Systems and methods for synthesizing graphene-like nanomaterials using atmospheric brown's gas plasma

Abstract

Described herein are systems and methods for synthesizing graphene and graphene-like nanomaterials through plasma interaction with carbon-containing materials, including waste materials, such as recyclable byproducts from used tires (e.g., carbon black and plastic waste). An apparatus for producing graphene-like material comprises a plasma torch generated from Brown's gas and uses a process gas containing a carbon-based species subjected to ultra-high temperatures to induce thermal exfoliation. The exfoliated material undergoes ultra-rapid cooling in a liquid medium, facilitating further exfoliation and preventing reaggregation. The apparatus operates as a single-step, chemical-free system without the need for intercalates, solvents, or catalysts, and is designed to function at atmospheric pressure in oxidizing or non-oxidizing inert media. The system enables high-yield, scalable production of graphene and other nanomaterials, while being cost-effective and environmentally sustainable.

Description

Docket BU0126PCT SYSTEMS AND METHODS FOR SYNTHESIZING GRAPHENE-LIKE NANOMATERIALS USING ATMOSPHERIC BROWN’S GAS PLASMAINVENTORS:Valery SerbezovJason NaydenovSvetlin SerbezovJordan NaydenovKrassimir PetkovNikola ZlatanovCROSS REFERENCE TO RELATED PATENT APPLICATIONS

[0001] The present application claims priority benefit to co-pending and commonly-assigned U.S. Provisional Patent Application No. 63 / 746,870 and U.S. Provisional Patent Application No. 63 / 746,873, both filed on January 17, 2025 and listing as inventors Valery Serbezov, Jason Naydenov, Svetlin Serbezov, Jordan Naydenov, Krassimir Petkov, and Nikola Zlatanov, which application is herein incorporated by reference as to its entire content. Each reference mentioned herein is incorporated by reference herein in its entirety.A. Technical Field

[0002] The present disclosure relates generally to nanotechnology and carbon nanomaterials. More particularly, the present disclosure relates to systems and methods for large-scale production of graphene-like materials by using a plasma-based process that employs plasma from Brown’s gas (HHO) to transform carbon-containing materials including waste, such as plastic waste, into graphene nanomaterials, graphene oxide, and reduced graphene oxide for applications in energy storage, electronics, sensors, composite materials, industrial processes, thermal management, and biomedical technologies.B. Background

[0003] Graphene is widely recognized as a revolutionary nanomaterial due to its exceptional properties, which significantly differ from bulk materials. However, the growing demand for graphene also presents environmental and health risks, primarily due to conventional synthesis methods, the raw materials used, and their associated impacts. To mitigate these risks, clean, sustainable production technologies that utilize waste-derived carbon sources must be developed. Graphene and its derivatives, such as graphene oxideDocket BU0126PCT (GO) and reduced graphene oxide (rGO), are typically synthesized using top-down or bottom-up approaches. The top-down method, which involves graphite exfoliation, is the most common for large-scale production. However, it is expensive, relies on a limited supply of high-purity graphite, and requires multi-step, energy-intensive processes involving harsh chemicals like solvents and oxidants. These factors result in low yields, batch-to-batch variability, and high production costs. Conversely, the bottom-up approach utilizes carbonaceous precursors to synthesize graphene through methods such as Chemical Vapor Deposition (CVD), pyrolysis, epitaxial growth, and laser-induced graphene (LIG). While promising, these techniques consume high energy, are costly, and often yield non-uniform graphene sheets, limiting their scalability.

[0004] To address these challenges, recent research has focused on alternative, low-cost, and environmentally friendly sources for graphene nanomaterial synthesis, such as plastic waste, used tires, biomass (coconut husks, pine bark, sugarcane bagasse), and carbon-rich gases (methane, ethanol, and methanol). Given that plastic waste and used tires are among the most significant global pollutants, their conversion into graphene could provide a sustainable, circular economy solution. According to the United Nations, plastic production exceeded 400 million tons in 2020, is expected to double by 2035, and may reach 1.6 billion tons by 2050, underscoring the urgent need for sustainable waste management.

[0005] Among the most promising methods for graphene nanomaterial synthesis from renewable waste materials are pyrolysis-based techniques and Flash Joule Heating (FJH). Other techniques, such as CVD, pyrolysis with carbonization, and thermal decomposition, are also being explored. However, these methods often suffer from multi-step complexity, the use of toxic chemicals, inconsistent graphene quality, and high energy requirements.

[0006] Plasma-based methods have long been used in nanotechnology, nanoparticle synthesis, coatings, fullerenes, and carbon nanotubes (CNTs). While plasma-based graphene nanomaterial synthesis is promising, existing methods suffer from relatively low yield, high energy consumption, electrode wear, and process variability. Although FJH is a type of plasma process, its reliance on arc discharge with conductive additives and strict energy input parameters makes large-scale graphene production challenging. Recent advancements in Atmospheric Pressure Microwave Plasma (APMP) have shown potential for converting micro- sized plastic waste into graphene nanomaterials by breaking it down into hydrocarbon gases (methane, ethylene, hydrogen, etc.), which are then plasma-dissociated into graphene. However, such processed still suffer from low yield, high energy consumption, andDocket BU0126PCT inconsistent product quality. Current industrial-scale plasma graphene synthesis methods share common limitations, such as material- specific process adaptations, inconsistent graphene quality, low production yields, high energy demand, and environmental concerns.

