KR102634951B1 - High performance nanodiamond abrasive material and preparing method thereof - Google Patents

Abstract

Explosive synthetic nanodiamond abrasives have an atomic percentage of oxygen on the surface of the nanodiamonds of 0% to 12.5%, an elemental content of carbon of 87.5% to 100%, and nanodiamonds are formed by an explosion reaction. will be.

Description

High-performance nanodiamond abrasive and manufacturing method thereof {HIGH PERFORMANCE NANODIAMOND ABRASIVE MATERIAL AND PREPARING METHOD THEREOF}

A high-performance nanodiamond abrasive and a method for manufacturing the same are provided.

Detonation nanodiamond (DND, Detonation Nanodiamond) formed through an explosive reaction has a very small particle size of several nanometers, and a specific surface area that is about tens to hundreds of times larger than that of ordinary diamond. In addition, explosively synthesized nanodiamonds have little toxicity in vivo and are biocompatible due to the stability of the structure. Additionally, because explosively synthesized nanodiamonds have unique electrical, chemical, and optical properties, their industrial use value has recently been increasing. For example, explosive synthetic nanodiamonds have excellent heat resistance, wear resistance, and chemical resistance, and are used in precision abrasives, high-hardness processing machines/tools, high-performance lubricants, wear-resistant/friction-resistant coatings, electrical and electronics, IT, aerospace, national defense, etc. It is applied industrially in medicine, cosmetics, etc.

Explosive synthetic nanodiamonds can be manufactured through processes such as synthesis, purification, and dispersion. In explosive synthesis nanodiamond manufacturing, an instantaneous high temperature and high pressure is generated through a very short explosion process, and nanodiamonds are synthesized through this. Explosively synthesized nanodiamonds have high hardness because they basically contain carbon with an sp ³ structure that makes up diamond, and at the same time, they contain graphite or amorphous carbon, which is carbon with an sp ² structure that is inevitably generated during the synthesis process. Chemical purification that involves acid treatment using sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, etc. to remove graphite or amorphous carbon, which is carbon of the sp ² structure, from the explosively synthesized nanodiamond soot and increase the purity of the explosively synthesized nanodiamonds. The method is widely used. In addition, functional ^groups such as hydroxyl group (OH), carboxyl group (COOH), carbonyl group (C=O), and hydrocarbon group (CH) formed on the surface of the explosively synthesized nanodiamond due to the bond (defect) of the sp 2 structure on the surface of the explosively synthesized nanodiamond. As a result, explosively synthesized nanodiamonds can be well dispersed in solvents such as water.

Meanwhile, as the next-generation semiconductor industry gradually moves to SiC-based, improvement in the performance of abrasives is urgently required. However, in the case of conventional diamond abrasives, although the polishing speed is excellent, it has limitations in surface roughness after polishing. In addition, conventional explosion-synthesized nanodiamonds have a spherical shape with a size of about 2 to 10 nm, but the polishing speed is slow.

One embodiment is to provide a nanodiamond abrasive with excellent polishing performance and a method for manufacturing the same.

One embodiment is intended to greatly improve surface roughness after polishing while speeding up the polishing speed.

In addition to the above tasks, embodiments according to the present invention can be used to achieve other tasks not specifically mentioned.

The explosive synthetic nanodiamond abrasive according to one embodiment has an atomic percentage of oxygen on the surface of the nanodiamonds of 0% to 12.5%, an elemental content of carbon of 87.5% to 100%, and an explosion reaction. Nanodiamonds are formed.

Oxygen functional groups on the surface of nanodiamonds may be reduced by treatment with N ₂ H ₄ or NaBH ₄ .

The average surface roughness Ra (arithmetical average roughness) of the polishing object may be 10 nm or less.

When the platen rotation speed of the polishing machine is 200 rpm, the head rotation speed is 100 rpm, and the reverse rotation is 2.5 DaN, the rate of decrease in the surface roughness Ra (arithmetical average roughness) of the polishing object for 60 minutes from the start of polishing. may be 2 nm/min or more.

A method of manufacturing an explosive-synthesized nanodiamond abrasive according to an embodiment includes the steps of mixing explosive-synthesized nanodiamonds and N ₂ H ₄ or NaBH ₄ and heating them to surface treat the explosive-synthesized nanodiamonds, surface-treated explosive-synthesized nanodiamonds It includes the steps of separating, and washing and drying the separated explosive synthetic nanodiamonds.

