Apparatus, methods, and systems for dispersing particles and exfoliating NANO- and micro-structures in a medium

Abstract

An apparatus and method are provided for continuously dispersing nano-particles and synthesizing two-dimensional (2D) materials via exfoliation within a liquid medium. In one embodiment, the apparatus includes a rotor and stator with a variable gap between their surfaces, an input channel for untreated material, and an outlet for processed particles. Cavitation, high shear, and impact forces generated in the gap facilitate dispersion and exfoliation. The input material comprises a liquid medium, agglomerated or unexfoliated particles, and at least one wetting, dispersing, and stabilizing agent. The system may include a container for collecting treated material and a drive mechanism for rotor rotation. Resulting compositions are homogeneous blends of dispersed nano- particles or exfoliated 2D platelets, suitable for use as additives or masterbatches.

Description

APPARATUS, METHODS, AND SYSTEMS FOR DISPERSING PARTICLES AND EXFOLIATING NANO- AND MICRO-STRUCTURES IN A MEDIUMTechnical Field

[0001] The present invention relates to the field of material processing equipment, and more particularly to apparatus, methods, and systems for dispersing particles and exfoliating larger particles into nano-scale and micro-scale structures (such as two-dimensional platelets) within a liquid medium.Background of the Invention

[0002] In advanced materials processing, there is a strong need to efficiently produce high- concentration dispersions of nanoparticles and two-dimensional (2D) materials (in platelet form) from bulk particulate feedstocks. Such dispersions are valuable for composites, coatings, electronics, and other applications. Conventional dispersion techniques often struggle to achieve uniform exfoliation and dispersion at scale, especially when particle surfaces are incompatible with the medium, leading to agglomeration and poor stability. High-energy processes (mechanical shear, cavitation, impact) are typically required to overcome inter-particle forces and surface tension effects, but existing technologies (e.g. ultrasonic baths, conventional high- shear mixers) have limitations in throughput and efficiency for high-viscosity or high-solid- content systems.

[0003] Researchers and engineers are exploring diverse means of imparting energy to the system, encompassing mechanical, chemical, and thermal methodologies. Traditional technologies face scalability issues and struggle to generate high-concentration nano particle dispersions or effectively exfoliate 2D materials at higher concentrations. To address this limitation and enhance downstream processing efficiency while minimizing formulation adjustments, there is a growing demand for high concentration masterbatches or dispersions. Conventional technologies prove inadequate at these concentrations, prompting the need for innovative solutions to meet the evolving demands of such applications. What is needed is an improved continuous-processing apparatus that applies intense localized forces to break apartparticle agglomerates and exfoliate layered materials, while allowing for high throughput and minimal dilution.Summary of the Invention

[0004] It will be appreciated by those skilled in the art that other variations of the embodiments described below may also be practiced without departing from the scope of the invention.Further note, these embodiments, and other embodiments of the present invention will become more fully apparent from a review of the description and claims which follow.

[0005] In one embodiment, the present invention addresses the aforementioned challenges by combining cavitation, high shear, and impact forces in a patterned rotor-stator configuration. This design enables scalable and high-throughput production of nanoparticle dispersions and D- material platelets in various liquid media. The apparatus and methods described herein allow for uniform dispersion of nanoparticles and effective exfoliation of larger particles into nano- and micro-scale structures, even at relatively high solids concentration.

[0006] The within disclosure also describes a system that not only addresses the challenges of conventional dispersion technologies but also opens new frontiers in the scalable and high- throughput production of nano-particle dispersions and exfoliated 2D materials. The unique combination of cavitation, high shear, and impacting forces, orchestrated by the patterned rotor and stator system, positions this invention as a breakthrough in the field of materials processing, promising advancements in various industrial applications.

[0007] In one embodiment, the present invention provides improved apparatus, systems, and methods for continuous dispersion of particles and synthesis of two-dimensional materials in platelet form by exfoliating larger particles within a fluid medium. In one embodiment, the invention provides an apparatus for continuous dispersion of nanoparticles and synthesizing two- dimensional materials in platelet form through exfoliation of larger particles. The apparatus comprises (a) a rotor having an outer surface with a pattern of machined grooves or protruding elements of varying depths; (b) a stator positioned around the rotor such that a gap is formed between the rotor’s surface and the stator’s inner surface; (c) at least one inlet channel configured to introduce untreated particulate material into the gap; and (d) at least one outletchannel configured to remove treated material from the gap. As the rotor is driven to rotate at high speed within the stationary stator, cavitation occurs and intense shear and impact forces are generated in the medium flowing through the gap. These forces break down particle agglomerates and exfoliate larger particles into nano-sized fragments and platelet-shaped 2D materials.

