Device and method for preparing graphene by flash evaporation method

Abstract

The invention discloses a device and a method for preparing graphene by a flash evaporation method. The device comprises a vacuum device, an induction device, a charging device, a control system and a detection system, wherein the vacuum device consists of a vacuum box, a quartz cover, a raw material clamp and a copper electrode; the induction device is composed of an inductor, a diode, an inductor charging switch, an electromagnet, an iron sheet and a spring. The charging device consists of a capacitor, a charging indicator lamp and a power supply; the control system is composed of a pre-energization device, a flash evaporation switch and a computer terminal. The detection system consists of a pressure sensor, a temperature sensor, a component sensor and a detection window; the method mainly comprises the following steps: preparing a sample and setting initial conditions; graphene is prepared through a flash evaporation method; subsequently detecting and processing a product; the equipment realizes preparation of high-purity powdery graphene, requires less energy compared with a traditional method, and is lower in equipment and raw material cost and more flexible in preparation method.

Description

Technical Field

[0001] The present invention belongs to the field of composite material manufacturing, and particularly relates to a device and method for preparing graphene by flash evaporation method. Background Art

[0002] Graphene is a typical carbon allotrope with two-dimensional crystal structure characteristics. Its carbon atoms are closely and regularly arranged in a hexagonal honeycomb lattice structure with a single atomic layer thickness through sp2 hybrid orbitals and π bonds. This structure endows graphene with excellent mechanical, thermal, electrical and other properties. However, in the industrialization process of graphene, there are problems of low-cost mass production of high-quality graphene.

[0003] Conventional graphene preparation methods at the present stage: mechanical exfoliation, oxidation-reduction, liquid-phase exfoliation, chemical vapor deposition (CVD), cannot meet the requirements of high quality and low cost. Mechanical exfoliation faces problems such as uneven thickness of graphene, low exfoliation efficiency, poor controllability and inability to achieve industrial mass production during preparation. Due to the limitations of the process itself, liquid-phase exfoliation has low efficiency in controlling the reduction of graphene layers. In some products, fine graphite is even doped, and this kind of graphene is often impure and seriously contaminated on the surface. In oxidation-reduction, the graphite lattice is easily damaged during preparation, resulting in a large number of defects and surface groups, and the defects and groups cannot be completely eliminated during the reduction process. At the same time, due to the growth of graphene only occurring on the surface of the catalytic substrate in chemical vapor deposition, the catalytic temperature is relatively high, and the actual yield is also very low, making it impossible to achieve low-cost industrial mass production. Therefore, traditional graphene preparation methods all have certain limitations and disadvantages.

[0004] Compared with conventional methods, the raw materials of the flash evaporation method are cheaper and have less demanding performance requirements for raw materials. At the same time, according to the literature, the flash evaporation method can better retain the properties of graphene itself and has low energy consumption. Data shows that only 7.2 KJ is required to produce 1 g of graphene. Summary of the Invention

[0005] Aiming at the above defects or improvement requirements of the prior art, the present invention provides a device and method for preparing graphene by flash evaporation method, which can achieve the preparation of high-quality and low-cost graphene.

[0006] The present invention is realized through the following technical solutions:

[0007] A device for preparing graphene by flash evaporation method includes: a vacuum device, an induction device, a charging device, a control system, and a detection system.

[0008] The vacuum device is used to clamp the sample and create a vacuum environment. Since the main material of the quartz cover fixture in the device is quartz, it also has the functions of electrical insulation and physical protection.

[0009] The induction device consists of an inductance device and an electromagnet attraction device. Its main function is to control the rapid closing and opening of a switch according to the current intensity and time to achieve flash evaporation. The inductance device is used to achieve changes in current intensity and direction. The electromagnet attraction device mainly includes an electromagnet, an iron sheet, and a spring;

[0010] The charging device consists of a capacitor and a charging indicator light. Its main function is to store sufficient electrical energy;

[0011] The control system consists of a computer terminal and a switch. It is mainly used to control the on-off of the circuit and run the flash evaporation program;

[0012] The detection system consists of a sensor and an observation window. The sensor is used to detect relevant accurate data and observe the progress of the reaction;

[0013] Furthermore, the pre-charging process can be operated using a computer terminal to control the closing and opening of the pre-charging switch and accurately control a short time interval;

[0014] Furthermore, a temperature sensor and a cooling system can be set in the circuit part of the preparation device to prevent thermal damage to the induction element and wires, thus causing errors;