The method of manufacturing a nanodiamond abrasive may further include dispersing the dried explosively synthesized nanodiamonds using an ultrasonic disperser.

The method for producing a nanodiamond abrasive may further include the step of precipitating the dispersed explosively synthesized nanodiamonds using a centrifuge.

The step of separating the explosively synthesized nanodiamonds may be using a pressurized filter device.

According to one embodiment, a nanodiamond abrasive with excellent polishing performance and a manufacturing method thereof can be provided.

According to one embodiment, the surface roughness after polishing can be greatly improved while the polishing speed is fast.

Figures 1A to 1C are 3D images showing changes in surface roughness according to polishing time for commercial abrasives, explosively synthesized nanodiamonds before surface treatment, and explosively synthesized nanodiamonds after surface treatment, respectively.
Figures 2a and 2b are graphs showing the change in surface roughness according to polishing time for commercial abrasives, explosively synthesized nanodiamonds before surface treatment, and explosively synthesized nanodiamonds after surface treatment, respectively.
Figure 3 is a graph showing the change in particle size value according to centrifugal force of each explosively synthesized nanodiamond before and after surface treatment using N ₂ H ₄ .
Figure 4 is a FT-IR spectrum of each explosion-synthesized nanodiamond before and after surface treatment using various molar ratios of N ₂ H ₄ .
Figure 5 is a UV-Raman spectrum of each explosion-synthesized nanodiamond before and after surface treatment using various molar ratios of N ₂ H ₄ .
Figure 6 is a graph showing I _Dia /I _G values for each of the explosively synthesized nanodiamonds before and after surface treatment using various molar ratios of N ₂ H ₄ .
Figure 7 is an XPS spectrum for each of the explosion-synthesized nanodiamonds before and after surface treatment using various molar ratios of N ₂ H ₄ .
Figure 8 is a graph showing element content values based on XPS analysis for each of the explosively synthesized nanodiamonds before and after surface treatment using various molar ratios of N ₂ H ₄ .

With reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification. Additionally, in the case of well-known and well-known technologies, detailed descriptions thereof are omitted.

Throughout the specification, when a part is said to “include” a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

Next, a high-performance nanodiamond abrasive according to an embodiment will be described in detail.

According to one embodiment, by treating the surface of the explosive-synthesized nanodiamond with N ₂ H ₄ , the oxygen functional group on the surface of the explosive-synthesized nanodiamond can be removed and the oxygen functional group can be reduced, thereby improving the polishing performance of the explosive-synthesized nanodiamond. It can be improved.

The atomic percentage of oxygen on the surface of the nanodiamond may be 0% to 12.5%, and the elemental content of carbon may be 87.5% to 100%. When the elemental content of oxygen exceeds 12.5% and the elemental content of carbon is less than 87.5%, the oxygen functional group on the surface of the explosively synthesized nanodiamond increases, and the polishing performance of the explosively synthesized nanodiamond may be reduced.

When polishing using a nanodiamond abrasive according to an embodiment, the average surface roughness Ra (arithmetical average roughness) of the polishing object can be made to 10 nm or less. Accordingly, surface roughness can be greatly improved.

In the case of polishing using a nanodiamond abrasive according to an embodiment, when the platen rotation speed of the polisher is 200 rpm, the head rotation speed is 100 rpm, and the reverse rotation is 2.5 DaN, the polishing period is 60 minutes from the start of polishing. , the reduction rate of the surface roughness Ra (arithmetical average roughness) of the polishing object may be 2 nm/min or more. Accordingly, the polishing speed can be greatly improved.

Explosively synthesized nanodiamonds may be refined nanodiamond soot.

Nanodiamond suits are diamonds with nano-sized particles and can be formed through an explosive reaction. Nanodiamond suit may contain carbon impurities such as graphite and amorphous carbon during the explosive synthesis process.

Explosively synthesized nanodiamonds may contain carbon with an sp ³ structure and carbon with an sp ² structure. For example, carbon having an sp ³ structure may be diamond, etc., and may exhibit a peak at about 1330 cm ^-1 in a UV-Raman spectrum. Carbon having an sp ² structure may be graphite, graphene, carbon nanotube, etc., and may exhibit a peak at about 1590 cm ^-1 in the UV-Raman spectrum.

