CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application Ser. No. 63337056, filed on April 30, 2022, and entitled “Graphene derived from plastic waste and production method thereof,” which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure generally relates to a process for producing graphene, and more particularly to a continuous process for producing graphene from plastic waste.

BACKGROUND

[0003] Nano graphene platelets (NGPs) are commonly well-known to have superior electrical and thermal conductivity, intrinsic mechanical strength, and chemical features. Consequently, durability of a scalable process for graphene production in large quantities is critical and vital for manufacturing next generation of industrial composites, energy storage materials, and other 2-dimensional (2D) or 3 -dimensional (3D) material fields.

[0004] Recently, there has been an emphasis on utilizing waste sources to synthesize NGPs which could potentially support waste management and the establishment of a circular economy. As a result, researchers and businesses have been encouraged to devise cost-effective and gentle techniques for recycling and upcycling plastic waste in order to manufacture graphene and its derivatives. For instance, boron has been employed as a catalyst for the reaction in an approach that is based on direct and indirect conditions, and the resultant graphite was exfoliated through liquid-phase agitation. This method necessitates a high temperature for carbonization (700 °C) and is quite lengthy, taking at least 24 hours to finish. Thereby, there is need to develop an efficient and effective process for converting waste plastic into graphene, taking into account important criteria such as the use of fewer hazardous chemicals, more time- and energy-saving processes, and environmentally friendly procedures.

SUMMARY

[0005] This summary is intended to provide an overview of the subject matter of the present disclosure, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description below and the drawings.

[0006] In an exemplary embodiment, the present disclosure describes an exemplary process for producing an exemplary carbon material comprising at least 70% by mass of graphene from waste carbonaceous materials. An exemplary process may comprise forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials to a size between 200 and 500 meshes, forming an exemplary mixture by blending 100 parts by weight of exemplary carbonaceous powder with 0.025-0.25 parts by weight of an exemplary catalyst, and producing an exemplary carbon material by carbonizing an exemplary mixture in an exemplary reaction vessel filled with an exemplary inert gas.

[0007] In an exemplary embodiment, an exemplary catalyst may comprise 30-45 (%wt.) of polyaniline, 10-19 (%wt.) of montmorillonite, 15-25 (%wt.) of reduced graphene oxide, and 20-

30 (%wt.) of graphite oxide. [0008] In an exemplary embodiment, carbonizing an exemplary mixture in an exemplary reaction vessel may comprise producing an exemplary first heated mixture by heating up an exemplary mixture to a temperature between 130 °C and 160 °C in an exemplary first zone of an exemplary reaction vessel by exposing an exemplary mixture to an exemplary first plurality of electric heating elements mounted in an exemplary first zone, producing an exemplary second heated mixture by heating up an exemplary first heated mixture to a temperature between 250 °C and 340 °C in an exemplary second zone of an exemplary reaction vessel, and producing an exemplary carbon material by heating up an exemplary second heated mixture in an exemplary third zone of an exemplary reaction vessel by applying at least 3 cycles of an exemplary electric shock to an exemplary second heated mixture.

[0009] In an exemplary embodiment, heating up an exemplary first heated mixture to a temperature between 250 °C and 340 °C in an exemplary second zone of an exemplary reaction vessel may comprise, simultaneously, exposing an exemplary first heated mixture to an exemplary second plurality of electric heating elements and at least 5 cycles of microwave radiation.

[00010] In an exemplary embodiment, an exemplary cycle of microwave radiation may comprise an on-period with an exemplary time duration between 8 and 12 seconds and an off- period with an exemplary time duration between 1 and 3 seconds, wherein an exemplary on- period may comprise a microwave radiation with a frequency between 1 and 20 GHz.

[00011] In an exemplary embodiment, an exemplary cycle of electric shock may comprise an on-period with an exemplary time duration between land 3 seconds and an off- period with an exemplary time duration between 0.5 and 1.5 seconds, wherein an exemplary on-period may comprise an electric shock with a voltage between 3.5 and 15 kv. [00012] This Summary is provided to introduce a selection of concepts in a simplified form; these concepts are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[00013] The present disclosure is disclosed more in detail with reference to the drawings in which:

[00014] FIG. 1A illustrates a flowchart of an exemplary process for producing an exemplary carbon material comprising at least 70% by mass of graphene from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure.

[00015] FIG. IB illustrates a flowchart of an exemplary method for carbonizing an exemplary mixture, consistent with one or more exemplary embodiments of the present disclosure.

[00016] FIG. 2A illustrates a schematic perspective view of an exemplary reaction vessel for carbonizing an exemplary mixture, consistent with one or more exemplary embodiments of the present disclosure.

[00017] FIG. 2B illustrates a schematic front view of an exemplary reaction vessel for carbonizing an exemplary mixture, consistent with one or more exemplary embodiments of the present disclosure.

[00018] FIG. 3A illustrates a flowchart of an exemplary process for producing an exemplary exfoliated graphene powder from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure.

[00019] FIG. 3B illustrates a flowchart of an exemplary method for exfoliating an exemplary carbon material, consistent with one or more exemplary embodiments of the present disclosure. [00020] FIG. 4A illustrates a flowchart of an exemplary process for producing an exemplary exfoliated graphene powder with a purification of at least 90% from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure.

[00021] FIG. 4B illustrates a flowchart of an exemplary method for, simultaneously, exfoliating and purifying an exemplary carbon material, consistent with one or more exemplary embodiments of the present disclosure.

[00022] FIG. 5A illustrates an exemplary transmission electron microscopy (TEM) image of an exemplary carbon material comprising at least 70% by mass of graphene, consistent with one or more exemplary embodiments of the present disclosure.

[00023] FIG. 5B illustrates an exemplary field emission scanning electron microscopy (FESEM) image of an exemplary carbon material comprising at least 70% by mass of graphene, consistent with one or more exemplary embodiments of the present disclosure.

[00024] FIG. 6A illustrates an exemplary TEM image of an exemplary exfoliated graphene powder, consistent with one or more exemplary embodiments of the present disclosure.

[00025] FIG. 6B illustrates an exemplary FESEM image of an exemplary exfoliated graphene powder, consistent with one or more exemplary embodiments of the present disclosure. [00026] FIG. 7A illustrates an exemplary TEM image of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure.