[0007] Accordingly, what is needed are systems and methods that overcome the limitations of existing methods and devices.SUMMARY OF INVENTION

[0008] The systems and methods herein relate to the synthesis of graphene and graphene-like nanomaterials using a Brown’s gas plasma torch, which enables the conversion of carbon-containing materials, including carbon black from used tires, plastic waste, pulp, and paper, into high-quality graphene nanomaterials, GO, and rGO. In embodiments, industrial-scale graphene production is achieved through a single-step, ultra-fast process that eliminates the need for externally added chemicals, intercalates, solvents, or catalysts, including metals. Unlike conventional methods that rely on costly and limited graphite sources, embodiments herein utilize post-consumer and recycled carbon materials.

[0009] Various embodiments operate within a temperature range of approximately 350 °C to 3500 °C in either ambient or inert atmosphere, such as argon or nitrogen, taking advantage of the unique properties of HHO plasma, which allows for adaptive interaction with different carbon-containing materials. The HHO plasma torch automatically adjusts its temperature and ionic composition according to the material being processed, eliminating the need for technical adaptations or reconstruction of the device. The resulting graphene yield is dependent on the carbon content of the process material, with high-carbon sources, such as graphite and carbon black with a purity exceeding 99%, producing yields ranging from 85% to 95%. Compared to conventional techniques, such as CVD, Thermal Decomposition with CVD, pyrolysis with carbonization, and FJH, the superior yields and efficiency is achieved, while significantly reducing processing times.

[0010] The method addresses key challenges in nanomaterial production, including selectivity towards specific chemical compounds, morphology control, and scalability for industrial applications. Conventional top-down plasma torch methods require multiple processing steps involving high temperatures, catalytic agents, and controlled vacuum or inert gas environments. In contrast, the present disclosure integrates a programmable control mechanism utilizing a material- specific interaction grid within the reaction chamber. The grid material can be preselected based on its thermal and chemical properties, enabling controlled absorption of plasma energy and precise temperature regulation. This results in efficientDocket BU0126PCT shock heating, thermal expansion, and exfoliation of graphene layers, followed by rapid cooling to prevent clustering or unwanted structural changes. The method may be further enhanced by an optional ultrasonic treatment that improves exfoliation and dispersion of the synthesized nanomaterials.

[0011] The disclosed method and device are inherently scalable and adaptable. The single plasma torch or nozzle can be expanded by scanning across several planes or converted into a burner coupled with a reaction chamber, which can be cylindrical or conical for rapid adiabatic cooling and allows the process to be carried out at atmospheric pressure in an oxidizing or non-oxidizing inert medium. The chamber may be cooled or heated as required, and additional gases, including inert and reactive gas mixtures, may be introduced to optimize reaction conditions. The exfoliated graphene material may be directed by gravity and gas flow into a collection vessel, which may also be cooled or heated to further refine the process.

[0012] A key advantage is that carbon does not need to be electrically conductive, expanding the range of usable precursor materials. Additionally, the processes are highly efficient in utilizing cracked material species that pass through the reaction chamber, followed by ultra-rapid cooling directly in a liquid medium. The cooling liquid may include distilled water, liquid nitrogen, or solid-phase materials such as dry ice. The synthesis process benefits from cavitation and ultrasonic action within the collection vessel, further enhancing material separation and exfoliation.

[0013] The ultra-fast nature of such methods enables processing times ranging from several tens of seconds to a few minutes, depending on the input material. The duration of plasma interaction may be controlled by the flow rate of the carrier gas and the pressure of the HHO flame-forming gas, ensuring precision and consistency in the final product. The process can be operated in a continuous or pulsed mode, allowing for further optimization based on specific application requirements.

[0014] The methods and devices herein enable the synthesis of a broad range of graphene-based materials, including graphene oxide, reduced graphene oxide, porous graphene, and other nanoscale carbon phases and nanocomposites. Unlike classical chemical synthesis of graphene oxide, which involves multiple steps and the use of strong oxidizing agents such as potassium chlorate, nitric acid, and sulfuric acid, various embodiments eliminate hazardous chemicals in an environmentally safe and scalable manner. Additionally, various methods may be used for the synthesis of functionalized graphene nanomaterials viaDocket BU0126PCT both covalent and non-covalent modifications, incorporating elements such as oxygen, metals, sulfur, phosphorus, and polymers to tailor graphene’s properties for specific applications.

[0015] The resulting graphene HHO material comprises predominantly of sp2-hybridized carbon atoms and exhibits a high degree of structural purity, with at least 85% of the product comprising single-layer or few-layer graphene sheets of 2 to 10 stacked planes. The disclosed methods and devices also facilitate the formation of hybrid nanomaterials, such as metal-ceramic nanoparticles and polymer-carbon composites, enabling new functionalities across various industries.

[0016] Potential applications include energy storage systems, including batteries and supercapacitors, as well as electronics, sensors, robotics, composite materials, coatings, and biomedical applications. The unique properties of graphene, such as high electrical and thermal conductivity, mechanical strength, and chemical resistance, make it an ideal candidate for water desalination, thermoelectric devices, ultra-sensitive biosensors, bacterial and viral filtration, and even graphene-enhanced bone regeneration. Additionally, graphene’s use in lightweight, high-strength composite materials is of significant interest to the automotive and aerospace industries. This offers a clean, scalable, and cost-effective alternative to conventional graphene production methods while providing superior product quality and yield. By transforming waste materials into valuable nanomaterials, this technology contributes to sustainable manufacturing practices.

