Systems and methods for manufacturing nanocarbon materials by pulsed discharge in liquid

Abstract

A system for manufacturing nanomaterials may include a first electrode; a second electrode separated from the first electrode by a gap; and a chamber configured to enclose the first electrode, the second electrode, and a liquid. The system may also include a power source configured to provide electrical energy to at least one of the first electrode and the second electrode; and a pump configured to flow the liquid through a gap between the first electrode and the second electrode. The invention also relates to a method for manufacturing a nanomaterial, and to a manufactured material comprising carbon nanoparticles.

Description

[0001] This application is a divisional application based on a patent application with an application date of June 5, 2020, application number 202080052835.5, and invention name: "System and method for manufacturing nanocarbon materials by pulse discharge in liquid".

[0002] Related Applications

[0003] This application claims priority to and the benefit of U.S. Provisional Application No. 62 / 858,554, filed on June 7, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present disclosure relates generally to nanomaterial fabrication, and more particularly, to systems and methods for fabricating nanomaterials by pulsed electrical discharges in liquids. Background Art

[0005] Nanomaterials include carbon nanoparticles (e.g., nanodiamonds or fullerenes) and are useful in many industries, such as electronics, chemistry, construction, medicine, etc. Nanodiamonds form part of a family of carbon nanomaterials, along with fullerenes and nanotubes, that have attracted great interest in recent years for their potential to provide exceptional mechanical, optical, surface, and biocompatibility properties in certain circumstances. Exhibiting the outstanding bulk properties of diamond, but in the form of nanoscale films or nanoscale particles, makes nanodiamonds an inexpensive yet potentially high-performance choice for many applications, such as reinforcing polymer fillers and materials for additive manufacturing, friction-reducing additives for oils and lubricants, additives in coatings, delivery agents or contrast agents for biomedicine, fine polishing abrasives, catalysts in chemical and power applications, etc.

[0006] One way to synthesize nanomaterials (including nanodiamonds) is by explosion in a closed chamber filled with ice or an inert gas as a coolant. The diamond yield after the explosion (up to 90%) depends on the synthesis conditions, especially the heat capacity of the coolant. For separation and purification, the explosion products need to be boiled in nitric acid.

[0007] However, such processes may be associated with significant challenges that may limit the industrial application of nanomaterials. One challenge is that many nanomaterials may have high manufacturing costs and may involve polluting byproducts and / or hazardous processes. For example, in order to convert nanodiamonds from a dry powder form to a suspension (also referred to as a "dispersion") form, the nanodiamonds may be dispersed in a liquid. However, the cost of dispersing purified nanodiamonds in a liquid may be significantly higher than the cost of producing nanodiamond powder (e.g., by explosion).

[0008] Another challenge potentially associated with nanomaterial and / or nanodiamond production is that it can be difficult or expensive to homogenize (e.g., evenly disperse) nanomaterials within other substances. In some cases, nanodiamond particles can have a tendency to agglomerate or aggregate, especially when dry powder nanoparticles are mixed with liquids.

[0009] The third challenge in the production of nanomaterials and / or nanodiamonds is that it may be difficult to manipulate the particle size of the nanomaterial after it is produced (e.g., further reduce the particle size). For example, the typical size of the nanodiamond produced by the explosion may be 5 nanometers (nm), which (as a comparison) is still larger than the 1nm nanodiamond observed in meteorites (e.g., having one or more graphene caps on the crystal surface). It is unknown whether this nanodiamond particle size of about 1 nanometer exists naturally on Earth. Certain manufacturing techniques can be used to reduce the size of nanodiamonds (or other nanomaterials). Such techniques may include etching nanodiamonds in oxygen. However, such methods may be difficult or impractical for industrial use.

[0010] Therefore, for wider industrial applications of nanomaterials, there is a need to reduce the manufacturing cost of nanomaterials, homogenize nanomaterial particles with liquids, and reduce the size of nanomaterial particles. The currently disclosed technology aims to address these and other challenges. Summary of the invention

[0011] One aspect of the present disclosure is directed to a system for manufacturing nanomaterials. The system may include a first electrode; a second electrode separated from the first electrode by a gap; and a chamber configured to enclose the first electrode, the second electrode, and a liquid. The system may also include a power source configured to provide electrical energy to at least one of the first electrode and the second electrode; and a pump configured to flow the liquid through the gap between the first electrode and the second electrode.

[0012] Another aspect of the present disclosure is directed to a method for making a nanomaterial. The method may include filling a chamber with a liquid, the chamber enclosing a first electrode and a second electrode; setting parameters of a power source electrically connected (coupled) to the first electrode and the second electrode; controlling the flow rate of the liquid during a production phase of a plurality of carbon particles, the carbon particles being generated by a plasma pulse in a gap between the first electrode and the second electrode; and removing a dispersion of the plurality of carbon particles from the chamber.

[0013] Other embodiments may include: a fabricated material comprising carbon nanoparticles, wherein the carbon nanoparticles each include a diamond core; and at least one graphene cap on a surface of the diamond core, wherein the carbon nanoparticles have an average size between 0.5 nanometers and 3 nanometers.

[0014] Other systems and methods are also discussed herein.

[0015] The present invention includes the following embodiments:

[0016] 1. A system for manufacturing nanomaterials, comprising:

[0017] a first electrode;

[0018] a second electrode separated from the first electrode by a gap;

[0019] a chamber configured to enclose the first electrode, the second electrode, and a liquid;

[0020] a power source configured to provide electrical energy to at least one of the first electrode and the second electrode; and

[0021] A pump configured to flow the liquid through the gap between the first electrode and the second electrode.

[0022] 2. A system as described in item 1, wherein the second electrode is arranged parallel to the first electrode.

[0023] 3. A system as described in any of items 1-2, wherein the first electrode comprises a slender member.

[0024] 4. A system as described in any of items 1-3, wherein the second electrode comprises one of a slender member or a flat member.

[0025] 5. The system of clause 4, wherein the flat member comprises one of a pad or a plate.

[0026] 6. The system of any one of clauses 3 to 5, wherein the elongated member comprises one of a rod or a needle.

[0027] 7. A system as described in any of items 1-6, wherein the power supply is configured to provide a pulsed electrical output to at least one of the first electrode or the second electrode.

[0028] 8. A system as described in clause 7, wherein the power of the pulsed electrical output is greater than or equal to 1 megawatt.

[0029] 9. A system as described in any of items 7-8, wherein the pulse duration of the pulsed electrical output is greater than or equal to 10 nanoseconds and less than or equal to 40 nanoseconds.

[0030] 10. A system according to any one of clauses 7 to 9, wherein the pulse frequency of the pulsed electrical output is greater than or equal to 100 Hz.

[0031] 11. The system of any one of clauses 7 to 10, wherein the pulsed electrical output is configured to induce a plasma pulse in the liquid to generate a plurality of carbon particles in the liquid.

[0032] 12. The system of clause 11, wherein the average size of the plurality of carbon particles is between 0.5 nm and 1.5 nm.

[0033] 13. The system of any one of clauses 11-12, wherein the plurality of carbon particles comprises a diamond core covered by at least one graphene cap.

[0034] 14. The system of clause 13, wherein the at least one graphene cap is positioned symmetrically relative to the diamond core.

[0035] 15. A system as described in item 14, wherein the plurality of carbon particles are configured to be used as at least one of: an additive for solar panels to improve efficiency; an additive for luminescent markers for medical purposes; an additive for luminophores for quantum dot displays and light sources; or an additive for paints, coatings, or plastics that absorb ultraviolet radiation.

[0036] 16. The system of clause 13, wherein the at least one graphene cap is asymmetrically positioned relative to the diamond core.

[0037] 17. The system of clause 16, wherein the plurality of carbon particles are configured to change the viscosity of the lubricant when included as an additive to the lubricant.