[00027] FIG. 7B illustrates an exemplary FESEM image of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure. [00028] FIG. 7C illustrates an exemplary Raman spectrum of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure.

[00029] It is understood that the following description and references to the figures concern exemplary embodiments of the present disclosure and shall not be limiting the scope of the claims.

DETAILED DESCRIPTION

[00030] In the following detailed description, numerous specific details are set forth by way of examples to provide a thorough understanding of the relevant teachings related to the exemplary embodiments. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well-known methods, procedures, and components have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.

[00031] The following detailed description is presented to enable a person skilled in the art to make and use the process disclosed in exemplary embodiments of the present disclosure. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the art that these specific details are not required to practice the disclosed exemplary embodiments. Descriptions of specific exemplary embodiments are provided only as representative examples. Various modifications to the exemplary implementations will be plain to one skilled in the art, and the general principles defined herein may be applied to other implementations and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the implementations shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein. [00032] Several approaches have been developed to create graphene from waste resources, particularly plastics. Nevertheless, prior methods may not be suitable, particularly for industrial utilization, due to certain demands such as high temperatures, hazardous chemicals, and timeconsumption. Disclosed herein is an exemplary process for producing graphene from waste plastics. An exemplary embodiment may comprise a continuous, facile, and environmentally friendly process for producing graphene from waste plastics. In an exemplary embodiment, an exemplary process of producing graphene from waste plastics may be employed on an industrial scale, which would be beneficial due to its low time and cost consumption.

[00033] FIG. 1A illustrates a flowchart of exemplary process 100 for producing a carbon material comprising at least 70% by mass of graphene (process 100) from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, exemplary process 100 may include forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials (step 102), forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst (step 104), and producing an exemplary carbon material by carbonizing an exemplary mixture in an exempalry reaction vessel (step 106). “Waste carbonaceous material” may refer to a post-consumer plastic that is no longer needed for its intended purpose. “Waste carbonaceous material” may be equivalent to “waste plastics” or “feedstock of waste plastic”. Waste plastics may include but are not limited to municipal solid waste (MSW), industrial waste or other waste forms. Waste plastic may refer to thermoplastic materials that may include a composition, composite, or mixture of one or more of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET), as well as other thermoplastic and thermosetting plastic materials. Waste plastic may be composed of about 80% thermoplastics and about 20% thermosets. Non-limiting sources of municipal waste include domestic items (food and beverage containers, packaging foam, electronic equipment cases, flooring, thermal insulation foams), agricultural items (mulch films, feed bags, fertilizer bags, etc.), and automobile wrecking. Sources of industrial waste plastic may include construction and demolition companies (polyvinyl chloride pipes and fittings, tiles, and sheets), electric and electronic industries (switch boxes, cable sheaths, cassette boxes, TV screens), automotive industries (spare parts for cars: fan blades, seat coverings, battery containers, front grills), etc. In an exemplary embodiment, PET wastes may be used as a starting raw material for graphene production.

[00034] In an exemplary embodiment, exemplary process 100 may be a continuous process. “Continuous process” may refer to a process that may operate based on a continuous flow, as opposed to batch, intermittent, or sequenced operations. In an exemplary embodiment, exemplary process 100 may be a discontinuous process. “Discontinuous process” may refer to a process that may happen in stages with intervals between them.

[00035] In further detail with respect to FIG. 1A, in an exemplary embodiment, step 102 may include forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials. In an exemplary embodiment, forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials includes grinding a plurality of exemplary waste carbonaceous materials using an exemplary shredder. In an exemplary embodiment, forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials includes first crushing a plurality of exemplary waste carbonaceous material to exemplary waste particles with lower size, then grinding exemplary waste particles into exemplary carbonaceous powder form. In an exemplary embodiment, forming an exemplary carbonaceous powder with a determined size range by grinding exemplary waste carbonaceous materials includes grinding a plurality of exemplary waste carbonaceous materials using one machine or device or a combination of more than one machine. In an exemplary embodiment, an exemplary shredder may be used for forming an exemplary carbonaceous powder by grinding exemplary waste carbonaceous materials in a single step. In an exemplary embodiment, an exemplary shredder for grinding exemplary waste carbonaceous materials in a single step may comprise a cylindrical housing, two hexagonal shafts, plurality of blades attached to the lateral surfaces of exemplary hexagonal shafts, and plurality of permanent blades attached to exemplary inner surface of exemplary cylindrical housing of exemplary shredder. In an exemplary embodiment, an exemplary shredder for grinding exemplary waste carbonaceous materials in a single step may comprise a cylindrical housing with a diameter-to-length ratio of about 0.14, wherein two hexagonal shafts with a length of about 125 cm and a pitch of about 0.17 cm may be mounted inside an exemplary housing of an exemplary shredder. An exemplary shredder may include a plurality of exemplary blades with a height of about 25 mm attached to the lateral surfaces of exemplary hexagonal shafts of exemplary shredder. Furthermore, a plurality of exemplary permanent blades may be attached to exemplary inner surface of exemplary cylindrical housing of exemplary shredder. Each respective permanent blade may have a pyramid shape with a sharp tip, wherein each pyramid has a height of about 21 mm. Also, exemplary blades with a pyramid shape may be distributed on exemplary inner surface of exemplary cylindrical housing of exemplary shredder at a distance of about 32 mm from each other. In an exemplary embodiment, forming exemplary carbonaceous powder by grinding exemplary waste materials like PET includes grinding exemplary waste PET using an exemplary shredding machine to an average size between 200 and 500 mesh.