[0017] In some aspects of the disclosure, an apparatus for producing graphene-like material by using brown’s gas plasma may comprise one or more inlets configured to receive brown’s gas and a carbon-containing substance; a process chamber may comprise: one or more nozzles configured to direct the brown’s gas within the process chamber; electrodes configured to use electrical power to generate a plasma that, when interacting with the carbon-containing substance, causes thermal expansion that converts at least some of the carbon-containing substance into atomic-level material; a grid may comprise openings configured to control a flow of the brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing an exfoliation efficiency; a cooling chamber configured to use a cooling medium that enables a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene-like material may comprise atomic layers; a collection tank configured to receive the graphene-like material and enable a cooling andDocket BU0126PCT precipitation process to prevent reaggregation; and a filter configured to recover solid-phase graphene-like material from the collection tank.

[0018] In some aspects, the apparatus may further comprise an ultrasonic chamber configured to enhance a liquid-phase exfoliation by generating cavitation effects during a liquid shock cooling process. The brown’s gas may be provided substantially at atmospheric pressure, and where the graphene-like material may be graphene-like nanoscale carbon material. The plasma may be ignited at a first pressure and maintained at a second pressure. The cooling medium may comprise a liquid. The liquid may comprise distilled water.

[0019] In some aspects, the brown’s gas may be directed into the process chamber at an angle different from a flow direction of the carbon-containing substance. The openings generate vortices when exposed to the plasma to enhance an exfoliation and stabilize a plasma-material interaction.

[0020] In some aspects of the disclosure, a method for producing graphene-like material by using brown’s gas plasma may comprise applying a brown’s gas plasma to a carbon-containing substance to cause a thermal expansion that converts at least some of the carbon-containing substance into atomic-level material; regulating a plasma-material interaction by directing a flow of brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing exfoliation efficiency; using a cooling medium in a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene-like material may comprise atomic layers; using a cooling and precipitation process to prevent reaggregation; and using a solid-liquid separation process to recover solid-phase graphene-like material from the cooling medium.

[0021] In some aspects, the method may further comprise applying ultrasonic energy to the cooling medium to cause cavitation effects in the solid-phase graphene-like material that enhance liquid-phase exfoliation of the carbon-containing substance. The brown’s gas may be provided at substantially atmospheric pressure and may be directed into a process chamber at an angle different from a flow direction of the carbon-containing substance. The vortices enhance the plasma exposure.

[0022] In some aspects of the disclosure, a system for producing graphene-like material by using brown’s gas plasma may comprise an apparatus configured to produce graphene-like material. The apparatus may comprise: one or more inlets configured to receive brown’s gas and a carbon-containing substance; a process chamber may comprise: one or more nozzles configured to direct the brown’s gas within the process chamber that may comprise an outletDocket BU0126PCT configured to remove process gas; electrodes configured to use electrical power to ignite and generate a plasma that, when interacting with the carbon-containing substance, causes thermal expansion that converts at least some of the carbon-containing substance into atomic-level material; a grid may comprise openings configured to control a flow of the brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing an exfoliation efficiency; a cooling chamber configured to use a cooling medium that enables a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene-like material may comprise atomic layers; a collection tank configured to receive the graphene-like material and enable a cooling and precipitation process to prevent reaggregation; a filter configured to recover solid-phase graphene-like material from the collection tank. The system also may further comprise a power source configured to generate the electrical power; and one or more flow controllers configured to control an input flow of the brown’s gas and an input flow of the carbon-containing substance.

[0023] In some aspects, the system may further comprise an ultrasonic chamber configured to enhance a liquid-phase exfoliation by generating cavitation effects during a liquid shock cooling process.Docket BU0126PCT BRIEF DESCRIPTION OF THE DRAWINGS

[0024] References will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments. Items in the figures are not to scale.

[0025] FIG. 1 is a schematic representation of an HHO-based process for synthesizing graphene and graphene-like materials in an atmospheric environment, according to various embodiments of the present disclosure.

[0026] FIG. 2A - FIG. 2C depict SEM micrographs of the precursor material Carbon Black (CB) obtained, derived from the pyrolysis of waste tires, according to various embodiments of the present disclosure.

[0027] FIG. 3A - FIG. 3C depict SEM micrographs of reduced graphene oxide HHO-G1 (rGO-Gl HHO) synthesized from CB using the HHO-based process illustrated in FIG. 1.

[0028] FIG. 4A - FIG. 4C depict SEM micrographs of reduced graphene oxide HHO-G2 (rGO G2 HHO) synthesized from CB using the HHO-based process illustrated in FIG. 1.

[0029] FIG. 5A depicts Raman shift of the precursor material CB, according to various embodiments of the present disclosure.

[0030] FIG. 5B depicts Raman shift of rGO-Gl synthesized from CB using the HHO plasma process in FIG. 1, at temperature of 2700 °C, according to various embodiments of the present disclosure.

[0031] FIG. 5C depicts Raman shift of rGO-G2 HHO synthesized from CB using the HHO plasma process in FIG. 1, at temperature of 3200 °C, according to various embodiments of the present disclosure.

[0032] FIG. 6A depicts XRD patterns of CB and the corresponding diffraction pattern of rGO-Gl HHO, synthesized via the HHO plasma process in FIG. 1, at temperature of 2700 °C, according to various embodiments of the present disclosure.

[0033] FIG. 6B depicts XRD patterns comparing CB and rGO-G2 HHO, synthesized using the process in FIG. 1, at a temperature of 3200 °C, according to various embodiments of the present disclosure.

