A preparation of functional carbon materials via vacuum infusion method

Abstract

The present invention relates to a method for preparing functional carbon materials via vacuum infusion method comprising a tank, a tank for wet carbon powder, a tank for dry carbon powder, a reactor, a reagent tank, a flow cell, an ultrasonic generator, an ultrasonic transducer, an energy generator, and a cooling tank. The preparation of high performance functional carbon materials include wet and dry carbon powder, which shortening the duration for preparing functional carbon materials, reducing concentration of solution in the reaction. This method is also a continuous process, which is high performance and eco-friendly process.

Description

[0001] A PREPARATION OF FUNCTIONAL CARBON MATERIALS VIA VACUUM INFUSION

[0002] METHOD

[0003] Field of the invention

[0004] Engineering and applied science, especially related to a preparation of functional carbon materials via vacuum infusion method.

[0005] Background of the invention

[0006] A functional carbon material is very important in fields of science and technology since the functional carbon material is outstanding physical properties - lightweight, high flexibility, durability, good electrical and thermal conductivity, and high reactivity in composite material preparation. Due to the fact that the functional carbon material consists of carbon as a core structure and functional groups that can be modified, they are various properties depending on specific applications. Therefore, the functional carbon material has wide applications in various industries, including energy, electronics, composites, coatings, biomedicine, sensors, and catalysts.

[0007] The preparation of functional material can be conducted by two main processes: direct functionalization and indirect functionalization. The direct functionalization can be subdivided into the following methods: (1) covalent functionalization, (2) non-covalent functionalization, (3) inorganic functionalization, (4) doping of heteroatom, and (5) immobilization mediate. Meanwhile, the indirect functionalization is a method for preparing functional material by grafting.

[0008] For both Thailand and international patent database, we found that the functional carbon materials can be prepared by using ultrasonic in functionalization process, and can also increase the dispersion into the medium. Below is the examples.

[0009] CN102516829A, “ultrasonic assisted method for preparing polymer functionalized graphene”, discloses a method for preparing polymer functionalized graphene by using ultrasonic. According to this method, ultrasonic devices are applied for radiating the ultrasonic frequency to mixtures of polymer and graphene. When the ultrasonic is applied, the graphene layers are broken, and induced to the reaction with the degraded polymer chain. The large molecule can rapidly occur the grafting onto the layer. The results show polymer functionalized graphene has good dispersion and high stability in polymer matrix, and has an excellent mechanical properties. US20130331501A1 , “Isolation of carbon nanotubes by chemical functionalization”, discloses a method for preparing functionalized carbon nanotubes by using ultrasonic and chemical modification, that is, free radical polymerization, esterification, in order to form functional group onto the carbon nanotube. The ultrasonic can assist separate carbon nanotube via mechanical force, along with the chemical modification, which causes the good interaction between carbon nanotube and surroundings that can be applied for the coating system.

[0010] A journal of Ultrasonics Sonochemistry, 90, 2022, “Influence of the ultrasound cavitation intensity on reduced graphene oxide functionalization” (DOI 10.1016 / j .ultsonch.2022.106212), discloses the influence of ultrasonics to the preparation of reduced graphene oxide functionalized with polyvinyl alcohol (PVA). Such PVA can be attached on surface of reduced graphene. It was found that ultrasonic with 50% amplitude can appropriately occur the combination of particle size distribution and relative degree of functionalization in order to form the stable functionalized reduced graphene oxide dispersion.

[0011] A j ournal of Nano letter, volume 2, 2022, (https: / / doi.org / 10.1021 / nl010083x), “Sonication-Assisted Functionalization and Solubilization of Carbon Nanotubes” discloses carbon nanotubes that are solubilized by reacting with poly(propionylethylenimine-co- ethylenimine). It was found that Diimide-activated amidation reaction which activated by diimide for the reaction is significantly improved in both efficiency and productivity by using ultrasonic within the condition. In addition, it was found that the carbon nanotubes are shortened in different length based on duration of ultrasonic process. This method enables to prepare the soluble carbon nanotubes, and can select the average length with high efficiency.

[0012] Ajournal of Nano Materials, 2019, (https: / / doi.org / 10.1155 / 2019 / 2836372), “Chemical Functionalization of Helical Carbon Nanotubes: Influence of Sonication Time and Concentrations of Sulfuric and Nitric Acids with 3: 1 Mixing Ratio”, discloses the functionalization of helical configurations of carbon nanotubes (HCNTs) by using ultrasonic in mixtures of sulfuric acid and nitric acid in the ratio of 3 : 1 in order to react or bond, and improve the dispersion in matrix of other materials, especially in polymer. This method can improve the mechanical property, thermal conductivity, electrical conductivity, and magnetic property of polymer matrix.