Before and after treatment in a hydrogen gas atmosphere, the sp ³ /sp ² carbon ratio in nanodiamonds can be maintained without change. The sp ³ /sp ² carbon ratio in nanodiamonds may have the same value as the intensity ratio based on the UV-Raman spectrum. For example, the strength ratio of nanodiamonds satisfies Equation 1.

[Equation 1]

Intensity ratio = Intensity at 1330 cm ^-1 / Intensity at 1590 cm ^-1

Additionally, the intensity ratio of nanodiamonds may have the same value as the intensity at the diamond peak relative to the intensity at the G peak ( I _Dia /I _G ) based on the UV-Raman spectrum. For example, the strength ratio of nanodiamonds satisfies Equation 2.

[Equation 2]

Intensity ratio = Intensity at Diamond peak / Intensity at G peak

Next, a method for manufacturing a nanodiamond abrasive according to an embodiment will be described in detail.

The manufacturing method of nanodiamond abrasives includes the steps of mixing and heating explosive-synthesized nanodiamonds and N ₂ H ₄ to surface treat the explosive-synthesized nanodiamonds, separating the surface-treated explosive-synthesized nanodiamonds, and separating the separated explosive-synthesized nanodiamonds. It includes the steps of washing and drying nanodiamonds.

Explosive synthesis nanodiamond and N ₂ H ₄ are mixed and heated. For example, when N ₂ H ₄ is in a liquid state, heating may be performed at about 60° C. to about 100° C. for about 0.5 hours to about 36 hours. Here, if the heating temperature is lower than about 60°C, the reduction reaction may not occur effectively. When N ₂ H ₄ is a gaseous phase, heating may proceed at about 100° C. to about 500° C. for about 0.5 hours to about 36 hours. When N ₂ H ₄ is a liquid or a vapor phase, the heating time ranges from about 0.5 hours to about 36 hours, and production efficiency can be maintained while a reduction reaction occurs.

The molar ratio of mixing the explosively synthesized nanodiamond and N ₂ H ₄ may be about 1:0.05 to 1:15. If it is less than 1:0.05, the amount of N ₂ H ₄ may be too small for a reduction reaction to occur sufficiently, and the reaction rate may be too slow, resulting in reduced reaction efficiency. If 1:15 or more, N ₂ H ₄ reaches saturation, there may be little effect on improving polishing speed and surface roughness, and environmental friendliness may be reduced due to the toxicity of N ₂ H ₄ .

In addition to N ₂ H ₄ , explosively synthesized nanodiamonds and NaBH ₄ (sodium borohydride) can be mixed and heated to improve polishing speed and surface roughness after polishing.

The surface-treated explosively synthesized nanodiamonds are separated. For example, a pressurized filter device may be used.

The separated explosive synthetic nanodiamonds are washed and dried. For example, explosively synthesized nanodiamonds can be washed repeatedly using ultrapure water. The cleaned explosive nanodiamonds can be dried in a vacuum oven.

The dried explosively synthesized nanodiamonds are dispersed using an ultrasonic disperser. During ultrasonic dispersion, the method of cooling after dispersion can be repeatedly performed considering the temperature rise. After dispersion, the explosively synthesized nanodiamonds are precipitated using a centrifuge, and only the supernatant is separated to prepare a dispersion solution for polishing.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only examples of the present invention and the present invention is not limited to the following examples.

Experimental Example 1 (Manufacture of polishing disc)

Cut a titanium rod with a diameter of about 1 cm into about 1 cm long, place it in a mounting press together with about 25 g of phenolic resin, heat it at about 170 ° C. and about 100 bar for about 10 minutes, and cool it for about 7 minutes. A sample disk with a diameter of approximately 3.5 cm is manufactured. While supplying coolant to the sample disk using abrasive paper, the titanium cutting surface of the sample disk was cut about 10 degrees under the conditions of a disk rotation speed of about 200 rpm, a head rotation speed of about 100 rpm, and a reverse rotation of about 2.5 DaN. By grinding minute by minute, an abrasive disk is produced. The manufactured polishing disc is used to evaluate polishing performance.