[0038] 18. The system according to any one of clauses 11 to 17, wherein the plurality of carbon particles and the liquid form a dispersion.

[0039] 19. The system of any one of clauses 14-18, wherein the plurality of carbon particles are configured to function as at least one of: a friction reducing additive for a lubricant; a wear reducing agent for a lubricant; an antioxidant for a lubricant; or an additive for increasing thermal conductivity of a lubricant, coolant or polymer.

[0040] 20. The system of any of clauses 1 to 19, wherein the first electrode comprises a first end, and the gap is between the first end and the second electrode.

[0041] 21. The system according to any of clauses 1 to 20, wherein the gap is greater than or equal to 0.3 mm and less than or equal to 3 mm.

[0042] 22. The system according to any one of clauses 1 to 21, wherein the pump is further configured to drive the liquid to flow through the gap in the opposite direction of erosion of the first electrode.

[0043] 23. The system according to any one of clauses 1 to 22, wherein the pump is further configured to drive the liquid to flow through the gap to remove air bubbles.

[0044] 24. The system according to any one of items 1 to 23, wherein the pump is further configured to drive the liquid to flow through the gap in a continuous manner.

[0045] 25. The system according to any one of items 1 to 24, wherein the pump is further configured to drive the liquid to flow through the gap in an intermittent manner.

[0046] 26. The system according to any one of items 1 to 25, wherein the liquid comprises an organic substance.

[0047] 27. The system of clause 26, wherein the organic substance comprises a benzene ring.

[0048] 28. The system according to any one of items 1 to 27, wherein the liquid is an organic fluid.

[0049] 29. The system according to any one of items 1 to 28, wherein the pump is connected to a liquid source and is further configured to inject the liquid from the liquid source into the chamber.

[0050] 30. The system according to any one of items 1 to 29, wherein the chamber further comprises an inlet and an outlet.

[0051] 31. The system of clause 30, wherein the pump is connected to the inlet and the outlet and is configured to drive the liquid from the inlet to the outlet.

[0052] 32. The system according to any one of clauses 1 to 31, further comprising:

[0053] a capacitor electrically connected to the power source; and

[0054] An inductor electrically connected to an end of the capacitor and one of the first electrode or the second electrode.

[0055] 33. A method for producing a nanomaterial, comprising:

[0056] filling a chamber with a liquid, the chamber enclosing a first electrode and a second electrode;

[0057] setting parameters of a power source electrically connected to the first electrode and the second electrode;

[0058] controlling the flow rate of the liquid during a production phase of a plurality of carbon particles produced by a plasma pulse in a gap between the first electrode and the second electrode; and

[0059] The dispersion of the plurality of carbon particles is removed from the chamber.

[0060] 34. A manufactured material comprising carbon nanoparticles, each of the carbon nanoparticles comprising:

[0061] Diamond core; and

[0062] At least one graphene cap on a surface of the diamond core, wherein the average size of the carbon nanoparticles is between 0.5 nanometers and 3 nanometers.

[0063] 35. The manufactured material of item 34, wherein the carbon nanoparticles are contained in a liquid to form a dispersion.

[0064] 36. A manufactured material as described in item 35, wherein the liquid comprises an organic substance.

[0065] 37. The manufactured material of clause 36, wherein the organic substance comprises benzene rings.

[0066] 38. The manufactured material of any one of items 35-37, wherein the liquid is an organic fluid.

[0067] 39. The manufactured material of any one of items 34 to 38, wherein the at least one graphene cap is symmetrically located on the surface of the diamond core.

[0068] 40. The manufactured material of any one of items 35 to 39, wherein the dispersion of the carbon nanoparticles in the liquid has a viscosity between 0.01 and 0.1 Pascal-seconds, and wherein the concentration of the carbon nanoparticles in the dispersion is less than 1%.

[0069] 41. A manufactured material as described in item 40, wherein the carbon particles are configured for use as at least one of: an additive for solar panels to improve efficiency; an additive for luminescent markers for medical purposes; an additive for luminophores for quantum dot displays and light sources; or an additive for paints, coatings or plastics that absorb ultraviolet radiation.

[0070] 42. The manufactured material of any one of items 34 to 38, wherein the at least one graphene cap is asymmetrically located on the surface of the diamond core.

[0071] 43. The manufactured material of any one of items 34-42, wherein the carbon nanoparticles are configured to change the viscosity of a lubricant when included as an additive to the lubricant.

[0072] 44. A manufactured material as described in any of items 34-43, wherein the carbon nanoparticles are configured for use as at least one of: a friction reducing additive for a lubricant; a wear reducing agent for a lubricant; an antioxidant for a lubricant; or an additive for a lubricant, coolant or polymer to increase thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 is a schematic diagram illustrating an exemplary system for manufacturing nanomaterials consistent with the disclosed embodiments.

[0074] Figure 2A-2B is a schematic diagram illustrating an exemplary electrode configuration for fabricating nanomaterials consistent with the disclosed embodiments.

[0075] Figure 2C This is consistent with the disclosed embodiment. Figure 2A-2B Schematic diagram of the erosion electrode in the electrode configuration.

[0076] Figure 2D This is consistent with the disclosed embodiment. Figure 2A-2B Schematic diagram of the bubbles generated in the electrode configuration.

[0077] Figures 3A-3C is a schematic diagram illustrating another exemplary electrode configuration for fabricating nanomaterials consistent with the disclosed embodiments.

[0078] Figures 4A-4B is a schematic diagram illustrating yet another exemplary electrode configuration for fabricating nanomaterials consistent with the disclosed embodiments.

[0079] Figure 5A-5B is a schematic diagram illustrating yet another exemplary electrode configuration for fabricating nanomaterials consistent with the disclosed embodiments.

[0080] Figure 6A-6B is a schematic diagram illustrating yet another exemplary electrode configuration for fabricating nanomaterials consistent with the disclosed embodiments.

[0081] Figure 7 is a schematic diagram illustrating exemplary waveforms of pulsed current and pulsed voltage of a power supply consistent with disclosed embodiments.

[0082] Figure 8 is a schematic diagram illustrating exemplary waveforms of an actual discharge current and an actual discharge voltage discharged into a working fluid consistent with disclosed embodiments.

[0083] Fig. 9 Is a schematic diagram illustrating an exemplary waveform of a discharge power of a plasma pulse discharged to a working liquid consistent with the disclosed embodiments.

[0084] Fig.10 is a schematic diagram illustrating an exemplary circuit for fabricating nanomaterials consistent with disclosed embodiments.

[0085] Fig.11 is a schematic diagram illustrating exemplary waveforms of serial pulses of current and voltage for fabricating nanomaterials consistent with disclosed embodiments.

[0086] Fig.12 is a transmission electron microscope (TEM) image illustrating the structure of nanomaterials produced consistent with disclosed embodiments.

[0087] Fig.13 is a graphical representation illustrating the size distribution of a nanoparticle dispersion determined by dynamic light scattering (DLS) methods consistent with disclosed embodiments.

[0088] Fig.14 is a dark field scanning transmission electron microscope (STEM) image illustrating the size of dry nanoparticles consistent with disclosed embodiments.

[0089] Fig.15 is a schematic diagram illustrating an exemplary setup for separating two types of dispersions consistent with the disclosed embodiments.

[0090] Figures 16A-16B It is explained by Fig.15 Illustrations of the surface structures of two types of dispersions are shown and consistent with disclosed embodiments.

[0091] Figures 16C-16D is a diagram illustrating the positional symmetry of a graphene cap on a nanodiamond core consistent with disclosed embodiments.

[0092] Fig.16E is a graphical representation plotting exemplary viscosity versus shear rate for two types of liquid dispersions including nanoparticles made using disclosed embodiments.

[0093] Figures 16F-16G Exemplary X-ray photoelectron spectroscopy (XPS) curves associated with nanomaterials made using disclosed embodiments are shown.

