CN115181957A

CN115181957A - Preparation and application of functional diamond micro-nano powder and complex

Info

Publication number: CN115181957A
Application number: CN202211028274.2A
Authority: CN
Inventors: 宋建华
Original assignee: Beijing Aike Ruite Diamond Tools Co
Current assignee: Beijing Aike Ruite Diamond Tools Co
Priority date: 2022-08-25
Filing date: 2022-08-25
Publication date: 2022-10-14
Anticipated expiration: 2042-08-25
Also published as: CN115181957B

Abstract

The application discloses preparation and application of functional diamond micro-nano powder and a complex. In a first aspect, the present application provides a functional diamond micro-nano powder and a preparation process thereof, which can be directly applied to various electrochemical electrodes, preparation of super capacitors, biosensors, drug delivery for targeted medical treatment, quantum computation, color center application for quantum transmission, and invisible wave-absorbing materials. In a second aspect, the present application provides a diamond polymer and a preparation process thereof, and the obtained diamond polymer can be widely applied in the industries of precision measuring instruments, shielding materials, radiation-resistant materials and frictional wear. In a third aspect, the present application provides a diamond composite and a preparation process thereof, wherein the diamond composite can be applied to electrochemical electrode materials and photocatalyst porous framework materials.

Description

Preparation and application of functional diamond micro-nano powder and complex

Technical Field

The application relates to the technical field of novel functional materials, in particular to preparation and application of functional diamond micro-nano powder and a complex.

Background

The diamond is an inert material with highest hardness, highest thermal conductivity, high acid resistance and high alkali resistance, and the diamond has excellent performance, so that the diamond can be widely applied to the fields of electricity, thermal engineering, optics and the like. Diamond, which is a member of ultra-wide band gap semiconductor materials (band gap width 5.5 ev), has excellent physical and chemical properties, such as high carrier mobility, high thermal conductivity, high breakdown electric field, high carrier saturation rate, and low dielectric constant. Based on these excellent performance parameters, diamond is considered to be the most promising material for the preparation of next generation high power, high frequency, high temperature and low power consumption electronic devices, and is known in the industry as "ultimate semiconductor".

Diamond micropowder is usually prepared from graphite by using a unique directional blasting method, and is mainly used in the working procedures of ultraprecise finishing, grinding and polishing of the surface of a workpiece. With the development of electronic technology, the polishing requirements of various precision devices such as optoelectronic crystals, computer hard disk substrates, optical components, semiconductor integrated circuit silicon wafers and the like are increasing day by day, in order to meet the processing requirements of the precision devices, the demand of diamond fine powder is increasing, and meanwhile, higher requirements are provided for the crystal form, uniformity and mechanical properties of the diamond fine powder so as to meet the grinding and polishing requirements of high efficiency and high precision. Therefore, research on the growth process of high-quality and high-grade diamond micro powder and improvement of the synthesis technical level of the diamond micro powder become the focus of attention of the artificial diamond industry.

Currently, there are two main methods for producing diamond, a high temperature High Pressure (HPHT) method and a Chemical Vapor Deposition (CVD) method. As is well known, the high-temperature and high-pressure method is a process of converting graphite into diamond by means of a metal catalyst under a static high-pressure condition, but it is difficult to synthesize ultra-fine diamond micropowder by using the method, and the catalyst metal nickel, manganese, cobalt and the like cannot enter the diamond and cannot be removed, and the ultra-pure diamond cannot be obtained by using the high-temperature and high-pressure method.

The Chemical Vapor Deposition (CVD) method is also an important method for diamond synthesis, and by using the method, the growth rate of diamond can be effectively controlled to obtain a layer of diamond film. However, in some fields, the ultra-pure diamond film synthesized by the above method cannot be directly applied, and quantitative and qualitative doping is required to impart certain specific properties to the diamond film.

Therefore, there is a need to develop a diamond material with a wide application range and good economic benefits, which can not only obtain high-purity diamond with few impurities and defects, but also realize quantitative and qualitative doping.

Disclosure of Invention

In order to solve at least one technical problem, a diamond material with wide application range and good economic benefit is developed, and the application provides preparation and application of functional diamond micro-nano powder and a composite body.

In a first aspect, first, the process for preparing diamond micro-nano powder provided by the application comprises the following steps:

a1, substrate particle pretreatment;

A. adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle matrix prepared in the step A1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact diamond layer;

a3, peeling the loose diamond layer deposited in the step A2 in an impact mode, and separating a peeling layer to obtain a remainder which is a byproduct diamond polymer;

and A4, crushing the stripping layer in the step A3, and purifying to obtain the diamond micro-nano powder.

By adopting the technical scheme, the pretreated particle matrix can form a good film-substrate adhesion foundation, so that a compact diamond layer grows. By adopting two different modes of homogeneous or heterogeneous epitaxy, the diamond layer can be correspondingly adjusted according to the requirements of structure and property and the purity requirement. The loose layer can be easily peeled off by adopting a mode of air flow impact or high-pressure microjet impact, the obtained diamond micro-nano powder has extremely high impact resistance after the peeled loose diamond layer is subjected to crushing treatment, and is particularly suitable for polishing processing of high-precision devices. In addition, the epitaxially grown compact diamond layer can be more attached to the substrate particle matrix under the condition that the loose diamond layer grows for multiple times, so that a more compact coating film is formed, the substrate material with the compact layer can be repeatedly used, and the economic benefit of the preparation process is further improved.

