Method for producing graphene sheets and hollow carbon nanostructures as well as crystalline twisted bilayer / few-layer graphene thereby produced

Abstract

There is provided a method for producing graphene or a hollow carbon nanostructure such as hollow spherical, ellipsoidal and tubular nanostructures. The method comprises a) mixing together water, an organic solvent that is immiscible with water, and a surfactant to prepare a suspension of self-assembled surfactant templates, b) adding a monomer to the suspension, c) polymerizing the monomer to form a polymer on the self-assembled surfactant template, and d) decomposing the polymer into carbon, thereby forming graphene or the hollow carbon nanostructure. There is also provided crystalline twisted bilayer or few-layer graphene which can be produced by this method.

Description

METHOD FOR PRODUCING GRAPHENE SHEETS AND HOLLOW CARBON NANOSTRUCTURES AS WELL ASCRYSTALLINE TWISTED BILAYER I FEW-LAYER GRAPHENE THEREBYPRODUCEDCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit, under 35 U.S.C. § 119(e), of U.S. provisional application Serial No. 63 / 513,597, filed on July 14, 2023. All documents above are incorporated herein in their entirety by reference.FIELD OF THE INVENTION

[0002] The present invention relates to a method for producing graphene sheets, including in the form of crystalline twisted bilayer / few-layer graphene, and hollow carbon nanostructures. More specifically, the present invention is concerned with a method that allows controlling various characteristics of the graphene sheets and hollow carbon nanostructures produced, such as morphology, structure, shape, size, crystallinity, etc. The present invention also relates to crystalline twisted bilayer / few-layer graphene that can be obtained using this method.BACKGROUND OF THE INVENTION

[0003] Carbon nanomaterials are of interest for multiple applications including bioimaging, drug delivery, sensing, and photocatalysis. Certain carbon nanomaterials, such as zero dimensional fullerenes, one-dimensional carbon nanotubes and two-dimensional graphene, are composed of entirely sp2bonded carbon atoms, and have attracted much attention because of their unique physical and structural properties1.

[0004] Graphene has been produced by several methods including liquid phase exfoliation38, chemical vapor deposition39, and reduction of graphene oxide40.

[0005] Carbon nanoparticles (CNPs) are a well-studied member of the wider class of carbon nanomaterials because they are inexpensive, non-toxic, and safe2. Other advantages of CNPs, such as high biocompatibility, easy surface functionalization, and environmental friendliness, have led to their use in very important fields such as drug delivery in the human body and as catalysts in green chemistry3

[0006] The main obstacle to the further development of CNPs is the difficulty of controlling their size and shape, as well as the exact nature of carbon-carbon bonding within them. The majority of synthetic methods developed to date involve the pyrolysis of various abundant and inexpensive sources of carbon, such as sugars,5plants,6fruit juice,7and coffee.8After pyrolysis, the CNPs are extracted from the resulting soot, a process that is often tedious and inefficient, and produces very small quantities of polydisperse nanoparticles with poorly defined properties. In addition, this high-temperature method does not allow for the control over the size and the shape of nanoparticles9.

[0007] In an effort to overcome this lack of control, Gu and coworkers10reported the use of Metal-Organic Frameworks (MOFs) in a hard template-assisted method to synthesize CNPs. They loaded glucose as carbon source into the MOF before heating at 200 °C for 2h to produce the CNPs. After the formation of the CNPs, the hard template is removed by etching, adding an additional step to the process. Furthermore, the MOF hard template is restricted to very small sizes and does allow for the preparation of particles of different shapes or hollow structures11. Another challenge of the hard template approach is that scale up for industrial applications is very difficult.

[0008] Also, high temperature synthetic methods generally lead to the formation of amorphous, disordered CNPs, without a well-defined shape, and which often tend to aggregate during their preparation and isolation.12

[0009] Graphene is a two-dimensional allotrope of carbon composed of sp2hybridized atoms organized in a hexagonal crystalline lattice. The extended delocalisation of Ti-electrons within a single graphene sheet gives rise to extraordinary electronic properties, making graphene the subject of extensive research. More recently, twisted graphene obtained by stacking two or more layers on top of each other with a precise twist angle between them - see Fig.1 - has attracted great attention, driven in large part by the report of unconventional superconductivity in bilayers twisted at a specific “magic” angle. In fact, the electronic band structure of twisted graphene is influenced by the twist angle between the graphene layers. By tuning the twist angle, it becomes possible to precisely control the electronic structure and energy band of graphene, resulting in the development of novel electrical, optical, and diverse physical properties. The Moire superlattice can lead to magnetic properties. The magnetic states arise due to the formation of correlated electron states and the breaking of inversion symmetry within the twisted graphene structure, which can be further fine-tuned and controlled by adjusting the twist angle. This tunability offers opportunities for engineering magnetic behavior in graphene-based devices such as magnetic sensing, and magnetic storage devices.

[0010] The development of experimental methods for the preparation of twisted graphene is essential to both the investigation of its fundamental physics and the exploration of potential applications. Preparation methods reported to date include SiC-based epitaxial growth, chemical vapor deposition, pick-up and transfer, and folding techniques. All these methods involve either extreme conditions of high temperature or the tedious manipulation of individual exfoliated layers. Furthermore, these synthetic routes provide graphene in very low yield. Thus, methods to prepare twisted graphene structures, ideally through methods that provide a precise control over the twist angle, still need to be developed.SUMMARY OF THE INVENTION