[0094] Fig.16H is a graphical representation of the luminescence spectrum and initial UV spectrum of a liquid dispersion comprising symmetrically capped nanoparticles made using disclosed embodiments.

[0095] Fig.16I is a graph illustrating the relationship between the absorption coefficient and wavelength of light for a liquid dispersion including symmetrically capped nanoparticles made using disclosed embodiments.

[0096] Fig.17is a graphical representation illustrating the coefficient of friction of lubricants with and without nanomaterial additives consistent with disclosed embodiments.

[0097] Fig.18 is a graphical representation illustrating viscosity index of working fluids having different nanomaterial additive concentrations consistent with disclosed embodiments.

[0098] Fig.19 is a flow chart of an exemplary process for making nanomaterials consistent with the disclosed embodiments. DETAILED DESCRIPTION

[0099] The present disclosure describes systems and methods for manufacturing nanomaterials by pulse discharge in liquids. In some embodiments, a plasma system can be used to generate electric pulse discharges in liquids. For example, a short plasma pulse can be discharged (emitted) in a liquid dielectric to produce nanoparticles as a dispersion, which can be directly mixed with other substances without causing condensation or aggregation. In some embodiments, a plasma system can use controllable and adjustable parameters, which are selected to produce nanoparticles (e.g., nanodiamonds, carbon onions, or fullerene mixtures) with nanoscale size and optical and mechanical characteristics. The nanoparticles produced can have a size of about 1 nanometer (nm) (e.g., an average particle size between about 0.5nm and 1.5nm). The nanomaterials produced can have many practical applications, such as in lubricants, paints, polishing, plastic modification, surface modification and coatings, solar panel modification, medical uses, etc.

[0100] Before describing in detail certain embodiments of the present disclosure, it will be understood that the present disclosure is not limited in its application to the construction details and arrangements of parts set forth in the following description or shown in the accompanying drawings. The inventive concept may include embodiments other than the described embodiments and embodiments practiced and executed in various ways. In addition, it will be understood that the words and terms used herein and in the accompanying drawings are for descriptive purposes and should not be considered as limiting. Therefore, those skilled in the art will understand that the concepts on which the present disclosure is based can be easily used as the basis for designing other structures, methods and systems for achieving the several purposes of the present disclosure.

[0101] Reference will now be made in detail to the exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.Where possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0102] Figure 1 is a schematic diagram illustrating an exemplary system 100 for manufacturing nanomaterials consistent with the disclosed embodiments. Figure 1In the embodiment, the system 100 includes a reactor chamber 102, a circulation pump 104 and a power supply 106. The reactor chamber 102 may be filled with a working liquid 103 (e.g., a dielectric liquid). For example, the working liquid 103 may include an organic liquid (e.g., xylene, o-xylene, benzene, ethanol, etc.). Inside the reactor chamber 102, a high voltage electrode 108 and a ground electrode 110 may be immersed in the working liquid 103 with a (certain) gap and may be connected to the power supply 106. The power supply 106 may generate a pulse voltage or current and output it to the high voltage electrode 108 and the ground electrode 110. In some embodiments, the power supply 106 may have adjustable parameters and frequencies for generating a pulse voltage or current.

[0103] A high voltage electrical pulse 112 (e.g., a dielectric breakdown or plasma pulse) may be discharged (emitted) between the high voltage electrode 108 and the ground electrode 110 through the working liquid 103. The high voltage electrical pulse 112 may induce an electrochemical reaction in the working liquid 103, whereby nanoparticles (e.g., nanocarbon particles) may be generated and dispersed in the working liquid 103. In some embodiments, the gap between the high voltage electrode 108 and the ground electrode 110 may be adjustable (e.g., 0.3 to 3 millimeters or "mm").

[0104] The circulation pump 104 can inject the working liquid 103 into the reactor chamber 102 through the inlet 105 and can flow the working liquid 103 in the reactor chamber 102 along the direction 113. In some embodiments, when in operation, the circulation pump 104 can inject a certain amount of pure working liquid (e.g., excluding nanoparticles) from the pure working liquid source 114 into the reactor chamber 102 via the inlet 105. The circulation pump 104 can control the flow rate of the working liquid 103 in the reactor chamber 102. In some embodiments, in a "continuous mode", the circulation pump 104 can continuously inject the working liquid 103 into the reactor chamber 102 through the inlet 105, and the generated nanoparticles can be continuously discharged from the reactor chamber 102 through the outlet 107 in the form of a nanoparticle suspension 116 (e.g., a mixture of unreacted working liquid 103 and generated nanoparticles). In the continuous mode, the concentration of the nanoparticle suspension 16 (e.g., the proportion of the produced nanoparticles in the mixture) can be controlled by adjusting (e.g., by the circulation pump 104) the flow rate of the working liquid 103 in the reactor chamber 102. In some embodiments, in the "intermittent mode", the circulation pump 104 can intermittently inject the working liquid 103 into the reactor chamber 102 through the inlet 105, and the produced nanoparticles can be intermittently discharged from the reactor chamber 102 in the form of the nanoparticle suspension 116 through the outlet 107. In the intermittent mode, the concentration of the nanoparticle suspension 116 can be controlled by setting the stationary time of the working liquid 103 in the reactor chamber 102 (e.g., the time interval during which the circulation pump 104 does not inject the working liquid 103 into the reactor chamber 102).

[0105] For continuous mode or intermittent mode, the concentration of the nanoparticle suspension 116 can be controlled by the liquid treatment time (e.g., the amount of time the working liquid is subjected to the plasma discharge caused by applying electrical energy to the electrodes (including the electrode 108)). The concentration of the nanoparticle suspension 116 can be further controlled by changing the power associated with the input of the high-voltage electric pulse 112. For example, when the input power of the high-voltage electric pulse 112 is 200 watts, the system 100 can produce nanomaterials at an hourly production capacity of up to about 2 grams. In some embodiments, the power of the high-voltage electric pulse 112 may be greater than or equal to 1 megawatt (MW). In some embodiments, the pulse duration of the high-voltage electric pulse 112 may be greater than or equal to 10 nanoseconds and less than or equal to 40 nanoseconds. In some embodiments, the pulse frequency of the high-voltage electric pulse 112 may be greater than or equal to 100 Hz.

[0106] In order to control the generation of nanoparticles in the working liquid 103, the gap between the high voltage electrode 108 and the ground electrode 110 may be configured to remain substantially constant. In some embodiments, at least one of the high voltage electrode 108 or the ground electrode 110 may have a shape of an elongated member (e.g., a needle or a rod (rod)) that may be parallel to the other electrode. For example, the high voltage electrode 108 may include an elongated member, and the ground electrode 110 may include a flat member (e.g., a pad or a plate) parallel to the elongated member. In another example, the ground electrode 110 may include an elongated member, and the high voltage electrode 108 may include a flat member parallel to the elongated member.

[0107] Figure 2A-2B is a schematic diagram illustrating an exemplary electrode configuration 200 for fabricating nanomaterials consistent with disclosed embodiments. Figure 2A , the high voltage electrode 108 is an elongated member fixed at the first end 202, and the second end 204 (e.g., the free end) of the high voltage electrode 108 extends toward the direction 113 by a length L (e.g., 30 mm, 35 mm, 40 mm, or any other suitable length). The ground electrode 110 is a flat member (e.g., having a thickness h, such as 3 mm, 4 mm, or any other suitable thickness) that also extends toward the direction 113. The ground electrode 110 may be substantially parallel to the high voltage electrode 108. The gap between the high voltage electrode 108 (e.g., including the second end 204) and the ground electrode 110 may have a distance d (e.g., 2 mm, 3 mm, or any other suitable spacing). Figure 2A is a side view of the electrode configuration 200, and Figure 2B 1 is a top view of the electrode structure 200 (e.g., viewed along direction 113). Figure 2B As shown in FIG. 2 , in the electrode configuration 200 the high voltage electrode 108 includes only one elongated member.