Optionally, in the process for preparing the functional diamond micro-nano powder, the substrate particles are selected from one of granular diamond, granular ceramic and granular metal.

Optionally, in the process for preparing the functional diamond micro-nano powder, the granular ceramic is selected from one of silicon carbide, silicon nitride, aluminum oxide and silicon dioxide.

Optionally, in the process for preparing the functional diamond micro-nano powder, the particulate metal is selected from one of molybdenum, tungsten, titanium, tantalum, and hard alloy.

By adopting the technical scheme, the research field of the composite coating material can be further widened, so that the micro-nano composite material has more purposes and functions.

Optionally, in the preparation process of the functional diamond micro-nano powder, the shape of the substrate particles is selected from one of a sphere, a polyhedron and a plate.

Optionally, the pretreatment method of the substrate particles includes the following steps:

a11, cleaning the surface of the particle matrix, performing ultrasonic treatment by using diamond micropowder-alcohol suspension, and prefabricating seed crystals on the surface of the substrate;

and A12, purifying and drying the substrate material with the surface prefabricated seed crystal obtained in the step A11. By adopting the technical scheme, the roughening of the substrate material and the method for pre-implanting the diamond seed crystal can enable the substrate material and the diamond compact layer to form a firm bonding state.

Optionally, in step a11, the surface cleaning process is to remove oil and dirt by using an organic solution.

Optionally, in step a11, the diamond powder in the diamond powder alcohol suspension includes 50wt% of 5 μm diamond powder and 50wt% of 40 μm diamond powder.

Optionally, in the step a11, the ultrasonic treatment is performed for 30 to 60min.

Optionally, a preparation process of the functional diamond polymer, step a12, the purification and drying process is to sequentially wash with absolute ethyl alcohol and deionized water and dry.

By adopting the technical scheme, the problem of oxide layer residue on the surface of the substrate material can be better solved, the surface of the material can have proper roughness, and new impurities are not easy to introduce while the operation is convenient.

Optionally, in the step A2, the diamond particle size selected by the dense diamond layer is 1 to 10 μm.

Optionally, in the step A2, the deposition thickness of the dense diamond layer is 5 to 100 μm.

Optionally, in the step A2, the diamond particle size selected by the loose diamond layer is 0.005-100 μm.

Optionally, in the step A2, the deposition thickness of the loose diamond layer is 10 to 300 μm.

By adopting the technical scheme, different diamond particle sizes and different deposition thicknesses are selected to deposit the compact layer and the loose layer, so that the diamond polymer is ensured to have higher bonding strength, the loose diamond layer can be easily peeled off, and the process flow is simplified.

Optionally, in step A3, the impact mode is selected from one of air flow impact and high-pressure microjet impact.

Optionally, the step A3 is repeated multiple times in the functional diamond micro-nano powder preparation process.

Secondly, the functional diamond micro-nano powder provided by the application has the size of 0.005-100 mu m.

Optionally, the purity of the functional diamond micro-nano powder is greater than 99.99%.

Finally, the functional diamond micro-nano powder is applied to the preparation of various electrochemical electrodes and super capacitors, biosensors, drug delivery of targeted medical treatment, quantum computation, color center application of quantum transmission and invisible wave-absorbing materials.

By adopting the technical scheme, the functional diamond micro-nano powder prepared by the method can be adjusted in performance and structure according to actual needs in different fields, can adapt to more application ranges, and expands the research field of micro-nano composite materials.

In a second aspect, there is provided, in a first aspect, a diamond aggregate comprising a particulate substrate and a dense diamond layer epitaxially grown from the particulate substrate, the shear strength between the particulate substrate and the diamond dense layer being greater than the tensile strength of diamond itself.

Secondly, the application provides a preparation technology of diamond polymer, including the following steps:

b1, pretreating substrate particles;

b2, adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle matrix prepared in the step B1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact layer;

and B3, stripping the loose diamond layer deposited in the step B2 by using an impact mode, and separating the stripped layer to obtain the diamond polymer.

Optionally, a diamond polymer, in step B2, the dense diamond layer is doped with an inorganic element.

Optionally, a diamond polymer, and the doping element is selected from one of group iii or group v elements.

Optionally, a diamond polymer, and the doping process is selected from one or more of gas doping, solid doping and liquid doping.

Finally, the application provides an application of the diamond polymer in the industries of precision measuring instruments, shielding materials, radiation-resistant materials and frictional wear.

In a third aspect, the present application provides, in a first aspect, a functional diamond composite comprising a substrate particle matrix, a dense diamond layer epitaxially grown on the substrate particle matrix, and a loose diamond layer deposited on top of the dense diamond layer.