[00036] In further detail with respect to FIG. 1A, in an exemplary embodiment, step 104 may include forming a mixture by blending an exemplary carbonaceous powder with an exemplary catalyst. In an exemplary embodiment, forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst includes blending exemplary carbonaceous powder with an exemplary catalyst using a twin-screw extruder. In an exemplary embodiment, forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst includes blending exemplary carbonaceous powder and catalyst using a single-screw extruder. In an exemplary embodiment, blending of an exemplary carbonaceous powder with an exemplary catalyst using an exemplary twin-screw extruder may be performed by an exemplary method including: i) weighing 100 parts by weight of exemplary carbonaceous powder and .025-0.25 parts by weight of exemplary catalyst, ii) feeding exemplary weighed carbonaceous powder and catalyst into exemplary twin-screw extruder through an exemplary feeder of exemplary twin-screw extruder. An exemplary mixture comprising exemplary carbonaceous powder and exemplary catalyst in exemplary twin-screw extruder may be heated through an exemplary extruder to a temperature between 150 °C and 160 °C, gradually. In an exemplary embodiment, the ratio of screw length to screw diameter (L/D ratio) in an exemplary twin-screw extruder may be between 5:1 and 7:1. In an exemplary embodiment, retention time of exemplary mixture in exemplary twin-screw extruder may be between 5 and 20 minutes. “Retention time’ ’ may refer to the amount of time that an exemplary mixture may remain in an exemplary twin-screw extruder after injection. In other words, an exemplary time duration between feeding of an exemplary carbonaceous powder and an exemplary catalyst to an exemplary twin-screw extruder and obtaining of an exemplary mixture from an exemplary die of an exemplary twin-screw extruder may be between about 5 and 20 minutes. The temperature of exemplary mixture at an exemplary die of exemplary twin-screw extruder may be in an exemplary range between 70 °C and 80 °C. In an exemplary embodiment, exemplary mixture may be prepared in form of powder, paste, or granular, etc. [00037] “Blending” or “blended” an exemplary mixture using an exemplary twin-screw extruder may refer to combining materials together. In an exemplary embodiment, forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst may include feeding 100 g of an exemplary carbonaceous powder and 0.05 g of an exemplary catalyst into an exemplary twin-screw extruder at a temperature level between 15 °C and 35 °C.

[00038] In an exemplary embodiment, an exemplary catalyst may be a composite or a nanocomposite comprising 30-45 (%wt.) of polyaniline (PANI), 10-19 (%wt.) of montmorillonite, 15-25 (%wt.) of reduced graphene oxide (RGO), and 20-30 (%wt.) of graphite oxide. In an exemplary embodiment, montmorillonite may include an exemplary montmorillonite modified with different cations. In an exemplary embodiment, an exemplary montmorillonite modified with different cations may include sodium-montmorillonite. In an exemplary embodiment, graphite oxide may be selected from the group consisting of natural graphite oxide, chemically modified graphite oxide, exfoliated graphite oxide, and a combination thereof. In an exemplary embodiment, different RGOs with different oxygen contents may be used for preparing an exemplary catalyst. In an exemplary embodiment, exemplary process 100 may further comprise producing an exemplary catalyst and blending an exemplary freshly produced catalyst with an exemplary carbonaceous powder using an exemplary twin-screw extruder. In an exemplary embodiment, an exemplary catalyst may have a particle size in a range between 10 nm and 250 nm, more specifically 25 nm to lOOnm.

[00039] In further detail with respect to FIG. 1A, in an exemplary embodiment, step 106 may include producing a carbon material by carbonizing an exemplary mixture in an exemplary reaction vessel. In an exemplary embodiment details of step 106 for producing a carbon material by carbonizing an exemplary mixture in an exemplary reaction vessel are described in context of elements presented in FIG. IB. FIG. IB illustrates a flowchart of an exemplary method for carbonizing an exemplary mixture, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIG. IB, details of exemplary step 106 of exemplary process 100 may include: forming an exemplary first heated mixture by heating up an exemplary mixture in an exemplary first zone of an exemplary reaction vessel (step 108), forming an exemplary second heated mixture by heating up an exemplary first heated mixture in an exemplary second zone of an exemplary reaction vessel (step 110), forming an exemplary carbon material by heating an exemplary second heated mixture in an exemplary third zone of an exemplary reaction vessel (step 112).

[00040] In an exemplary embodiment, carbonizing an exemplary mixture may be carried out in an exemplary reaction vessel. “Carbonization” may refer to a process in which an organic matter is concentrated/ converted without air into carbon or a carbonic residue. FIG. 2A illustrates a schematic perspective view of an exemplary reaction vessel 200 for carbonizing an exemplary mixture (reaction vessel 200), consistent with one or more exemplary embodiments of the present disclosure. FIG. 2B illustrates a schematic front view of an exemplary reaction vessel 200, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, reaction vessel 200 may comprise a cylinder 202, at least one screw 203, a feeder 204, a first plurality of electric heating element 205, a first zone 206, a second plurality of electric heating element 207, a second zone 208, a plurality of microwave radiator 209, a third zone 210, a programmable control system 212, a plurality of electrical equipment 214, and a pumping system 216.

[00041] In an exemplary embodiment, an exemplary reaction vessel 200 may include a microwave-electric shock-assisted furnace. Referring to FIGs. 2, an exemplary mixture may be fed into reaction vessel 200 through feeder 204 which is connected to cylinder 202. The reaction may be carried out in cylinder 202 which is enclosed and filled with an inert or inactive gas such as, but not limited to, argon or nitrogen. At least one screw 203 may be mounted in cylinder 202, horizontally. An exemplary mixture may be pushed forward to the exit port or die of cylinder 202 through the rotational movement of screw(s) 203. The different heating mechanisms may be provided on the outer surface of cylinder 202, by which an exemplary mixture may be heated, burnt, or converted to another substance. In an exemplary embodiment, first plurality of electric heating elements 205 may be mounted in first zone 206 of reaction vessel 200. In an exemplary embodiment, the length of first zone 206 may be around 10% of length of cylinder 202, wherein approximately 20%-25 % of exemplary carbonization process may be performed. First plurality of electric heating elements 205 may heat or bum an exemplary mixture to a temperature between 130 °C and 160 °C in first zone 206. It should be more explained that each respective zone of reaction vessel 200 may be related to a certain length of reaction vessel 200 that may heat an exemplary mixture using a special mechanism. It should be mentioned that first zone 206, second zone 208, and third zone 210 may be distinguished by exemplary heating mechanism. However, an exemplary mixture may flow through cylinder 202 form first zone 206 to second zone 208, and then third zone 210, continuously. In an exemplary embodiment, plurality of second electric heating elements 207 may be mounted in second zone 208 of reaction vessel 200. Furthermore, plurality of microwave radiators 209 may be mounted in second zone 208 of reaction vessel 200. An exemplary mixture in second zone 208 may be heated or burnt using both second plurality of electric heating elements 207 and microwave radiators 209. Second plurality of electric heating elements 207 and microwave radiator(s) 209 may heat or burn an exemplary mixture to a temperature between 250 °C and 340 °C in second zone 208, simultaneously. It means, some part of required heat in second zone 208 may be provided using second plurality of electric heating elements 207 and the other part may be provided using microwave radiation produced by microwave radiator(s) 209. In an exemplary embodiment, microwave radiator(s) 209 may continuously emit radiation. In an exemplary embodiment, microwave radiator(s) 209 may have a cycle of radiation. For example, each cycle of radiation may comprise an on-period with a certain range of time duration and an off-period with a certain range of time duration. Microwave radiation during on-period operation may have a frequency between 1 and 20 GHz. In an exemplary embodiment, the length of second zone 208 may be around 60%-70% of length of cylinder 202, wherein approximately 35%-45% of exemplary carbonization process may be performed. In an exemplary embodiment, two electrodes (not shown here) may be mounted in third zone 210 of reaction vessel 200. An electric discharge between two electrodes may produce an electric -shock by which an exemplary mixture may be heated or burnt. The length of third zone 210 may be around 20%-30% of length of cylinder 202, wherein approximately 25%-30% of exemplary carbonization process may be performed. Two electrodes may be made of bronze or copper metals. In an exemplary embodiment, an exemplary mixture may be exposed to the electric- shock continuously. In an exemplary embodiment, an exemplary may be exposed to a cycle of electric -shock, wherein each cycle of electric -shock may comprise an on-period with a certain time duration and an off-period with a certain time duration. Exemplary electric shock during on-period operation may have a voltage between 3.5 and 15 kv.