[0013] According to the prior art mentioned above, the functional carbon materials preparation using ultrasonic for assisting dispersion in medium and functionalized process has been disclosed and has similar objectives on this invention. This invention generally relates to a method for preparing functional carbon materials via vacuum infusion method which improve to support the synthesis and has a condition control by reactor providing ultrasonic generator which activates the reaction with functionalized reagent, in which the reagent can easily penetrate to each layers of functional carbon materials, and activates the reaction effectively. The preparation of functional carbon material using vacuum infusion method can shorten the duration of reaction and reduce the concentration of reagents.

[0014] Summary of the invention

[0015] This invention is directly related to a method for preparing functional carbon material via vacuum infusion method, comprising a tank, a tank for wet carbon powder, a tank for dry carbon powder, a reactor, a reagent tank, a flow cell, an ultrasonic generator, an ultrasonic transducer, an energy generator, and a cooling tank. The preparation of high performance functional carbon materials include wet and dry carbon powder, which shortening the duration for preparing functional carbon materials, reducing concentration of solution in the reaction.

[0016] The objectives of this invention is for improving the process for preparing functional carbon material via vacuum infusion method in order to shorten the duration for preparing functional carbon material and reduce the concentration of reagent in this reaction. This process also eliminates the chemical residues occurred in preparation of functional carbon materials by recycling such the residues, and this method is also a continuous process, which is high performance and eco-friendly process.

[0017] Various purposes and features of the present invention will become clearer when considered together with the accompanying drawings and the best detailed description of the invention which will be described below.

[0018] Brief description of the drawings

[0019] The accompanying drawings, which are included herein to provide a further understanding of the present disclosure and are incorporated herein to constitute a part of the present specification. The accompanying drawings illustrate embodiments of the present disclosure and are used in conjunction with the following description to illustrate the concepts of the present disclosure.

[0020] Figure 1 illustrates the flow chart and component of this process according to the present invention. Figure 2 illustrates images from scanning electron microscope (SEM) of carbon material (a) before and (b) after functionalization process.

[0021] Figure 3 illustrates results from Raman Spectroscopy between carbon materials with and without functionalization process.

[0022] Detailed description of the invention

[0023] This description of this invention will be made by illustrating the invention and referring to it by means of drawings and photographs to illustrate and clarify the description, and identical parts in these drawings will be represented by the same reference numbers. This is without any limitation and the scope of the invention will be in accordance with the appended claims.

[0024] This invention relates to a method for preparing functional carbon material via vacuum infusion method using the reactor with ultrasonic generator for activation with functionalized reagent, which the solution can be easily permeated in the functional material layer. This process is able to produce Taylor Vortex, which is a specific fluid flow that shear stress can be produced on carbon materials.

[0025] The shearing stress can peel the layer of carbon materials, causing the reagent can penetrate into each layer easily, and activate the reaction effectively, which can shorten the duration of reaction and reduce the concentration of reagent, along with the process can eliminates the chemical residues occurred in preparation of functional carbon materials by recycling such the residues, and this method is also a continuous process, which is high performance and eco-friendly process.

[0026] The method for preparing functional carbon material via vacuum infusion method comprising a tank (1), a tank for wet carbon powder (2), a tank for dry carbon powder (3), a reactor (4), a reagent tank (5), a flow cell (6), an ultrasonic generator (7), an ultrasonic transducer (8), an energy generator (9), and a cooling tank (10).

[0027] Wherein, the tank (1) is connected to a butterfly valve for controlling open-close the tank (1) in order to convey the carbon powder to the tank, and the tank further comprises air pressure machine, and vibration system for assisting biomass powder convey to the tank.

[0028] The tank includes a tank for wet carbon powder (2) and a tank for dry carbon powder (3), which serves as a tank for preparation wet carbon powder and dry carbon powder before conveying into the reactor (4), which are closed container for receiving carbon powder and reagent from the reagent tank (5), and mixing together via using vacuum infusion method, and then conveying to flow cell (6)

[0029] The flow cell (6) is provided to work together with ultrasonic assembly to feed the reagent to ultrasonic generator and feed back to the flow cell (6) to convey to the cooling tank (10), wherein the ultrasonic assembly comprises ultrasonic generator (7) and ultrasonic transducer (8) working together with the an energy generator (9) to generate energy.

[0030] Wherein, the ultrasonic assembly is provided with 20-40 kHz of frequency and 50-100% of amplitude with 2 kW of energy.