Secondly, the application provides a preparation method of the diamond composite body, which comprises the following steps:

c1, substrate particle pretreatment;

c2, depositing a compact diamond layer on the substrate particle matrix prepared in the step C1 by adopting a mode of homoepitaxy or heteroepitaxy;

and C3, continuously depositing a loose diamond layer outside the substrate particles of the dense diamond layer deposited in the step C2 to obtain the diamond composite.

Finally, the application provides an application of the diamond composite body in electrochemical electrode materials and photocatalyst porous framework materials.

In summary, the invention includes at least one of the following beneficial technical effects:

1. the compact diamond layer prepared by the method has high bonding strength and excellent wear resistance with the substrate particle matrix. The substrate material obtained after pretreatment and the dense diamond layer can form a tight bonding state. Meanwhile, the compact diamond layer grown in an epitaxial mode can further reduce the pores under the continuous impact of the loose diamond layer, is more attached to the particle matrix, and forms a more compact diamond layer film so as to ensure that the substrate material with the compact layer can be reused. After the peeled loose diamond layer is subjected to crushing treatment, the obtained diamond micro-nano powder has extremely high impact resistance, is particularly suitable for polishing high-precision devices, has great advantages in crystal form and surface quality compared with detonation-method fine micro-powder, and is simple in process flow and strong in operability. The preparation process can effectively control the performance of the diamond micro-nano powder obtained by the loose diamond layer after crushing treatment qualitatively and quantitatively while ensuring that the diamond polymer has high bonding strength, and further improves the economic benefit of the application.

2. The diamond layer grows in two different modes of homoepitaxy or heteroepitaxy, and can be correspondingly adjusted according to the required functional requirements and the requirements of different purities; the applied matrix shape is developed into various irregular particles from a more regular block and a plate, crystal particles can be extended from polycrystal to monocrystal, base particles are developed into non-metal materials from metal, a layer of required film can be grown on various substrate materials, the operation is convenient, and the process is simple. 3. The grain sizes of the two layers of settled layers designed by the application all belong to a range value, and the grains have good grading relation. Firstly, the grading relationship is adopted, so that a compact diamond layer can form a compact filling structure and a self-compact stacking system with a microscopic layer, the pore structure of a plating layer is effectively improved, the compactness is increased, and a diamond polymer has excellent wear resistance and high bonding strength; and secondly, the loose layer adopts the grading relation, so that better impact resistance can be obtained.

4. The loose diamond layer obtained by the application is prepared from the diamond micro-nano powder obtained after crushing treatment, the particle surface is smooth and clean, no obvious growth defect exists, and the obtained micro-powder is concentrated in size and is suitable for processing high-precision devices and the like. In addition, other elements can be selectively doped or not doped when the loose diamond is deposited, so that the obtained diamond micro-nano powder can be quantitatively and qualitatively doped with the diamond as required to realize the compatibility, reliability stability and economy in the aspects of biomedicine in the aspects of biology, such as drug delivery, nano robots and biomarkers; in the field of quantum computation and quantum communication, NV color centers, siV color centers and the like can be prepared by preparing diamond containing N, si and the like in a quantitative doping manner to realize photoelectric transmission; in the electrochemical field, the super capacitor is used as a core component for energy storage and rapid charge and discharge, and boron-containing diamond powder with different resistivity can also be used as the best choice; in the aspect of converting carbon dioxide into green fuel by utilizing solar energy, the doped diamond can also be used as a photocatalyst; similarly, in the ultra-precise field of semiconductors and the like, the function of ultra-pure diamond is also irreplaceable.

5. When this application preparation diamond micro-nano powder, the accessory substance diamond polymer and overall structure's of production diamond complex, it all has extensive application space, has the practicality, can produce very big economic benefits.

Drawings

FIG. 1 is a schematic view of a polygonal structure of a diamond polymer according to the present application;

FIG. 2 is a schematic view of a circular structure of a diamond polymer according to the present application;

FIG. 3 is a schematic view of the overall construction of a diamond compact according to the present application;

FIG. 4 is a SEM topography of a boron doped bulk diamond layer of example 1 of the present application;

FIG. 5 is a SEM topography of a layer of high purity loose diamond of example 2 of the present application;

FIG. 6 is a SEM topography of the dense diamond layer of example 4 of the present application;

in the figure, 1, a particle matrix; 2. a diamond compact coating; 3. and (5) loosening the coating of the diamond.

Detailed Description

The present application is described in further detail below with reference to figures 1-6 and examples.

In a first aspect, first, a process for preparing a diamond micro-nano powder provided by the present application includes the following steps:

a1, substrate particle pretreatment;

a2, adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle base body prepared in the step A1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact diamond layer;

a3, peeling the loose diamond layer deposited in the step A2 in an impact mode, and after a peeling layer is separated, obtaining a remainder which is a byproduct diamond polymer;

Finally, the functional diamond micro-nano powder provided by the application can be applied to various electrochemical electrodes, preparation of super capacitors, biosensors, drug delivery of targeted medical treatment, quantum computation, color center application of quantum transmission and invisible wave-absorbing materials.

