JP3073986B1 - Fullerene manufacturing equipment - Google Patents

Abstract

An object of the present invention is to improve the yield and cost of producing fullerenes. A generating unit (1) for generating fullerenes is provided.
The generating unit 1 includes a chamber 11 configured to introduce a gas therein, and a pair of electrodes 12 and 13 opposed to each other via a discharge gap d to generate an arc discharge in the chamber 11. An exhaust passage 18 having a nozzle portion 12d provided inside the one electrode 12 and having one end open to a position facing the discharge gap d and having a nozzle portion 12d for expanding a flowing gas therein. d to make it function as an arc gas and evaporate carbon in the discharge gap d. Then, the carbon vapor g2 is taken into an exhaust system 18 provided in one electrode 12 and
It was configured to self-cool by being expanded by 2d and exhausted as fullerene gas g3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for producing fullerenes suitable for producing fullerenes and endohedral fullerenes (hereinafter referred to as fullerenes).

[0002]

2. Description of the Related Art Fullerenes are carbon allotropes having a high carbon number such as C60 and C70. C60 has a truncated icosahedral soccer ball-like lattice structure, and higher fullerenes are not spherical but have a hollow structure.

[0003] It has been shown that such fullerenes can be artificially produced by evaporating carbon and then cooling it.
Research on purification is also actively pursued.

[0004] One of the specific refining apparatuses is configured so that fullerene gas passes through a plurality of zones arranged sequentially from the upstream side to the downstream side, and a cooling unit is provided in each zone. Before entering each zone sequentially, the carbon vapor is heated by a heater, and the fullerene raw material is heated, evaporated and introduced into the first zone, whereby a predetermined component is captured in the cooling section, and the remainder is transferred to the next stage. By heating and evaporating to a lower temperature than the above-mentioned zone and introducing it by evaporating, a specific component different from the above-mentioned component is captured in the cooling unit. I can do it.

[0005]

Therefore, the above-described conventional device has the following problems to be solved.

That is, in the conventional refining apparatus, the soot-like fullerene raw material once generated by cooling is heated and evaporated again in each zone, and then cooled and precipitated in the cooling section. For this reason, a heating mechanism for heating the fullerene raw material to the sublimation temperature of the fullerene raw material, for example, about 500 to 600 ° C. is required in the first stage, and a heating mechanism corresponding thereto is required in the subsequent stages, and the apparatus is large-scale. There is a disadvantage that it becomes a thing.

[0007]

In order to solve the above problems, the present invention employs the following configuration.

That is, according to the present invention, in order to efficiently purify the generated fullerenes, the purifying section is provided with a plurality of cooling zones having a temperature gradient gradually decreasing from the upstream side to the downstream side, A catch plate is arranged in each cooling zone, and a nozzle portion is provided between each cooling zone.While the fullerene gas passes through each cooling zone from the upstream side to the downstream side, the fullerene gas is sequentially supplied. It is configured to cool and separate and purify components of fullerenes having a sublimation temperature corresponding to the trap plate in each cooling zone.

When fullerene gas is introduced into the refining section having such a configuration, the fullerene gas is cooled by adiabatic expansion when passing through the nozzle section between the cooling zones, and is accelerated to accelerate the next cooling zone. Collision with capture plate. At this time, if the temperature of the capturing plate is lower than the sublimation point of the component of the fullerenes, the component sublimates and adheres to the capturing plate, but if the temperature of the capturing plate is equal to or higher than the sublimation point of the component of the fullerenes, The components pass through in a gaseous or reevaporated state, sublimate on a trapping plate located at a temperature lower than the sublimation point located downstream, and adhere to and are trapped on the trapping plate without re-evaporation. Therefore, according to the present invention, it is possible to separate and take out only the components unique to each capture plate. Moreover,
Since the gas can be cooled by the nozzles formed between the cooling zones along the temperature gradients, the expected components can be effectively deposited in each cooling zone with a simple configuration.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the apparatus for producing fullerenes according to this embodiment includes a generating section 1 for producing fullerenes, and a purifying section 2 for separating and purifying fullerenes for components having different sublimation temperatures. It is provided with.