[0034] FIG. 7 is a flowchart of an exemplary process for producing graphene-like material by using Brown’s gas plasma, according to various embodiments of the present disclosure.Docket BU0126PCT DETAILED DESCRIPTION OF EMBODIMENTS

[0035] In the following description, for purposes of explanation, specific details are set forth in order to provide an understanding of the disclosure. It will be apparent, however, to one skilled in the art that the disclosure can be practiced without these details. Furthermore, one skilled in the art will recognize that embodiments of the present disclosure, described below, may be implemented in a variety of ways, such as a process, an apparatus, a system / device, or a method on a tangible computer-readable medium.

[0036] Components, or modules, shown in diagrams are illustrative of exemplary embodiments of the disclosure and are meant to avoid obscuring the disclosure. It shall be understood that throughout this discussion components may be described as separate functional units, which may comprise sub-units, but those skilled in the art will recognize that various components, or portions thereof, may be divided into separate components or may be integrated, including, for example, being in a single system or component. It should be noted that functions or operations discussed herein may be implemented as components. Components may be implemented in software, hardware, or a combination thereof.

[0037] Furthermore, connections between components or systems within the figures are not intended to be limited to direct connections. Rather, data between these components may be modified, re-formatted, or otherwise changed by intermediary components. Also, additional or fewer connections may be used. It shall also be noted that the terms “coupled,” “connected,” “communicatively coupled,” “interfacing,” “interface,” or any of their derivatives shall be understood to include direct connections, indirect connections through one or more intermediary devices, and wireless connections. It shall also be noted that any communication, such as a signal, response, reply, acknowledgment, message, query, etc., may comprise one or more exchanges of information.

[0038] Reference in the specification to “one or more embodiments,” “preferred embodiment,” “an embodiment,” “embodiments,” or the like means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the disclosure and may be in more than one embodiment. Also, the appearances of the above-noted phrases in various places in the specification do not necessarily all refer to the same embodiment or embodiments.

[0039] The use of certain terms in various places in the specification is for illustration and should not be construed as limiting. The terms “include,” “including,” “comprise,” “comprising,” and any of their variants shall be understood to be open terms, and anyDocket BU0126PCT examples or lists of items are provided by way of illustration and shall not be used to limit the scope of this disclosure.

[0040] Any headings used herein are for organizational purposes only and shall not be used to limit the scope of the description or the claims. Each reference / document mentioned in this patent document is incorporated by reference herein in its entirety.

[0041] The present disclosure describes an industrial-scale process for synthesizing high-quality graphene and graphene-like nanosheets through the interaction of a Brown gas (HHO) plasma torch with carbon-containing materials. The synthesis process may occur in three distinct stages: 1) thermal decomposition of a carbon-containing substance within a reaction vessel, 2) rapid cooling of the dissociated material, leading to the nucleation of graphene structures, and 3) the controlled growth of these nuclei into few-layer graphene and graphene-like nanosheets.

[0042] As used herein, the term “carbon-containing substance” refers to any carbon-containing compound or substance composed primarily of carbon. The terms “plasma,” “HHO plasma torch,” and “plasma burner” may be used interchangeably to describe the high-energy ionized gas system that facilitates the synthesis process. The term “thermal zone” refers to the region where the plasma achieves a near or complete thermodynamic equilibrium.

[0043] The terms “graphene-like nanomaterials” and “graphene nanosheets” refer to crumpled graphene nanosheets having one or more layers of sp2-bonded carbon atoms arranged in a honeycomb lattice. Stacked nanosheets exhibiting curled, curved, or buckled morphologies result in a 3D structure. Depending on their specific characteristics, the synthesized materials may be referred to as “graphene nanoplatelets,” “graphene nanoflakes,” “few-layers graphene,” or simply “graphene.”

[0044] A fundamental principle in nanomaterial synthesis is the rapid introduction of energy into the system, followed by immediate cooling to prevent reaggregation. Systems and methods disclosed herein utilize a high-energy plasma generated from Brown’s gas, which is produced via water electrolysis. The Brown’s gas plasma interacts with carbon-based waste materials, such as charcoal, carbon black from used tires, and plastic waste, thus resulting in graphene formation through high-temperature exfoliation, followed by rapid thermal contraction.

[0045] Brown’s gas, named after researcher Yuli Brown, is generated by electrolysis, splitting water into hydrogen and oxygen. Unlike conventional fuels, Brown’s gas plasma hasDocket BU0126PCT unique properties, including high ionization, electrical conductivity, and the ability to sustain combustion even in vacuum and underwater. It has a high energy density (-15,000 J / L), comparable to laser-material interaction; can reach temperatures of up to 4000 °C. Additionally, Brown’s gas is implosive in nature, producing only water vapor as a byproduct, which makes it an environmentally safe and non-polluting energy source.

[0046] The Brown’s gas plasma torch adapts to different carbon-containing materials, enabling effectively exfoliation of graphene layers from waste materials without requiring complex process adjustments. Additionally, this eliminates the need for harsh chemicals and catalysts, reduces batch-to-batch inconsistencies, and significantly lowers overall energy consumption, facilitating a single-step, high-yield graphene production process.

[0047] It shall be noted that while embodiments described herein are framed in the context of atmospheric environments, one skilled in the art will recognize that the concepts of the present disclosure are not so limited and may equally be used under superatmospheric, underpressure, or vacuum-controlled process conditions.

[0048] FIG. 1 is a schematic representation of a device and method for synthesizing graphene and graphene-like materials using a plasma process operating in an atmospheric environment, according to various embodiments of the present disclosure. In embodiments, a plasma is generated by an HHO generator that utilizes Brown’s gas 1. Device 100 comprises one or more inlets (e.g., inlet 16) for process gas 3 and to-be-processed material 2, which may be any suitable carbon-containing substance; process chamber 4; electrodes 5; nozzle 6; plasma 7; grid 8; thermocouple 9; exhaust outlet 10; plasma-induced exfoliation zone 11; cooling chamber 12; cooling medium 13; sonication device 14; storage tank 15; and inlet 16.