In a second aspect, there is provided, in a first aspect, a diamond aggregate comprising a particulate substrate and a dense diamond layer epitaxially grown from the particulate substrate, the shear strength between the particulate substrate and the diamond dense layer being greater than the tensile strength of the diamond itself.

Secondly, the application provides a preparation technology of the diamond polymer, which comprises the following steps:

b1, pretreating substrate particles;

b2, adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle substrate prepared in the step B1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact layer;

c1, pretreating substrate particles;

c2, depositing a compact diamond layer on the substrate particle base body prepared in the step C1 by adopting a homoepitaxy or heteroepitaxy mode;

Before the application, the existing diamond micro powder is usually prepared from graphite by using a unique directional blasting method and is mainly used in the working procedures of ultraprecise finishing processing, grinding and polishing of the surface of a workpiece. With the development of electronic technology, the polishing requirements of various precision devices such as optoelectronic crystals, computer hard disk substrates, optical components, semiconductor integrated circuit silicon wafers and the like are increasing day by day, in order to meet the processing requirements of the precision devices, the requirements of diamond fine powder are increasing, and meanwhile, higher requirements are provided for the crystal form, uniformity and mechanical properties of the diamond fine powder so as to meet the grinding and polishing requirements of high efficiency and high precision.

The inventors of the present application found in practice that the methods for producing diamond mainly include both a high temperature High Pressure (HPHT) method and a Chemical Vapor Deposition (CVD) method. As is well known, the high-temperature and high-pressure method is a process of converting graphite into diamond by means of a metal catalyst under a static high-pressure condition, but it is difficult to synthesize ultra-fine diamond micropowder by using the method, and the catalyst metal nickel, manganese, cobalt and the like cannot enter the diamond and cannot be removed, and the ultra-pure diamond cannot be obtained by using the high-temperature and high-pressure method.

The inventor of this application has designed the technical scheme of this application to above-mentioned new technical problem, through adopting the chemical vapor deposition method, sets for corresponding preparation parameter, handles through special technology again, has obtained a functional diamond micro-nano powder of this application, and this micro-nano powder can select whether to dope other elements in the course of handling to adapt to different application field's requirement. In addition, the diamond polymer formed by combining the substrate particle matrix and the compact layer also has higher bonding strength, can be applied to the friction and wear industry, and has higher economic benefit.

The design of this application has fully considered the strippability, the shock resistance on loose diamond layer, has compromise diamond polymer wear resistance and bonding strength's promotion simultaneously. According to the method, a special deposition mode is firstly designed during design, two different modes of homoepitaxy or heteroepitaxy are adopted for different substrate particle matrixes, the grown crystal layer can adapt to the requirements of different application fields, and corresponding adjustment can be carried out according to the actual requirements of industrial application and the requirement of purity. Secondly, the application designs a special deposition system: a dense diamond layer and a loose diamond layer are sequentially deposited on the surface of a substrate particle matrix, the dense diamond layer and the particle matrix are combined and can be directly applied to the fields of friction and wear industry and electrochemistry, the loose diamond layer is correspondingly adjusted according to field requirements, and the diamond micro-nano powder with better impact resistance is obtained after crushing treatment. Finally, the loose diamond layer can be easily peeled off under the action of airflow impact or high-pressure microjet, and after the peeled loose diamond layer is subjected to crushing treatment, the obtained diamond micro-nano powder has extremely high impact resistance, is particularly suitable for polishing of high-precision devices, and has great advantages in crystal form and surface quality compared with detonation-method fine micro-powder. In addition, the dense diamond layer grown in an epitaxial mode can be more attached to the substrate particle matrix under the condition that the loose diamond layer grows for multiple times, so that a more dense coating film is formed, the substrate material with the dense layer can be repeatedly used, and the economic benefit of the preparation process is further improved.

In addition, the grain sizes of the two layers of the settled layers designed by the application belong to a range value, and the grains have good grading relation. Firstly, the grading relationship is adopted, so that a compact diamond layer can form a compact filling structure and a self-compact stacking system with a microscopic layer, the pore structure of a plating layer is effectively improved, the compactness is increased, a diamond polymer has excellent wear resistance and high bonding strength, and the service life of the diamond polymer can be prolonged; and the loose diamond layer adopts the grading relation, so that better impact resistance can be obtained.

Meanwhile, the substrate particle matrix is pretreated in order to enhance the bonding strength of the diamond polymer film layer and the substrate material. The substrate material obtained after pretreatment is beneficial to greatly improving the film-substrate adhesive force when the compact layer is deposited. In addition, in order to further expand the application field of the diamond micro-nano powder, a high-purity gas stripping loose layer is selected, or certain elements are doped into the loose diamond layer through a special doping process, so that the loose diamond layer becomes a novel inorganic material with different functions, which is suitable for the development requirements of modern science and technology. The diamond polymer and the diamond micro-nano powder prepared in the way have strong practicability, wide application range, excellent performance and extremely high economic benefit.

Finally, the economic benefit and the practicability of the whole process are fully considered when the compound system is designed, so that the design is selected. The design can obtain the diamond polymer with high bonding strength and excellent friction resistance, can also obtain the diamond micro-nano powder with strong shock resistance, and can be suitable for the high-end field.