[00042] It should be mentioned that, a programmable control system 212 such as programmable logic controller (PLC) may be used for adjusting the temperature in each respective zone of reaction vessel 200, state-on/off time of microwave radiation in second zone 208, power of each respective electric heating elements, power of electric shock in third zone 210, carbonization rate, the retention time of an exemplary mixture in each respective zone. Furthermore, electrical equipment 214 and pumping system 216 placed in the boxes under cylinder 202, may be used for setting up the reaction vessel 200. [00043] In further detail with respect to FIG. IB and FIGs. 2, in an exemplary embodiment, step 108 may include forming an exemplary first heated mixture by heating up an exemplary mixture in first zone 206 of reaction vessel 200. In an exemplary embodiment, forming an exemplary first heated mixture by heating up an exemplary mixture in first zone 206 of reaction vessel 200 includes: i) feeding an exemplary mixture into reaction vessel 200 through feeder 204, ii) heating up an exemplary mixture during moving in first zone 206 to a temperature between 130 °C and 160 °C. In an exemplary embodiment, heating up an exemplary mixture during moving in first zone 206 to a temperature between 130 °C and 160 °C may include exposing an exemplary mixture to first plurality of electric heating elements 205 mounted in first zone 206. In an exemplary embodiment, feeding an exemplary mixture into reaction vessel 200 through feeder 204 may include entering an exemplary mixture into exemplary cavity between screw 203 and cylinder 202. In an exemplary embodiment, an exemplary mixture fed into cylinder 202 of reaction vessel 200 may be pushed forward by rotational motion of screw 203. In an exemplary embodiment, forming an exemplary first heated mixture by heating up an exemplary mixture in first zone 206 of reaction vessel 200 may include converting an exemplary mixture to an exemplary first heated mixture after passing through first zone 206 of reaction vessel 200.

[00044] In further detail with respect to FIG. IB, in an exemplary embodiment, step 110 may include forming an exemplary second heated mixture by heating up an exemplary first heated mixture in second zone 208 of reaction vessel 200. In an exemplary embodiment, forming an exemplary second heated mixture by heating up an exemplary first heated mixture in second zone 208 of reaction vessel 200 may include: i) entering an exemplary first heated mixture continuously from first zone 206 into second zone 208 of reaction vessel 200 through the rotational motion of screw 203, ii) heating up an exemplary first heated mixture in second zone 208 of reaction vessel 200. In an exemplary embodiment, heating up an exemplary first heated mixture in second zone 208 of reaction vessel 200 includes, simultaneously, exposing an exemplary first heated mixture to second plurality of electric heating elements 207 and at least 5 cycles of microwave radiation. In an exemplary embodiment, heating mechanisms in second zone 208 may include using second plurality of electric heating elements 207 and microwave radiation produced by microwave radiator 209. In an exemplary embodiment, an exemplary first heated mixture arrived to second zone 208 may be heated to a temperature between 250 °C and 340 °C using both heating mechanisms used in second zone 208, simultaneously. In an exemplary embodiment, an exemplary first heated mixture may be simultaneously exposed to second plurality of electric heating elements 207 and at least 5 cycles of microwave radiation, wherein each respective cycle of microwave radiation comprises an on-period with a time duration between 8 and 12 seconds and an off-period with a time duration between 1 and 3 seconds. In an exemplary embodiment, microwave radiation during on-period operation may have a frequency between 1 and 20 GHz. For example, when an exemplary first heated mixture arrives to second zone 208, an exemplary first heated mixture may be continuously heated using second plurality of electric heating elements 207 that are programmed to heat an exemplary first heated mixture to an exemplary certain temperature range. Simultaneously, an exemplary first heated mixture that is heated by second plurality of electric heating elements 207, may be exposed to microwave radiator 209. In an exemplary embodiment, microwave radiator 209 may emit an exemplary microwave radiation continuously. In an exemplary embodiment, microwave radiation may be emitted using an exemplary discontinuous cycle. In an exemplary embodiment, an exemplary discontinuous cycle of microwave radiation may comprise an on-period with a time duration of 10 seconds and an off-period with a time duration of 2 seconds. In an exemplary embodiment, an exemplary second heated mixture may be produced at the end of second zone 208 of reaction vessel 200.