[0015] Furthermore, the sensor detects the temperature after the disappearance of the fire while detecting the reaction temperature, avoiding the operator taking out the product just after the high-temperature reaction ends, thus causing burns. At the same time, it detects the exhaust gas composition after the disappearance of the fire to avoid the operator being poisoned by the gas;

[0016] Furthermore, when necessary, the clamping part area of the device can be increased to improve production efficiency and facilitate industrialization;

[0017] (Innovation points of the device, write them down separately in several parts)

[0018] (Name) method, including the following steps

[0019] Step 1: Prepare a sample (20*20*1mm). Material selection: anthracite, coke, carbon black;

[0020] Step 2: Clamp the sample with two copper sheets and place it in a quartz cover fixture;

[0021] Step 3: Tighten the fixture and apply a pressure of 10 Mpa;

[0022] Step 4: Close and lock the observation window;

[0023] Step 5: Evacuate the air and detect the pressure through the sensor until it reaches 10 mmHg;

[0024] Step 6: Disconnect K1, close the pre-power-on switch for 0.5 s every 1 s for pre-charging;

[0025] Step 7: Charge the capacitor until the brightness of the indicator light stabilizes;

[0026] Step 8: Disconnect the charging switch, disconnect the pre - power - on switch, and close K1 and K2 (see the circuit diagram);

[0027] Step 9: The computer runs the power - on program, and the electromagnet is first powered on and then quickly powered off;

[0028] Step 10: Observe the phenomenon through the observation window to detect the reaction state;

[0029] Step 11: Detect the reaction temperature and waste gas components through sensing;

[0030] Step 12: After the flame in the observation port disappears, open the observation window and take out the product;

[0031] Step 13: Conduct subsequent processing or testing on the product. Description of the Drawings

[0032] Figure 1 : Circuit diagram of the flash evaporation device

[0033] Figure 1 The numbers in it represent: 1 - vacuum chamber (1Kpa), 2 - quartz cover, 3 - raw material clamp, 4 - copper electrode, 5 - pre - power - on power supply (50V), 6 - pre - power - on switch, 7 - flash evaporation switch, 8 - inductor, 9 - diode, 10 - diode, 11 - computer, 12 - electromagnet, 13 - iron sheet, 14 - spring, 15 - inductor charging switch, 16 - power supply, 17 - charging indicator light

[0034] C1, C2, C3 - detachable capacitors (60mF)

[0035] R1, R2, R3, R4, R5 - resistors

[0036] Figure 2 : Vacuum chamber

[0037] Figure 2 Among them: The size of the vacuum chamber is 400 * 400 * 400 (mm), the size of the quartz tube is 25mm in outer diameter, 20mm in inner diameter, and 160mm in length, the sample size is 20 * 20 * 1mm, the vacuum degree is 10mmHg (low vacuum, vacuum), the discharge time is 10ms, the maximum voltage is 300 - 600v, and the temperature is 3300K Detailed Implementation Modes

[0038] The technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the drawings;

[0039] Such as Figure 1 、 2, an apparatus for preparing graphene by flash evaporation in the present invention; mainly composed of a vacuum device, an induction device, a charging device, a control system, and a detection system; the control system can control the on-off of the circuit and run the flash evaporation program; the vacuum device is mainly composed of a vacuum chamber 1, a quartz cover 2, a raw material clamp 3, and a copper electrode 4; the induction device is mainly composed of an inductor 8, diodes 9 / 10, an inductor charging switch 15, an electromagnet 12, an iron sheet 13, and a spring 14; the charging device is mainly composed of a capacitor, a charging indicator light 17, and a power supply 16; the control device is mainly composed of a pre-power-on device 5 / 6, a flash evaporation switch 7, and a computer terminal 11; the detection device is mainly composed of a pressure sensor, a temperature sensor, a composition sensor, and a detection window.