[0031] Wherein carbon powder is selected from carbon derived from minerals, from synthetic nanocarbon, from petroleum, porous carbon and hard carbon from biomass, from recycle process, or a combination thereof.

[0032] The preparation process of functional carbon materials by using dry carbon power includes the following steps. a) The carbon powder is filtered with a sieve to obtain 200 to 1000 microns of carbon powder, and then weighed before storing in the tank (1). b) Convey carbon powder from step a) to the reactor (4). c) Mix the chemical mixture from the reagent tank (5) which comprising;

[0033] - Add QUAB 188 solution (3-Chloro-2-hydroxypropyltrimethyl ammonium chloride) as the functionalized reagent, and then add water by using the injector in ratio of 1 : 1 by mole of 3.5% by weight of sodium hydroxide (NaOH)

[0034] - Inject 3.0-4.0 % by weight of sodium hydroxide with 50-60 by weight concentration, then add water by using the injector, and leave it for 30-40 minutes.

[0035] - Add 1.50-2.80 by weight of fumaric acid. d) Then convey the mixtures from step c) to the flow cell (6) and the ultrasonic assembly to feed the reagent to ultrasonic generator and feed back to the flow cell (6), cure for 1-2 days, and to convey to the cooling tank (10) to obtain the functional carbon materials. The preparation process of functional carbon materials by using wet carbon power includes the following steps. a) The carbon powder is filtered with a sieve to obtain 200 to 1000 microns of carbon powder, and then store in the tank (1). b) Convey carbon powder from step a) to the tank via air pressure machine, and then weight the carbon powder and reduce the pressure within the tank. c) Release the carbon powder from the tank with butterfly valve for controlling open and close the release of powder, in order to prevent the air from exhaust fan into the tank, which could cause the tank to swell and explode, and cause the spreading of carbon powder. Then the carbon powder is released to a small tank with the vibration system in order to reduce the stuck of carbon powder. d) Covey the carbon powder from step c) to the tank for wet carbon powder (2) having a rotary valve to divide the carbon powder, and provide the filter for preventing air flow back into the small tank. e) Mix the carbon powder from the tank for wet carbon powder (2) with water into the mixer in order to obtain semi-liquid before conveying to mixing tank to stir at 100- 500 rpm for 30 minutes, wherein, within the tank, the concentration of semi-liquid carbon powder is controlled at 18-23 mol / L at 15-20 degrees Celsius and a density of l-2 kg / L. f) The carbon from step e) is coarsely filtered via sieve, wherein, within the tank for wet carbon powder (2), the plate heat exchanger is provided to control temperature of semi-liquid carbon powder at 25-28 degrees Celsius in order to obtain the wet carbon powder. g) Convey carbon powder from step a) to the reactor (4), wherein the wet carbon powder has preferably 20-22 mol / L of concentration, at 33-36 degrees Celsius. h) Mix the chemical mixture from the reagent tank (5) which comprising;

[0036] - Add QUAB 188 solution (3-Chloro-2-hydroxypropyltrimethyl ammonium chloride) as the functionalized reagent, and sodium hydroxide (NaOH) in the ratio of 1 : 1 by mole, where the pH is controlled at 10-12 within the reactor (4), and then add the dry sodium hydroxide (NaOH) with concentration of 3.0-4.0 by weight with controlling pH at 10-12. i) Mix the mixtures from step h) for 2-4 hours, at 35-50 degrees Celsius, and adjust the pH at 5-7 by controlling the temperature at 32-37 degrees Celsius. j) The mixtures from step i) is pumped to the cooling system via pump to control the temperature at 27 to 55 degrees Celsius, with providing a pressure gauge to control the pressure in the system before entering to the flow cell (6) to feed the reagent to ultrasonic assembly and feed back to the the cooling tank (10). k) The wet carbon powder from the the cooling tank (10) from step j) is fed into the washing tank with an agitator to prevent the precipitation at the bottom of the tank, then the temperature is adjusted with a plate heat exchanger to prevent the swelling of carbon powder before being coarsely filtered and fed into a hydrocyclone to wash reagent out from the carbon powder which is controlled at pH 5-7, and 20-22 mol / L concentration before filtering with sieve and convey to the storage tank. l) Centrifuge carbon powder from step k) at 5-10 rpm, for 5-10 minutes per round, and then add the water at Siphon chamber to allow the water flow back to wastewater hole and into the basket with high pressure to drain the water out the carbon powder. Then, the carbon powder is washed and shaken off to obtain the carbon power cake. m) The carbon powder cake from step 1) is dried to eliminate the humid to remain a moisture content of 25 to 30% by beating the carbon powder apart and a flash dryer, respectively. n) The carbon powder cake from step 1) is dried to eliminate the humid to remain a moisture content of 11 to 13% by cyclone, and then feed into the cooling cyclone to obtain wet functional carbon material.