[00045] In an exemplary embodiment, step 112 may include forming an exemplary carbon material by heating up an exemplary second heated mixture in third zone 210 of reaction vessel 200. In an exemplary embodiment, forming an exemplary carbon material by heating up an exemplary second heated mixture in third zone 210 of reaction vessel 200 may include: i) entering an exemplary second heated mixture continuously into third zone 210 of reaction vessel 200 through the rotational motion of screw 203, ii) heating up an exemplary second heated mixture in third zone 210 of reaction vessel 200. In an exemplary embodiment, heating up an exemplary second heated mixture in third zone 210 of reaction vessel 200 may include applying at least 3 cycles of an electric shock to an exemplary second heated mixture. As previously described in context of elements presented in FIGs. 2, there are two electrodes in third zone 210 for producing an electric shock. In an exemplary embodiment, an exemplary carbon material may be produced by heating n exemplary second heated mixture in third zone 210 of reaction vessel 200 by applying at least 3 cycles of an electric shock to an exemplary second heated mixture, wherein each respective cycle of the electric shock comprises an on-period with a time duration between land 3 seconds and an off-period with a time duration between 0.5- 1.5 seconds. An electric shock applied to an exemplary second heated mixture during on-period operation may have a voltage between 3.5 and 15 kv. In an exemplary embodiment, step 106 for producing an exemplary carbon material by carbonizing an exemplary mixture in an exemplary reaction vessel comprises producing an exemplary carbon material by carbonizing an exemplary mixture in an exemplary reaction vessel for a time duration between about 15 minutes to 1 hour, more specifically 17 to 35 minutes. [00046] FIG. 3A illustrates a flowchart of exemplary process 300 for producing an exemplary exfoliated graphene powder (process 300) from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, process 300 may include forming an exemplary carbonaceous powder by grinding an exemplary waste carbonaceous materials (step 102), forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst (step 104), producing an exemplary carbon material comprising at least 70% by mass of graphene by carbonizing an exemplary mixture (step 106), and exfoliating an exemplary carbon material (step 114).

[00047] In an exemplary embodiment details of step 114 for exfoliating an exemplary carbon material are described in context of elements presented in FIG. 3B. FIG. 3B illustrates a flowchart of an exemplary method for exfoliating an exemplary carbon material, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIG. 3B, details of exemplary step 114 of exemplary process 300 may include: forming an exemplary mixture of an exemplary carbon material and water (step 116), circulating an exemplary mixture of an exemplary carbon material and water in a hydrodynamic nano-cavitation reactor (step 118), and forming an exemplary exfoliated graphene powder by drying an exemplary circulated mixture of an exemplary carbon material and water (step 120).

[00048] In an exemplary embodiment, step 116 may include forming an exemplary mixture of an exemplary carbon material and water. In an exemplary embodiment, forming an exemplary mixture of an exemplary carbon material and water includes forming an exemplary mixture of an exemplary carbon material and water comprising an exemplary carbon material and water with a weight ratio (carbon material: water) of 1:1. In an exemplary embodiment, forming an exemplary mixture of an exemplary carbon material and water may include mixing 50 g of exemplary carbon material with 50 g of water using a mixer. In an exemplary embodiment, ethanol also may be used instead of water for forming an exemplary mixture of an exemplary carbon material and water. In an exemplary embodiment, water may be selected from the group consisting of pure water, ultrapure water, general grade laboratory water, reverse osmosis (RO) water, distilled water, and a combination thereof. In an exemplary embodiment, step 118 may include circulating an exemplary mixture of an exemplary carbon material and water in an exemplary hydrodynamic nano-cavitation reactor .“Hydrodynamic nano-cavitation reactor” may refer to a reactor for the hydrodynamic generation of homogeneous, oscillating cavitation bubbles in a fluid. An exemplary hydrodynamic nano-cavitation reactor may have a pressure in the range of 2 and 8 bar. In an exemplary embodiment, circulating an exemplary mixture of an exemplary carbon material and water in an exemplary hydrodynamic nano -cavitation reactor includes circulating an exemplary mixture of an exemplary carbon material and water in an exemplary hydrodynamic nano-cavitation reactor for a time duration between 5 and 50 minutes. In an exemplary embodiment, forming an exemplary exfoliated graphene powder by circulating an exemplary mixture of an exemplary carbon material and water in an exemplary hydrodynamic nano-cavitation reactor includes exfoliating an exemplary carbon material by producing exemplary bubbles or nano-bubbles in an exemplary nano-cavitation reactor. In an exemplary embodiment, at the end of the step 118, a dispersion of exfoliated graphene in water (or ethanol) may be produced.

[00049] In an exemplary embodiment, step 120 may include forming an exemplary exfoliated graphene powder by drying an exemplary circulated mixture of an exemplary carbon material and water. In an exemplary embodiment, forming an exemplary exfoliated graphene powder by drying an exemplary circulated mixture of an exemplary carbon material and water includes drying an exemplary circulated mixture of an exemplary carbon material and water using a dryer.

In an exemplary embodiment, drying an exemplary circulated mixture of an exemplary carbon material and water may include: i) producing an exemplary solid phase of an exemplary circulated mixture of an exemplary carbon material and water by centrifuging an exemplary circulated mixture of an exemplary carbon material and water, ii) subsequently, drying an exemplary solid phase of an exemplary circulated mixture of an exemplary carbon material and water using an exemplary oven or vacuum oven.

[00050] FIG. 4A illustrates a flowchart of an exemplary process 400 for producing an exemplary exfoliated graphene powder with a purification of at least 90% (process 400) from waste carbonaceous materials, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, process 400 may include forming a carbonaceous powder by grinding an exemplary waste carbonaceous materials (step 102), forming an exemplary mixture by blending an exemplary carbonaceous powder with an exemplary catalyst (step 104), producing an exemplary carbon material comprising at least 70% by mass of graphene by carbonizing an exemplary mixture in an exemplary reaction vessel(step 106), and simultaneously, exfoliating and purifying an exemplary carbon material (step 122).

[00051] In an exemplary embodiment, details of step 122 for simultaneously, exfoliating and purifying an exemplary carbon material are described in context of elements presented in FIG. 4B. FIG. 4B illustrates a flowchart of an exemplary method for, simultaneously, exfoliating and purifying an exemplary carbon material, consistent with one or more exemplary embodiments of the present disclosure. Referring to FIG. 4B, details of exemplary step 122 of exemplary process 400 may include: forming an exemplary mixture of an exemplary carbon material and water (step 124), mixing an exemplary mixture of an exemplary carbon material and water with an exemplary intercalating agent (step 126), circulating an exemplary mixed mixture in an exemplary hydrodynamic nano-cavitation reactor (step 128), separating an exemplary circulated mixture into an exemplary solid phase and an exemplary liquid phase (130), and forming an exemplary exfoliated graphene powder with a purification of at least 90% (step 132).

