Method for separating carbon isotopes using electromigration

Abstract

The present invention relates to a carbon isotope separation apparatus and a method for separating carbon isotopes using the same. Specifically, the carbon isotope separation apparatus according to one embodiment is made of a magnetic metal and includes a pocket portion in the center for storing a carbon mixture, electrode connecting portions at both ends, and a graphite deposition portion between the pocket portion and the electrode connecting portions, and can efficiently separate and concentrate carbon isotopes by electromigration.

Description

[Technical Field]

[0001] This invention relates to a method for separating and concentrating carbon isotopes using electromigration. [Background technology]

[0002] Isotope separation technology is a technique for separating a specific isotope from an isotope mixture composed of identical elements with different atomic weights.

[0003] On the other hand, carbon has a natural composition ratio of 98.89% carbon-12( 12 C) and 1.1% carbon-13 ( 13 Carbon has two stable isotopes, and each isotope is a very useful material in various industrial fields, making it one of the most important raw materials for isotope separation and enrichment. However, the technologies currently used for separating carbon isotopes have drawbacks, such as requiring expensive equipment and specialized skills, using materials harmful to the environment and human health, and having low separation efficiency. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] One aspect of the present invention provides a separation apparatus capable of efficiently separating and concentrating carbon isotopes, and a method for separating carbon isotopes using the same. [Means for solving the problem]

[0005] One aspect of the present invention provides a carbon isotope separation apparatus comprising a pocket portion for storing a carbon mixture in the center, electrode connecting portions at both ends, and a graphite deposition portion between the pocket portion and the electrode connecting portions, wherein the carbon isotope separation apparatus is formed of a magnetic metal.

[0006] The magnetic metal may be nickel or cobalt.

[0007] The carbon isotope separation apparatus may further include a Joule heating device connected to the electrode connection.

[0008] Another aspect of the present invention is the step of connecting the electrode connecting portion of the carbon isotope separation apparatus to the electrode of the Joule heating apparatus, and the step of connecting the pocket portion of the carbon isotope separation apparatus 12 C and 13 The present invention provides a method for separating carbon isotopes, comprising the steps of introducing a carbon mixture containing C and dissolving the carbon mixture by Joule heating, and precipitating graphite by electromigration.

[0009] The precipitated graphite 12 The C content is of the carbon mixture. 12 The content may be 16 at% or more relative to the C content.

[0010] The aforementioned Joule heating may create a temperature gradient that decreases from the pocket towards both ends.

[0011] The temperature of the pocket portion may be 1300°C to 1400°C, and the temperature of the graphite deposition portion may be 800°C to 1200°C.

[0012] The electromigration may be carried out for 20 to 60 hours. [Effects of the Invention]

[0013] The present invention provides a method for separating carbon isotopes using electromigration, which allows for the production of refined graphite while simultaneously separating and concentrating carbon isotopes in an economical and environmentally friendly manner. Specifically, one embodiment of this method for separating carbon isotopes is environmentally friendly because it does not use materials harmful to the human body or the environment, and it has the advantages of a simple process and high energy efficiency, making it potentially applicable to industrial settings. [Brief explanation of the drawing]

[0014] [Figure 1] It is a photograph of a carbon isotope separation device according to an embodiment. [Figure 2] It is a photograph of a carbon isotope separation device connected to a Joule heating device according to an embodiment. [Figure 3] It is a photograph of a carbon isotope separation device after performing electromigration according to an embodiment. [Figure 4] It is a temperature gradient graph in the regions a to e shown in FIG. 3. [Figure 5] It is a Raman spectrum in the regions a to e shown in FIG. 3. [Figure 6] It is an image of the boundary between the deposited graphite region and the magnetic metal (nickel) region observed with a scanning electron microscope after performing electromigration according to an embodiment. [Figure 7] It is a graph showing the content (at%) of 13C in the carbon mixture source and the content of 13C in the graphite deposition part after performing electromigration in Examples 1 to 10.

Mode for Carrying Out the Invention

[0015] Unless otherwise defined herein, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description herein are for the purpose of effectively describing specific examples only and are not intended to limit the present invention.

[0016] The singular forms used in the present invention are intended to include the plural forms as well, unless otherwise indicated in the context.

[0017] Throughout this specification, when a component is described as "including", "comprising", "containing", or "having", it means that it can further include other components, rather than excluding other components, unless otherwise stated to the contrary, and does not exclude elements, materials, or steps not additionally recited.

[0018] As used herein, numerical ranges include lower and upper limits, all values ​​within those ranges, increments logically derived from the form and width of the defined range, all double-limited values, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. Unless otherwise defined in the specification of the present invention, values ​​outside the numerical range that may arise due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0019] Unless otherwise defined herein, “approximately” may refer to values ​​up to 30%, 25%, 20%, 15%, 10%, or 5% of the specified value.