The following specific examples 1 to 8 of the present application, and examples 1 to 8 respectively provide a diamond micro-nano powder, which includes the following preparation processes:

example 1

S1, cleaning high-temperature and high-pressure single-crystal diamond particles by using organic solution, and then using diamond micro powder-wine

Carrying out ultrasonic treatment on the fine suspension to obtain surface prefabricated seed crystals;

s2, purifying the surface prefabricated seed crystal obtained in the step S1 to obtain a single crystal substrate;

s3, placing the pretreated diamond substrate into a cavity of reaction equipment in a homoepitaxy mode, and depositing a compact diamond layer on the surface of the diamond substrate by adopting a direct-current jet CVD (chemical vapor deposition) process, referring to FIG. 1, wherein the deposition parameters are as follows: deposition temperature: at a temperature of 850 ℃ to obtain a high-purity,

argon flow: 8SLM

Hydrogen flow rate: 2.8 the number of SLMs is 2.8,

flow rate of methane: 80sccm

Cavity pressure: 3 the voltage of the power supply is higher than the voltage of the power supply,

deposition time: 2 hours;

s4, adjusting the deposition parameters of the equipment, and continuously depositing a loose diamond layer on the compact diamond layer, wherein the deposition parameters are as follows: deposition temperature: at a temperature of 850 ℃ to obtain a high-purity,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the number of SLMs is 2.8,

flow rate of methane: the flow rate of the carbon nanotube is 150sccm,

cavity pressure: 3Kpa of the first time point and the second time point,

B/C：10000pm，

deposition time: 10 hours;

s5, introducing a gas boron source into the loose diamond layer in a gas doping mode, wherein the doping level is 10000ppm;

s6, utilizing a mode of air flow impact or high-pressure micro-jet impact to the loose micro-particles deposited in the step S4

Stripping the meter-level plating layer to obtain a diamond polymer;

and S7, repeating the deposition and peeling process of the loose layer, and crushing the peeled loose layer to obtain the diamond micro-nano powder.

Wherein the organic solution is selected from one of alcohol, acetone and methane (same as examples 2-16); the doping process is selected from one or more of gas doping, solid doping and liquid doping (same as the doping embodiment); the doping elements may be typical group iii and group v elements such as P, N, si, ba, li, etc., or may be other inorganic elements (as in the doping examples). For example, the doping amount of boron is more than 1 × 1019atoms cm ^-3 The resistivity of the doped powder can be controlled to be 1-500 m omega cm.

Example 2

S1, cleaning single crystal diamond particles synthesized at high temperature and high pressure by using organic solution, and then using diamond

Carrying out ultrasonic treatment on the micro powder-alcohol suspension to obtain surface prefabricated seed crystals;

s2, purifying the surface prefabricated seed crystal obtained in the step S1 to obtain a single crystal substrate; s3, placing the pretreated diamond substrate into a cavity of reaction equipment in a homoepitaxy mode, depositing a compact diamond layer on the surface of the diamond substrate by adopting a direct current jet CVD (chemical vapor deposition) process,

the deposition parameters were: deposition temperature: at the temperature of 850 ℃,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the SLM to be switched on,

flow rate of methane: the flow rate of the carbon black is 80sccm,

deposition time: 2 hours;

s4, adjusting the deposition parameters of the equipment, and continuously depositing a loose diamond layer on the compact diamond layer, wherein the deposition parameters are as follows: deposition temperature: at the temperature of 850 ℃,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the number of SLMs is 2.8,

flow rate of methane: at a rate of 130sccm,

deposition time: 8 hours;

s5, stripping the loose micron-sized coating deposited in the step S4 by using an airflow impact or high-pressure micro-jet impact mode to obtain a diamond polymer;

and S6, repeating the deposition and peeling process of the loose layer, and crushing the peeled loose layer to obtain the diamond micro-nano powder. In step S5, high-purity gas or micro-jet impact is adopted to peel off the loose layer, and finally the obtained diamond polymer is crushed, purified and sorted to obtain single crystal diamond powder, wherein the impurity content of the single crystal diamond powder is less than 1ppm. (same as undoped example) example 3

The difference from example 1 is that: s1, cleaning polycrystalline diamond particles synthesized by a CVD method through an organic solution, and then carrying out ultrasonic treatment on the polycrystalline diamond particles through a diamond micro powder-alcohol suspension to obtain surface prefabricated seed crystals.

Example 4

The difference from example 2 is that: s1, cleaning polycrystalline diamond particles synthesized by a CVD (chemical vapor deposition) method by using an organic solution, and carrying out ultrasonic treatment by using a diamond micro powder-alcohol suspension to obtain surface prefabricated seed crystals;

example 5

The difference from example 2 is that: by adopting a microwave plasma CVD method, the method has the advantages that,

the deposition parameters in step S3 are set as: deposition temperature: at a temperature of 700 c,

hydrogen flow rate: the flow rate of the liquid is 500sccm,

flow rate of methane: the flow rate of 5sccm,

cavity pressure: the pressure of the water is 8kPa,

deposition time: 10h;

the deposition parameters in step S4 are set as: deposition temperature: at a temperature of 700 c,

hydrogen flow rate: the flow rate of the liquid is 500sccm,

flow rate of methane: the flow rate of the carbon black is 15sccm,

cavity pressure: the pressure of the mixed gas is 8kPa,

deposition time: and (5) 30h.