[0108] In some embodiments, a high voltage electrical pulse 112 may be discharged (emitted) between the second end 204 of the high voltage electrode 108 and the ground electrode 110. Such a pulse 112 may be generated by applying electrical energy to one or both of the electrodes 108 and 110. To facilitate the formation of the pulse 112 at the second end 204 of the high voltage electrode 108, the high voltage electrode 108 may be configured such that the electric field (generated by the applied electrical energy) may reach a maximum value at the second end 204. In some cases, as the discharge through the pulse 112 continues, the high voltage electrode 108 may be worn or eroded from the second end 204, wherein the length L may decrease. Figure 2C is a schematic diagram illustrating an eroded high voltage electrode 108 in an electrode configuration 200 consistent with disclosed embodiments. Figure 2C In the embodiment, the second end portion 204 of the high voltage electrode 108 has been corroded, and the extension length of the high voltage electrode 108 is shorter than Figure 2AHowever, because the high voltage electrode 108 and the ground electrode 110 are parallel, the distance d of the gap can be kept constant even if the length L is reduced.

[0109] In the electrode configuration 200, because the distance d of the gap can be kept constant, the energy and other parameters of the high-voltage electric pulse 112 (e.g., parameters optimized for nanoparticle generation) can also remain stable during the generation of nanoparticles. Moreover, because the high-voltage electrode 108 is an elongated member, such a geometry can extend the life of the high-voltage electrode 108 (e.g., ending when L becomes substantially 0). In addition, when the high-voltage electrode 108 is eroded at the second end 204, metal nanoparticles can escape from the second end 204, and the metal nanoparticles can be used as a catalyst for the generation of nanoparticles. For example, if the high-voltage electrode 108 includes iron, the iron nanoparticles escaping from the second end 204 during the pulse discharge event can, for example, promote the generation of nanodiamonds from the working liquid 103 (e.g., an organic liquid such as xylene).

[0110] In some embodiments, when the high voltage electrical pulse 112 is discharged in the working liquid 103, gas bubbles (eg, hydrogen from the pyrolysis of the organic liquid) may be generated. Figure 2D is a schematic diagram illustrating bubbles generated in an electrode configuration 200 consistent with the disclosed embodiments. Figure 2D In the embodiment of the present invention, a plurality of bubbles 206 are generated near the second end 204. Since the breakdown voltage of a gas is generally lower than the breakdown voltage of a liquid, the bubbles generated by a previous pulse discharge can change the discharge conditions of a subsequent pulse discharge. For example, if the bubbles generated by a previous pulse discharge remain in the same position until a subsequent pulse discharge occurs, the breakdown voltage of the subsequent pulse discharge can decrease because the subsequent pulse discharge can have a dielectric breakdown in a gas rather than in a liquid. Such bubbles and their movement characteristics can affect (e.g., limit) the frequency with which a pulse discharge event can occur. The slower the bubbles migrate away from the pulse discharge site, the lower the frequency of pulse discharges that can be used for effective particle generation. Therefore, in some cases, the bubble movement characteristics can be a limiting factor in the ability to generate nanoparticles.

[0111] To facilitate the removal of bubbles from the pulse discharge region (e.g., near the second end 204), direction 113 may be selected as the flow direction of the working liquid 103 from the fixed end (e.g., the first end 202) of the high voltage electrode 108 to the free end (e.g., the second end 204), as shown in FIG. Figure 2A , and a pump may be used to cause the working fluid 103 to flow in direction 113. In some embodiments, if the working fluid 103 (e.g., Figure 1If the flow rate (controlled by the circulation pump 104 in the working fluid 103) is high enough, the bubbles generated by the previous pulse discharge at the pulse discharge area can be taken away by the working fluid 103 before the next pulse discharge occurs, so the discharge conditions of each next pulse discharge can be kept basically the same as for the previous pulse discharge. By making the working fluid flow and taking the generated bubbles away from the pulse discharge area, the frequency of repeated pulse discharges can be increased, and thus the production capacity of nanoparticles can also be improved.

[0112] In some embodiments, the high voltage electrode 108 may include more than one elongated member. Figures 3A-3C is a schematic diagram illustrating an exemplary electrode configuration 300 for manufacturing nanomaterials consistent with the disclosed embodiments. Figure 3A-3B As shown in , the electrode configuration 300 can be similar to the electrode configuration 200 except that the high voltage electrode 108 includes two elongated members (e.g., two rods). For example, the two elongated members can have similar geometric parameters (e.g., length L, distance d, etc.). In some embodiments, by providing two elongated members, the high voltage electrode 108 can increase its working life and nanoparticle production capabilities. Figure 3A may be a side view of the electrode configuration 300, and Figure 3B This may be a top view of electrode configuration 300 (eg, looking against direction 113 ).

[0113] like Figure 3C As shown in , the electrode configuration 300 can be enclosed in a reactor chamber 102 having a cylindrical geometry. The two elongated members of the high-voltage electrode 108 can be fixed near the bottom of the reactor chamber 102. In some embodiments, in order to make the electrode erosion of the electrode configuration 300 more uniform and the repetition frequency of the pulse discharge higher, in addition to the direction 113, the working liquid 103 can also be made to flow along the second direction 302 (for example, the fluid flow can present flow direction components along the two directions 302 and 113) to improve the dielectric breakdown between the two elongated members of the high-voltage electrode 108.

[0114] In some embodiments, the high voltage electrode 108 may include a plurality of elongated members. Figures 4A-4B is a schematic diagram illustrating an exemplary electrode configuration 400 for manufacturing nanomaterials consistent with the disclosed embodiments. Figures 4A-4B As shown in FIG. 4 , the electrode configuration 400 can be similar to the electrode configuration 300 except that the high voltage electrode 108 includes more than two elongated members (e.g., 10 rods, less than 10 rods, or more than 10 rods). The electrode configuration 400 can be used to expand (amplify) the ability of nanoparticle production because each free end of the elongated members of the high voltage electrode 108 can discharge the high voltage electrical pulse 112 to the ground electrode 110. Figure 4A is a top view of the electrode configuration 400, and Figure 4B is a perspective view of the electrode structure 400 .

[0115] In some embodiments, the high voltage electrode 108 and the ground electrode 110 may each include a multi-layer structure. Figure 5A-5B is a schematic diagram illustrating an exemplary electrode configuration 500 for manufacturing nanomaterials consistent with the disclosed embodiments. Figure 5A-5B As shown in , electrode configuration 500 may include multiple electrode layers, each of which may be similar to electrode configuration 400 (eg, each layer of high voltage electrode 108 may include more than two elongated members). Electrode configuration 500 may be used to further expand the capability of nanoparticle production. Figure 5A A top view of an electrode configuration 500 may be provided, and Figure 5B A perspective view of electrode configuration 500 may be provided.

[0116] In some embodiments, both the high voltage electrode 108 and the ground electrode 110 may include elongated members (ie, electrodes that do not include flat members). Figure 6A-6B is a schematic diagram illustrating an exemplary electrode configuration 600 for manufacturing nanomaterials consistent with the disclosed embodiments. Figure 6A-6B As shown in , the electrode configuration 600 may include multiple electrode layers (e.g., multiple layers of high voltage electrodes 108 and ground electrodes 110 arranged in an alternating sequence), each of which may include only elongated members (e.g., parallel rods). The electrode configuration 600 may be used to promote dielectric breakdown between layers to increase the frequency of repeated pulse discharges, thereby increasing the ability of nanoparticle generation. Fig. 6A is a top view of the electrode configuration 600, and Figure 6B is a perspective view of the electrode configuration 600 .