[0020] In this specification, "Joule heating" refers to the process by which heat is generated when an electric current flows through a conductor.

[0021] In this specification, "electromigration" refers to the phenomenon in which atoms in a metal move along the electric current when an electric current is applied to the metal.

[0022] The following provides a detailed description of this disclosure. However, this is illustrative only and the disclosure is not limited to the specific embodiments described herein.

[0023] One aspect of the present invention provides an apparatus capable of separating and concentrating carbon isotopes using electromigration, and a method for separating carbon isotopes using the same.

[0024] A carbon isotope separation apparatus according to one embodiment (Figure 1) is made of a magnetic metal and may include a pocket portion in the center for storing a carbon mixture, electrode connecting portions at both ends, and a graphite deposition portion between the pocket portion and the electrode connecting portions.

[0025] As the magnetic metal, any magnetic metal with a high solubility in carbon can be used without limitation, and as a non-limiting example, it may be nickel or cobalt.

[0026] The carbon isotope separation device according to one aspect may further include a joule heating device connected to the electrode connection part (FIG. 2).

[0027] Another aspect of the present invention provides a method for separating carbon isotopes using the above-described carbon isotope separation device.

[0028] The method for separating carbon isotopes according to one aspect includes connecting the electrode connection part of the above-described carbon isotope separation device to the electrode of the joule heating device, and 12 C and 13 introducing a carbon mixture containing C into the pocket part of the carbon isotope separation device, and dissolving the carbon mixture by joule heating, and a step of depositing graphite by electromigration.

[0029] The content of 12 C in the precipitated graphite may be 1 at% or more, 2 at% or more, 5 at% or more, or 10 at% or more, or 16 at% or more, or 95 at% or less, or 92 at% or less, or 90 at% or less with respect to the content of 12 C in the carbon mixture. That is, according to the method for separating carbon isotopes according to one aspect, it can be seen that by electromigration, 12 C, which is a relatively lighter isotope, diffuses faster through the metal and is deposited at a concentrated content compared to the carbon mixture source. By repeating the above separation method, it is expected that pure 13 C and 12 C can be separated.

[0030] According to one embodiment of the carbon isotope separation method, the Joule heating can create a temperature gradient that decreases from the pocket portion toward both ends. The graphite deposition portion refers to the section in which carbon atoms that had moved by electromigration are precipitated due to the decreasing temperature gradient.

[0031] In this case, when Joule heating is performed using a direct current, graphite is deposited only in the graphite deposition area on the negative electrode side with respect to the pocket, while when alternating current is used, graphite can be deposited in both graphite deposition areas on both sides with respect to the pocket.

[0032] The temperature of the pocket portion when performing the electromigration may be within a temperature range in which carbon can dissolve, for example, 1,300°C to 1,400°C or 1,300°C to 1,350°C, and the temperature of the graphite deposition portion may be 800°C to 1,200°C, or 900°C to 1,200°C, or 900°C to 1,100°C.

[0033] The electromigration may be carried out for 20 to 60 hours, 30 to 60 hours, or 40 to 60 hours, and may be carried out under an argon atmosphere.

[0034] The above-mentioned implementation examples will be explained in more detail below with reference to specific embodiments. However, the following embodiments are for illustrative purposes only and do not limit the scope of rights.

[0035] The physical properties of the examples were measured as follows.

[0036] 1. Scanning Electron Microscope (SEM) The graphite deposition region was characterized using a scanning electron microscope (FEI Verios 460) under the conditions of an electron acceleration voltage of 10 kV and a beam current of 0.8 nA.

[0037] 2. Raman Spectrum Using a confocal Raman microscope (Horiba LabRAM HR Evolution), mapping mode was performed with a 532nm laser source, x100 objective lens, 10% (~3mW) laser output, single accumulation, and a 0.5-second acquisition time. The resulting spectrum was analyzed using OriginPro software and is shown.

[0038] [Example 1] A 99.9 wt% pure nickel metal bulk (Shaanxi Super Metal Materials Co. Limited) was processed into the form of a carbon isotope separation device (Figure 1). The carbon isotope separation device formed from the nickel was annealed in an argon:hydrogen = 1:3 atmosphere, and both ends were connected to electrode holders of a Joule heating device (Figure 2).

[0039] after that, 12 C carbon powder (Alfa Aesar) and 13 A carbon mixture source, prepared by mixing C carbon powder (Cambridge Isotope Laboratories Inc.) in a 10 / 90 weight ratio, was ball-milled and then introduced into the pocket of a carbon isotope separator. Subsequently, electromigration was performed for 50 hours under an argon atmosphere by applying a DC current to the pocket, setting the temperature to 1350°C (Figure 3). The temperature was monitored through a side window of the furnace using a pyrometer focused on the lower end region of the pocket.