More specifically, as shown in FIGS. 1 and 2, the generating unit 1 arranges a pair of electrodes 12 and 13 in a chamber 11 which is a vacuum vessel, Is configured. The chamber 11 is airtight, and a heat insulating material 14 is arranged at a position surrounding the arc discharge region S set at the center.
A gas introduction system 15 is connected to part of the gas introduction system. The electrode 12 on the cathode side is made of a graphite material on the tip 12a side and a copper electrode material on the base end 12b side,
The tip 12a penetrates through the chamber one time and is positioned in the arc discharge region S. The electrode 12 has a vertical hole 12c opening at a distal end 12a as a component of the exhaust passage 18 at an axial center position, and the diameter of the vertical hole 12c is different from the diameter of the distal end and the proximal end thereof. The nozzle portion 12d is formed so that the diameter of the nozzle portion 12d widens toward the base end side. The chamber 11 is formed in a vertical hole 12c closer to the base end side than the nozzle portion 12d.
An exhaust pipe 16 is connected from outside. On the other hand, the electrode 13 on the anode side is made of a graphite material on the tip 13a side and a copper electrode material on the base end 13b.
1 is positioned at a position opposite to the tip 12a of the electrode on the cathode side in the arc discharge region S via a predetermined discharge gap d, and the vertical hole is formed in the tip 13a to stabilize the discharge. A vertical hole 13c having substantially the same diameter as the diameter of the tip side of 12a is formed. The chamber 11 has a structure in which the cooling portion 11x can cool the through portion of any of the electrodes 12 and 13 with water. X
Even if the tip 13a is consumed by the arc discharge as shown by, even if the tip 13a is consumed by arc discharge, the arc between the tip 12a of the electrode 12 on the cathode side is inserted by sequentially inserting the whole into the chamber 11. The discharge gap d can be kept constant. In this embodiment, a DC power supply 17 is connected to the electrodes 12 and 13 so that the temperature of the arc discharge gap S is equal to the temperature at which carbon evaporates, for example, 4000.
Electricity is supplied so as to be about 6000C. In the case of a DC arc, the voltage is 20 to 30 V,
A current of 100 A or more flows when the electrode diameter is 10 mm.

That is, the generator 1 introduces a gas g1 such as He from the gas introduction system 15 into the chamber, and supplies the gas g1 to the discharge gap d to function as an arc gas. As shown in FIG. 2, the graphite constituting the anode 13
After evaporating from the side a, the carbon vapor g2 is opened at the center of one of the electrodes 12 by the gas flow.
Into the vertical hole 12c. The nozzle 12d is adiabatically expanded and self-cooled, and exhausted as fullerene gas g3 (gas containing fullerene). As the gas g1, argon and the like can be used in addition to helium.

On the other hand, the purifying section 2 is disposed downstream of the exhaust pipe 16 connected to the generating section 1, and has a cylindrical case 21 and an axis of the case 21 as shown in FIG. A water cooling pipe 22 inserted at the center position, a plurality of disc-shaped capturing plates 23 attached to the water cooling pipe 22 and housed in the case 21 to close an intermittent position in the longitudinal direction of the case 21; A part of each catching plate 23 is cut out so that one end side and the other end side of the inner space are connected in a staggered manner, or a bent portion 23a is formed as shown in the figure, and the inner surface of the case 21 facing the inner surface. And a gap between the pair of adjacent capture plates 23 is defined as a cooling zone Z. Then, while the fullerene gas g3 passes through each cooling zone Z from the upstream side to the downstream side, components of the fullerenes having a sublimation temperature corresponding to the trapping plate 23 of each cooling zone Z are separated and purified. Thus, a constant temperature gradient is formed in the same direction. The downstream end of the case 21 is connected to an exhaust unit 25 including a mechanical booster pump 25a and a rotary pump 25b.

That is, the apparatus for producing fullerenes in this embodiment guides the fullerene gas g3 generated in the generator 1 to the purifier 2 via the exhaust pipe 16 without changing the phase state. Fullerenes can be continuously produced. In addition,
The fullerene gas g3 generated in the generation unit 1 is about 600 ° C., and the fullerene gas g3 is guided to the purification unit 2 while maintaining this temperature. Heater 31 for preventing temperature drop
Is wrapped around. A water cooling pipe 32 is wound around the final stage of the refining unit 2, and the temperature of the final cooling zone Z is set to around room temperature, for example, 30 ° by the water cooling pipe 32.
It cools to about C. A temperature difference between the cooling zones Z is set so as to equally distribute the temperature gradient during this period.
In terms of pressure, the inlet pressure of the refining unit 2 is about 10 Torr, and the outlet pressure is about 0 and 1 Torr.

If the generator 1 is provided, the carbon vapor generated by the arc discharge passes through the exhaust passage 1 opening from the periphery to the center in the open discharge gap d.
8 when it flows toward the vertical hole 12c,
The vapor density increases. Further, since the gas always flows through the discharge gap d and the discharge surface is kept clean, it is expected that the discharge is stabilized. Then, in the process of rapidly cooling the gas g2 by adiabatic expansion in the nozzle portion 12d in the vertical hole 12c constituting the exhaust system passage 18, the steam becomes supersaturated and diffuses, thereby effectively producing fullerenes in the gas. Can be promoted. In particular, the present embodiment simply uses carbon vapor g
2 is converged on the vertical hole 12c having a small diameter.
Because it does not use the pinch effect of the jet,
The temperature of the carbon vapor g2 is not excessively increased, and not only is the subsequent generation of fullerenes in the nozzle portion 12d promoted, but also the downstream cooling can be effectively performed to improve the yield of fullerenes. . Further, since the gas g1 introduced in FIG. 1 functions as a carrier gas, an arc gas and a quenching gas thereafter, the apparatus is simplified and the gas consumption is reduced as compared with a case where these gases are separately introduced from the outside. Cost can be reduced.