[0117] Figure 7 is a diagram illustrating exemplary waveforms of pulse current and pulse voltage of power supply 106 consistent with disclosed embodiments. Figure 7 , exemplary pulsed current and voltage are represented by lines 702 and 704, respectively. Figure 7 The pulse current may include an actual discharge current (e.g., through the gap between the high voltage electrode 108 and the ground electrode 110) and a capacitive current that charges the capacitance between the electrodes (e.g., the high voltage electrode 108 and the ground electrode 110). For example, the actual discharge current may be determined as the difference between the measured pulse current (e.g., from the high voltage electrical pulse 112) and the capacitive current.

[0118] Figure 8 is a schematic diagram illustrating exemplary waveforms of actual discharge current and actual discharge voltage discharged into the working fluid 103 consistent with the disclosed embodiments. Figure 8 , exemplary actual discharge current and voltage are represented by lines 802 and 804, respectively. Figure 8 As shown in , the duration to create a plasma channel in a liquid (e.g., dielectric breakdown) (e.g., 20 nanoseconds or "ns") is about one-fifth the duration to eliminate the plasma channel and destroy the bubble (e.g., 100 ns).

[0119] Fig. 9 1 is a schematic diagram illustrating an exemplary waveform of the discharge power of the high voltage electric pulse 112 discharged to the working fluid 103 consistent with the disclosed embodiments. Fig. 9 As shown in , the peak value of the discharge power may be high. In some cases, such a high discharge power may result in the formation of shock waves (eg, in the form of bubbles) in the working liquid 103.

[0120] Fig.10 is a schematic diagram illustrating an exemplary circuit 1000 for fabricating nanomaterials consistent with disclosed embodiments. For example, the nanomaterials may include nanoparticles of nanoscale size (eg, 0.5 to 3 nm). Fig.10 The power supply 106, the reactor chamber 102, the discharge pulse capacitor C dis. , an inductor L and a capacitor C representing the self-capacitance of the wire of the circuit 1000 circ. In some embodiments, C circ. can be adjusted, for example by installing with C dis. Another capacitor (or variable capacitor) connected in parallel. Fig.10 As shown in FIG. 1 , when the power supply 106 is supplied to C dis. As it charges, it also charges the inductor L. After a period of time (typically short), C dis. The voltage can be high enough to cause C circ. Electrical breakdown. C circ. A discharge may begin through the plasma channel, causing its voltage to drop, and one or more bubbles may expand as a shock wave (e.g., in a Figure 2A C circ. The discharge and expansion of the bubble can be completed in an ultra-short process (eg, between 1 ns and 50 ns).

[0121] When C circ. When the voltage of C drops to substantially zero, the power supply 106 supplies power to C dis. The power input can also be reduced to essentially zero because C dis. Through the inductor L and C circ. At this point, the bubble can be destroyed due to instability, and C circ. The discharge can be stopped (i.e., C circ. can be turned on again). circ. After the discharge stops, C circ.The voltage may start to rise again (e.g., by C dis. charging) until C circ. Again high enough for the next electrical breakdown event to occur.

[0122] In some embodiments, the above process can be repeated at a high frequency (eg, 0.5-2 MHz), thereby generating a series of high voltage electrical pulses 112 until C dis. The energy is consumed. dis. When the energy of C is consumed, the power supply 106 may start to supply C dis. Charging. When C dis. With C circ. Such a process may be possible when the ions are of the same order of magnitude. Fig.11 is a diagram illustrating exemplary waveforms of serial pulses of current and voltage for fabricating nanomaterials consistent with disclosed embodiments. Fig.11 , exemplary pulsed current and voltage are represented by lines 1102 and 1104, respectively.

[0123] In some embodiments, when manufacturing nanomaterials, system 100 can be based on Figure 2A-11 One or more of the above are provided. Reactor chamber 102 can be filled with working liquid 103 (e.g., under the action of circulating pump 104). Parameters of power supply 106 (e.g., especially output power and pulse frequency) can be set for production. During production, the flow rate of working liquid 103 and the composition of bubbles generated can be monitored and controlled. After the processing time after production, nanoparticle suspension 116 can be removed from system 100. Nanoparticle suspension 116 can then be analyzed, used directly or dried (e.g., by evaporating working liquid 103 at different temperatures to produce dry nanoparticle powder).

[0124] The dry nanoparticle powder produced during the manufacturing process may have a low electrical conductivity (e.g., 10 5 -5×10 7 Ohm cm). The main chemical element of the nanoparticles produced is carbon (mixed with a small amount of iron from the electrode). In some embodiments, nanoparticle powders can be produced on the surface of silicon crystals, where the nanoparticles can be aggregated into hexagonal shapes, such as Fig.12 as shown in .

[0125] Fig.12 is a transmission electron microscope (TEM) image illustrating the structure of the nanomaterial produced consistent with the disclosed embodiments. Fig.12 As shown in , the nanomaterial is uniform and the aggregated nanoparticles have a typical size of 10-20 nm. The actual size of a single nanoparticle may be significantly smaller.

[0126] Fig.13 is a graphical representation of the size distribution of a nanoparticle dispersion determined by dynamic light scattering (DLS) consistent with the disclosed embodiments. Fig.13 As shown in , most of the produced nanoparticles have a size of about 1 nm. Fig.14 is a dark field scanning transmission electron microscope (STEM) image illustrating the size of dried nanoparticles consistent with the disclosed embodiments. Fig.14 As shown in , the average size of the produced nanoparticles is about 1 nm (eg, between about 0.5 nm and about 1.5 nm).

[0127] In the nanomaterial produced, two types of dispersions (e.g., suspensions comprising a fluid mixed with nanoparticles) may be obtained. The two types of dispersions may be formed by separating a first type of particles from a second type of particles to provide two different dispersions. As described, the structural differences of the two types of nanodiamond particles produced as a result of the disclosed plasma discharge technique result in the respective dispersions possibly having different properties (e.g., transmittance, viscosity, etc.). Fig.15 is a schematic diagram illustrating an exemplary setup for separating or generating two types of dispersions consistent with the disclosed embodiments. Fig.15 , a mixed dispersion containing two types of nano-diamond particles may be poured into a container 1502 having a negative electrode 1504 with a flat bottom and a positive electrode 1506 with a "grater-type" top with sharp needles to provide a high electric field gradient. After applying a high voltage (e.g., 10 kV) between the negative electrode 1504 and the positive electrode 1506, the first type of nano-diamond particles (included in the dispersion region 1510) may not be affected by the high voltage. As a result, the first type of nano-diamond particles will not migrate in response to the applied voltage (or may migrate less than the second type of nano-diamond particles). In contrast, the second type of nano-diamond particles (e.g., shown in the dispersion region 1508 as a result of the migration) may be affected by the applied voltage and may begin to move downward (e.g., away from the positive electrode 1506), as shown by the parallel black arrows 1512. As a result of the applied voltage, dispersion region 1510 may be left with a higher concentration of the first type of nano-diamond particles than the second type of nano-diamond particles. Similarly, dispersion region 1508 may be left with a higher concentration of the second type of nano-diamond particles than the first type of nano-diamond particles.

[0128] This contrasting behavior of the two types of dispersions 1508 and 1510 may be caused by the different electric dipole moments of their particles in the solvent. For example, the first type of nano-diamond particles may have a weak electric dipole moment, and the second type of nano-diamond particles may have a stronger electric dipole moment. For example, by applying an electric field (e.g., a high voltage between the negative electrode 1504 and the positive electrode 1506), the two types of dispersions 1508 and 1510 may be separated because the particles with a strong electric dipole moment may be attracted by one of the electrodes (e.g., the negative electrode 1504), and the particles with a weak electric dipole moment may be less affected by the electric field generated by the applied voltage.