Experimental Example 2 (Evaluation of Polishing Performance)

Add about 10 g of explosion-synthesized nanodiamonds and about 2.5914 mL of N ₂ H ₄ (explosion-synthesized nanodiamonds: N ₂ H ₄ = 1:0.1 to 10 mol ratio) into a reaction device with about 100 mL of ultrapure water, and heat at about 80°C. By reacting for 24 hours, the surface of the explosively synthesized nanodiamond is treated.

About 10g of explosively synthesized nanodiamond = about 10g/12 (g/mol) = about 0.83 mol

0.1 mol ratio N ₂ H ₄ = about 0.83 mol*0.1 = about 0.083 mol

After completion of the reaction, the surface-treated explosively synthesized nanodiamonds are separated using filter paper (0.025㎛ VSWP Nitrocellulose membrane filter, Mllipore) in a filter device pressurized with argon gas (Ar) at about 4 bar. Next, it is washed twice using approximately 100 mL of ultrapure water, and the drying process is performed in a vacuum oven at approximately 60°C. About 10 g of each explosive synthetic nanodiamond before and after surface treatment is made into 1000 g using ultrapure water at about 1 wt%, and dispersion is carried out for about 15 minutes using an ultrasonic disperser (Amplitude 100%). Considering the rise in temperature of the solution, dispersion for about 5 minutes and then cooling for about 15 minutes are repeated three times. After dispersion, precipitation proceeds at about 4,000 rpm for about 10 minutes using a centrifuge, and only the supernatant is separated and used as a dispersion solution for polishing.

The polishing performance experiment is conducted under the same conditions: platen rotation speed of approximately 200 rpm, head rotation speed of approximately 100 rpm, reverse rotation of approximately 2.5 DaN, and abrasive and lubricant solution input speed of approximately 0.06 mL/s. In this polishing performance evaluation, commercial abrasives, explosively synthesized nanodiamonds before surface treatment, and explosively synthesized nanodiamonds surface treated with N ₂ H ₄ were used. The commercial abrasive is a commercially available abrasive (Diamond suspension reflex LDP 1μ, PRESI Trade Co., Ltd), and 1 L of lubricating solution (LUBRICANT REFLEX LUB, PRESI Trade Co., Ltd) is used along with the abrasive. Polishing cloths are used on the polishing platen. 50-60% of N ₂ H ₄ used in this example is a Sigma Aldrich product.

In this embodiment, the surface roughness was measured using a non-contact 3D surface profiler using a 5x lens, WSI (White light interferometry) mode, 3x scan rate, and high accuracy conditions. ) Using an analyzer, it is analyzed two or more times at a random location. Surface roughness is compared with the Ra (arithmetical average roughness) average value.

Figures 1A to 1C and Figures 2A and 2B are 3D images and surface roughness values of the change in surface roughness over time after polishing for commercial abrasives, explosively synthesized nanodiamonds before surface treatment, and explosively synthesized nanodiamonds after surface treatment, respectively. represents. Here, the surface treatment is performed using N ₂ H ₄ at a molar ratio of 0.1 using the above-described method.

Referring to FIGS. 1A to 1C and 2A and 2B, in the case of commercial abrasives, the speed at which the surface roughness converges is very fast, but it has a limitation of converging to a surface roughness of about 70 nm. Additionally, the explosion-synthesized nanodiamonds before surface treatment converge to a surface roughness of approximately 10 nm, but the convergence speed is very slow. However, explosion-synthesized nanodiamonds surface-treated with N ₂ H ₄ at a molar ratio of 0.1 have a very fast surface roughness convergence rate, converging to a surface roughness of about 3 nm.

Referring to Figures 2a and 2b, for each of the commercial abrasives, explosively synthesized nanodiamonds before surface treatment, and explosively synthesized nanodiamonds after surface treatment, the average reduction rate of surface roughness Ra from the start of polishing to 60 minutes is about 0.75 nm/min. , 1.56 nm/min, and 3.6 nm/min.