[0008] In one embodiment, the apparatus further comprises a motor coupled to the rotor to drive its rotation at the desired speed. In another embodiment, the rotor and / or stator surfaces are patterned (for example, with protruding fins or multi-step profiles) to direct the flow and maximize collisions between particles and the rotor / stator surfaces, thereby enhancing the dispersion and exfoliation processes. In one embodiment, the untreated material comprises a slurry of agglomerated nanoparticles (such as carbon nanotubes, graphene, graphite, boron nitride, or combinations thereof) in a liquid medium (for example, water, organic solvents, or polymerizable resins). As the rotor spins, the material circulates through the narrow, variablewidth gap (“g” in FIG. 1), and the well-dispersed nanoparticles or exfoliated 2D platelets exit through the outlet for collection.

[0009] In one embodiment, the present invention provides a method of dispersing nanoparticles within a medium. The method comprises (a) passing an untreated particle-laden medium through a gap between a rotor and a stator; (b) rotating the rotor at high speed as the material passes through the gap; and (c) collecting the medium, now containing dispersed nanoparticles, from an outlet channel. In another embodiment, the invention provides a method of synthesizing 2D materials in platelet form by exfoliation of larger particles. This method similarly comprises (a) passing an untreated material through a gap between a rotor and a stator; (b) rotating the rotor during the passage to induce cavitation and shear; and (c) collecting the medium containing the exfoliated 2D materials.

[0010] In one embodiment, the present invention is an apparatus for continuous dispersion of nano- particles and synthesizing 2D materials in the form of platelets through the exfoliation of larger particles within a medium, the apparatus comprising: (a) a rotor featuring machined grooves of varying depths along its surface, (b) a stator, (c) a gap formed between the rotor and stator surface, (d) at least one input channel into the system to feed the system with the untreatedmaterial, and (e) an outlet channel from the system to remove the treated particles from the system,. As the rotor turns at high speeds within the stationary stator, it induces cavitation, generates high shear forces, and applies impactful energies concurrently.

[0011] In one embodiment, the apparatus further comprises a driving means linked to the rotor for rotating the rotor in the predetermined direction.

[0012] In one embodiment, the patterned arrangement of the rotor and stator elements strategically directs the flow, maximizing the collision and interaction between particles and facilitating the exfoliation process.

[0013] In one embodiment, the untreated material comprises a mixture of agglomerated nanoparticles, including carbon nanotubes, graphene, graphite particles, boron nitride particles and / or particle blends in a liquid medium.

[0014] In another embodiment, the present invention is a method of dispersing the nano-particles within a medium, the method comprising: (a) passing an untreated material through a gap formed between the rotor and the stator surface, (b) the rotating of the rotor while the untreated material passes through the gap, (c) collecting the medium containing the dispersed nano-particles.

[0015] In another embodiment, the present invention is a method of synthesizing 2D materials in the form of platelets through the exfoliation of larger particles within a medium, the method comprising: (a) passing an untreated material through a gap formed between the rotor and the stator surface, (b) the rotating of the rotor while the untreated material passes through the gap, (c) collecting the medium containing the 2D materials.

[0016] In another embodiment, the present invention is a composition, substance, dispersion, or compound produced by an apparatus according to an apparatus of the present invention.

[0017] In one embodiment of the present invention, the composition, substance, dispersion or compound is a 2D materials in the form of platelets and / or sheets suspended in a liquid medium.

[0018] In another embodiment of the present invention, the composition, substance, dispersion or compound is a homogenous blend of particles suspended in a liquid.

[0019] In one embodiment, the invention includes a composition produced by the apparatus or method, the composition comprising dispersed nanoparticles and / or 2D platelets suspended in a liquid medium. For example, the composition may include graphene, hexagonal boron nitride, transition metal dichalcogenides, MXenes, or phosphorene platelets dispersed in a resin or solvent.

[0020] The liquid medium may include water, organic solvents (e.g., N-methyl-2 -pyrrolidone (NMP), dimethylformamide (DMF)), oils, epoxy resins, or latexes, depending on the end application. The concentration of dispersed nanomaterials can typically range from 0.5 wt.% to 40 wt.%, depending on the viscosity of the medium and the intended use case.

[0021] Target applications for these dispersions include conductive coatings, thermal interface materials, EMI shielding, anticorrosion films, composite reinforcement, flexible electronics, battery electrodes, and high-performance lubricants. The improved dispersion quality achieved by the disclosed apparatus or method enhances the mechanical, electrical, and / or thermal properties of the final material system.