[0049] In embodiments, carbon-containing material 2 may be injected into process chamber 4 simultaneously with Brown’s gas 1, e.g., in the same direction. Material 2 may be injected in various forms, e.g., as a solid, gas, liquid, gas mixture or any combination thereof. Brown’s gas 1 may be mixed with any suitable process gas 3 such as argon, nitrogen, helium, hydrogen, oxygen, alcohols, hydrocarbons, carbon-containing gases, or corresponding mixtures thereof. An exemplary working gas pressure is 1 atm to 4-5 atm, with an exemplary velocity range of 1 m / s to 30 m / s.

[0050] In embodiments, plasma torch (or burner) 7 within Brown’s gas generator 100 may be ignited between two or more electrodes 5, which may comprise cathodes and anodes made of conductive material, such as copper, tungsten, or other suitable metals. Plasma ignition and generation may utilize direct current, alternating current, radio-frequency, or aDocket BU0126PCT directed flame, e.g., at flame temperatures ranging from 50 °C to 80 °C or higher. A gas discharge may be initiated through a dielectric, such as a dielectric wall (not shown), utilizing inductive and / or capacitive coupling mechanisms. A suitable power source (also not shown) may operate in continuous or pulsed mode, e.g., at one or more frequencies.

[0051] Flow rates of Brown’s gas 1, process gas 3, and process material 2 may be adjusted as needed. The gas discharge environment within process chamber 4 may be atmospheric, superatmospheric, underpressure, or vacuum-controlled. Process chamber 4 may be constructed in in various geometries, including cylindrical or conical shapes, e.g., to aid adiabatic cooling and optimize thermal expansion of process material 2 as it passes through plasma grid 8.

[0052] Plasma 7 may be ignited once Brown’s gas 1 exits nozzle 6. It is noted that while in FIG. 1 the directions of plasma torch 7 is depicted as aligned with the movement of process material 2, this is not intended as a limitation on the scope of the present disclosure as alternative configurations, including angled or multi-directional orientations of torch 7 are envisioned.

[0053] In embodiments, grid 8 comprises any number of openings ranging from several hundred micrometers to several millimeters in size, constructed from material suitable for high-temperature materials. Grid 8 may be fabricated from metals, alloys, dielectrics, ceramics, semiconductors, or graphite-based materials that, capable of withstanding temperatures from about 200 °C to 3500 °C without significant degradation.

[0054] As shown in FIG. 1 , grid 8 may be located in process chamber 4 in proximity to plasma torch 7 to facilitate control and pre-selection of process temperatures for plasmainteraction with process material 2. In embodiments, the temperature of grid 8 may be adjustable to optimize exfoliation of different carbon-containing substances 2. Grid 8 facilitates the passage of process material 2 through its perforations while creating vortices that may aid in improving thermal homogenization of the processed material and enhance exfoliation. As depicted in the example in FIG. 1 , the temperature of grid 8 may be measured by thermocouple 9.

[0055] In embodiments, process gas exiting process chamber 4 is vented through exhaust generated gas outlet 10. During operation, process material 2 undergoes rapid heating by impact with plasma 7 in plasma-induced exfoliation zone 11 causing exfoliation of process material 2 due to thermal expansion. In embodiments, additional thermal interactionDocket BU0126PCT with the heated surfaces of grid 8 leads to further heating of processing material 2, thermal expansion, and structural exfoliation of the atomic lattice.

[0056] In embodiments, openings in grid 8 create vortices that further enhance plasmamaterial interactions, increasing exfoliation of layered bulk material and are highly favorable for dimension reduction of process materials particles, and partial vaporization of micro-sized particles.

[0057] In embodiments, subsequent rapid thermal contraction is performed using liquid shock cooling of processed material in cooling chamber 12, which may be constructed as part of processing chamber 4 to use cooling medium 13, to carry out additional exfoliation and stabilization graphene-like material comprising atomic layers. Cooling medium 13 may be any suitable cooling liquid (e.g., distilled water), cooling gas, or other cooling substances.

[0058] In embodiments, exfoliated carbon material within cooling medium 13 may be subjected to additional processing techniques, such as mechanical agitation, sonication, or cavitation methods, to further separate graphene-like layers and prevent reaggregation. In the example in FIG. 1, cooling chamber 12 is located within sonication device 14 enabling liquid-phase exfoliation. In embodiments, sonication device 14 contributes to an efficient, fine, and thorough dispersion, by means of cavitation exfoliation of the processed material.

[0059] Sonication methods, such as treatment in distillated water, enable the synthesis of high-yield nanomaterials in an environmentally safe manner, eliminating the need for hazardous chemicals. In applications where sonication device 14 is implemented as an ultrasonic device, it may operate at a frequency range from several tens of kilohertz to several megahertz, e.g., from 15 kHz to 1.5 MHz, at any desired power level. The sonication duration may be adjusted in accordance with other parameters of device 14, such as power, frequency, viscosity, and temperature.

[0060] Once exfoliated, the graphene-like nanomaterial enters tank 15, where it is allowed to settle, e.g., at ambient temperature for about 15-30 minutes allowing micro-sized graphite to precipitate. The resulting aqueous suspension may be separated into distinct phases through a decantation process. A first purification step may involve filtration using fine-mesh filters (e.g., filter paper) to remove coarse micro-sized particulates. The precipitate mainly comprises micro-sized graphite material and liquid-phase graphene-like nanosized material, including graphene sheets, GO, and rGO.