[0129] The different properties of the two types of dispersions can be explained by the different molecular structures of the manufactured nanodiamond particles. For example, the nanodiamond particles manufactured using the disclosed system and method may include a diamond core capped with hybridized carbon atoms to form a graphene cap surface of the diamond core. The graphene cap may include a single layer of graphene, a multilayer of graphene, or a mixture thereof. Each layer of the graphene cap may include one or more carbon atoms. Figures 16A-16B is a diagram illustrating the surface structures of two types of nanodiamond particles included in two types of dispersions consistent with the disclosed embodiments. Figures 16A-16B In the embodiment of the present invention, each of the nanomaterials includes a structure having a nanodiamond core (cores 1602 and 1604) and at least one graphene cap (graphene caps 1606 and 1608) on the surface of the core. The size of the graphene cap on the surface of the core may determine the size of the band gap, which may be about 3.4 to 4 eV for a core size of about 1 nm. The particles with the smallest band gap may correspond to the absorption drop wavelength of the particles of the first type of dispersion in xylene.

[0130] The positional symmetry of the graphene caps can explain the dipole characteristics (e.g., dipole moment) of the nanoparticles. The first type of nanodiamond particles can have at least one graphene cap symmetrically located on the surface of its diamond core. For the present disclosure, the first type of nanoparticles / nanodiamonds can also be referred to as "symmetrically capped particles," "symmetrically capped nanodiamond particles," or "symmetrically capped nanoparticles." The nanodiamond particles of the second type of dispersion can have at least one graphene cap that is asymmetrically located on the surface of its diamond core. For the present disclosure, the second type of nanoparticles can also be referred to as "asymmetrically capped particles," "asymmetrically capped nanodiamond particles," or "asymmetrically capped nanoparticles." Figures 16C-16D is a diagram illustrating the positional symmetry of a graphene cap on a nanodiamond core consistent with disclosed embodiments. Fig. 16CShowing the asymmetric position of the graphene cap on a 1-nm nanodiamond core. From left to right, Fig. 16C Nuclei with one cap, two caps, and three caps are shown, all asymmetric. Fig. 16C The particles in the dispersion may be asymmetrically capped particles that may form a second type of dispersion or may be more closely associated with a second type of dispersion. For example, the second type of dispersion may have a higher concentration of asymmetrically capped particles than symmetrically capped particles. Fig.16D Shown are the symmetrical positions of four graphene caps on a 1-nm nanodiamond core. Fig.16D The particles in the dispersion may be symmetrically capped particles that may form the first type of dispersion or be more closely associated with the first type of dispersion. For example, the first type of dispersion may have a higher concentration of symmetrically capped particles than asymmetrically capped particles.

[0131] On a macroscopic scale, a first type of dispersion comprising a dispersion of symmetrically capped particles may remain unaggregated and may move separately and individually in the working liquid 103. In some embodiments, the first type of dispersion may be transparent to visible light and may be stable. The second type of dispersion may include asymmetrically capped particles (at least in a higher concentration than in the first type of dispersion). When dispersed in the working fluid, the asymmetrically capped particles may combine to form a dynamic structure. In addition, as noted, these nanodiamond particles may include graphene caps that asymmetrically cover the diamond core. In some embodiments, the second type of dispersion may be black at a concentration of the second nanodiamond particle type above 0.01%.

[0132] The two types of dispersions may also differ in other properties. For example, varying the concentration of the asymmetrically capped particles may vary the viscosity of the corresponding dispersion. Fig.16E is a graph plotting exemplary viscosity versus shear rate for two types of liquid dispersions including nanoparticles made using disclosed embodiments. Fig.16E In the graph, the vertical axis represents viscosity (in Pascal-seconds or Pa·s), and the horizontal axis represents shear rate (i.e., the rate at which one layer of fluid passes over an adjacent layer, in s -1 ).exist Fig.16E In the embodiment of the present invention, the first type of dispersion 1610 has a concentration of symmetrically capped particles in the range of about 0.003-1%, and the second type of dispersion 1612 has a concentration of asymmetrically capped particles of about 1%. Fig.16E As shown in , the two types of dispersions can exhibit different viscosity characteristics. Fig.16E, the first type of dispersion 1610 can have a viscosity that remains nearly constant as the shear rate varies. Notably, the viscosity of the dispersion 1610 can remain nearly constant even when the concentration of the nanoparticles varies (e.g., four lines are shown relative to the dispersion 1610, each line having a different nanoparticle concentration selected from between 0.003-1%. On the other hand, the second type of dispersion 1612 can have a viscosity that varies with the shear rate. For example, as the shear rate increases, the viscosity of the second type of dispersion 1612 decreases (e.g., from about 0.1 Pa·s to less than about 0.01 Pa·s for the shear rates tested). It should also be noted that changing the relative concentrations of symmetrically capped and asymmetrically capped particles in the two types of dispersions can also affect the viscosity (and / or other properties) of the dispersions. For example, by increasing the concentration of asymmetrically capped particles (those having asymmetric graphene caps) or increasing the concentration of asymmetrically capped particles relative to the concentration of symmetrically capped particles, the viscosity of the corresponding dispersion (e.g., for a certain shear rate) can increase.

[0133] In some embodiments, in the second type of dispersion, the ratio between SP2 hybridization (e.g., graphene cap) and SP3 hybridization (e.g., nanodiamond core) can be studied using X-ray photoelectron spectroscopy (XPS) technology. XPS analysis shows that for the first type of dispersion, the SP2:SP3 hybridization ratio can be close to 60%:40%, and for the second type of dispersion, the SP2:SP3 hybridization ratio can be close to 40%:60%. In addition, SP2:SP3 can also be affected by the duration of heating the nanoparticle powder in hot hydrogen (e.g., 550°C). The longer the treatment duration, the higher the ratio of SP3 hybridization can be. According to the above-mentioned characteristics of the nanoparticle dispersion, both types of dispersions may include a crystalline nanomaterial (e.g., nanodiamond) core with a size of about 1 nm, having a certain amount of SP2 hybridized carbon atoms (e.g., "graphene cap") on its surface. In addition, as can be seen from Figures 16C-16D It can be seen that the SP2:SP3 ratios in the symmetric and asymmetric nanoparticles can correspond to the SP2:SP3 ratios observed in the nanoparticles of the first and second types of dispersions.

[0134] Fig.16F is a graphical representation of an XPS spectrum of carbon C1s illustrating a satellite spectrum with a second type of dispersion consistent with embodiments of the present disclosure. Figure 16G is a graphical representation illustrating the approximation of carbon C1s by SP2 and SP3 peaks of a second type of dispersion consistent with embodiments of the present disclosure.

[0135] In addition to different electrical properties, the two types of dispersions may also have different optical properties. For example, a dispersion of the first type in xylene may be studied by observing its ability to emit light under ultraviolet (UV) and visible light irradiation. The results show that the luminescence spectrum of the first type of dispersion may be independent of the excitation wavelength (e.g., up to 380 nm) and the type of liquid (e.g., xylene, water, etc.). The results also show that the first type of dispersion may have a high absorption coefficient (e.g., greater than 1000 cm-1) up to a wavelength of about 470 nm. -1 )(See Fig.16I ). For example, Fig.16A The particles represented by may exhibit a minimum band gap of about 4 eV corresponding to an absorption drop wavelength of 400 nm. Fig. 16B The particles represented may exhibit a minimum band gap of about 3.7 eV corresponding to an absorption drop wavelength of 470 nm.

[0136] Fig.16H is a graphical representation illustrating an emission spectrum 1614 and an initial ultraviolet spectrum 1616 of a first type of dispersion consistent with embodiments of the present disclosure. Fig.16I is a graph illustrating the relationship between the absorption coefficient of a first type of dispersion and the wavelength of light consistent with an embodiment of the present disclosure. Fig.16I As shown, the first type of dispersion may have an absorption coefficient of about 1000 near a wavelength of 470 nm.

[0137] Due to their different physical properties, the two dispersions can be used for different purposes. For example, the first type of nanoparticle dispersion can have little or no effect on the viscosity of the liquid, and can therefore be used as an additive to be homogenized with other substances (e.g., paints, plastics, protective coatings, electrolytes, etc.) to modify those substances and their properties. In another example, the second type of nanoparticle dispersion can increase viscosity and has a strong thixotropic effect, and can therefore be used to control the viscosity of the liquid (e.g., for developing new lubricants, modifying the properties of plastics, etc.).