[0022] In one embodiment, the present invention is an apparatus for continuous dispersion of nano-particles and synthesizing 2D materials in the form of platelets through the exfoliation of larger particles within a medium, the apparatus comprising a rotor, stator, a gap formed between the rotor and stator surface, with the gap distance varying along the rotor from the inlet side to the outlet side, at least one input channel into the system, to feed the system with the untreated material, and an outlet channel from the system to remove the treated particles from the system, wherein the rotor and stator are configured to disperse the nano-particles and exfoliated the 2D material using forces of cavitation, high shear, and impacting forces.

[0023] In one embodiment, the present invention is a method of dispersing nanoparticles in a liquid medium, comprising feeding an untreated particle-laden medium into a gap between a rotor and a stator, rotating the rotor at high speed while the medium passes through the gap, and collecting the medium from an outlet channel, the collected medium containing dispersed nanoparticles, wherein the rotation of the rotor generates cavitation and high shear forces in the medium, thereby disrupting particle agglomerates and dispersing the particles.

[0024] In one embodiment, the present invention is a method of synthesizing two-dimensional platelets by exfoliation of larger particles in a liquid medium, comprising passing an untreated particle-laden medium including layered bulk particles through a gap between a rotor and a stator; rotating the rotor at high speed while the medium passes through the gap, and collecting the medium from an outlet, the collected medium containing exfoliated two-dimensional platelets, wherein the rotation of the rotor induces cavitation and shear forces that cleave the layered particles into platelets.Brief Description of the Drawings

[0025] In the drawings, preferred embodiments of the invention are illustrated by way of example. It is to be expressly understood that the drawings are only for the purpose of illustration and as an aid to understanding and are not intended as a definition of the limits of the invention. The embodiments herein will be understood from the following description with reference to the drawings, in which:

[0026] FIG. l is a schematic cross-sectional view of an apparatus according to one embodiment of the present invention. The drawing indicates various dimensions: “g” designates the gap between the rotor surface and the stator surface, “x” designates the space between adjacent rotor blade 60s, “y” designates the width of a rotor blade 60, and “D” designates the height of a rotor blade 60.

[0027] FIG. l is a schematic diagram of another embodiment of the apparatus, showing a stator inner surface with protruding fins angled toward the rotor.

[0028] FIG. 3 is a schematic diagram of another embodiment, illustrating a rotor having ascending and descending multi-step protrusions on its surface.Detailed Description of Embodiments

[0029] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated inthe drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. In particular, all terms used herein are used in accordance with their ordinary meanings unless the context or definition clearly indicates otherwise. Also, unless indicated otherwise except within the claims the use of “or” includes “and” and vice-versa. Non-limiting terms are not to be construed as limiting unless expressly stated or the context clearly indicates otherwise (for example, “including”, “having”, “characterized by” and “comprising” typically indicate “including without limitation”). Singular forms included in the claims such as “a”, “an” and “the” include the plural reference unless expressly stated or the context clearly indicates otherwise. Further, the stated features and / or configurations or embodiments thereof the suggested intent may be applied as seen fit to certain operating conditions or environments by one experienced in the field of art. As used herein, the terms “about” and “approximate,” when used in reference to a numerical value or range, are intended to account for variations that may arise from measurement limitations or tolerances and are meant to encompass values that are within ±10%, or within the limits of experimental accuracy, of the stated value or range unless otherwise specified. All ranges disclosed herein are inclusive unless otherwise indicated.Apparatus for Dispersion and Exfoliation

[0030] In one embodiment, the present invention uses cavitation, high shear, and impacting to achieve continuous dispersion of nanoparticles and exfoliation of 2D materials. The Apparatus 100 and system of the present invention is used to produce nano and / or micro particles dispersed within a medium or 2D materials in the form of platelets within a medium. Micro and nano particles can be defined as particles which have at least one dimension in the nano or micro scale.

[0031] Referring now to FIG. 1, one embodiment of the present invention is an apparatus 100 for continuous dispersion of nanoparticles and exfoliation of larger particles. The Apparatus 100 includes a rotor 10 mounted on a shaft 20. The shaft 20 is coupled to a motor 15 (for example, an electric motor 15) that drives rotor 10 to rotate about its axis. Surrounding the rotor 10 is a stator 30, forming an annular chamber 35. In one embodiment, the rotor 10 has an outer surfacepatterned with grooves, blades 60, or protruding elements of varying depths along its length. The stator 30 inner surface may also have a corresponding pattern of protrusions or fins, such that a non-uniform gap “g” exists between the rotor 10 surface and stator 30 surface. This gap “g” is narrow (on the order of micrometers to millimeters) and may vary along the flow path. The narrow gaps (“g” in Figure 1) between the stator 30 and rotor 10 surfaces serve to induce particle milling, thereby further enhancing the dispersion and exfoliation of the particles within the dispersion / exfoliation chamber 35.