When the fullerene gas g3 is introduced into the refining section 2 having the above configuration, the fullerene gas g3 is cooled by adiabatic expansion when passing through the nozzles 24 between the cooling zones Z and accelerated. It collides with the capture plate 23 of the cooling zone Z of the next stage. At this time, the capturing plate 23
Is lower than the sublimation point of the fullerene component, the component sublimates and adheres to the capture plate 23. However, if the temperature of the capture plate 23 is equal to or higher than the sublimation point of the fullerene component, the component becomes gaseous. Pass through the shape or re-evaporation, sublimated by the capture plate 23 at a temperature lower than the sublimation point located downstream,
It is captured without adhering thereto without re-evaporation. Therefore, according to the present embodiment, it is possible to separate and extract only the components unique to each capture plate 23. Specifically, in addition to C60 and C70, C7
6, C78, C82, C84, C90, C96, etc., and the sublimation temperature is 400 ° C. under reduced pressure of C60, 450 ° C. of C70, and the higher the sublimation temperature, the higher the sublimation temperature. Then, in the refining section of this embodiment, Cz, C9
x, C8x, C7x, C70, C60,... are sequentially deposited on the trapping plates 23 of each cooling zone Z in order from higher-order fullerenes. In addition, since the gas can be cooled by the nozzle portion 24 formed between the cooling zones Z along the temperature gradient, the components expected in each cooling zone Z can be effectively deposited with a simple configuration. Can be made. Cz deposited near the first stage and Cy deposited near the last stage are giant clusters, fine clusters, etc. which have become fullerenes and have failed.

Further, if the generator 1 and the purifier 2 are connected as described above, the fullerene gas g3 generated at a high temperature in the generator 1 is continuously sent to the purifier 2 as it is. Since it is used for purification by cooling, there is no need to intervene unnecessary cooling and heating steps in the middle, and a large improvement in the whole apparatus can be expected in terms of space, time, power and efficiency.

The specific configuration of each section is not limited to the illustrated embodiment. For example, a hole is made in the electrode on the anode side, and a metal rod or reactive gas
Can be included to generate endohedral fullerenes. In addition, by scanning with the opposing electrode as a surface, it is expected that the nanotubes are grown perpendicular to the electrode. Further, a scraper may be provided in each cooling zone so that fullerenes adhering to the trap plate are continuously collected below the cooling zone. In addition, the refining unit can adopt a configuration other than the above. FIG. 4 (a), (b)
Shows an example as a schematic plane cross section and a vertical cross section. The inside of the case 41 is divided into a plurality of cooling zones Z by a partition plate 42.
In each cooling zone Z, a scroll-shaped guide plate 43 functioning as a capture plate is arranged, and a gas swirling flow path 44 is formed inside, and flows through the swirling flow path 44. The gas escapes upward through the cylindrical portion 45 provided at the center, and flows out to the swirl flow path 44 of the next cooling zone Z through the nozzle portion 46 provided in a part of the partition plate 42. ing. By doing so, cooling for each cooling zone Z can be performed more accurately.

Other specific configurations can be variously modified without departing from the spirit of the present invention.

[0021]

As described above, according to the apparatus for producing fullerenes provided with the refining section of the present invention, fullerenes can be separated and taken out for each cooling zone, and the fullerenes can be separated along each cooling zone. The predetermined temperature gradient can also be simply realized by the nozzle portion of the capturing plate.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged view showing a generation unit of FIG. 1;

FIG. 3 is an enlarged view showing a purification unit of FIG. 1;

FIG. 4 is a schematic sectional view corresponding to FIG. 3, showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Generating part 2 ... Purification part 11 ... Vacuum container (chamber) 12, 13 ... Electrode 12d ... Nozzle part 18 ... Exhaust system 23 ... Cooling zone 24 ... Nozzle part g1 ... Gas g2 ... Carbon vapor g3 ... Fullerene gas S ... Discharge gap Z: cooling zone

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C01B 31/02 101 CA (STN)

Claims (1)

(57) [Claims] An apparatus for producing fullerenes comprising a purifier for purifying fullerenes, wherein the purifier comprises:
In addition to a plurality of cooling zones having a temperature gradient that gradually decreases from the upstream side to the downstream side, a catch plate is arranged in each cooling zone, and a nozzle portion is provided between each cooling zone. While the fullerene gas passes through each cooling zone from the upstream side to the downstream side, the fullerene gas is sequentially cooled by the nozzle unit, and the components of the fullerenes having a sublimation temperature corresponding to the trapping plate of each cooling zone are removed. An apparatus for producing fullerenes, wherein the apparatus is configured to be separated and purified.