[0061] Further purification may be achieved by controlled evaporation of residual water from the aqueous suspension at temperatures around 40 °C to 60 °C to yield solid-phaseDocket BU0126PCT material, which represents the synthesized graphene-like nanomaterials. In embodiments, subsequent processing steps, such as centrifugation, may be applied to further separate nanomaterials and enhance their quality.

[0062] EXAMPLES

[0063] High-quality graphene typically comprise 10 or fewer atomic layers, with particle thicknesses ranging from 0.5 nm to 10 nm and widths of 50 nm or larger. When analyzed using Raman spectroscopy with an incident laser wavelength of 633 nm, these graphene structures exhibit a characteristic D, G, and 2D bands, located at about 1333 cm1, 1584 cm1, 2661 cm1, respectively. Graphene oxide is an oxygen-functionalized form of graphene, structured as a two-dimensional (2D) material with a hexagonal carbon lattice, typically derived from oxidized graphite or other carbon-rich precursors. Reduced graphene oxide is a chemically or thermally treated variant of GO, in which the oxygen content is significantly reduced, restoring properties similar to pristine graphene. The ID / IC ratio, commonly used to evaluate defect density in graphene, may be less reliable when applied to GO and rGO due to variations in oxidation levels.

[0064] The examples provided herein are based on experimental methods and implemented on devices such as the one illustrated in FIG. 1. The characterization and analysis of the synthesized graphene-like nanomaterials was conducted using the following techniques:

[0065] - The physical structure was characterized using X-ray diffraction (XRD) and a Panalytical Empyrean diffractometer. Measurements were performed using powder X-ray diffraction geometry scans.

[0066] - Surface morphology of the product samples was examined using Scanning Electron Microscopy (SEM) in both secondary electron and backscattering electron imaging (SE and BE respectively) mode. Elemental composition analysis was performed using Energy-dispersive X-ray analysis (EDX).

[0067] - Non-destructive chemical analysis, which provides detailed information about chemical structure, phase and polymorphy, crystallinity, and molecular interaction, was performed using Raman Spectroscopy using a micro-Raman visible spectrometer equipped with a Peltier-cooled CCD detector and a He-Ne laser (633 nm, 0.5 mW).

[0068] - The elemental composition across the surface or in-depth profiling of synthesized materials was measured using X-ray photoelectron spectroscopy (XPS) and non-monochromatized Al Ka (1486.6 eV) radiation in an electron spectrometer under lx 108PaDocket BU0126PCT base pressure. The spectrometer resolution was calculated from the Ag 3d5 / 2line an analyzer transmission energy of 20 eV. The full with at half maximum (FWHM) on this line is 1 eV. The spectrometer was calibrated against the using Ag 4f? / 2line (84 eV) and the sample’s charge was estimated from the Cis (285 eV) spectra from natural hydrocarbon contamination on the surface. The accuracy of the binding energies (BEs) measured was 0.2 eV.

[0069] FIG. 2A - FIG. 2C depict SEM micrographs of the CB precursor material, derived from the pyrolysis of waste tires. The particles range in size from 40 pm to 50 pm, with a carbon content of 77.3% (microanalysis performed in accordance with standard NF EN 15407). The SEM images provide magnified views of the spherical CB particles, revealing homogeneous morphology and surface characteristics.

[0070] The composition of the light fraction is as follows: hydrogen (1.18%), nitrogen (0.39%), and oxygen (less than 0.2%). Additionally, trace amounts of metals, organic compounds-BTEX, chlorobenzenes, PAN-naphthalene aromatic solvents-were detected by determined to be insignificant.Example 1

[0071] According to an exemplary embodiment, CB 2 is introduced into process chamber 4 together with atmospheric air 3 through inlet 16. The pressure of the atmospheric air 3 is slightly above ambient, ranging from 800 Torr to 900 Torr, with a flow velocity of 20 m / s. In addition to facilitating material transport, atmospheric air also serves to control the temperature of grid 8, while indirectly cooling the plasma-induced exfoliation zone by changing flow dynamics. The volume of CB powder introduced into Brown’s gas generator 100 is 380 mm3.

[0072] To ignite the plasma, a high-voltage ignition pulse is applied to electrodes 5, operating at a DC voltage of 10 kV and a pulse frequency of 3 Hz. The distance between electrodes 5 made of cooper material is 6 mm. Brown’s gas generator 100 produces HHO gas that is automatically and synchronously injected into process chamber 4 through nozzle 6, forming plasma torch 7. Plasma ignition occurs when the high-voltage pulse applied to electrodes 5. After a stabilization period of about 2-8 minutes, inlet 16 is opened to pass the carbon-containing material 2 into the plasma interaction zone.

[0073] Plasma torch 7, which may be configured as a distributed plasma burner, is directed to grid 8, which is made from heat-resistant material, such as graphite, and has openings of sizes from 200 m to 800 pm. Grid 8 has a diameter of 70 mm and a thickness of 10 mm. The openings are arranged in concentric circles around the center of grid 8, which isDocket BU0126PCT located in plasma-induced exfoliation zone 11 and exposed to high temperatures. The temperature of grid 8, which serves to control the plasma-material interaction, is monitored using thermocouple 9, reaching levels between 2500 °C and 3500 °C. In this example, grid 8 is heated to 2700 °C.

[0074] As CB microparticles traverse the plasma torch 7 and pass through heated grid 8, they undergo an intense thermal shock, leading to structural exfoliation of graphene layers. The formation of vortices around the perforations of grid 8 further enhances exfoliation efficiency by promoting uniform delamination of layered carbon structures. The controlled interaction of plasma and process material further improves exfoliation homogeneity. Any minimal gaseous byproducts are generated during the process are extracted via exhaust outlet 10.