[0032] The chambers formed between the inner surface of the stator and the adjacent rotor blades (“x”), in combination with the height "D" of the rotor blades, play a critical role in the device's high-efficiency mixing mechanism. When the rotor operates at speeds exceeding 1000 rpm, these chambers generate intense turbulent flow conditions. This turbulent regime results in vigorous shear forces and high-energy collisions between particles suspended in the fluid medium, promoting rapid and uniform dispersion of nanoparticles or 2D materials. As the mixture travels through these dynamic chambers, it is subsequently forced through a narrower annular gap denoted as "g". This thinner gap acts as a secondary processing zone, where the already well-distributed mixture undergoes additional high-shear milling. The constricted geometry of this region further refines the particle dispersion by subjecting the suspension to increased localized shear stress, which helps break down any remaining agglomerates and ensures a homogeneous mixture. This process of turbulent mixing followed by gap-based shearing is repeated continuously along the axial length of the rotor, enabling consistent and scalable production of well-dispersed formulations. If required, the system also supports recirculation, allowing the mixture to be processed multiple times through the apparatus. This optional recirculation loop enhances the degree of dispersion and enables fine-tuning of the final product properties for demanding applications in coatings, adhesives, energy storage, and advanced composites.

[0033] In one embodiment, the apparatus 100 further includes an inlet channel 40 (or inlet 40) leading into the gap region (“G”) and an outlet channel 50 leading out of the gap. In operation, an untreated particle-laden medium 80 (for example, a slurry 80 of particles in a liquid) is fed into the inlet 40. The rotor 10 is rotated at high speed (for example, above 1,000 rpm, and insome cases exceeding 3,000 rpm or even 10,000 rpm or greater) relative to the stator 30. This rotation imparts shear and induces cavitation in the fluid flowing through the gap.

[0034] As previously indicated, Fig. 1 indicates various dimensions: “g” designates the gap between the rotor surface and the stator surface, “x” designates the space between adjacent rotor blade 60s, “y” designates the width of a rotor blade 60, and “D” designates the height of a rotor blade 60. In one embodiment, these dimensions are as follows: g = approximately lOmm-lum; D = approximately 1000mm to 25mm; x = approximately 50mm - 5mm; and y = approximately 50mm - 5mm

[0035] In one embodiment, the apparatus 100 comprises a rotor 10 that can be rotated on a shaft 20 by a motor 15 and enclosed within a stator 30. Relative to the rotor 10 edge surface, the stator 30 surface can be stationary. The patterned arrangement of the rotor 10 and stator 30 elements strategically directs the flow of the material, maximizing the collision and interaction between particles and facilitating the exfoliation process. Additionally, the patterned arrangement induces cavitation and high shear flows, promoting efficient dispersion of agglomerated particles into individual or nano-sized particles and facilitating the exfoliation process. The untreated material is introduced into the stator 30 through the inlet. As the rotor 10 spins at high speeds, including speeds greater than 1000 rpm, greater than 3000 rpm, or greater than 10,000rpm, the product is circulated through the gap between the rotor 10 surface and the stator 30 surface, “g”. The well dispersed nano-particles and exfoliated 2D materials then reach the outlet and is collected in a material collecting vessel or similar Apparatus 100. In addition, further processing of the material may involve recirculating the slurry 80 through the system multiple times.

[0036] The turbulent flow patterns induced by the rotating rotor 10 intensify the mixing and intermingling between the particles and the surrounding medium. This turbulence facilitates aggressive particle collision, enhancing the likelihood of interactions between adjacent particles and between particles and the rotor 10 blades 60. As a result, the shear forces are more effectively transmitted to the particles, leading to the disintegration of agglomerated structures. This process fosters the separation of individual or nano-sized particles from the bulk material, promoting uniform dispersion throughout the slurry 80. Consequently, the combined effects ofturbulence and shear forces synergistically contribute to the effective dispersion and exfoliation of the material within the dispersion / exfoliation chamber 35.

[0037] As rotor 10 spins, it draws the medium through the gap “g” (both via a pump and through the pumping action of the rotor 10 itself). The patterned rotor 10 / stator 30 surfaces induce turbulent flow and local pressure changes. Specifically, regions of low pressure can form, causing the liquid to vaporize and create cavitation bubbles. When these bubbles travel to higher- pressure regions and collapse, they generate intense local shear. These forces effectively break apart agglomerated particles and exfoliate layered materials. Simultaneously, the direct collisions between particles and the fast-moving rotor blades 60 or protrusions create additional impact forces that fragment the particles.