Example 6

The difference from example 1 is that: adopting a microwave plasma CVD method; wherein, the first and the second end of the pipe are connected with each other,

hydrogen flow rate: the flow rate of the liquid is 500sccm,

flow rate of methane: the flow rate of 5sccm,

cavity pressure: the pressure of the water is 8kPa,

deposition time: 10h;

hydrogen flow rate: the flow rate of the carbon black is 500sccm,

flow rate of methane: the flow rate of the carbon black is 15sccm,

cavity pressure: the pressure of the water is 8kPa,

P/C：5000ppm，

deposition time: and (5) 30h.

Example 7

The difference from example 1 is that: s1, cleaning monocrystalline silicon particles by using an organic solution, and performing ultrasonic treatment by using a diamond micro powder-alcohol suspension to obtain surface prefabricated seed crystals; s3, placing the pretreated monocrystalline silicon substrate into a cavity of reaction equipment in a heteroepitaxy mode, and depositing a compact diamond layer on the surface of the monocrystalline silicon substrate by adopting a hot filament CVD (chemical vapor deposition) process; s5, simultaneously introducing a gas silicon source into the loose diamond layer in a gas doping mode; wherein, the first and the second end of the pipe are connected with each other,

the deposition parameters in step S3 are set as: deposition temperature: at the temperature of 800 ℃,

hydrogen flow rate: at a flow rate of 400sccm,

flow rate of methane: CH4/H2=1%,

cavity pressure: the pressure of the mixture is 6kPa,

deposition time: 20h;

the deposition parameters in step S4 are set as: deposition temperature: at the temperature of 800 ℃,

hydrogen flow rate: the flow rate of the carbon nano tube is 400sccm,

flow rate of methane: CH4/H2=1%,

cavity pressure: the pressure of the mixed gas is 6kPa,

Si/C：3000PM，

the deposition time was 70h.

Example 8

The difference from example 2 is that: s1, cleaning monocrystalline silicon particles by using an organic solution, and performing ultrasonic treatment by using a diamond micro powder-alcohol suspension to obtain surface prefabricated seed crystals; s3, placing the pretreated monocrystalline silicon substrate into a cavity of reaction equipment in a heteroepitaxy mode, and depositing a compact diamond layer on the surface of the monocrystalline silicon substrate by adopting a hot filament CVD (chemical vapor deposition) process; wherein the content of the first and second substances,

the deposition parameters in step S3 are set as: deposition temperature: at a temperature of 800 c,

hydrogen flow rate: at a flow rate of 400sccm,

flow rate of methane: CH4/H2=1%,

cavity pressure: the pressure of the mixture is 6kPa,

deposition time: 20h;

the deposition parameters in step S4 are set as: deposition temperature: at a temperature of 800 c,

hydrogen flow rate: at a flow rate of 400sccm,

flow rate of methane: CH4/H2=1%,

cavity pressure: the pressure of the mixture is 6kPa,

deposition time: and (4) 70h.

Examples 9 to 11 provide a diamond polymer body comprising the following preparation process:

example 9

S1, cleaning spherical sintered silicon carbide with the diameter of 5mm by using an organic solution, and carrying out ultrasonic treatment by using a diamond micro powder-alcohol suspension to obtain surface prefabricated seed crystals;

s2, purifying the surface prefabricated seed crystal obtained in the step S1 to obtain a single crystal substrate; s3, placing the pretreated diamond substrate into a cavity of reaction equipment in a heteroepitaxy mode, and depositing a compact diamond layer on the surface of the diamond substrate by adopting a direct-current jet CVD (chemical vapor deposition) process, wherein the deposition parameters are as follows:

deposition temperature: at a temperature of 880 c,

argon flow: the flow rate of the water is 8SL,

hydrogen flow rate: 2.8 the SLM to be switched on,

flow rate of methane: the flow rate of the carbon black is 80sccm,

deposition time: 5 hours;

s4, adjusting the deposition parameters of the equipment, and continuously depositing a loose diamond layer on the compact diamond layer, wherein the deposition parameters are as follows:

deposition temperature: at the temperature of 850 ℃,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the number of SLMs is 2.8,

flow rate of methane: at a rate of 130sccm,

deposition time: 8 hours;

and S5, stripping the loose micron-sized coating deposited in the step S4 by using an airflow impact or high-pressure micro-jet impact mode to obtain the diamond polymer.

The obtained diamond polymer can be directly used for grinding media prepared from ultra-pure ultrafine powder, and can also be used for measuring heads for precision measurement after the surface of the diamond polymer is polished (the surface roughness after polishing is less than 5 nm).

Example 10

The difference from example 9 is that: in the step S1, spherical molybdenum particles with the diameter of 5mm are adopted to be cleaned by organic solution, and the reference is made to FIG. 2; wherein, the deposition parameters in step S3 are set as:

deposition temperature: at the temperature of 900 ℃,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the SLM to be switched on,

flow rate of methane: the flow rate of the carbon black is 80sccm,

deposition time: for 10 hours.