[0075] Exfoliated carbon nanomaterial then enters cooling chamber 12, where it is rapidly quenched by cooling medium 13, undergoing a thermal shock cooling that prevents reaggregation and stabilizes the synthesized graphene- like nanomaterials

[0076] The resulting exfoliated material is collected in storage tank 15. Additionally, cooling chamber 12 containing cooling medium 13 may be integrated with sonication device 14 to induce cavitation effects to enhance liquid-phase exfoliation and improving the yield and quality of the final graphene product.

[0077] The functionalization of graphene can be achieved by replacing atmospheric air 3, which in this case serves as an oxidizer to facilitate the synthesis of GO or rGO, with other gases such as argon, nitrogen helium, fluorine, carbonaceous materials, or mixtures thereof. By modifying the gas environment in this manner, the oxidation and reduction characteristics of the synthesized graphene-like nanomaterials can be accurately controlled.

[0078] FIG. 3A - FIG. 3C depict SEM micrographs of reduced graphene oxide HHO-G1 (rGO-Gl HHO) synthesized from CB through the HHO process in an atmospheric environment, at a temperature of 2700 °C, according to various embodiments of the present disclosure. The interatomic spacing or average thickness dimension of layers (X-Y dimension) is around 0.35 nm to 12 nm. For reference, scale bars are shown in micrographs for reference.

[0079] The SEM micrographs shown in FIG. 3A-3C, FIG. 4A-4C indicate that rGO structures form an almost continuous layered morphology. Raman spectrum of CB, the precursor material, the starting material, exhibits a prominent peak G with DI, D2, D3, and D4 bands. FIG. 5A illustrates the Raman shift of the precursor CB material, showing aDocket BU0126PCT distinct peak at approximately 1086 cm-1, characteristic of calcite (CaCO3). This peak corresponds to the Ag vibrational mode, confirming the presence of carbonate structures. The different notation of these peaks can be D, D’, D”, D*. The key peaks in the graphene Raman spectra are D, 2D and G. For rGO, the G and D peaks appear at 1584 cm'1and 1352 cm1, respectively, as shown in FIG. 5B and 5C. FIG. 5B depicts Raman shift of rGO-Gl synthesized from CB at a process temperature of 2700 °C using the HHO plasma method described with reference to FIG. 1, demonstrating spectral characteristic shifts associated with graphene oxide reduction. FIG. 5C depicts Raman shift of rGO-G2 HHO synthesized from CB at process temperature of 3200 °C, further confirming structural modifications induced by high-temperature processing.

[0080] The Raman spectra indicate that rGO exhibits a reduced defect density, with an estimated defect concentration of approximately l%-3%. FIG. 6A depicts XRD patterns of CB and the corresponding diffraction pattern of rGO-Gl HHO, synthesized via the HHO plasma process at temperature of 2700 °C, according to various embodiments of the present disclosure. FIG. 6B depicts comparative XRD analysis of CB and rGO-G2 HHO, synthesized using the process in FIG. 1, at a temperature of 3200 °C, revealing changes in crystallinity and phase transformations, according to various embodiments of the present disclosure. The XRD patterns were measured across a 20 range of 5 °C to 70 °C. With A denoting the peak of amorphous graphite CB, G denoting the graphite peak, and G2 denoting the graphite reflection from planes with more complex indices from (010); (-110); (011); and (-111). Peaks were identified as follows: (A) represents amorphous graphite CB, (G) denotes the characteristic graphite peak, and (G2) represents graphite reflections from complex lattice planes indexed as (010), (-110), (011), and (-111). The peaks centered at 20 = 11.7° and 20 = 25.8° correspond to interlayer spacing of 4.47 A and 3.53 A, respectively. These results demonstrate exfoliation and reduction processes in graphene and GO, indicating the successful removal of intercalated water molecules and oxygen-containing functional groups.

[0081] It is noted that the experiments and results herein are provided by way of illustration and were performed under specific conditions using a specific embodiment or embodiments; accordingly, neither these experiments nor their results shall be used to limit the scope of the disclosure of the current patent document.Example 2

[0082] This experiment follows essentially the same methodology as Example 1 discussed above, with the exception that the process temperature in plasma-inducedDocket BU0126PCT exfoliation zone 11 and grid 8 was increased to 3200 °C, resulting in the synthesis of reduced graphene oxide (rGO-G2). The synthesized material was examined in the same using SEM, Raman Spectroscopy and XRD analysis.

[0083] FIG. 4A - FIG. 4C depict SEM micrographs of reduced graphene oxide HHO-G2 (rGO G2 HHO) synthesized from CB using the HHO-based process illustrated in FIG. 1, at a temperature of 3200 °C. The bonded atomic layers appear much smaller in size and are on the order of 30 pm to 60 pm. As the process temperature increases, a reduction in the number of connected layers and their thinning is observed, indicating a more effective exfoliation process. Scale bars are provided in the micrographs. Analysis of Raman spectra for morphologies of CB (FIG. 3), synthesized rGOl and rGO2 (FIG. 3 A - FIG. 3C) and rGO-G2 (FIG. 4 A - FIG. 4C) is illustrated in FIG. 5A - FIG. 5C. The XRD patterns corresponding to CB, rGOl, and rGO2 are shown in FIG. 6A - FIG. 6B.