[0038] In this way, the combined effects of cavitation, shear, turbulence, and impact cause bulk particles (such as graphite flakes or other layered materials) to exfoliate into thin platelets, and cause particle agglomerates (such as bundles of nanotubes or nanopowders) to disperse into individual nano- and micro-particles. The well-dispersed medium then exits through outlet. The output can be collected in a vessel for further use. In some embodiments, the outlet is connected to a collection tank (and optionally back to the inlet 40 via a recirculation pump) so that the material can be processed in multiple passes for thorough dispersion. In one embodiment, the system uses closed-loop recirculation to achieve the desired dispersion.

[0039] The rotor 10 and stator 30 surface can be of various patterns. For example, the stator 30 surface can contain protruding surfaces angled toward the rotor 10, creating a gap between the rotor 10 and stator 30 surfaces and enhancing the narrow surface area between them, as shown in Figure 2. The rotor 10 can feature protruding surfaces strategically positioned along its length, extending outward from the central shaft 20. These protrusions vary in depth, creating a dynamic surface profile that enhances the dispersion and exfoliation process. One embodiment of this design is illustrated in Figure 3 with ascending and descending multi-step configurations, showcasing the versatility and adaptability of the geometry of rotor 10 surface.

[0040] The rotor 10 and stator 30 can also be composed of durable materials resistant to wear, such as stainless steel, aluminum alloys, hardened alloys, or ceramics.

[0041] In one embodiment, the input material 80, typically a particle slurry 80, is initially stored in a container before being pumped into the dispersion / exfoliation chamber 35 through the inlet 40 using a slurry or liquid pump. Within the system, the material flows under the combined influence of the external pump and the pumping action induced by the rotor 10. As the material traverses through the chamber 35, it undergoes dispersion and exfoliation processes facilitated by the dynamic motion of the rotor 10 and the structured layout / gap pattern of the system. Once the processing is complete, the material exits the chamber 35 through the outlet and is collected in a designated vessel for further processing or usage. To optimize the dispersion and exfoliation outcomes, the material can be recirculated through the dispersion / exfoliation chamber 35 multiple times, ensuring thorough processing and consistent product quality.

[0042] In one embodiment, the input material consists of: a liquid medium, agglomerated and / or unexfoliated particles, and at least one wetting, dispersing, and stabilizing agent.

[0043] The presence of varying gap sizes between the rotor 10 and stator 30 surfaces, coupled with the specific shapes of these surfaces and the critical speed of the rotor 10, creates conditions conducive to the inception of hydrodynamic cavitation. Hydrodynamic cavitation occurs when the fluid undergoes rapid changes in pressure and velocity, leading to the formation of vapor-filled cavities or bubbles. These bubbles subsequently undergo rapid expansion and violent collapse upon reaching regions of higher pressure, resulting in the generation of intense shear forces. The turbulent flow induced by hydrodynamic cavitation exerts high shear forces on the surfaces of the particles present in the slurry 80. These shear forces effectively break down agglomerates, facilitating the dispersion of individual particles or nano-sized particles. Additionally, the violent collapse of cavitation bubbles near the surfaces of the particles further contributes to the disruption of agglomerates, promoting effective dispersion and exfoliation of the material.

[0044] As indicated above, the rotor 10 and stator 30 surface can be of various patterns, including blades 60, pins, or steps 70 (or stepped protrusions 70). For example, the stator 30 surface can contain protruding surfaces angled toward the rotor 10, creating a gap between the rotor 10 and stator 30 surfaces and enhancing the narrow surface area between them, as shown in Figure 2. The rotor 10 can feature protruding surfaces strategically positioned along its length, extending outward from the central shaft 20. These protrusions vary in depth, creating a dynamicsurface profile that enhances the dispersion and exfoliation process. One embodiment of this design is illustrated in Figure 3 with ascending and descending multi-step configurations, showcasing the versatility and adaptability of the geometry of rotor 10 surface. In Figure 3, the rotor 10 has a multiple ascending and descending steps 70 along each blade 60 (creating a multi- step profile) so that the gap height changes in discrete increments as the fluid flows past each blade 60. In another embodiment shown in FIG. 2, the stator 30 inner wall includes angled fins that narrow the gap on one side. These patterns serve to accelerate the fluid, induce secondary flows, and focus energy on the particles.

[0045] The turbulent flow patterns induced by the rotating rotor 10 intensify the mixing and intermingling between the particles and the surrounding medium. This turbulence facilitates aggressive particle collision, enhancing the likelihood of interactions between adjacent particles and between particles and the rotor blades 60. As a result, the shear forces are more effectively transmitted to the particles, leading to the disintegration of agglomerated structures. This process fosters the separation of individual or nano-sized particles from the bulk material, promoting uniform dispersion throughout the slurry 80. Consequently, the combined effects of turbulence and shear forces synergistically contribute to the effective dispersion and exfoliation of the material within the dispersion / exfoliation chamber 35.