[0011] In accordance with the present invention, there is provided:Embodiment 1. A method for producing graphene or a hollow carbon nanostructure, such as a hollow sphere, a hollow ellipsoid, or a hollow rod, preferably graphene, a) mixing together water, an organic solvent that is immiscible with water, and a surfactant to prepare a suspension of self-assembled surfactant templates, b) adding a monomer to the suspension,c) polymerizing the monomer to form a polymer on the self-assembled surfactant template, and d) decomposing the polymer into carbon, thereby forming graphene or the hollow carbon nanostructure.Embodiment 2. The method of embodiment 1 , wherein step a) comprises dissolving the surfactant in one of i) water and ii) the organic solvent, thereby producing a mixture, and then mixing this mixture with the other of i) water and ii) the organic solvent.Embodiment 3. The method of embodiment 2, wherein step a) comprises dissolving the surfactant in the organic solvent, thereby producing a mixture, and then mixing this mixture with water.Embodiment 4. The method of any one of embodiments 1 to 3, wherein the surfactant comprises bis(2- ethylhexyl) sulfosuccinate (AOT), preferably is AOT.Embodiment 5. The method of any one of embodiments 1 to 4, wherein the organic solvent comprises hexane, preferably is hexane.Embodiment s. The method of any one of embodiments 1 to 5, wherein the mixing in step a) is done by mechanical stirring for e.g., 10 minutes.Embodiment / . The method of any one of embodiments 1 to 6, wherein step a) comprises preparing a solution of the surfactant in one of i) water and ii) the organic solvent, and then adding this solution to the other of i) water and ii) the organic solvent.Embodiment s. The method of embodiment 7, wherein step a) comprises preparing a solution of the surfactant in the organic solvent, and then adding this solution to waterEmbodiment 9. The method of any one of embodiments 1 to 8, wherein the self-assembled surfactant templates are spherical, ellipsoidal, cylindrical, or lamellar in shape.Embodiment 10. The method of embodiment 9, wherein the self-assembled surfactant templates are lamellar in shape, thereby yielding graphene.Embodiment 11. The method of any one of embodiments 1 to 10, further comprising adjusting the proportions of water, surfactant, and organic solvent used at step a) so as to adjust the shape of the self-assembled surfactant templates.Embodiment 12. The method of any one of embodiments 1 to 11, wherein the monomer is soluble in only one phase selected from i) the organic solvent and i) water, and polymerization of the monomer requires a polymerization reactant that is insoluble the phase in which the monomer is soluble.Embodiment 13. The method of embodiment 12, comprising adding the polymerization reactant at step a) or at step b).Embodiment 14. The method of embodiment 13, wherein step a) comprises preparing a solution of the polymerization reactant in one of i) water and ii) the organic solvent, and then adding this solution to theother of i) water and II) the organic solvent.Embodiment 15. The method of embodiment 14, wherein step a) comprises preparing a solution of the polymerization reactant in water, and then adding this solution to the organic solvent.Embodiment 16. The method of any one of embodiments 1 to 15, wherein the polymer is a polyyne or a polyene.Embodiment 17. The method of embodiment 16, wherein the polymer is a polyyne.Embodiment 18. The method of embodiment 17, wherein the monomer is an acetylenic monomer, preferably acetylene, butadiyne, hexatriyne, [n]oligoynes where n > 3, silyl-protected acetylene, silyl-protected butadiyne, silyl-protected triyne, silyl-protected [n]oligoynes where n >3, preferably a silyl-protected butadiyne, most preferably 1, 4-bis(trimethylsilyl) butadiyne.Embodiment 19. The method of embodiment 16 or 17, wherein the monomer is polymerized into the polyyne at step c) by Glaser coupling, Eglinton reaction, Hay coupling, Cadiot-Chodkiewicz coupling, or palladium- catalyzed alkyne homocoupling.Embodiment 20. The method of embodiment 19, wherein the monomer is polymerized at step c) by Eglinton reaction.Embodiment 21. The method of embodiment 20, wherein the polymerization reactant is a cupric salt, preferably copper (II) fluoride or copper (II) triflate.Embodiment 22. The method of embodiment 16, wherein the polymer is a polyene.Embodiment 23. The method of embodiment 22, wherein the monomer is an acetylenic monomer, preferably acetylene, butadiyne, hexatriyne, [n]oligoynes where n > 3, silyl- protected acetylene, silyl-protected butadiyne, silyl-protected triyne, silyl-protected [n]oligoynes where n >3, preferably a silyl-protected butadiyne, most preferably 1, 4-bis(trimethylsilyl) butadiyne, or a cycloalkene made of alternating single and double carbon-carbon double bond, preferably cyclooctatetraene.Embodiment 24. The method of embodiment 22 or 23, wherein the monomer is polymerized into the polyene at step c) by Ziegler-Natta reaction or by Ring opening metathesis (ROMP)Embodiment 25. The method of any one of embodiments 1 to 24, wherein the decomposing at step d) is spontaneous and step d) is a step of allowing the decomposition to occur.Embodiment 26. The method of any one of embodiments 1 to 24, wherein the decomposing is performed by heating the polymer, irradiating the polymer, or adding pressure to the polymer.Embodiment 27. The method of any one of embodiments 1 to 26, further comprising after step d)functionalizing the graphene or hollow carbon nanostructure.Embodiment 28. The method of any one of embodiments 1 to 27, further comprising isolating and purifying the graphene or hollow carbon nanostructure.Embodiment 29. Crystalline twisted bilayer or few-layer graphene.Embodiment 30. The twisted graphene of embodiment 29, being made of up to 10 stacked graphene layers, preferably up to 5 stacked graphene layers, and more preferably up to 3 stacked graphene layers.Embodiment 31. The twisted graphene of embodiment 29 or 30, being made of 2 to 5 stacked graphene layers.Embodiment 32. The twisted graphene of any one of embodiments 29 to 31 , being highly crystalline.Embodiment 33. The twisted graphene of any one of embodiments 29 to 32, being substantially free of amorphous graphene.Embodiment 34. The twisted graphene of any one of embodiments 29 to 33, exhibiting, when analyzed by electron diffraction, hexagonal diffraction spots with spacings corresponding to crystalline graphene sheets over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges.Embodiment 35. The twisted graphene of any one of embodiments 29 to 34, exhibiting a Moire pattern when observed by transmission electron microscopy (TEM) or high-resolution transmission electron microscopy (HRTEM).Embodiment 36. The twisted graphene of any one of embodiments 29 to 35, having a high level of purity, for example being substantially free of atoms other than carbon atoms.Embodiment 37. The twisted graphene of any one of embodiments 29 to 36, being substantially free of any other allotrope of carbon.Embodiment 38. The twisted graphene of any one of embodiments 29 to 37, appearing as pure graphene when analyzed by Raman spectroscopyEmbodiment 39. The twisted graphene of any one of embodiments 29 to 38, having a Raman spectrum free of peaks attributed to substances other than graphene.Embodiment 40. The twisted graphene of any one of embodiments 29 to 39, having a twist angle of between 1 and 45°, preferably between 1 and 30°.Embodiment 41. The twisted graphene of any one of embodiments 29 to 40, appearing to be intact over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.Embodiment 42. The twisted graphene of any one of embodiments 29 to 41 , appearing to be free of holes over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.Embodiment 43. The twisted graphene of any one of embodiments 29 to 42, appearing to be free structural defects over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.Embodiment 44. The twisted graphene of any one of embodiments 29 to 43, having an average width and an average length between about 200 nm and about 1000 nm, preferably between about 200 nm and about 500 nm.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In the appended drawings:

[0013] Fig. 1 shows twisted bilayer graphene, specifically the atomic scale Moire pattern created by overlapping two twisted sheets of graphene (Ponor, CC BY-SA 4.0).

[0014] Fig. 2 shows Transmission Electron Microscopie (TEM) images of carbon nanomaterials in different shapes: hollow carbon nanospheres (a), carbon nanorods (b), carbon honeycomb-like layers (c), and a mixture of hollow carbon nanorods and nanospheres (d).

[0015] Fig. 3 shows the ternary composition diagram for AOT / aqueous copper (II) triflate / hexane mixtures. Compositions are expressed in terms of volume fractions and points labelled a, b, c and d correspond to the compositions employed as templates for the synthesis of CNPs. Lines correspond to compositions of constant water / surfactant molar ratios, W, as indicated.

[0016] Fig. 4 shows a schematic illustration of the critical packing parameter.

[0017] Fig. 5 shows a schematic representation of the change in surfactant aggregate shape with increasing water content.

[0018] Fig.6 shows a table representing the morphology definition for before and after polymerization.

[0019] Fig. 7 shows a scheme diagram of the synthesis of hollow carbon nanostructures by using reverse micelle asthe template.

[0020] Fig. 8 shows a scheme diagram of changing the size of micelles at the low water content.

[0021] Fig. 9 shows DLS analysis of micelles at different water content.

[0022] Fig. 10 shows the XRD pattern (a) and XRD graph (b) of sample a.

[0023] Fig. 11 shows the electron diffraction patterns of carbon nanospheres (a); carbon honeycomb-like layer (b).

[0024] Fig. 12 shows the EDS analysis of sample c.

[0025] Fig. 13 shows the XPS quantitative elemental composition analysis (at. %) for sample c.

[0026] Fig. 14 shows the deconvolution of the carbon 1s XPS signal obtained from sample b (Figure 14A) and c (Figure 14B).

[0027] Fig. 15 shows the first-derivative C KLL Auger spectra recorded for different carbon nanostructures.

[0028] Fig. 16 shows the ATR FTIR spectra of sample c.

[0029] Fig. 17 shows a POM image of reverse cylindrical micelle.

[0030] Fig. 18 shows TEM images of carbon nanomaterials in different shapes: hollow carbon nanospheres (a), carbon nanorods (b), carbon honeycomb-like layers (c), and a mixture of hollow carbon nanorods and nanospheres (d).

[0031] Fig. 19 is a schematic representation of the lamellar phase of the AOT / water / hexane system. The middle region corresponds to the aqueous phase and both the external regions correspond to the organic phase.

[0032] Fig. 20 shows TEM images of carbon nanomaterials prepared by the polymerization of acetylene (A) or butadiyne (B) and corresponding electron diffraction patterns (C) and (D).

[0033] Fig. 21 shows the electron diffraction patterns of carbon nanomaterials prepared by the polymerization of acetylene (A) or butadiyne (B) annotated with colored hexagons and white lines to highlight the presence of layers at three different angular orientations.

[0034] Fig. 22 shows a TEM image and an electron diffraction pattern of graphene multilayers prepared by the polymerization of acetylene.

[0035] Fig. 23 is a zoomed out TEM image of the twisted graphene of Example 3.

[0036] Fig. 24A to K show TEM images with and without the area studied by 2D Fast Fourier T ransform (FFT) outlined (top, left and right respectively), 2D FFT frequency image at bottom left and reconstructed TEM image at bottom right of several bilayers / few-layers of the twisted graphene of Example 3.

[0037] Fig. 25A and B show TEM images (left) and electron diffraction measurement images (right) of two bilayers / few-layers of the twisted graphene of Example 3.

[0038] Fig. 26 shows the SAXS scattering curve of the lamellar phase.

[0039] Fig. 27 shows the SAXS PDDF graph of the lamellar phase.

[0040] Fig. 28 shows the deconvolution of the carbon 1s XPS signal obtained from prepared twisted graphene of Example 3.DETAILED DESCRIPTION OF THE INVENTION

[0041] Turning now to the invention in more details, there is provided a method for producing graphene sheets or hollow carbon nanostructures.