[0138] In one embodiment, as a practical application, the generated second type of nanomaterial suspension can be used as a friction reducing additive for lubricants. Fig.17 17 is a graph illustrating the coefficient of friction of lubricants with and without the addition of nanomaterial additives produced by the disclosed embodiments. Lubricants with and without the friction reducing additive are shown as lines 1702 and 1704, respectively. The coefficient of friction of the lubricants was measured as follows: -1 The rotating steel cone is pressed against the steel cylindrical hole with a controlled force at a cylinder rotation frequency of . The modified lubricant is added with 0.5% dry nanomaterial additive. Fig.17As shown in , the modified lubricant can reduce its friction coefficient even at higher pressures compared to the unmodified lubricant, which indicates the improvement after adding the nanomaterial additive.

[0139] In another embodiment, the resulting second type of nanomaterial suspension can be used as an additive for a low viscosity silicone lubricant to increase its viscosity at high temperatures. Fig.18 is a graphical representation of the viscosity index of working fluids having different concentrations of nanomaterial additives consistent with the disclosed embodiments. For example, the working fluid may include xylene. In another example, the working fluid may be other types of fluids (e.g., lubricants), such as Society of Automotive Engineers (SAE) standard motor oils (e.g., SAE 20W-50, SAE 15W-40, SAE 10W-30, SAE 5W-30, etc.). It should be noted that the working fluid may include other types of fluids / lubricants and is not limited to the above examples. The viscosity index is a characteristic indication of the increase in viscosity of a lubricant as the temperature decreases. In some embodiments, the nanomaterial may be added to a lubricant (e.g., a silicone lubricant) in a suspension, where the working fluid (e.g., xylene) may be evaporated and the stage of producing a dry powder is thereby avoided. As Fig.18 As shown in FIG. 5 , five fluid dispersions (e.g., working liquids having five different nanomaterial additive concentrations) are presented. From fluid dispersion 1 to fluid dispersion 5, the concentration of the nanomaterial additive decreases, wherein fluid dispersion 1 has the highest nanomaterial additive concentration and fluid dispersion 5 has the lowest nanomaterial additive concentration. Fig.18 As shown in , fluid dispersion 1 shows a stable viscosity index over a wide temperature range and shows a viscosity index of about 1000. As the concentration of the nanomaterial additive decreases, the viscosity index increases more as the temperature decreases. Fluid dispersion 1 can provide better lubricant performance compared to fluid dispersions 2 to 5. In other words, the addition of nanoparticles (e.g., asymmetric nanodiamond particles) made according to embodiments of the present disclosure can significantly improve the viscosity properties of the working fluid even at a concentration in the range of 0.001% to 3%, or more particularly in the range of 0.5% to 1.5%.

[0140] Fig.19 1 is a flow chart of an exemplary process 1900 for manufacturing nanomaterials consistent with embodiments of the present disclosure. Process 1900 includes steps 1902-1908. As an example, process 1900 may be combined with Figure 1-18 It should be noted that the manufacturing process can be implemented in various configurations and is not limited to the above examples.

[0141] In step 1902, a reactor chamber (e.g., reactor chamber 102) is filled with a liquid (e.g., working liquid 103). Figure 1 As shown in , the circulation pump 104 can pump the working liquid from the pure working liquid source 114 through the inlet 105 into the reactor chamber 102. The reactor chamber can enclose a first electrode (e.g., a high voltage electrode 108), a second electrode (e.g., a ground electrode 110), and a liquid. The first electrode and the second electrode can have a gap. In some embodiments, the gap is greater than or equal to 0.3 mm and less than or equal to 3 mm. The first electrode and the second electrode can be parallel (connected in parallel). The first and second electrodes can be electrically connected to a power supply (e.g., power supply 106) so that a plasma pulse (e.g., a high voltage electrical pulse 112) can be generated in the gap when the power supply provides a pulsed electrical output (e.g., a voltage or current).

[0142] In step 1904, the parameters of the power source (e.g., power source 106) may be set, adjusted, etc. For example, the parameters of the power source may be selected so that the discharge power of the high voltage electrical pulse 112 may be 1 MW or higher, and the frequency of the pulse electrical output may be 100 Hz or higher. In some embodiments, the pulse duration of the high voltage electrical pulse 112 may be greater than or equal to 10 nanoseconds and less than or equal to 40 nanoseconds.

[0143] In step 1906, the flow rate of the liquid is controlled during the carbon particle production phase. The carbon particles can be produced in the liquid by the plasma pulses between the gaps. For example, the flow rate can be controlled by a pump (e.g., circulation pump 104). The flow rate can be controlled to optimize the production rate of the nanoparticles (e.g., rapid removal of the nanoparticles). Figure 2D In some embodiments, the average size (e.g., diameter) of the produced carbon particles may be 1 nanometer. In some embodiments, the carbon particles may include a diamond core (e.g., such as a graphene cap) capped (covered) with at least one graphene cap. Figures 16A-16D ).

[0144] In some embodiments, at least one graphene cap may be symmetrically located on a diamond core of a first type of carbon particle (e.g., a symmetrically capped particle) (e.g., as Fig.16D ), wherein the first type of carbon particles can be used as at least one of the following: an additive for solar panels to improve efficiency, an additive for luminescent markers for medical use, an additive for luminophores for quantum dot displays and light sources, or an additive for paints, coatings, or plastics that absorb ultraviolet light. In some embodiments, at least one graphene cap can be asymmetrically located on the diamond core of the second type of carbon particles (e.g., asymmetrically capped particles) (e.g., as Figures 16A-16C). The first or second type of carbon particles can be used as at least one of the following: a friction reducing additive for a lubricant, a wear reducing agent for a lubricant, an antioxidant for a lubricant, or an additive for increasing thermal conductivity of a lubricant, a coolant, or a polymer.

[0145] In step 1908, a dispersion comprising carbon particles and a liquid (e.g., nanoparticle suspension 116) is removed from the reactor chamber (e.g., via outlet 107). In some embodiments, the production phase can be operated in a continuous mode, wherein the dispersion can be continuously removed from the chamber. In some embodiments, the production phase can be operated in an intermittent mode, wherein the dispersion can be removed from the chamber after a processing time after the production phase. In some embodiments, the dispersion can include a first type of dispersion (e.g., comprising primarily symmetrically capped carbon particles) and a second type of dispersion (e.g., comprising primarily asymmetrically capped carbon particles), as previously described.

[0146] The dispersion may be analyzed, used, or further processed after step 1908. For example, the dispersion may be separated into a first type of dispersion and a second type of dispersion.

[0147] In one embodiment, taking system 100 as an example, the reactor chamber 102 may be filled with a certain amount (e.g., 1 liter) of reagent-grade working fluid 103 (e.g., o-xylene). The parameters of the power supply 106 may be selected so that the discharge power of the high-voltage electric pulse 112 can reach 1.5 MW, wherein the average pulse repetition frequency is 1000 Hz. During the production process, the flow rate of the working fluid 103 and the bubbles generated by the high-voltage electric pulse 112 (e.g., Figure 2D The bubbles 206 in the liquid can be removed from the system 100 after a processing time after production. The nanoparticle suspension 116 including the liquid and the nanoparticles can be removed from the system 100. The nanoparticle suspension 116 can be further separated into different types for analysis, use, or further processing. In one example, using the above settings, after running for four hours, the production process can produce 0.9 grams of 1-nm symmetrically capped carbon nanoparticles and 1.2 grams of asymmetrically capped carbon nanoparticles.