[0046] In addition, the narrow gaps ('g' in Figure 1) between the stator 30 and rotor 10 surfaces serve to induce particle milling, thereby further enhancing the dispersion and exfoliation of the particles within the dispersion / exfoliation chamber 35.

[0047] The inlet channel 40 can be connected to a feed hopper or pump that continuously delivers the untreated mixture. The outlet channel 50 can lead to a collection chamber 35. In one embodiment, the system is designed for continuous flow. In one implementation, a centrifugal or gear pump delivers the slurry 80 to inlet 20, and the rotor’s 10 rotation further helps convey the fluid through the gap.

[0048] The Apparatus 100 is capable of processing a variety of materials. The untreated material may include solids that are to be exfoliated or dispersed; for example, it may include layered solids like graphite, graphite oxide, transition metal dichalcogenides, or other platy minerals for2D material production. It may also include nano-powders or bundled nanomaterials that need to be dispersed. The liquid medium may be aqueous or non-aqueous (e.g. organic solvent, resin, or surfactant solution) selected based on the material system.

[0049] Overall, the apparatus 100 of the present invention provides a robust solution for continuous high-shear dispersion and exfoliation.Operation and Advantages

[0050] When operating the apparatus 100, the synergy of mechanical effects leads to high dispersion efficiency. The narrow and varying gap causes fluid velocities and pressures to fluctuate rapidly. As noted, cavitation bubbles form and collapse, producing strong micro-jets and shock waves. This breaks inter-particle bonds. The high shear zones near the rotor 10 surface pull particles apart. Turbulence ensures mixing and repeated collisions. Collectively, these effects transform a poorly dispersed feed into a stable suspension of very fine particles or platelets.

[0051] An advantage of this design is scalability: because the rotor 10-stator 30 assembly can be built in larger diameters and the flow can be continuous, high throughputs can be achieved. Additionally, by adjusting the rotor 10 speed, gap geometry, and number of passes, the process can be tuned for different materials (e.g., softer vs. harder particles) and targeted particle sizes.Methods

[0052] In another embodiment, the present invention is a method of dispersing the nanoparticles within a medium, the method comprising: (a) passing an untreated material through a gap formed between the rotor 10 and the stator 30 surface, (b) the rotating of the rotor 10 while the untreated material passes through the gap, (c) collecting the medium containing the dispersed nanoparticles.

[0053] In another embodiment, the present invention is a method of synthesizing 2D materials in the form of platelets through the exfoliation of larger particles within a medium, the method comprising:(a) passing an untreated material through a gap formed between the rotor 10 and the stator 30 surface, (b) the rotating of the rotor 10 while the untreated material passes through the gap, (c) collecting the medium containing the 2D materials.Method of Dispersing Nanoparticles

[0054] In one embodiment, the present invention provides a method for dispersing nanoparticles within a medium using the above Apparatus 100. As illustrated in one embodiment, the method comprises:

[0055] Feeding untreated material: An untreated material (e.g. a slurry containing agglomerated particles) is introduced into the apparatus 100 through the inlet, so that it enters the narrow gap between rotor 10 and stator 30.

[0056] Rotating the rotor 10: The rotor 10 is rotated at high speed while the material passes through the gap. The rotation induces cavitation, high shear forces, and turbulent flow within the gap as described above.

[0057] Collecting dispersed medium: The medium, now containing dispersed nanoparticles (and any exfoliated platelets), exits through the outlet channel 50 and is collected.

[0058] By this method, particle agglomerates are continuously broken apart and dispersed. In some implementations, the fluid may be recirculated through the Apparatus 100 for multiple cycles (including via a continuous single-pass operation, until a desired dispersion quality (e.g., particle size distribution or homogeneity) is achieved. Rotor 10 speed, flow rate, and processing time can be adjusted according to the material and desired outcome.Method of Exfoliating Layered Materials

[0059] Similarly, in one embodiment, the invention encompasses a method of synthesizing two- dimensional platelets by exfoliating larger layered particles in a medium. The steps 70 are essentially the same as the dispersion method, with the exception that the feedstock is specifically a layered material. For example, to produce graphene platelets, the untreated material may consist of graphite flakes suspended in a liquid. The material is passed through therotor 10-stator 30 gap while the rotor 10 spins, applying intense shear and impact. This shearing action cleaves the layered crystal structure of graphite, yielding thin graphene platelets. The method includes collecting the liquid containing the exfoliated platelets.

[0060] This method can be applied to other layered solids (e.g. hexagonal boron nitride, M0S2, etc.) to produce their respective 2D platelets. Optionally, chemical additives or pre-treatments can be used to facilitate exfoliation.Composition of Dispersed Material

[0061] In another embodiment, the present invention is a composition, substance, dispersion, or compound produced by an Apparatus 100 according to an Apparatus 100 of the present invention.