[0042] Indeed, the present method allows to produce graphene sheets (sometimes referred herein below as lamellar carbon nanostructure) and hollow carbon nanostructures i.e., carbon nanostructures that are hollow. Hollow carbon nanostructures that can be produced by the method of the invention include hollow spheres, hollow ellipsoids and hollow rods. Of note, the hollow carbon nanostructures produced by the present method are typically different from fullerenes and conventional carbon nanotubes, for example having thicker walls.

[0043] The method of the invention can be tailored (in a way explained further below) to produce either graphene sheets or hollow carbon nanostructures. Advantageously, it is possible to tailor the method to produce graphene sheets or a single type of hollow carbon nanostructure.

[0044] Advantageously, in embodiments, the graphene sheets produced by the method of the invention are in the form of crystalline twisted bilayer or few-layer graphene. Thus, there is also provided crystalline twisted bilayer or fewlayer graphene. As well known in the art, graphene sheets can be in the form of monolayer graphene, bilayer graphene, or few-layer graphene. Monolayer graphene is a single sheet of graphene. Bilayer graphene is made of two stacked layers of graphene. Few-layer graphene (FLG) is defined as having in between 3 and 10 stacked graphene layers.

[0045] In embodiments, the twisted bilayer or few-layer graphene of the invention is made of up to 10 stacked graphene layers, preferably up to 5 stacked graphene layers, and more preferably up to 3 stacked graphene layers. In preferred embodiments, the twisted graphene of the invention is made of 2 to 5 graphene layers.

[0046] The twisted bilayer or few-layer graphene of the invention has a surface, which is comprised of planes made of all outermost graphene layers and edges at the boundaries of the graphene layers.

[0047] The twisted graphene of the invention is crystalline, preferably highly crystalline. Preferably, the twisted graphene of the invention is substantially free of amorphous graphene. Amorphous graphene is graphene made of carbon atoms arranged in irregularly shaped hexagons, and typically other polygons, such as pentagons. In contrast, crystalline graphene is made of carbon atoms arranged in regularly shaped hexagons forming a so-called honeycomb structure. Amorphous graphene can also be referred to as “disorder” in a graphene sheet. In embodiments, the twisted graphene of the invention, when analyzed by electron diffraction, exhibits hexagonal diffraction spots with spacings corresponding to crystalline graphene sheets, over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges.

[0048] In embodiments, the twisted bilayer or few-layer graphene of the invention exhibits a Moire pattern when observed by transmission electron microscopy (TEM) or high-resolution transmission electron microscopy (HRTEM).

[0049] In embodiments, the twisted graphene of the invention has a high level of purity. For example, in embodiments, the twisted graphene of the invention is free of any other allotrope of carbon. Other allotropes of carbon include for example graphene monolayers, graphite, hollow carbon nanostructure (including those produced by the method the invention), fullerenes, carbon nanotubes, and the like. In embodiments, the twisted graphene of the invention is substantially free of atoms other than carbon atoms. In embodiments, the twisted graphene of the invention appears to be pure graphene when analyzed by Raman spectroscopy, in other words, no peak attributed to substances other than graphene can be observed in the Raman spectrum of the twisted graphene of the invention.

[0050] In embodiments, the twisted graphene of the invention has a twist angle of between 1 and 45°, preferably between 1 and 30°.

[0051] In embodiments, the twisted graphene of the invention, when observed by TEM, appears to be intact, for example being free of holes and / or other structural defects (being hole-free and structure defect-free), over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges.

[0052] In embodiments, the twisted graphene of the invention has an average width and an average length between about 200 nm and about 1000 nm, preferably between about 200 nm and about 500 nm.

[0053] In alternative embodiments, the graphene sheets produced by the method of the invention are bilayer or fewlayer graphene that are not twisted, i.e. they are regular graphene sheets. In other word, when stacked the twist angle between to graphene sheet is about zero.

[0054] In alternative embodiments, the graphene sheets produced by the method of the invention are monolayers of graphene.

[0055] This method represents the first known chemical synthesis for graphene sheets, especially twisted graphene, in solution as opposed to a deposition on a solid substrate. This is a major advantage for preparing suspensions of sufficient concentrations for printing. Current methods involve the exfoliation of graphite into graphene, but the yields are very low, and it is the most poorly ordered sheets (those with defects) that are dispersed preferentially. The TEM images of the graphene sheets produced by the present method (see Figures 2 and 18) show a very high degree of order. Furthermore, the method of the invention is also first known chemical synthesis to produce in bulk twisted bilayer or few-layer graphene, especially crystalline and / pure twisted graphene.

[0056] Also, the present method can be performed at room temperature, which is a significant advantage relative to other methods. Furthermore, the method has a very high yield, for example above 80%. All the chemicals used in the method of the invention (except for the monomer that produced the graphene sheets or hollow carbon nanostructures) can be recovered and reused.

[0057] Furthermore, the graphene sheets produced by the method of the invention can be dispersed to makeconductive inks that can be printed using conventional printing techniques.

[0058] The method of the invention comprises: a) mixing together water, an organic solvent that is immiscible with water, and a surfactant to prepare a suspension of self-assembled surfactant template, b) adding a monomer to the suspension, c) polymerizing the monomer to form a polymer on the self-assembled surfactant template, and d) decomposing the polymer into carbon, thereby forming graphene or the hollow carbon nanostructure.Step a) - preparing the dispersion

[0059] As noted above, the dispersion is prepared by mixing together water, an organic solvent, and a surfactant.

[0060] Any organic surfactant can be used in the present method. Indeed, all surfactants can form the micellar and lamellar phases on which the present method relies. In embodiments, the surfactant comprises bis(2-ethylhexyl) sulfosuccinate (AOT). In preferred embodiments, the surfactant is bis(2-ethylhexyl) sulfosuccinate (AOT).