Experimental Example 3

It is known that one of the polishing factors has a high impact on the particle size of the abrasive. When manufacturing explosive synthetic nanodiamonds before and after surface treatment in the above-mentioned Experimental Example 2, after dispersion and centrifugation at about 4,000 rpm for about 10 minutes, the change in particle size is measured using a particle size analyzer. Referring to Figure 3, the particle size after centrifugation is 0.1 mol of N ₂ H ₄ and does not change before or after surface treatment of the explosively synthesized nanodiamond. Accordingly, it can be seen that the improvement in polishing speed and polishing surface roughness by the N ₂ H ₄ surface-treated explosive synthetic nanodiamond abrasive in Experimental Example 2 was not caused by a change in the particle size of the abrasive.

Experimental Example 4

To determine whether the polishing speed and polished surface roughness were improved in Experimental Example 2 by changing the surface functional group of the explosive-synthesized nanodiamond before and after N ₂ H ₄ surface treatment, FT IR spectrum (Fourier-transform infrared spectroscopy) analysis was performed. do. The analysis sample is prepared by adding 1 mg of the explosive synthetic nanodiamond sample before and after N ₂ H ₄ surface treatment to about 200 mg of KBr, grinding them, and making pellets. Surface treatment of the explosively synthesized nanodiamonds was performed in the same manner as in Experimental Example 2 described above at a ratio of 1:0.1 mol, 1:1 mol, and 1:10 mol between the explosively synthesized nanodiamonds and N ₂ H ₄ . In FT-IR analysis, the pellet is measured after being dried in a vacuum oven at about 150°C for about 12 hours or more, and the FT-IR spectrum is displayed by scanning 128 times with a resolution of 4 cm ^-1 . The FT-IR spectrum is displayed by baseline correction and normalization under the condition of straight lines (1 iteration). Referring to Figure 4, the -OH peak at 1385 cm ^-1 , 1630 cm ^-1 and 3163 cm ^-1 , the C=O peak at 1763 cm ^-1 , and the peak with the maximum value between 1000 cm ^-1 and 1140 cm ^-1 are formed by the COC functional group. appear. The peak at 1257 cm ^-1 also appears due to -CO of ether, and no change in the intensity of any particular peak is seen, and no new peak is created. This means that surface functional groups are not created on the surface of the explosively synthesized nanodiamonds by N ₂ H ₄ surface treatment, and there is no change in the surface functional groups. Accordingly, it can be seen that the improvement in polishing speed and polishing surface roughness by the N ₂ H ₄ surface-treated explosive synthetic nanodiamond abrasive in Experimental Example 2 was not caused by a change in the surface functional group of the explosive synthetic nanodiamond.

Experimental Example 5

In order to determine whether the polishing speed and polishing surface roughness were improved in Experimental Example 2 by the sp ³ /sp ² carbon ratio of the explosively synthesized nanodiamond before and after surface treatment with N ₂ H ₄ , UV-Raman spectroscopy was used. This goes on. The explosively synthesized nanodiamond is surface treated in the same manner as in Experimental Example 2 described above at a ratio of 1:0.1 mol, 1:1 mol, and 1:10 mol between the explosively synthesized nanodiamond and N ₂ H ₄ . Analysis is performed using an excitation frequency of approximately 325 nm (He-Cd laser) in back-scattering geometry, and the 1325 cm ^-1 diamond peak and 1590 cm ^-1 G-band peak are analyzed. The I _Dia /I _G value is calculated. A 100x lens is used and the exposure time is fixed to 180 seconds. Laser power is maintained within approximately 10%. Background removal uses a fixed point subtraction method in the range of 900 to 2000 cm ^-1 . Figure 5 is a measured UV-Raman spectrum.

In explosively synthesized nanodiamonds, the sp ³ /sp ² carbon ratio can be maintained without change. The sp ³ /sp ² carbon ratio in nanodiamonds may have the same value as the intensity ratio based on the UV-Raman spectrum. For example, the strength ratio of nanodiamonds satisfies Equation 1.

[Equation 1]

Intensity ratio = Intensity at 1330 cm ^-1 /Intensity at 1590cm ^-1

Additionally, the intensity ratio of the explosively synthesized nanodiamond may have the same value as the intensity at the diamond peak relative to the intensity at the G peak (I _Dia /I _G ) based on the UV-Raman spectrum. For example, the strength ratio of nanodiamonds satisfies Equation 2.