[0040] The following combines Figure 1 , Figure 2 to illustrate the (name) device and method in the present invention;

[0041] Step 1: Prepare the sample (20*20*1mm) Material selection: anthracite, coke, carbon black;

[0042] Step 2: Clamp the sample with two 4s and place it in the 2 fixture;

[0043] Step 3: Tighten the fixture and apply a pressure of 10 Mpa;

[0044] Step 4: Close and lock the observation window;

[0045] Step 5: Evacuate the air and detect the pressure through the sensor until it reaches 10 mmHg;

[0046] Step 6: Disconnect K1, close 6 every 1 s for 0.5 s for pre-charging;

[0047] Step 7: Charge the capacitor until the brightness of the indicator light is stable;

[0048] Step 8: Disconnect the charging switch, disconnect 6, and close K1 and K2 (see the circuit diagram);

[0049] Step 9: 11 runs the power-on program, and 12 is powered on first and then quickly powered off;

[0050] Step 10: Observe the phenomenon through the observation window and detect the reaction state;

[0051] Step 11: Detect the reaction temperature and waste gas composition through sensing;

[0052] Step 12: After the fire in the observation port disappears, open the observation window and take out the product;

[0053] Step 13: Further process or detect the product. (Exactly the same as the previous steps, and all the parts involved in the steps should correspond to the serial numbers in the figure one by one)

[0054] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the protection scope of the present invention.

Claims

1. An apparatus and method for preparing graphene by flash evaporation method, characterized in that: The equipment includes: a vacuum device, an induction device, a charging device, a control system, and a detection system. This device is dedicated to solving the problem of preparing high-purity powdered graphene; The vacuum device is used to clamp the sample and create a vacuum environment. Since the main material of the quartz cover fixture in the device is quartz, it also has the functions of electrical insulation and physical protection; The induction device consists of an inductance device and an electromagnet attraction device. Its main function is to quickly close and disconnect the switch according to the current intensity and time to achieve flash evaporation. The inductance device is used to achieve changes in current intensity and direction. The electromagnet attraction device mainly includes an electromagnet, an iron sheet, and a spring; The charging device consists of a capacitor and a charging indicator light, and its main function is to store sufficient electrical energy; The control system consists of a computer terminal and a switch, and is mainly used to control the on-off of the circuit and run the flash evaporation program; The detection system consists of a sensor and an observation window. The sensor is used to detect relevant accurate data and observe the progress of the reaction.

2. The device for preparing graphene by flash evaporation method according to claim 1, characterized in that The different modules of the preparation device are controlled and operated by the control system. The operator can view the data of each sensor in real time through the computer terminal and control the preparation process.

3. The device for preparing graphene by flash evaporation method according to claim 1, characterized in that The vacuum device clamps the sample through a quartz fixture, uses a quartz cover to form a specific vacuum pressure environment, and insulates and electrically protects the operator at the same time.

4. The apparatus for preparing graphene by flash evaporation method according to claim 1, wherein The inductance part of the induction device can adjust the magnitude and direction of the current, and the electromagnet part is energized or de-energized according to the current change.

5. The device for preparing graphene by flash evaporation method according to claim 1, characterized in that The capacitor of the charging device stores sufficient electrical energy through charging, prepares energy for subsequent flash evaporation of graphene, and the indicator light reflects whether the charging is completed.

6. The apparatus for preparing graphene by flash evaporation method according to claim 1, characterized in that The control system device controls the charging of the capacitor to reserve the electrical energy required for flash evaporation by closing and disconnecting the switch, and then runs the electromagnet energization program through the computer terminal.

7. The apparatus for preparing graphene by flash evaporation method according to claim 1, characterized in that The detection system device detects the specific data of pressure, reaction temperature, and waste gas composition through a pressure sensor, a temperature sensor, and a component sensor respectively. The observation window is used to observe the progress of the reaction.

8. A method for preparing graphene by flash evaporation method, characterized in that It includes the following steps: Step 1: Select the materials for preparing the sample (20*20*1mm): anthracite, coke, carbon black; Step 2: Clamp the sample with two copper sheets and place it in the quartz cover fixture; Step 3: Tighten the fixture and apply a pressure of 10 Mpa; Step 4: Close and lock the observation window; Step 5: Evacuate the air and detect the pressure through the sensor until it reaches 10 mmHg; Step 6: Disconnect K1, close the pre-power-on switch for 0.5 s every 1 s for pre-charging; Step 7: Charge the capacitor until the brightness of the indicator light is stable; Step 8: Disconnect the charging switch, disconnect the pre-power-on switch, and close K1 and K2 (see the circuit diagram); Step 9: The computer runs the power-on program, and the electromagnet is first energized and then quickly de-energized; Step 10: Observe the phenomenon through the observation window and detect the reaction state; Step 11: Detect the reaction temperature and waste gas composition through the sensor; Step 12: After the fire in the observation port disappears, open the observation window and take out the product; Step 13: Perform subsequent processing or detection on the product.

Images