[0061] Any organic solvent that is immiscible with water can be used in the present method. In embodiments, the organic solvent comprises hexane. In preferred embodiments, the organic solvent is hexane.

[0062] The mixing in step a) can be performed in any way allowing to obtain the desired suspension. In embodiments, the mixing in step a) is done by mechanical stirring for e.g., 10 minutes.

[0063] The water, an organic solvent that is non-miscible with water, and a surfactant can be added at step a) in any order. In embodiments, step a) comprises dissolving the surfactant in one of i) water and ii) the organic solvent, thereby producing a mixture, and then mixing this mixture with the other of i) water and ii) the organic solvent. In preferred embodiments, step a) comprises dissolving the surfactant in the organic solvent, thereby producing a mixture, and then mixing this mixture with water.

[0064] This mixing causes the formation of self-assembled surfactant templates. Indeed, surfactant molecules can arrange in various ways in a biphasic (water / organic) system. They can form spheres, ellipsoids, cylinders, and lamellae. Thus, in embodiments, the self-assembled surfactant template is spherical, ellipsoidal, cylindrical, or lamellar, preferably lamellar. The shape of the carbon nanostructures ultimately produced will depend on the shape of the selfassembled surfactant template. For example, spherical / ellipsoidal micelles yield hollow spheres and ellipsoids, cylinders yield hollow rods, and lamellae yield graphene sheets.

[0065] The shape of the self-assembled surfactant template can be controlled by varying the proportions of water, surfactant and organic solvent used at step a). Therefore, in embodiments, the method of the invention further comprises adjusting the proportions of water, surfactant and organic solvent used at step a) so as to adjust the shape of the self-assembled surfactant templates.

[0066] Spherical micelles typically exist at concentrations relatively close to the critical micelle concentration (CMC)of the water / organic solvent / surfactant system used. At higher surfactant concentrations, micelles typically form asymmetric micelles (ellipsoids) and eventually (at still higher concentration) cylindrical and lamellar structures. Also, increasing the water water / surfactant ratios typically leads to the formation of larger micelles. Furthermore, increasing water content leads to the transformation of spherical micelles into cylindrical micelles and eventually from cylindrical micelles into lamellae.

[0067] The shape of self-assembled surfactant template formed by a particular surfactant is also influenced by the geometry of the surfactant molecules. Elongating the hydrophobic chain(s) of the surfactant typically leads to bigger reverse-micelles. Further, oil-soluble surfactants tend to self-associate into reverse micelles in nonpolar solvents i.e., they arrange with their polar groups oriented towards the center of the micelle (which may also enclose some water). For note, in “regular” micelles, surfactant molecules arrange around droplet of the organic solvent with their polar groups oriented away from the center of the micelle (which typically contains the organic solvent).

[0068] Non-limiting examples of surfactants including:• anionic surfactants, such as sodium dodecyl sulfate and other dodecyl sulfate salts, alkylbenzene sulfonates, dodecyl phosphate and other phosphate esters,• cationic surfactants such as cetyltrimethylammonium bromide (CTAB) and other quaternary ammonium salts; and• non-ionic surfactant such as Igepal (octylphenoxy poly(ethyleneoxy)ethanol, branched), Triton X-100 (Polyethylene glycol p-(1 ,1 ,3,3-tetramethylbutyl)-phenyl ether), and other octylphenol derivatives.Steps B and C - adding and polymerizing the monomer

[0069] In steps b) and c), a monomer is added and polymerized at the surface of the self-assembled surfactant template. Polymerization away from the surface of the self-assembled surfactant template, either in the organic or the aqueous (water) phase, should be limited to avoid the uncontrolled formation of the polymer.

[0070] There are various methods to achieve polymerization at the surface of the self-assembled surfactant template, while limiting polymerization elsewhere in the reaction system. One of these methods is to use a monomer: that is soluble in only one phase selected from i) the organic solvent and i) water, and which polymerization requires a polymerization reactant that is insoluble in the phase in which the monomer is soluble. Note that more than one polymerization reactant might be needed and used in the polymerization reaction, but at least one or them must be insoluble in the phase in which the monomer is soluble.In this way, the only location where the monomer and the polymerization reactant meet and can react is at the surface of the self-assembled surfactant template (which is at the interface between the aqueous phase and the organic solvent phase).

[0071] Therefore, in embodiments, the method comprises adding the polymerization reactant at step a) or at step b). When the polymerization reactant is added at step a), step a) comprises preparing a solution of the polymerizationreactant in one of i) water and ii) the organic solvent, and then adding this solution to the other of i) water and ii) the organic solvent. More preferably, step a) comprises preparing a solution of the polymerization reactant in water, and then adding this solution to the organic solvent (which as noted above may contain the surfactant).

[0072] There are various monomer / polymerization reactant combinations that both: meet the above solubility requirements and produce the polymer that will decompose as desired at step d).The nature of the monomer / polymerization reactant used will of course depend on the nature of the polymer to be produced.

[0073] In embodiments, the polymer is a polyyne or a polyene, preferably a polyyne. Herein, a “polyyne”, which is also sometimes called “carbyne” in the art, is a polymer containing a succession of carbon-carbon triple bonds attached to each other (... — — — ... ) and a “polyene” is a polymer containing a succession of carbon-carbon double bonds attached to each other (......)

[0074] When the polymer is a polyyne, the monomer is an acetylenic monomer, that is a monomer that comprises at least one carbon-carbon triple bond that can react in a polymerization reaction. In embodiments, the monomer is acetylene, butadiyne, hexatriyne, [n]oligoynes where n > 3, silyl-protected acetylene, silyl-protected butadiyne, silyl- protected triyne, silyl-protected [n]oligoynes where n >3. Non-limiting examples of silyl-protected butadiyne include 1 , 4-bis(trimethylsilyl) butadiyne. Preferably, the monomer is a silyl-protected butadiyne, most preferably 1, 4- bis(trimethylsilyl) butadiyne.

