. assist gas air intake opening, 7. free radical spin catching agent solution, 8. insulating vessel, 9. tubular insulation crust loam cake, 10. metallic nozzle.
Embodiment
Below in conjunction with drawings and Examples the utility model is further specified.
As shown in Figure 1 and Figure 2, the utility model comprises that high-voltage DC power supply 1, upper wall have the tubular insulation crust 3 of gas outlet 2, rotating nozzle type hollow metal corona discharge electrode 4, cylindric wire netting earthing pole 5, the disk-shaped glass container 8 that fills free radical spin catching agent solution 7 and tubular insulation crust loam cake 9 and form; Cylindric wire netting earthing pole 5 is housed in the tubular insulation crust 3, rotating nozzle type metal corona discharge electrode 4 is contained in metal net shaped earthing pole 5 centers, and be fixed on the tubular insulation crust loam cake 9, the lower end of rotating nozzle type metal corona discharge electrode 4 and metal net shaped earthing pole 5 lower ends are in same surface level, the insulating vessel 8 that fills free radical spin catching agent solution 7 is positioned over reactor bottom, the positive pole of high-voltage DC power supply 1 connects rotating nozzle type metal corona discharge electrode 4, minus earth.
Described rotating nozzle type hollow metal corona discharge electrode 4, its periphery is evenly equipped with the metallic nozzle 10 of thin footpath hollow as Fig. 2 (a), the metallic nozzle 10 of hollow is connected with rotating nozzle type hollow metal corona discharge electrode 4, the metallic nozzle 10 of hollow rotating nozzle type hollow metal corona discharge electrode 4 radially to be the circumference equal angles uniform, axially in the shape of a spiral or many helical structures, as Fig. 2 (b).
The top end opening 6 of rotating nozzle type hollow metal corona discharge electrode 4 can be done the assist gas air intake opening.Assist gas air intake opening 6 and gas outlet 2 can be sealed in the course of reaction, and as closed reactor, the assist gas that also can lead to certain flow is used to produce different types of free radical.
Electron spin resonance (ESR) instrument that is used to detect free radical is: the EHX-8 type that German Bruker company produces, test parameter is as shown in table 1.
Table 1. electron spin resonance (ESR) instrument running parameter
| Parameter List | Receiver |
| Operator：Bruker BioSpin Germany | Receiver Gain：1.00e+005 |
| Field | Phase：0.00deg |
| Center Field：3490.000G | Harmonic：1 |
| Sweep Width：100.000G | Mod.Frequency：100.00kHz |
| Resolution：1024 points | Mod.Amplitude：1.00G |
| Microwave | Signal Channel |
| Frequency：9.800~9.850GHz | Conversion：40.960ms |
| Power：19.500~20.500Mw | Time Constant：81.920ms |
| Sweep Time：41.943s |
Described electron paramagnetic resonance instrument, its composition mainly comprises with the lower part:
[1]. electromagnetic wave generator---the klystron (microwave system) of the resonant frequency of necessity is provided
[2]. the stabilizing magnetic field (magnet system) that provides by electromagnet
[3]. can make sample be in the sample cavity (resonator cavity) of all suitable direction of magnetic field and electromagnetic wave
[4]. detection system (comprising wave detector, amplifier, register etc.)
The spin catching agent that is used to capture free radical be DMPO (5,5-dimethyl-pyrroEine-1-oxide), be a kind of spin catching agent that is most widely used at present because soluble in water and other organic solvent, be widely used in the free radical research of liquid phase.DMPO can form comparatively stable spin adduct with active OH, O, H high, that the life-span is short, provides stronger resonance signal on the ESR spectrum, presents the characteristic spectral line that is easy to recognize.
Detection method and step:
1) spin catching agent is configured to the water of 0.001～0.1mol/L or benzole soln and places that to add a cover graduated cylinder standby;
2) with the special-purpose quartzy flat sample hose of ESR test with ethanol solution flushing repeatedly, and use N
2Dry up;
3) get the disk-shaped glass container (8) that this solution of 0.5ml splashes into reactor bottom, cover tight reactor loam cake (9);
4) if need to produce the variety classes free radical, can feed radical source gas (as air, oxygen, nitrogen, water vapor etc.) to reactor by hollow nozzle corona discharge electrode (4), gas is discharged by gas outlet (2);
5) give high-voltage DC power supply (1) power supply, make and produce tangible corona zone in the reactor;
6) control reaction time 1～100s in time closes power supply (1);
7) open reactor loam cake (9), with DMPO trapping solution (7) sucking-off in the glass disk, get 0.1～0.2mL and inject quartzy flat sample hose (10.5mm * 4.2mm * 43.5mm) with dropper;
8) under the room temperature with the sample hose in the high-pressure sodium lamp direct irradiation ESR resonant cavity, record ESR spectrum, and according to the WINEPR program of Bruker company, with computing machine analog record experiment ESR spectrum.