[00052] In further detail with respect to FIG. 4B, in an exemplary embodiment, step 124 may include forming an exemplary mixture of an exemplary carbon material and water. In an exemplary embodiment, forming an exemplary mixture of an exemplary carbon material and water includes forming an exemplary mixture of an exemplary carbon material and water comprising an exemplary carbon material and water with a weight ratio (carbon material: water) of 1:1. In an exemplary embodiment, forming an exemplary mixture of an exemplary carbon material and water may include mixing 50 g of exemplary carbon material with 50 g of water using a mixer. In an exemplary embodiment, ethanol also may be used instead of water for forming an exemplary mixture of an exemplary carbon material and water. In an exemplary embodiment, water may be selected from the group consisting of pure water, ultrapure water, general grade laboratory water, reverse osmosis (RO) water, distilled water, and a combination thereof.

[00053] In an exemplary embodiment, step 126 may include mixing an exemplary mixture of an exemplary carbon material and water with an exemplary intercalating agent. In an exemplary embodiment, mixing an exemplary mixture of an exemplary carbon material and water with an exemplary intercalating agent includes mixing an exemplary mixture of an exemplary carbon material and water with an intercalating agent, wherein the mixed mixture comprises the intercalating agent with a weight concentration between 1% and 5%. In an exemplary embodiment, mixing an exemplary mixture of an exemplary carbon material and water with an exemplary intercalating agent may include mixing 5 g of an exemplary intercalating agent with 95 g of an exemplary mixture of an exemplary carbon material and water using an exemplary mixer. In an exemplary embodiment, an exemplary intercalating agent may comprise 93-96 (%wt.) of water, 0.8-2 (%wt.) of acid carboxylic, 0.5-1.5 (%wt.) of acid citric, 0.5-1.5 (%wt.) of acid acetic, and 0.25-0.8 (%wt.) of sorbitane monooleate.

[00054] In an exemplary embodiment, step 128 may include circulating an exemplary mixed mixture in an exemplary hydrodynamic nano-cavitation reactor. In an exemplary embodiment, circulating an exemplary mixed mixture in an exemplary hydrodynamic nano-cavitation reactor includes exposing an exemplary mixed mixture to high-energy (nano)bubbles produced therein. In an exemplary embodiment, step 130 may include separating an exemplary circulated mixture into an exemplary solid phase and an exemplary liquid phase. In an exemplary embodiment, separating an exemplary circulated mixture into an exemplary solid phase and an exemplary liquid phase includes centrifuging an exemplary circulated mixture using an exemplary centrifuge with speed in a range between 4000 rpm and 6000 rpm. In an exemplary embodiment, step 132 may include forming an exemplary exfoliated graphene powder with a purification of at least 90%. In an exemplary embodiment, forming an exemplary exfoliated graphene powder with a purification of at least 90% includes drying an exemplary solid phase in an exemplary vacuum oven. In an exemplary embodiment, drying an exemplary solid phase in an exemplary vacuum oven includes drying an exemplary solid phase in an exemplary vacuum oven comprising a temperature level between 70 °C and 90 °C, for a time duration between 90 and 150 minutes. In an exemplary embodiment, drying an exemplary solid phase may include drying an exemplary solid phase in an exemplary oven.

EXAMPLES

Example 1: Producing a carbon material comprising at least 70% by mass of graphene powder from waste PET particles

[00055] In this example, a carbon material comprising at least 70% by mass of graphene powder was produced from waste PET particles utilizing a process similar to exemplary process 100 as presented in FIG. 1A. At first, 150 g of waste PET particles with an average size of 15 mm were ground to powder with the average size of 50 pm (mesh 300) using a shredder. The shredder has a cylindrical housing with a diameter-to-length ratio of 0.14, wherein two hexagonal shafts with a length of 125 cm and a pitch of 0.17 cm are mounted inside the housing. A plurality of blades with a height of 25 mm is attached to the lateral surfaces of the shafts. A plurality of permanent blades is attached to the inner surface of the cylindrical housing. Each respective permanent blade has a pyramid shape with a sharp tip, wherein each pyramid has a height of 21 mm. Also, the blades with a pyramid shape are distributed on the inner surface of exemplary cylindrical housing of exemplary shredder at a distance of 32 mm from others. In the next step, a mixture was formed by blending 100 g of waste PET powder with 0.1 g of an exemplary catalyst in an exemplary twin-screw extruder for a time duration of 8 minutes. An exemplary catalyst was a freshly prepared nanocomposite of PANVNa-MMT/RGO/graphite oxide (38%wt./ 14%wt./ 22%wt./ 26%wt.) with an average particle size of 75 nm. Waste PET powder and catalyst were fed to an exemplary twin-screw extruder at a temperature level between 25 °C and 30 °C, heated to a temperature between 150 °C and 160 °C, and mixed together to produce the mixture. The ratio of screw length to screw diameter (L/D ratio) of the utilized twin-screw extruder was in the range of 5:1 and 7:1. In the end, a carbon material comprising at least 70% by mass of graphene was produced by carbonizing an exemplary mixture using a process similar to step 106 of exemplary process 100 as presented in FIG. IB, using a microwave-electric shock assisted furnace for 20 minutes with 15 °C/min carbonization rate. An exemplary microwave-electric shock assisted furnace has three heating zone comprising a first zone, a second zone, and a third zone (as shown an exemplary reaction vessel 200 in FIGs. 2). An exemplary mixture is pushed forward to the exit port of exemplary microwaveelectric shock assisted furnace through the rotational motion of screw which is mounted inside the cylindrical housing of exemplary microwave-electric shock assisted furnace. In the first step of carbonization, an exemplary mixture was heated in the first zone of the microwave-electric shock assisted furnace to produce the first heated mixture using exemplary first plurality of electric heating elements to a temperature between 140 °C and 150 °C. In the second step of carbonization in the second zone, the second heated mixture was produced by heating the first heated mixture, simultaneously, via exemplary second plurality of electric heating elements and microwave radiation. The first heated mixture was exposed to at least 5 cycles of microwave radiation. Each cycle of microwave radiation comprised an on-period with a time duration of 10 seconds and an off-period with a time duration of 2 seconds. The microwave radiation during on- period operation had a frequency of about 14-17 GHz, preferably 15 GHz. The first heated mixture in the second zone was heated to around 289 °C. In the last step of carbonization, an electric shock was applied to the second heated mixture in the third zone, wherein the voltage of the electric shock was about 10 kv.