[0062] In one embodiment of the present invention, the composition, substance, dispersion or compound is a 2D materials in the form of platelets and / or sheets suspended in a liquid medium.

[0063] In various embodiments, the 2D materials may include, but are not limited to, Graphene, Hexagonal Boron Nitride (2D-hBN), Transition Metal Dichalcogenides (TMDCs), Trichalcogenides (TMTCs), MXenes, and Phosphorene.

[0064] In another embodiment of the present invention, the composition, substance, dispersion or compound is a homogenous blend of particles suspended in a liquid.

[0065] In various embodiments, the nano particles may include, but are not limited to, multiwalled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), Carbon Nanostructures (CNS), Carbon black nanoparticles, Branched carbon nanotubes, functionalized carbon nanotubes, Carbon nanotubes treated by various processes, Silver nanoparticles, Titanium Dioxide (TiO2) nanoparticles, Barium Titanate (BaTiO3) nanoparticles, and Silica nanoparticles.

[0066] For example, an embodiment provides a dispersion comprising two-dimensional materials in platelet form and / or nanoparticles, suspended in a liquid medium. Suitable 2Dmaterials include, but are not limited to, graphene, hexagonal boron nitride (h-BN), transition metal di chalcogenides (e.g., M0S2, WS2), transition metal tri chalcogenides, MXenes, and phosphorene. The particles (nano- or micro-) may include carbon nanotubes, nanopowders (e.g., TiCh, SiC>2, etc.), or other functional nanoparticles.

[0067] The resulting composition(s) can be used directly or incorporated into formulations (e.g., polymer composites, inks, coatings). Because the Apparatus 100 can produce high- concentration dispersions, the compositions may serve as masterbatches or premixes that can be diluted as needed.Examples

[0068] Example 1: 4 wt.% LGBT1001M Multi-walled CNT (MWCNT) pellets, as received, were dispersed in water using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 4000 rpm, and the processing time was 8 hours. This process yielded a homogeneous nanoparticle dispersion, with D90 less than 1 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over one year.

[0069] Example 2: 4 wt.% LG^ BT1001M MWCNT pellets, as received, were dispersed in N- Methyl-2-pyrrolidone (NMP) using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 4000 rpm, and the processing time was 12 hours. This process yielded a homogeneous nanoparticle dispersion, with D90 less than 1 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over six months.

[0070] Example 3: 2 wt.% ATHLOS™ carbon nano structures (CNS) pellets, as received from CABOT □ Corporation, were dispersed in water using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 4000 rpm, and the processing time was 8 hours. Thisprocess yielded a homogeneous nanoparticle dispersion, with D90 less than 1 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over one year.

[0071] Example 4: 2.5 wt.% ATHLOS™ CNS pellets, as received from CABOT^ Corporation, were dispersed in N-Methyl-2-pyrrolidone (NMP) using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 6000 rpm, and the processing time was 8 hours. This process yielded a homogeneous nanoparticle dispersion, with D90 less than 1 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over six months.

[0072] Example 5: 6 wt.% Cnano FT6120 MWCNT powder, as received from Jiangsu Cnano Technology Co. Ltd, were dispersed in water using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 4000 rpm, and the processing time was 8 hours. This process yielded a homogeneous nanoparticle dispersion, with D90 less than 1 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over one year.

[0073] Example 6: 3 wt.% TUBALL™ single-walled CNT (SWCNT) powder, as received from OCSiAl^, were dispersed in water using one embodiment of this invention. Polyvinylpyrrolidone (PVP) was used as a dispersing, stabilizing, and wetting additive in the formulation. The rotor rotated at a speed of 6000 rpm, and the processing time was 20 hours. This process yielded a homogeneous nanoparticle dispersion, with D90 less than 3 pm, as indicated by particle analysis data. The dispersion was stored to assess the stability of the system, and it was determined that the dispersion remained stable for over six months.

[0074] The scope of this disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that a person having ordinary skill in the art would comprehend. The scope of this disclosure is not limited to the example embodiments described or illustrated herein. Moreover, although thisdisclosure describes and illustrates respective embodiments herein as including particular components, elements, functions, operations, or steps, any of these embodiments may include any modification, combination or permutation of any of the components, elements, functions, operations, or steps described or illustrated anywhere herein that a person having ordinary skill in the art would comprehend. All such modifications, combinations and permutations are believed to be within the sphere and scope of the invention as defined by the claims appended hereto.