The molybdenum particles are removed from the obtained diamond polymer through laser perforation and chemical corrosion to obtain a hollow diamond sphere which can be directly used for radiation-proof materials.

Example 11

The differences from example 9 are: s6, introducing a gas boron source into the compact diamond layer in a gas doping mode, wherein the doping level is 10000ppm; the obtained diamond polymer can be directly used in the friction and wear industry.

Examples 12-13 provide a diamond composite, referring to fig. 3, comprising the following fabrication process:

example 12

S1, cleaning regular dodecahedron single crystal silicon with the diameter of an inscribed circle of 5mm by using an organic solution, and then carrying out ultrasonic treatment by using diamond micropowder-alcohol suspension to obtain surface prefabricated seed crystals;

s2, purifying the surface prefabricated seed crystal obtained in the step S1 to obtain a single crystal substrate; s3, placing the pretreated diamond substrate into a cavity of reaction equipment in a heteroepitaxy mode, and depositing a compact diamond layer on the surface of the diamond substrate by adopting a direct-current jet CVD (chemical vapor deposition) process, wherein deposition parameters are set as follows: deposition temperature: 860 c of the total weight of the mixture,

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the SLM to be switched on,

flow rate of methane: at a flow rate of 80sccm,

deposition time: 2 hours;

argon flow: the number of the 8SLM devices is 8,

hydrogen flow rate: 2.8 the number of SLMs is 2.8,

flow rate of methane: the flow rate of the carbon nanotube is 150sccm,

cavity pressure: 3Kpa of the first time interval and the second time interval,

B/C：10000pm，

deposition time: for 10 hours.

the obtained diamond composite can be directly used as a three-dimensional electrochemical electrode material and also can be directly used as a framework material of a photocatalyst.

Example 13

The difference from example 12 is that: without step S5, the resulting diamond composite may be used directly as an electrode material.

The above example partial parameter settings are recorded in table 1, as follows:

in the invention patent with the application number of CN108060407A and the invention name of 'a preparation method of a micro-nano multilayer composite diamond film', examples 1 to 3 are taken as comparative examples 1 to 3 of the application.

Comparative example 1

The above patent describes in paragraphs 0034 to 0037: the result shows that under the same test condition, the single-layer nano-diamond film has large-area film layer falling, the single-layer micron diamond film has obvious film layer falling and cracks, the double-layer composite diamond film does not have film layer falling, and only some tiny cracks are generated at the periphery of the indentation, which shows that the micro-nano double-layer composite diamond film has the adhesion performance superior to that of the single-layer diamond film.

Comparative example 2

The above patent describes in paragraphs 0038-0042: the result shows that in the reciprocating friction experiment, the average friction coefficient of the micro-nano multilayer composite diamond film is reduced by more than half compared with the friction coefficient of the single-layer micron diamond film and is close to the friction coefficient value of the single-layer nano diamond film, which shows that the micro-nano multilayer composite diamond film has tribological performance close to the single-layer nano diamond film.

Comparative example 3

The above patent describes in paragraph 0048-0052: the result shows that the multilayer diamond film milling cutter prepared by the method has the advantages that the machinable length is more than 4 times higher than that of the traditional hard alloy PCB milling cutter in the edge milling processing of the Printed Circuit Board (PCB), the processed surface quality of the product is good, and no obvious burr is generated. In the processing process, the multilayer diamond film milling cutter has no falling off of the film layer and has excellent film-substrate adhesion strength.

Experimental detection

1. Taking the example 1 as an example, the peeled boron-containing loose layer is crushed, and the obtained boron-containing diamond micro-nano powder has a morphology under the observation of an SEM scanning electron microscope, as shown in fig. 4.

2. Taking the example 2 as an example, the peeled loose layer is crushed, and the obtained ultra-pure diamond micro-nano powder has a morphology under SEM scanning electron microscope observation, as shown in FIG. 5.

3. Taking example 4 as an example, after peeling off the loose layer, a topography of the dense diamond layer observed by SEM scanning electron microscope is obtained, as shown in fig. 6.

4. Binding Strength detection

The bonding force between the substrate particle matrix and the compact diamond layer was measured by indentation, the indentation strength and cracking of the film were recorded, and the measured values were recorded in table 2.

5. Test of wear resistance

The wear ratios of examples 1 to 12 of the present application were measured in accordance with JB/T3235-1999 method for measuring wear ratio of sintered synthetic diamond, and the values are shown in Table 2.

6. Surface roughness measurement

The surface roughness of the surface of the test piece 1-12 of the application is tested by a needle tracing method, a contact pin is contacted with the surface to be tested during measurement, when the contact pin moves along the profile of the surface to be tested under the driving of a driver, the contact pin vertically moves in the direction vertical to the profile of the surface to be tested due to the uneven surface profile, the motion is converted into an electric signal through a sensor, and the electric signal is amplified and processed, so that the evaluation parameter value of the surface profile can be displayed by a display. The measured values are recorded in table 2.