[0075] Acetylenic monomers are generally soluble in the organic solvent, but not in water. As such, they are typically used with a polymerization reactant that is soluble in water, but not in the organic solvent. Examples of polymerization reactions that can be used to produce a polyyne include:

[0076] Therefore, in embodiments, the monomer is polymerized into a polyyne at step c) by Glaser coupling, Eglinton reaction, Hay coupling, Cadiot-Chodkiewicz coupling, or palladium-catalyzed alkyne homocoupling. In preferred embodiments, the polymerizing at step c) is performed via Eglinton reaction. Therefore, a cupric salt is used as the polymerization reactant that is insoluble in the phase in which the monomer is soluble. Preferably, cupric salt is copper(II) fluoride or copper (II) triflate.

[0077] When using silyl-protected monomers, a deprotecting agent may be used to remove the silyl protective groups. In preferred embodiments, the deprotecting agent is a fluoride salt, preferably KF.

[0078] When the polymer is a polyene, the monomer is also an acetylenic monomer as described above or a cycloalkene made of alternating single and double carbon-carbon double bonds (for example cyclooctatetraene).Examples of polymerization reactions that can be used to produce a polyene from acetylenic monomers include:Step D - decomposition

[0079] Step d) include the decomposition of the polymer into carbon to produce the desired graphene or the hollow carbon nanostructure.

[0080] In preferred embodiments, this decomposition is spontaneous and therefore step d) is simply a step of allowing the decomposition to occur. Examples of polymer that decompose spontaneously into carbon include polyynes and polyenes.

[0081] In alternative embodiments, the decomposition can be performed by heating the polymer, irradiating the polymer, or adding pressure to the polymer.Step E - Functionalization

[0082] In embodiments, the method of the invention further comprises functionalizing the graphene or hollow carbon nanostructure produced. Examples of said functionalization include: oxidation e.g., producing graphene oxide, reduction, oxidation followed by reduction e.g., producing reduced graphene oxide, click chemistry, covalent bond formation through radical chemistry, cycloaddition reactions, and halogenation.Step F - Isolation / pu rification

[0083] In embodiments, the method of the invention further comprises isolating the graphene or hollow carbon nanostructure produced from the liquid reaction system and purifying the graphene or hollow carbon nanostructure. This can be carried out according to methods well known in the art. For example, one or more cycles comprising isolation (e.g. by centrifugation) and redispersal in a liquid medium can be carried out.Definitions

[0084] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.

[0085] The terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise noted. In contrast, the phrase “consisting of” excludes any unspecified element, step, ingredient, or the like. The phrase “consisting essentially of” limits the scope to the specified materials or steps and those that do not materially affect the basic and novel characteristic(s) of the invention.

[0086] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All subsets of values within the ranges are also incorporated into the specification as if they were individually recited herein.

[0087] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

[0088] The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed.

[0089] No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0090] Herein, the term "about" has its ordinary meaning. In embodiments, it may mean plus or minus 10% or plus or minus 5% of the numerical value qualified.

[0091] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0092] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0093] The present invention is illustrated in further details by the following non-limiting examples.Example 1 - Facile fabrication of hollow or lamellar carbon nanomaterials by directed polymerization of butadiyne on the surface of reverse micelles

[0094] Uniform carbon nanomaterials of different shapes were prepared by a reverse microemulsion polymerizationmethod. One advantage of this method is the ability to control the precise shape of the carbon nanomaterials. The carbon nanomaterials were prepared by the room temperature polymerization of a butadiyne monomer on selfassembled surfactant templates formed in the ternary system containing sodium bis (2-ethylhexyl)sulfosuccinate (AOT), water, and hexane. The size and shape (spherical, cylindrical and lamellar phase) of the aggregated surfactant template depend on the composition of the ternary system, which was varied primarily through the water content parameter. After template removal by simple washing, the carbon nanomaterials were studied by morphological analysis (transmission electron microscopy and X-ray diffraction) and chemical characterization with a variety of methods, including energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy. Depending on the template shape, carbon nanomaterials were obtained in the form of hollow spheres, hollow ellipsoids, hollow rods or lamellar sheets that were graphene-like. The various characterization spectroscopies indicate that the obtained nanomaterials are primarily composed of carbon with high sp2 / sp3hybridization ratios.

[0095] Herein, a soft template method that can be employed at ambient conditions has been used for producing carbon nanomaterials. This soft template method, which is also called the self-assembly method,13has been used for nanoparticle synthesis14-23but has not been used for the preparation of carbon nanomaterials such as hollow spheres, hollow rods or graphene-like lamellar sheets.

[0096] Different self-assembled structures were created by controlling the composition of a ternary surfactant / water / solvent system and used as soft templates for the polymerization of butadiene to produce carbon nanomaterials.

[0097] One main objective was to control of the size and the shape of the carbon nanomaterials by modifying the size and shape of the surfactant template on which the carbon nanomaterials grow.2. Experimental section2.1. Materials

[0098] Sodium bis(2-ethylhexyl) sulfosuccinate (AOT), copper (II) triflate (Cu(OTf)2) and all solvents including hexane and methanol were purchased from Sigma Aldrich. The 1,4-bis (trimethylsilyl)butadiyne monomer was synthesized following the method of Jones et al24. Details are provided as supporting information.2.2. Preparation of surfactant self-assembled structures

[0099] The self-assembled templates were prepared by dispersing an aqueous salt solution containing Cu+2ions in a solution of AOT dissolved in hexane with simple mechanical stirring for 10 minutes. The Cu+2concentration in the aqueous solution was kept constant at 7x10-3 M for all experiments. Different template structures were obtained by varying the molar ratios of the three components (surfactant, solvent, aqueous solution) of the ternary system. The composition of the various samples investigated is provided in Table 1 .