[0084] FIG. 7 is a flowchart of an exemplary process for producing graphene-like material by using Brown’s gas plasma, according to various embodiments of the present disclosure. Process 700 for producing graphene-like material may starts at step 702 when a Brown’s gas plasma is applied to a carbon-containing substance to cause a thermal expansion that converts at least some of the carbon-containing substance into atomic-level material.

[0085] At step 704, a plasma-material interaction is regulated by directing a flow of Brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing exfoliation efficiency.

[0086] At step 706, a cooling medium is used in a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene-like material comprising atomic layers.

[0087] In embodiments, at step 706, cooling and precipitation processed may be used to prevent reaggregation.

[0088] Finally, at step 708, a solid-liquid separation process is used to recover solidphase graphene-like material from the cooling medium.

[0089] One skilled in the art shall recognize that: (1) certain steps may optionally be performed; (2) steps may not be limited to the specific order set forth herein; (3) certain steps may be performed in different orders; and (4) certain steps may be done concurrently.

[0090] It will be appreciated by those skilled in the art that the preceding examples and embodiments are exemplary and not limiting to the scope of the present disclosure. It is intended that all permutations, enhancements, equivalents, combinations, and improvementsDocket BU0126PCT thereto that are apparent to those skilled in the art upon a reading of the specification and a study of the drawings are included within the true spirit and scope of the present disclosure. It shall also be noted that elements of any claims may be arranged differently including having multiple dependencies, configurations, and combinations.

Claims

Docket BU0126PCT CLAIMS WHAT IS CLAIMED IS:

1. An apparatus for producing graphene-like material by using Brown’s gas plasma, the apparatus comprising:one or more inlets configured to receive Brown’s gas and a carbon-containing substance;a process chamber comprising:one or more nozzles configured to direct the Brown’s gas within the process chamber;electrodes configured to use electrical power to generate a plasma that, when interacting with the carbon-containing substance, causes thermal expansion that converts at least some of the carbon-containing substance into atomic-level material;a grid comprising openings configured to control a flow of the Brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing an exfoliation efficiency;a cooling chamber configured to use a cooling medium that enables a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene- like material comprising atomic layers;a collection tank configured to receive the graphene-like material and enable a cooling and precipitation process to prevent reaggregation; and a filter configured to recover solid-phase graphene-like material from the collection tank.

2. The apparatus of claim 1, further comprising an ultrasonic chamber configured to enhance a liquid-phase exfoliation by generating cavitation effects during a liquid shock cooling process.

3. The apparatus of claim 1, wherein the Brown’s gas is provided substantially at atmospheric pressure, and wherein the graphene-like material is graphene-like nanoscale carbon material.

4. The apparatus of claim 1, wherein the plasma is ignited at a first pressure and maintained at a second pressure.

5. The apparatus of claim 1, wherein the cooling medium comprises a liquid.Docket BU0126PCT 6. The apparatus of claim 5, wherein the liquid comprises distilled water.

7. The apparatus of claim 1, wherein the Brown’s gas is directed into the process chamber at an angle different from a flow direction of the carbon-containing substance.

8. The apparatus of claim 7, wherein the openings generate vortices when exposed to the plasma to enhance an exfoliation and stabilize a plasma-material interaction.

9. The apparatus of claim 1, wherein the process chamber comprises an outlet configured to remove process gas from the process chamber.

10. A method for producing graphene-like material by using Brown’s gas plasma, the method comprising the steps of:applying a Brown’s gas plasma to a carbon-containing substance to cause a thermal expansion that converts at least some of the carbon-containing substance into atomic-level material;regulating a plasma-material interaction by directing a flow of Brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing exfoliation efficiency;using a cooling medium in a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene-like material comprising atomic layers;using a cooling and precipitation process to prevent reaggregation; and using a solid-liquid separation process to recover solid-phase graphene-like material from the cooling medium.

11. The method of claim 10, further comprising applying ultrasonic energy to the cooling medium to cause cavitation effects in the solid-phase graphene-like material that enhance liquid-phase exfoliation of the carbon-containing substance.

12. The method of claim 10, wherein the Brown’s gas is provided at substantially atmospheric pressure and is directed into a process chamber at an angle different from a flow direction of the carbon-containing substance.

13. The method of claim 10, further comprising forming vortices by passing the Brown’s gas plasma through a grid comprising openings, wherein the vortices enhance the plasma exposure.

14. A system for producing graphene-like material by using Brown’s gas plasma, the system comprising:Docket BU0126PCT an apparatus configured to produce graphene-like material, the apparatus comprising:one or more inlets configured to receive Brown’s gas and a carbon-containing substance;a process chamber comprising:one or more nozzles configured to direct the Brown’s gas within the process chamber;electrodes configured to use electrical power to ignite and generate a plasma that, when interacting with the carbon-containing substance, causes thermal expansion that converts at least some of the carbon-containing substance into atomic-level material;a grid comprising openings configured to control a flow of the Brown’s gas and the atomic-level material to enhance plasma exposure, thereby enhancing an exfoliation efficiency;a cooling chamber configured to use a cooling medium that enables a rapid thermal contraction process that converts at least some of the atomic-level material into a graphene- like material comprising atomic layers;a collection tank configured to receive the graphene-like material and enable a cooling and precipitation process to prevent reaggregation; a filter configured to recover solid-phase graphene-like material from the collection tank;a power source configured to generate the electrical power; andone or more flow controllers configured to control an input flow of the Brown’s gas and an input flow of the carbon-containing substance.

15. The system of claim 14, further comprising an ultrasonic chamber configured to enhance a liquid-phase exfoliation by generating cavitation effects during a liquid shock cooling process.

Images