Table 2: performance measurement value

As can be seen from the data in table 2, the surface roughness was smooth in examples 1 to 13 of the present application; under the test condition of detecting the bonding strength, the diamond film does not fall off, and no crack is generated around the indentation, which shows that the substrate particles have excellent film-substrate adhesion strength, and the bonding strength of the substrate particles and the compact diamond layer is higher. In addition, the abrasion ratios of the examples 1 to 13 are all in a small value range, which shows that the polymer or the composite prepared by the method has excellent abrasion resistance.

The above are preferred embodiments of the present application, and the scope of protection of the present application is not limited thereto, so: equivalent changes in structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A preparation process of functional diamond micro-nano powder is characterized by comprising the following steps:

a1, pretreating a substrate particle matrix;

a2, adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle substrate prepared in the step A1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact diamond layer;

2. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein the substrate particle matrix is selected from one of granular diamond, granular ceramic and granular metal.

3. The preparation process of the functional diamond micro-nano powder according to claim 2, wherein the granular ceramic is selected from one of silicon carbide, silicon nitride, aluminum oxide and silicon dioxide.

4. The preparation process of the functional diamond micro-nano powder according to claim 2, wherein the granular metal is selected from one of molybdenum, tungsten, titanium, tantalum and hard alloy.

5. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein the substrate particle matrix is in a shape selected from a sphere, a polyhedron and a plate.

6. The preparation process of the functional diamond micro-nano powder as claimed in claim 1, wherein the pretreatment method of the substrate particle matrix comprises the following steps:

a11, cleaning the surface of a substrate particle matrix, performing ultrasonic treatment by using diamond micropowder-alcohol suspension, and prefabricating seed crystals on the surface of the substrate;

and A12, purifying and drying the substrate material with the surface prefabricated seed crystal obtained in the step A11.

7. The preparation process of the functional diamond micro-nano powder as claimed in claim 1, wherein in the step A2, the diamond granularity selected by the compact diamond layer is 1 to 10 μm.

8. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein in the step A2, the deposition thickness of the compact diamond layer is 5 to 100 μm.

9. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein in the step A2, the diamond granularity selected by the loose diamond layer is 0.005-100 μm.

10. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein in the step A2, the deposition thickness of the loose diamond layer is 10 to 300 μm.

11. The process for preparing a functional diamond micro-nano powder according to claim 1, wherein in the step A3, the impact mode is selected from one of air flow impact or high pressure microjet impact.

12. The preparation process of the functional diamond micro-nano powder according to claim 1, wherein the step A3 is repeated for a plurality of times.

13. A functional diamond micro-nano powder is characterized by being prepared by the preparation process of claims 1 to 12, wherein the size of the diamond micro-nano powder is 0.005 to 100 micrometers.

14. The functional diamond micro-nano powder according to claim 13, wherein the purity of the diamond micro-nano powder is more than 99.99%.

15. The diamond micro-nano powder of claim 13 is applied to various electrochemical electrodes, preparation of super capacitors, biosensors, drug delivery for targeted medical treatment, quantum computing, color center application of quantum transmission, and invisible wave-absorbing materials.

16. A diamond polymer comprising a substrate particle matrix and a layer of densified diamond layer epitaxially grown from the particle matrix, the shear strength between the diamond polymer particle matrix and the diamond densified layer being greater than the tensile strength of the diamond itself.

17. A process for preparing a diamond polymer according to claim 16, comprising the steps of:

b1, pretreating a substrate particle matrix;

b2, depositing a compact diamond layer on the substrate particle base body prepared in the step B1 by adopting a homoepitaxy or heteroepitaxy mode, and preparing a diamond polymer by adopting a chemical vapor deposition method; or adopting a homoepitaxy or heteroepitaxy mode, firstly depositing a compact diamond layer on the substrate particle matrix prepared in the step B1 by adopting a chemical vapor deposition method, and then continuously depositing a loose diamond layer on the compact layer;

18. A diamond polymer according to claim 17, wherein in step B2, the dense diamond layer is doped or undoped with an organic or inorganic element, and the loose diamond layer is doped with an organic or inorganic element.

19. A diamond polymer according to claim 18, wherein the doping element is selected from one of the group iii or group v elements.

20. A diamond polymer according to claim 18 wherein the doping process is selected from one or a combination of more than one of gas doping, solid doping and liquid doping.

21. Use of the diamond polymer body according to claim 16 in the industries of precision measuring instruments, shielding materials, radiation-resistant materials, and frictional wear.

22. A functional diamond composite comprising a substrate particle matrix, a layer of dense diamond epitaxially grown on the substrate particle matrix, and a layer of loose diamond deposited on top of the dense diamond.

23. A method of making a diamond compact according to claim 22, comprising the steps of:

c1, pretreating a substrate particle matrix;

and C3, continuously depositing a layer of loose diamond layer outside the substrate particle matrix of the dense diamond layer deposited in the step C2 to obtain the diamond composite.

24. Use of a diamond compact according to claim 22 in an electrochemical electrode material, a photocatalyst porous framework material.