[0100] Table 1 . Chemical composition of mixtures used as templates* added as solution containing 7x103M Cu+22.2.1 Determination of volume fractions

[0101] In order to compare the investigated mixtures with literature phase diagrams, molar compositions were converted to volume fractions following the method reported by Lisiecki et al25. The AOT volume is given by

[0103] where the DAOT, NAV and iftor are the number of surfactant moles, Avogadro’s number and the volume of an AOT molecule, respectively. The volume of a surfactant molecule is assumed to be constant and equal to 639A325.

[0104] Similarly, the water volume (Vw) is calculated as

[0105] Vw= nw. NAv. vw. 10-24cm3 / A3[2]

[0106] where on,, and vware the number of water moles and the volume of a single water molecule, respectively. The volume occupied by a water molecule in a reverse micelle is assumed to follow the logarithmic law provided in equation [3] and ranges from 15 to 30 A3for water contents in the range of 1-2025.

[0108] The volume fraction (0) is obtained with the following relation:

[0109] 0AOT= ^- [4]2.3. Polymerization step: Synthesis of carbon nanomaterials

[0110] Molecules containing a succession of alkyne bonds attached to each other, called polyynes, have been used for the production of carbon nanomaterials. They are known to be unstable and carbon nanotubes and even graphene sheets have been observed following the decomposition of polyynes26.

[0111] Polyynes were synthesized in one step using the Eglinton coupling of butadiyne (Scheme 1). 1 , 4-Bis (trimethylsilyl) butadiyne (50 mg, 0.0002 mol) and potassium fluoride (KF, 30 mg, 0.0005 mol) were added to the various template solutions described in Table 1 and the resulting mixture was stirred for 3 hours at room temperature and atmospheric pressure. The solution was then centrifuged to sediment the CNPs that form as the polyynesspontaneous decompose through crosslinking reactions26. Residual AOT was removed and the CNPs were purified by centrifugation at 5000 rpm for 20 minutes, at room temperature, followed by redispersion in methanol. Five centrifugation / dispersion cycles were performed.Scheme 1. Reaction scheme of Eglinton polymerization of butadiyne.2.4. Characterization

[0112] Samples for energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES) analyses were prepared by depositing few drops of a suspension of carbon nanomaterials in methanol on small pieces of a silicon wafer.

[0113] The EDS analysis were performed with a FEI Inspect F50 scanning electron microscope. For the EDS analysis, Au and Pd were used to coat the carbon nanomaterials for better conductivity. XPS and XAES data were recorded with PHI 5600-CI spectrometer (Physical Electronics, Eden Prairie, MN, USA). All samples were dried under vacuum before analysis. The C KLL Auger data were processed using MultiPak software (version 9.0).

[0114] Samples for transmission electron microscopy (TEM) and electron diffraction measurements were prepared by depositing a drop of a carbon nanomaterial suspension in methanol on carbon-coated nickel TEM grids and examined with a JEOL1230 microscope operated at 80 kV.

[0115] X-ray diffraction data were collected from few drops of a suspension of carbon nanomaterials in methanol on the metal holder operating at 40 kV and 30 mA.

[0116] Template micellar solution was characterized by dynamic light scattering (DLS). DLS was performed using a Malvern (Zetasizer Nano ZS) instrument equipped with a 633nm laser and photodiode detector.

[0117] Attenuated total reflection (ATR) was used to investigate the sample of carbon nanomaterials directly without special preparation. The ATR spectra were recorded on a Nicolet spectrometer and a golden gate diamond accessory. All spectra were recorded at 25°C with 64 scans at 4cm1resolution.3. Results and discussion3. 1 Morphology of the prepared carbon nanoma terials

[0118] TEM images of synthesized carbon nanomaterials for samples a, b, c, and d are presented in Fig. 2. The images clearly show that carbon nanomaterials of different morphologies, including hollow spheres, hollow ellipsoids, hollow rods and honeycomb-like (graphene-like) layers, are obtained. Since the various samples differ only in the proportions of water, surfactant and solvent employed, which are known to strongly influence the shape of the self-assembled surfactant structures, the results suggest that these structures do indeed serve as a template for the polymerization reaction.3.2 Phase behavior of the AOT / water-Cu2+ / hexane system

[0119] Regarding the ternary phase diagram for the specific AOT / water-Cu2+ / hexane system, it should be noted that copper (II) has been included in the reaction medium because it is required to catalyze the Eglinton polymerization reaction. The addition of salt, and divalent cations in particular, significantly modifies the phase behavior of anionic surfactants through a reduction in the electrostatic repulsions between headgroups that, in turn, modifies the surfactant critical packing parameter27. The template compositions selected for this study were based on the phase diagram reported by Lisiecki et al.28for Cu(AOT)2 / water / isooctane mixtures, which correspond to the closest analogous system available in the literature. The compositions of the templates employed for the preparation of samples a-d are represented on the ternary phase diagram shown in Fig. 3. By analogy to the phase diagram established for the Cu(AOT)2 / water / isooctane system28, these four compositions correspond to the formation of spherical reverse micelles, cylindrical micelles, lamellar phases, and a mixture of spherical and cylindrical micelles, respectively.3.3 Critical packing parameter and aggregate shape

[0120] The critical packing parameter of a surfactant molecule corresponds to the ratio of the cross-sectional area of the hydrophobic tail to the area of the polar head group29. This parameter therefore defines the curvature of the water / oil interface in a microemulsion and the shape of the surfactant self-assembled structures. The relationship between the critical packing parameter and the shape of surfactant assemblies is summarized in Fig. 4.