Fig. 3～Fig. 7 is the ESR simulation spectrogram and the actual detected spectrogram of different free radicals, wherein:
Fig. 3 is the ESR simulation spectrogram that DMPO captures the OH free radical; Fig. 4 is the ESR simulation spectrogram that DMPO captures H (or CnH2n+1) free radical; Fig. 5 is the ESR simulation spectrogram that DMPO captures the OO free radical; Fig. 6 is the ESR spectrogram of spin catching agent DMPO-aqueous solution; Fig. 7 is the ESR spectrogram of the inferior plasma corona discharge of air atmosphere DMPO-aqueous solution.
Above-mentioned embodiment is used for the utility model of explaining; rather than the utility model limited; in the protection domain of spirit of the present utility model and claim, any modification and change to the utility model is made all fall into protection domain of the present utility model.
Claims (2)
1. the capturing device of a discharge of plasma in low temperature generation free radicals in transient state is characterized in that: comprise that high-voltage DC power supply (1), upper wall have the tubular insulation crust (3) of gas outlet (2), rotating nozzle type hollow metal corona discharge electrode (4), cylindric wire netting earthing pole (5), the insulating vessel (8) that fills free radical spin catching agent solution (7) and tubular insulation crust loam cake (9) and form; Tubular insulation crust (3) inwall is equipped with cylindric wire netting earthing pole (5), rotating nozzle type metal corona discharge electrode (4) is contained in metal net shaped earthing pole (5) center, and be fixed on the tubular insulation crust loam cake (9), the lower end of rotating nozzle type metal corona discharge electrode (4) and metal net shaped earthing pole (5) lower end are in same surface level, the insulating vessel (8) that fills free radical spin catching agent solution (7) is positioned over reactor bottom, the positive pole of high-voltage DC power supply (1) connects rotating nozzle type metal corona discharge electrode (4), minus earth.
2. a kind of discharge of plasma in low temperature according to claim 1 produces the capturing device of free radicals in transient state, it is characterized in that: described rotating nozzle type hollow metal corona discharge electrode (4), its periphery is evenly equipped with the metallic nozzle (10) of hollow, the metallic nozzle of hollow (10) is connected with rotating nozzle type hollow metal corona discharge electrode (4), the metallic nozzle of hollow (10) rotating nozzle type hollow metal corona discharge electrode (4) radially to be the circumference equal angles uniform, axially in the shape of a spiral or many helical structures.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2006201091704U CN201000441Y (en) | 2006-11-01 | 2006-11-01 | Low temperature plasma discharge generating transient state free radical trapping device |
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| Application Number | Priority Date | Filing Date | Title |
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| CNU2006201091704U CN201000441Y (en) | 2006-11-01 | 2006-11-01 | Low temperature plasma discharge generating transient state free radical trapping device |
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| CN201000441Y true CN201000441Y (en) | 2008-01-02 |
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| CNU2006201091704U Expired - Lifetime CN201000441Y (en) | 2006-11-01 | 2006-11-01 | Low temperature plasma discharge generating transient state free radical trapping device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1959390B (en) * | 2006-11-01 | 2010-10-13 | 浙江大学 | Method and device for capturing free radicals in transient state generated by discharge of plasma in low temperature |
| CN102625730A (en) * | 2009-09-03 | 2012-08-01 | 国立大学法人大阪大学 | Method and device for supplying ions to liquid, and method and device for sterilizing |
-
2006
- 2006-11-01 CN CNU2006201091704U patent/CN201000441Y/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1959390B (en) * | 2006-11-01 | 2010-10-13 | 浙江大学 | Method and device for capturing free radicals in transient state generated by discharge of plasma in low temperature |
| CN102625730A (en) * | 2009-09-03 | 2012-08-01 | 国立大学法人大阪大学 | Method and device for supplying ions to liquid, and method and device for sterilizing |
| CN102625730B (en) * | 2009-09-03 | 2014-03-12 | 国立大学法人大阪大学 | Method and device for supplying ions to liquid, and method and device for sterilizing |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20080102 Effective date of abandoning: 20061101 |