[0148] In another embodiment, taking system 100 as an example, the reactor chamber 102 may be filled with a certain amount (e.g., 1 liter) of a mixture of 90% reagent grade o-xylene and 10% reagent grade isopropanol. The parameters of the power supply 106 may be selected so that the discharge power of the high voltage electric pulse 112 may reach 1.5 MW, wherein the average pulse repetition frequency is 1000 Hz. During the production process, the flow rate of the working liquid 103 and the bubbles generated by the high voltage electric pulse 112 (e.g., Figure 2DThe composition of the bubbles 206 in the nanoparticle suspension 116 can be determined. After a processing time after production, the nanoparticle suspension 116 including the liquid and the nanoparticles can be removed from the system 100. In one example, using the above settings, after four hours of operation, the production process can produce 0.12 grams of 1-nm symmetrically capped carbon nanoparticles and 0.15 grams of asymmetrically capped carbon nanoparticles. The nanoparticle suspension 116 can be further separated into different types for analysis, use or further processing. In one example, the nanoparticle suspension 116 can be separated into a first and a second type of dispersion and further analyzed by DLS, X-ray, XPS or gravimetric analysis techniques.

[0149] In another embodiment, taking system 100 as an example, the reactor chamber 102 may be filled with a certain amount (e.g., 1 liter) of a mixture of 90% reagent grade o-xylene and 10% reagent grade hexane. The parameters of the power supply 106 may be selected so that the discharge power of the high voltage electric pulse 112 can reach 1.5 MW, wherein the average pulse repetition frequency is 1000 Hz. During the production process, the flow rate of the working liquid 103 and the bubbles generated by the high voltage electric pulse 112 (e.g., Figure 2D The composition of the bubbles 206 in the nanoparticle suspension 116 can be determined. After a processing time after production, the nanoparticle suspension 116 including the liquid and the nanoparticles can be removed from the system 100. In one example, using the above settings, after four hours of operation, the production process can produce 0.3 grams of 1-nm symmetrically capped carbon nanoparticles and 0.25 grams of asymmetrically capped carbon nanoparticles. The nanoparticle suspension 116 can be further separated into different types for analysis, use or further processing. In one example, the nanoparticle suspension 116 can be separated into a first and a second type of dispersion and further analyzed by DLS, X-ray, XPS or gravimetric analysis techniques.

[0150] In another embodiment, taking system 100 as an example, the reactor chamber 102 may be filled with a certain amount (e.g., 1 liter) of industrial grade xylene including a mixture of o-xylene, m-xylene, p-xylene, and ethylbenzene. The parameters of the power supply 106 may be selected so that the discharge power of the high-voltage electric pulse 112 can reach 1.5 MW, wherein the average pulse repetition frequency is 1000 Hz. During the production process, the flow rate of the working liquid 103 and the bubbles generated by the high-voltage electric pulse 112 (e.g., Figure 2DThe composition of the bubbles 206 in the nanoparticle suspension 116 can be determined. After a processing time after production, the nanoparticle suspension 116 including the liquid and the nanoparticles can be removed from the system 100. In one example, using the above settings, after four hours of operation, the production process can produce 1.7 grams of 1-nm symmetrically capped carbon nanoparticles and 0.3 grams of asymmetrically capped carbon nanoparticles. The nanoparticle suspension 116 can be further separated into different types for analysis, use or further processing. In one example, the nanoparticle suspension 116 can be separated into a first and a second type of dispersion and further analyzed by DLS, X-ray, XPS or gravimetric analysis techniques.

[0151] As can be seen from the above examples, the presence of substances including benzene rings (e.g., aromatic substances) can be important for producing 1-nm nanoparticles with diamond cores. Other organic substances with different ratios of hydrogen to carbon can reduce the formation of carbon nanoparticles. In some embodiments, the ratio between the first and second types of dispersions can be controlled by adjusting the content of aromatic substances in the initial dielectric liquid.

[0152] As can be seen from the above description, the embodiments of the present disclosure provide systems and methods for manufacturing nano materials with low cost, effectiveness and safety. For example, system 100 does not require any special explosion-proof facilities or equipment. Moreover, the nano materials produced can be uniformly mixed with liquids. In addition, compared with the 5 nanometer sizes provided by the prior art, the size of the nanoparticles produced can be within the range of 1nm (for example, 0.5nm to 3nm). In addition, the disclosed system and method can promote the scale (enlargement) of production capacity. Exemplary applications have shown superior and promising characteristics for a wide range of industrial applications.

[0153] Although the present disclosure has been shown and described with reference to specific embodiments of the present disclosure, it will be understood that the present disclosure may be practiced without modification in other environments. The foregoing description has been presented for illustrative purposes. It is not exhaustive and is not limited to the precise form or embodiment disclosed. In view of the description and practice of the disclosed embodiments, changes and modifications will be apparent to those skilled in the art.

[0154] In addition, although illustrative embodiments have been described herein, those skilled in the art will understand the scope of any and all embodiments with equivalent elements, changes, omissions, combinations (e.g., across aspects of various embodiments), modifications and / or variations based on this disclosure. The limitations in the claims should be broadly interpreted based on the language used in the claims, and are not limited to the examples described in this specification or during the examination of the application. The examples should be interpreted as non-exclusive. In addition, the steps of the disclosed method can be changed in any way, including by reordering steps and / or inserting or deleting steps. Therefore, it is intended that the description and examples are considered to be illustrative only, with the true scope and spirit being indicated by the attached claims and their full range of equivalents.

Claims

1. A system for manufacturing nanomaterials, comprising: a first electrode; a second electrode separated from the first electrode by a gap; a chamber configured to enclose the first electrode, the second electrode, and a liquid; a power source configured to provide electrical energy to at least one of the first electrode and the second electrode; and A pump configured to flow the liquid through the gap between the first electrode and the second electrode.

2. A method for producing a nanomaterial, comprising: filling a chamber with a liquid, the chamber enclosing a first electrode and a second electrode; setting parameters of a power source electrically connected to the first electrode and the second electrode; controlling the flow rate of the liquid during a production phase of a plurality of carbon particles produced by a plasma pulse in a gap between the first electrode and the second electrode; and The dispersion of the plurality of carbon particles is removed from the chamber.

3. A manufactured material comprising carbon nanoparticles, each of the carbon nanoparticles comprising: Diamond core; and At least one graphene cap on a surface of the diamond core, wherein the average size of the carbon nanoparticles is between 0.5 nanometers and 3 nanometers.

4. The fabricated material of claim 3, wherein the carbon nanoparticles are contained in a liquid to form a dispersion.

5. The manufactured material of claim 4, wherein the liquid comprises an organic substance.

6. The fabricated material of claim 5, wherein the organic species comprises benzene rings.

7. A manufactured material as described in any of claims 4-6, wherein the liquid is an organic fluid.

8. The fabricated material of any one of claims 3-7, wherein the at least one graphene cap is symmetrically located on a surface of the diamond core.

9. The fabricated material of any one of claims 4-8, wherein the dispersion of the carbon nanoparticles in the liquid has a viscosity between 0.01 and 0.1 Pascal-seconds, and wherein the concentration of the carbon nanoparticles in the dispersion is less than 1%.

10. A manufactured material as described in claim 9, wherein the carbon particles are configured for use as at least one of: an additive for solar panels to improve efficiency; an additive for luminescent markers for medical purposes; an additive for luminophores in quantum dot displays and light sources; or an additive for paints, coatings, or plastics that absorb ultraviolet radiation.

11. The fabricated material of any one of claims 3-7, wherein the at least one graphene cap is asymmetrically located on the surface of the diamond core.

12. The fabricated material of any of claims 3-11, wherein the carbon nanoparticles are configured to change the viscosity of a lubricant when included as an additive to the lubricant.

13. The manufactured material of any one of claims 3-12, wherein the carbon nanoparticles are configured for use as at least one of: a friction reducing additive for a lubricant; a wear reducing agent for a lubricant; an antioxidant for a lubricant; or an additive for a lubricant, coolant, or polymer to increase thermal conductivity.

Images