[00056] After production, different analyses were done to characterize the carbon material comprising at least 70% by mass of graphene powder, including Field Emission Scanning Electron Microscopy (FESEM), and Transmission Electron Microscopy (TEM). FIG. 5A illustrates an exemplary TEM image 500 of an exemplary carbon material comprising at least 70% by mass of graphene, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 5A, graphene sheets are flat with no wrinkles or folds, nearly transparent, and have sharp corners. Areas 502 in FIG. 5A may show a plurality of graphene nanoplatelets stuck together. FIG. 5B an exemplary FESEM image 600 of an exemplary carbon material comprising at least 70% by mass of graphene, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 5B, graphene sheets have a small amount of imperfection such as surface wrinkles, folds or adlayers. Example 2: Producing an exfoliated graphene powder from waste PET particles

[00057] In this example, an exfoliated graphene powder was produced from waste PET particles utilizing a process similar to exemplary process 300 as presented in FIG. 3A. At first, 150 g of waste PET particles with an average size of 15 mm were ground to powder with the average size of 50 pm (mesh 300) using a shredder. The shredder has a cylindrical housing with a diameter- to -length ratio of 0.14, wherein two hexagonal shafts with a length of 125 cm and a pitch of 0.17 cm are mounted inside the housing. A plurality of blades with a height of 25 mm is attached to the lateral surfaces of the shafts. A plurality of permanent blades is attached to the inner surface of the cylindrical housing. Each respective permanent blade has a pyramid shape with a sharp tip, wherein each pyramid has a height of 21 mm. Also, the blades with a pyramid shape are distributed on the inner surface of exemplary cylindrical housing of exemplary shredder at a distance of 32 mm from others. In the next step, a mixture was formed by blending 100 g of waste PET powder with 0.1 g of an exemplary catalyst in an exemplary twin-screw extruder for a time duration of 8 minutes. An exemplary catalyst was a freshly prepared nanocomposite of PANVNa-MMT/RGO/graphite oxide (38%wt./ 14%wt./ 22%wt./ 26%wt.) with an average particle size of 75 nm. Waste PET powder and catalyst were fed to an exemplary twin-screw extruder at a temperature level between 25 °C and 30 °C, heated to a temperature between 150 °C and 160 °C, and mixed together to produce the mixture. The ratio of screw length to screw diameter (L/D ratio) of the utilized twin-screw extruder was in the range of 5:1 and 7:1. In the next, a carbon material comprising at least 70% by mass of graphene was produced by carbonizing an exemplary mixture using a process similar to step 106 of exemplary process 300 as presented in FIG. 3B, using a microwave-electric shock assisted furnace for 20 minutes with 15 °C/min carbonization rate. An exemplary microwave-electric shock assisted furnace has three heating zone comprising a first zone, a second zone, and a third zone (as shown an exemplary reaction vessel 200 in FIGs. 2). An exemplary mixture is pushed forward to the exit port of exemplary microwave-electric shock assisted furnace through the rotational motion of screw which is mounted inside the cylindrical housing of exemplary microwave-electric shock assisted furnace. In the first step of carbonization, an exemplary mixture was heated in the first zone of the microwave-electric shock assisted furnace to produce the first heated mixture using exemplary first plurality of electric heating elements to a temperature between 140 °C and 150 °C. In the second step of carbonization in the second zone, the second heated mixture was produced by heating the first heated mixture, simultaneously, via exemplary second plurality of electric heating elements and microwave radiation. The first heated mixture was exposed to at least 5 cycles of microwave radiation. Each cycle of microwave radiation comprised an on- period with a time duration of 10 seconds and an off-period with a time duration of 2 seconds. The microwave radiation during on-period operation had a frequency of about 14-17 GHz, preferably 15 GHz. The first heated mixture in the second zone was heated to around 289 °C. In the last step of carbonization, an electric shock was applied to the second heated mixture in the third zone, wherein the voltage of the electric shock was about 10 kv. In the end, an exfoliated graphene powder was produced by exfoliating the carbon material comprising at least 70% by mass of graphene utilizing a process similar to step 114 of exemplary process 300 as presented in FIG. 3B. Exfoliating the carbon material comprising at least 70% by mass of graphene may include preparing a 100 g mixture comprising carbon material and water (1:1 w/w) using a mixer. In an exemplary embodiment, an exemplary mixture was produced by mixing 50 g of carbon material with 50 g of water. In the next, an exemplary mixture of the carbon material and water was circulated in an exemplary hydrodynamic nano-cavitation reactor for a time duration of 20 minutes, wherein the hydrodynamic nano-cavitation reactor has a pressure in the range between 4 bar and 6 bar. In an exemplary embodiment, an exemplary mixture of the carbon material and water was exposed to high energy nano-bubbles produced in an exemplary hydrodynamic nano-cavitation reactor. In the end, an exfoliated graphene powder was produced by drying the circulated mixture of the carbon material and water by using an exemplary vacuum oven. After production, different analyses were done to characterize the exfoliated graphene powder, including FESEM, and TEM. FIG. 6A illustrates an exemplary TEM image 700 of an exemplary exfoliated graphene powder, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 6A graphene sheets are nearly transparent and have no sharp corners. Graphene sheets have a small amount of imperfection such as surface wrinkles and adlayers. It also may be found that the size of the graphene flakes is large. FIG. 6B illustrates an exemplary FESEM image 800 of an exemplary exfoliated graphene powder, consistent with one or more exemplary embodiments of the present disclosure. It may be assumed that the exfoliated graphene powder produced from the waste PET particle using the process described in Example 2 is mainly the material consisting of, possibly a few separated and exfoliated, randomly oriented graphene flakes that were mixed with larger flakes.