[0040] A photograph of the carbon isotope separation apparatus after electromigration is shown in Figure 3. Furthermore, the temperature gradient graph and Raman spectrum for regions a through e shown in Figure 3 are shown in Figures 4 and 5, respectively, and the scanning electron microscope measurement results for region c are shown in Figure 6.

[0041] Referring to Figure 4, it can be seen that a temperature gradient is formed with the temperature decreasing in both directions from the pocket region, and referring to Figure 5, it can be confirmed that the G and 2D peaks, which are Raman spectral peaks of graphite, are observed only in the region from c to d. In other words, it can be confirmed that graphite is deposited only in the temperature decreasing region (c to d) corresponding to the negative electrode direction with respect to the pocket region, and that graphite is deposited in the region where carbon is diffused by electromigration and the temperature decreases.

[0042] [Examples 2-5] Isotope ratio of carbon mixture source ( 12 C / 13 The procedure was carried out in the same manner as in Example 1, except that the weight ratio of C) was changed from 10 / 90 to 30 / 70, 50 / 50, 70 / 30, and 90 / 10.

[0043] [Example 6] The procedure was carried out in the same manner as in Example 1, except that 99.95 wt% pure cobalt metal bulk (Shaanxi Super Metal Materials Co. Limited) was used instead of nickel metal as the material for the carbon isotope separation apparatus.

[0044] [Examples 7-10] Isotope ratio of carbon mixture source ( 12 C / 13 The procedure was carried out in the same manner as in Example 6, except that the weight ratio of C) was changed from 10 / 90 to 30 / 70, 50 / 50, 70 / 30, and 90 / 10.

[0045] The weight ratios of 10 / 90, 30 / 70, 50 / 50, 70 / 30, and 90 / 10 used in the above embodiment are 12 C / 13 We measured the IRMS (Isotope Ratio Mass Spectrometry) of a carbon mixture source. 13 The results of calculating the C content (at%) are shown in Table 1 below. Furthermore, after electromigration in Examples 1 to 10, the Raman spectra of the graphite precipitates were obtained. 13The C content (at%) was calculated (Nano Lett. 2009, 9, 12, 4268-4272), and the carbon mixture source was... 13 The C content (at%) is shown in comparison in Figure 7.

[0046] [Table 1]

[0047] Referring to Figure 7, the graphite deposited by electromigration contains 13 It can be seen that the C content decreases compared to the initial carbon mixture source. In other words, due to electromigration, the relatively lighter isotope is... 12 We confirmed that C diffuses more rapidly through the metal and precipitates at a more concentrated content compared to the carbon mixture source. By repeating this experiment, we can achieve a pure 13 C and 12 It is expected that C is separable.

[0048] As described above, the disclosure has been explained by limited embodiments provided for the sake of a more general understanding of the disclosure, and the disclosure is not limited to the embodiments described above. A person with ordinary skill in the art to which the disclosure belongs can make various modifications and variations from such descriptions.

[0049] Therefore, the concept of the present invention should not be limited to the embodiments described above, and it can be said that not only the scope of the attached claims, but also equivalent or equivalent modifications to these claims, all fall within the scope of the concept of the present invention.

Claims

1. A carbon isotope separation apparatus comprising a pocket section in the center for storing a carbon mixture, electrode connecting sections at both ends, and a graphite deposition section between the pocket section and the electrode connecting sections, A carbon isotope separation apparatus in which the carbon isotope separation apparatus is made of a magnetic metal.

2. The carbon isotope separation apparatus according to claim 1, wherein the magnetic metal is nickel or cobalt.

3. The carbon isotope separation apparatus according to claim 1, further comprising a joule heating device connected to the electrode connection portion.

4. The steps of connecting the electrode connecting portion of the carbon isotope separation apparatus described in claim 1 to the electrode of the Joule heating apparatus, In the pocket portion of the carbon isotope separation apparatus １２ C and １３ The steps include adding a carbon mixture containing C and dissolving the carbon mixture by Joule heating, A method for separating carbon isotopes, comprising the step of precipitating graphite by electromigration.

5. The precipitated graphite １２ The C content of the carbon mixture １２ The method for separating carbon isotopes according to claim 4, wherein the content of carbon is 16 at% or more relative to the content of carbon.

6. The method for separating carbon isotopes according to claim 4, wherein the Joule heating creates a temperature gradient that decreases from the pocket portion toward both ends.

7. The method for separating carbon isotopes according to claim 6, wherein the temperature of the pocket portion is 1300°C to 1400°C, and the temperature of the graphite deposition portion is 800°C to 1200°C.

8. The method for separating carbon isotopes according to claim 4, wherein the electromigration is performed for 20 to 60 hours.

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