[0037] The functionalization on carbon powder is tested by using X-ray photoelectron spectroscopy (XPS). Non-functionalized carbon based materials, CAR-R1 is compared with anionic carbon materials, CAR-O" and cationic carbon materials, CAR-O+. The results of functionalization via XPS are shown in Table 1 and Table 2.

[0038] Table 1: X-ray photoelectron spectroscopy results between CAR-R1 and CAR-O'

[0039] Table 2: X-ray photoelectron spectroscopy results between CAR-R1 and CAR-O+

[0040] The results shows functionalized carbon based materials has amount of oxygen atoms higher than non-functionalized carbon based materials. The anionic carbon materials (CAR-0") and cationic carbon materials (CAR-O+) has a higher amount of oxygen atom by 66.44% and 35.51% , respectively, shown in Table 1 and 2.

[0041] The characterization of functional carbon is tested via scanning electron microscopy (SEM), and Raman Spectroscopy, shown in Figures 2 and 3.

[0042] Figure 2 shows the images from scanning electron microscope (SEM) of carbon material before and after functionalization process. It is found that morphology between functionalized and non-functionalized carbon material are not significantly different. Similarly, the results from Raman Spectroscopy shows that morphology between functionalized and non-functionalized carbon material do not significantly change. This indicates that the functionalization via chemical modification according to this invention does not affect to the morphology of functional carbon material. Although the present invention has been described in detailed description by means of the attached drawings, it is understood that modifications or alterations by a person who skilled in the art and science, within the scope and purpose of the invention, can be made. The scope of the present invention shall be in accordance with the embodiment of the invention as stated in the appended claims, including aspects of the invention, although it is not specifically stated in the claims, have a utility and produce results similar to those of the invention as stated in the claims.

[0043] Best mode for carrying out the invention

[0044] Best mode or preferred embodiment of the invention is as provided in the description of the invention.

Claims

Claims1. A preparation of functional carbon materials via vacuum infusion method, the method comprising: a) Preparation of wet solution; b) Preparation of dry carbon powder; c) Reaction process by reactor; and d) Washing process; and e) Dewatering process,Wherein the reaction process by reactor is characterized in that the preparation of high performance functional carbon materials include wet and dry carbon powder, which can be shortened to prepare in 1-2 days for preparing functional carbon materials by dry carbon powder, and 2-4 hours for preparing functional carbon materials by wet carbon powder, and the concentration of solution is reduced, where the ratio of functional reagent to sodium hydroxide is 1 : 1 by mole with controlling pH of 10-12, and using dry sodium hydroxide of 3.0-4.0 by weight.

2. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1, shortening the duration for preparing functional carbon materials, reducing concentration of solution in the reaction, and eliminating the chemical residues occurred in preparation of functional carbon materials by recycling such the residues. This method is also a continuous process via vacuum infusion method by using reactor with ultrasonic assembly for activation with functionalized reagent with 20-40 kHz of frequency, and 50- 100 of amplitude, which the solution can be easily permeated in the functional material layer. This process is able to produce Taylor Vortex, which is a specific fluid flow that shear stress can be produced on carbon materials.

3. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein wet carbon powder can be used in this method.

4. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein dry carbon powder can be used in this method.

5. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder from minerals is selected from graphite.

6. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder from synthetic nanocarbon is selected from graphene, carbon nanotube, carbon dot, fullerene, and derivatives of nanocarbon.

7. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder from petroleum is selected from petroleum coke, and carbon black.

8. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder from biomass is selected from activated carbon, porous carbon, and hard carbon.

9. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder from recycle process is selected from pyrolysis carbon black, activated carbon, and hard carbon.

10. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder is selected from carbon according to any one of claim 5 to 9, or the combination thereof.

11. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein carbon powder is selected from carbon according to any one of claim 5 to 9, or the combination thereof, and functional reagent is cationic or anionic reagent selected from amino group, imino, ammonium, sulfonate, phosphonium, or a combination thereof.

12. The preparation of functional carbon materials via vacuum infusion method as claimed in claim 1 or 2 , wherein the carbon power is selected from claim 10, wherein the functional reagent from claim 11 is UQAB188 (3-chloro-2-hydroxypropyltrimethyl ammonium chloride).

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