Claims

CLAIMSWhat is claimed is:

1. An apparatus for continuous dispersion of nano-particles and synthesizing two- dimensional materials in the form of platelets through the exfoliation of larger particles within a medium, the apparatus comprising: a. a rotor b. a stator c. a gap formed between the rotor and stator surface, with the gap distance varying along the rotor from the inlet side to the outlet side, d. at least one input channel into the system, to feed the system with the untreated material, and e. an outlet channel from the system to remove the treated particles from the system, wherein the rotor and stator are configured to disperse the nano-particles and exfoliated the two-dimensional material using forces of cavitation, high shear, and impacting forces.

2. The apparatus of claim 1, wherein the apparatus further comprises a container for receiving the dispersed nano-particles or exfoliated two-dimensional materials from the system.

3. The apparatus of claim 1, wherein the apparatus further comprises a driving means linked to the rotor for rotating the rotor in the predetermined direction.

4. The apparatus of claim 1, wherein the stator surface comprises a plurality of protrusions angled toward the rotor, creating a gap between the rotor and stator surfaces and enhancing the narrow surface area between them.

5. The apparatus of claim 1, wherein the rotor surface comprises a plurality of protrusions along its length, the plurality of protrusions extending outwardly from a central shaft, strategically positioned along its length.

6. A method of dispersing nanoparticles in a liquid medium, comprising: a. feeding an untreated particle-laden medium into a gap between a rotor and a stator; b. rotating the rotor at high speed while the medium passes through the gap; and c. collecting the medium from an outlet channel, the collected medium containing dispersed nanoparticles; wherein the rotation of the rotor generates cavitation and high shear forces in the medium, thereby disrupting particle agglomerates and dispersing the particles.

7. The method of claim 6, wherein the rotor is rotated at a speed greater than 1,000 revolutions per minute.

8. The method of claim 6, further comprising recirculating the medium through the gap multiple times until a desired degree of dispersion is achieved.

9. The method of claim 6, wherein the untreated medium comprises agglomerated particles selected from carbon nanotubes, graphene, graphite, and boron nitride.

10. A method of synthesizing two-dimensional platelets by exfoliation of larger particles in a liquid medium, comprising: d. passing an untreated particle-laden medium including layered bulk particles through a gap between a rotor and a stator; e. rotating the rotor at high speed while the medium passes through the gap; and f. collecting the medium from an outlet, the collected medium containingexfoliated two-dimensional platelets; wherein the rotation of the rotor induces cavitation and shear forces that cleave the layered particles into platelets.

11. The method of claim 10, wherein the layered particles comprise graphite, hexagonal boron nitride, or transition metal dichalcogenides.

12. The method of claim 10, wherein the collected medium contains two-dimensional platelets with lateral dimensions in the nanometer to sub-micrometer scale.

13. A continuous-flow apparatus for dispersing nanoparticles and exfoliating larger particles into two-dimensional platelets within a liquid medium, comprising: a. a rotor comprising a plurality of machined grooves or protruding elements of varying depths on its outer surface; b. a stator surrounding the rotor and defining a gap between the rotor’s outer surface and the stator’s inner surface; c. at least one inlet channel configured to introduce an untreated particle-laden medium into the gap; and d. at least one outlet channel configured to remove the treated medium from the gap; wherein the rotor is rotatable relative to the stator so as to induce cavitation and generate high shear and impact forces in the medium as it flows through the gap, thereby breaking apart particle agglomerates and exfoliating larger particles into nanoparticles and platelet-shaped 2D materials.

14. The apparatus of claim 13, wherein the rotor comprises a plurality of radially-extending blades, each blade having a stepped profile of varying height along its length.

15. The apparatus of claim 13, wherein the stator’s inner surface comprises a plurality of angularly spaced protruding fins or surfaces angled toward the rotor, forming alternating narrow and wide regions in the gap.

16. The apparatus of claim 13, further comprising a motor coupled to the rotor to drive rotation of the rotor at high speed.

17. The apparatus of claim 13, wherein the inlet channel is connected to a pump configured to circulate the medium through the gap.

18. The apparatus of claim 13, wherein the untreated particle-laden medium comprises a slurry of agglomerated nanoparticles selected from carbon nanotubes, graphene, graphite, boron nitride, and combinations thereof.

19. The apparatus of claim 13, wherein the liquid medium is selected from water, an organic solvent, or a polymerizable resin.

20. The apparatus of claim 13, wherein the rotor is rotatable at a speed greater than 1,000 revolutions per minute.

21. The apparatus of claim 13, wherein the outlet channel leads to a collection vessel configured to receive the dispersed particles and platelets.

22. A composition comprising a liquid medium and dispersed particles, wherein the particles include nanoparticles and two-dimensional platelets, and wherein the composition is produced by processing an untreated particle-laden medium through the apparatus of claim 1.

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