[Equation 2]

Intensity ratio = Intensity at Diamond peak / Intensity at G peak

Figure 6 is a graph showing I _Dia /I _G values for each explosive synthetic nanodiamond before and after N ₂ H ₄ surface treatment. Referring to FIG. 6, there is no change in the strength ratio of the explosively synthesized nanodiamond before and after N ₂ H ₄ surface treatment. Accordingly, in Experimental Example 2, the improvement in polishing speed and polishing surface roughness by the N ₂ H ₄ surface-treated explosive-synthesized nanodiamond abrasive was determined by the intensity ratio ( sp ³ /sp ² carbon ratio or purity change) of the explosive-synthesized nanodiamonds. It can be seen that it was not caused by .

Experimental Example 6

To confirm elemental changes on the surface of explosively synthesized nanodiamonds before and after N ₂ H ₄ surface treatment, X-ray photoelectron spectroscopy (XPS) analysis is performed. The explosively synthesized nanodiamond is surface treated in the same manner as in Experimental Example 2 described above at a ratio of 1:0.1 mol, 1:1 mol, and 1:10 mol between the explosively synthesized nanodiamond and N ₂ H ₄ . To confirm elemental changes on the surface of the explosively synthesized nanodiamond, an XPS survey scan is performed as shown in FIG. 7. Referring to Figure 7, only C 1s and O 1s peaks appear, which means that it is composed of C and O elements. To calculate the elemental changes in the explosively synthesized nanodiamond before and after N ₂ H ₄ surface treatment in more detail, the atomic percentages of C 1s and O 1s are calculated as shown in FIG. 8. Referring to FIG. 8, when surface treatment is performed at a molar ratio of N ₂ H ₄ of 0.1, the oxygen element ratio decreases from 13.55% to 11.17%. Additionally, when the molar ratio of N ₂ H ₄ increases from 0.1 to 10, the oxygen element ratio decreases to 10.83%.

In DND, which was hydrogenated using N ₂ H ₄ at a 1:0.1 molar ratio at a carbon element ratio of 82.67% and an oxygen element ratio of 13.55%, the carbon element ratio increased to 86.18%, the oxygen element ratio decreased to 11.17%, and 1 : 1 mol, 1 : 10 mol The carbon and oxygen element ratios of DND hydrogenated with N ₂ H ₄ also have similar element ratios. Accordingly, the polishing speed and polished surface roughness are improved by reducing the content of oxygen functional groups on the surface of the explosively synthesized nanodiamond.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. falls within the scope of rights.

Claims (8)

On the surface of nanodiamonds, the atomic percentage of oxygen is 0% to 12.5%, the atomic percentage of carbon is 87.5% to 100%, and a nanodiamond soot is formed by an explosive reaction,
The nanodiamonds are refined from the nanodiamond suit,
The purified nanodiamonds are explosive synthetic nanodiamond abrasives in which CH bonding reaction does not occur before or after treatment with N ₂ H ₄ or NaBH ₄ .
In paragraph 1:
An explosive synthetic nanodiamond abrasive in which oxygen functional groups are reduced on the surface of the nanodiamond by treatment with N ₂ H ₄ or NaBH ₄ .
In paragraph 2,
An explosive synthetic nanodiamond abrasive with an average surface roughness Ra (arithmetical average roughness) of the polishing object of 10 nm or less.
In paragraph 2,
When the platen rotation speed of the polishing machine is 200 rpm, the head rotation speed is 100 rpm, and the reverse rotation is 2.5 DaN, the rate of decrease in the surface roughness Ra (arithmetical average roughness) of the polishing object for 60 minutes from the start of polishing. is 2 nm/min or more, an explosive synthetic nanodiamond abrasive.
A step of surface treating the explosively synthesized nanodiamonds by mixing and heating the explosively synthesized nanodiamonds and N ₂ H ₄ or NaBH ₄ ;
Separating the surface-treated explosive synthetic nanodiamonds, and
Step of washing and drying the separated explosive synthetic nanodiamonds
Method for producing nanodiamond abrasives, including.
In paragraph 5,
A method for producing a nanodiamond abrasive, further comprising dispersing the dried explosively synthesized nanodiamonds using an ultrasonic disperser.
In paragraph 6:
A method for producing a nanodiamond abrasive, further comprising precipitating the dispersed explosively synthesized nanodiamonds using a centrifuge.
In paragraph 5,
The step of separating the explosively synthesized nanodiamonds is a method of producing a nanodiamond abrasive using a pressure filter device.