Example 3: Producing an exfoliated graphene powder with a purification of at least 90% from waste PET particles

[00058] In this example, exfoliated graphene powder with a purification of at least 90% was produced from waste PET particles utilizing a process similar to exemplary process 400 as presented in FIG. 4B. At first, 150 g of waste PET particles with an average size of 15 mm were ground to powder with the average size of 50 pm (mesh 300) using a shredder. The shredder has a cylindrical housing with a diameter-to-length ratio of 0.14, wherein two hexagonal shafts with a length of 125 cm and a pitch of 0.17 cm are mounted inside the housing. A plurality of blades with a height of 25 mm is attached to the lateral surfaces of the shafts. A plurality of permanent blades is attached to the inner surface of the cylindrical housing. Each respective permanent blade has a pyramid shape with a sharp tip, wherein each pyramid has a height of 21 mm. Also, the blades with a pyramid shape are distributed on the inner surface of exemplary cylindrical housing of exemplary shredder at a distance of 32 mm from others. In the next step, a mixture was formed by blending 100 g of waste PET powder with 0.1 g of an exemplary catalyst in an exemplary twin-screw extruder for a time duration of 8 minutes. An exemplary catalyst was a freshly prepared nanocomposite of PANI/Na-MMT/RGO/graphitc oxide (38%wt./ 14%wt./ 22%wt./ 26%wt.) with an average particle size of 75 nm. Waste PET powder and catalyst were fed to an exemplary twin-screw extruder at a temperature level between 25 °C and 30 °C, heated to a temperature between 150 °C and 160 °C, and mixed together to produce the mixture. The ratio of screw length to screw diameter (L/D ratio) of the utilized twin-screw extruder was in the range of 5:1 and 7:1. In the next, a carbon material comprising at least 70% by mass of graphene was produced by carbonizing an exemplary mixture using a process similar to step 106 of exemplary process 400 as presented in FIG. 4B, using a microwave-electric shock assisted furnace for 20 minutes with 15 °C/min carbonization rate. An exemplary microwave-electric shock assisted furnace has three heating zone comprising a first zone, a second zone, and a third zone (as shown an exemplary reaction vessel 200 in FIGs. 2). An exemplary mixture is pushed forward to the exit port of exemplary microwave-electric shock assisted furnace through the rotational motion of screw which is mounted inside the cylindrical housing of exemplary microwave-electric shock assisted furnace. In the first step of carbonization, an exemplary mixture was heated in the first zone of the microwave-electric shock assisted furnace to produce the first heated mixture using exemplary first plurality of electric heating elements to a temperature between 140 °C and 150 °C. In the second step of carbonization in the second zone, the second heated mixture was produced by heating the first heated mixture, simultaneously, via exemplary second plurality of electric heating elements and microwave radiation. The first heated mixture was exposed to at least 5 cycles of microwave radiation. Each cycle of microwave radiation comprised an on-period with a time duration of 10 seconds and an off- period with a time duration of 2 seconds. The microwave radiation during on-period operation had a frequency of about 14-17 GHz, preferably 15 GHz. The first heated mixture in the second zone was heated to around 289 °C. In the last step of carbonization, an electric shock was applied to the second heated mixture in the third zone, wherein the voltage of the electric shock was about 10 kv.

[00059] In the end, an exemplary exfoliated graphene powder with a purification of at least 90% was produced by simultaneously exfoliating and purifying an exemplary carbon material utilizing a process similar to step 122 of exemplary process 400 as presented in FIG. 4B. Simultaneously exfoliating and purifying an exemplary carbon material may include forming 100 g of exemplary mixture of exemplary carbon material and water with a weight ratio (carbon material: water) of 1:1 (1:1 w/w) using a mixer. Indeed, for producing exemplary mixture of exemplary carbon material and water, 50 g of carbon material was mixed with 50 g of water. In the next, an exemplary mixture of the carbon material and water with an intercalating agent was prepared by adding 5 g of an intercalating agent to 95 g of exemplary mixture of exemplary carbon material and water and mixing in a turbo mixer with a speed of 3000 rpm for 5 minutes. The intercalating agent comprised 94 (%wt.) of water, 1.2 (%wt.) of acid carboxylic, 1.1 (%wt.) of acid citric, 0.8 (%wt.) of acid acetic, and 0.55 (%wt.) of sorbitane monooleate. In the next, the mixed mixture was circulated in an exemplary hydrodynamic nano-cavitation reactor for 20 minutes, wherein the hydrodynamic nano-cavitation reactor has a pressure in the range of 4-6 bar. In the hydrodynamic nano-cavitation reactor, the mixed mixture was exposed to high energy nanobubbles produced therein. In the next, the circulated mixture in the hydrodynamic nanocavitation was separated into a solid phase and a liquid phase. Separation may carry out using a centrifuge with 4800 rpm, for 6 minutes. In the end, an exfoliated graphene powder with a purification of at least 90% was produced by drying the solid phase. Drying may carry out using a vacuum oven at a temperature level of 80 °C, for a time duration of 120 minutes.

[00060] After production, different analyses were done to characterize the at least 90% purified exfoliated graphene powder, including FESEM, and TEM. FIG. 7A illustrates an exemplary TEM image 900 of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure. As shown in FIG. 7A, graphene sheets are nearly transparent and have no sharp corners. Graphene sheets have a small amount of imperfection such as surface wrinkles and adlayers. It also may be found that the size of the graphene flakes is large, in the range of micrometers. However, there is no dark area in FIG. 7A that may be evidence of the production of the exfoliated graphene sheets. FIG. 7B illustrates an exemplary FESEM image 1000 of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure. FIG. 7C illustrates an exemplary Raman spectrum 1100 of an exemplary exfoliated graphene powder with a purification of at least 90%, consistent with one or more exemplary embodiments of the present disclosure. It is well-known that the integrated intensity ratio of the defect D band (at ca. 1347 cm ^-1 ) to the G band (at ca. 1594 cm ^-1 ), (7D//G ratio), is used to assess the extent of structural disorders or defects in the studied materials. As shown in FIG. 7C, the /D//G ratio of graphene powder obtained using the process described in Example 3 is 1.08 which is in the range of 0.83 to 1.93 as the known the /D//G value of graphene nano-platelets. Therefore, although the obtained results in /D//G value shows that the graphene may have some little defects, but as may be seen from FESEM image (FIG. 7B), no significant change in surface morphology has been observed. [00061] While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

[00062] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents.

[00063] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.

[00064] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[00065] The Abstract of the disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it may be seen that various features are grouped together in various implementations. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

[00066] While various implementations have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more implementations and implementations are possible that are within the scope of the implementations. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any implementation may be used in combination with or substituted for any other feature or element in any other implementation unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the implementations are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.