[0121] For a given surfactant, the water to surfactant molar ratio, W, (also referred to as the water content) is the most important parameter that affects the shape of self-assembled structures in microemulsion systems30. Lines corresponding to various water contents, ranging from 2 to 24, are plotted in Fig. 3. As water content is increased, the area occupied by the polar headgroups becomes larger due to an increase in hydration25. The resulting change in the critical packing parameter leads to the transformation of spherical micelles to cylindrical micelles and from cylindrical micelles to a lamellar structure at progressively higher water contents28. The transformations are shown schematically in Fig. 5.3.4 Evidence for soft-templating

[0122] A summary of the relationship between the predicted surfactant structure and the shape of synthesized carbon nanomaterials is provided in Fig. 6. Despite the fact that the phase diagram for the specific system investigated here has yet to be established, the correspondence between the predicted template structure and the structure of the carbon nanomaterials obtained by butadiyne polymerization is striking and supports the hypothesis that the surfactant selfassembled structures serve as templates during the polymerization reaction. In Fig. 2d, a mixture of carbon hollow rods and carbon hollow spheres is obtained after polymerization. In fact, for this sample, the water content is higher (W=24), and the size of the polar head group of the spherical micelle is larger compared to sample (a) which W is 2. Therefore, since they do not have enough space, some of these spherical micelles become elongated and form hollowcylindrical templates.

[0123] A second observation that strongly supports the hypothesis of templated polymerization is the fact that the resulting carbon nanostructures are hollow. Given that the monomer is soluble in the organic phase whereas the copper ions required to catalyze the polymerization reaction are present in the aqueous phase, the polymerization reaction will take place around the micelles at the water-organic interface. A schematic representation of the templated production of different shapes of carbon nanomaterials is shown in Fig. 7.3.5 Dimensions of the CNPs

[0124] The dimensions of the synthesized carbon nanomaterials, as estimated from TEM images, are summarized in Table 2.

[0125] Table 2: Dimensions of the synthesized carbon nanomaterials* Dimensions along the short axis in the case of ellipsoids and rods.

[0126] As the scheme of Fig. 8 shows, the size of reverse micelles can be adjusted in the nanometer range by watersurfactant molar ratio (water content). The micellar solutions employed as templates were characterized by dynamic light scattering and results are shown in Fig. 9. In the case of compositions corresponding to the formation of spherical micelles, the measured hydrodynamic diameter of 4.5 nm corresponds very closely to the inner dimensions of the hollow carbon nanospheres and further supports the hypothesis that the CNPs are formed by polymerization around the template structures.

[0127] Jang et al31prepared polypyrrole nanotubes in a AOT / hexane / water system by using reverse cylindrical micelles. The size of reverse cylindrical micelles and prepared polypyrrole nanotubes which they reported was 65 nm and 94 (±13) nm respectively. For the investigation of solvent effect, they replaced the solvent with heptane and octane and found that the diameter of polypyrrole nanotubes changed to 138 and 176 respectively which means that the diameter of reverse micelles increasing with the increasing the length of hydrocarbon chain of solvent. Also they proved that with increasing the water-AOT molar ratio, the nanotube diameter increased.3.6 Characterization of the carbon nanomaterials

[0128] The prepared carbon nanomaterials were characterized by XRD and electron diffraction. Similar x-ray diffraction patterns were obtained for all of the samples (except sample c) and indicate that these samples areamorphous. The pattern obtained for sample a is shown in Fig. 10a as an example. In the crystal structure, the XRD pattern shows some rings but there are no rings in the XRD pattern of sample a which means the structure is amorphous. Also, the XRD graph for the sample a is shown in the Fig. 10b. The result of XRD pattern is confirmed in the XRD graph (Fig. 10b) since XRD graph of sample a showed the broad peak with no sharp points which is another confirmation for amorphous structures. The XRD graph for the sample c showed some sharp peaks meaning this sample has a highly ordered structure. The electron diffraction result for carbon honeycomb-like (graphene-like) layers (Fig. 11b) shows a highly ordered structure. In fact, this organized pattern may have been obtained because the multiple layers are placed on top of each other with a discipline in different angles creating a honeycomb network. Fig. 11a shows the electron diffraction of sample a as an example and is consistent with the conclusion of an amorphous structure since there is no sharp rings in the pattern.

[0129] EDS analysis was performed for elemental analysis. As shown in Fig. 12, after polymerization, carbon is the main element of the obtained carbon nanomaterials confirming the success of the polymerization. The other elements such as Si, Au, and Pd are related to the substrate of deposition and coating respectively. The presence of oxygen is attributed to partial oxidation of the silicon substrate.

[0130] Fig. 12 shows the XPS elemental survey spectrum of sample c. XPS analysis also confirmed that the nanomaterials are primarily composed of carbon. The XPS high resolution analysis of carbon atoms shown in Fig. 14. The position of the carbon 1s signal indicates that the majority (74%) of carbon atoms in the samples are bonded to other carbon atoms. As shown in Fig. 14, the highest energy peak appears at 284.6 eV, meaning that most of the carbon-carbon bonds are double bonds.32The other smaller peaks at 286.2 and 288.6 eV correspond to the carbon atoms with one bond and two bonds to oxygen, respectively. These signals can be attributed to contamination of the silicon substrate as silicon wafers always show residual carbon -oxygen species which cannot be removed.

[0131] Table 3. Quantitative results of the XPS elemental composition analysis.

[0132] Table 4. Results of the XPS high resolution of carbon analysis.

[0133] Orbital hybridization plays an important role in determining the properties of carbon nanomaterials. Robertson33has provided a comprehensive review of the characterization and properties of different phases of amorphous carbon ranging from graphite (sp2) to diamond (sp3). For example, nanostructures rich in sp2-hybridized carbon exhibit good electrical conductivity properties whereas sp3-hybridized carbon nanostructures are insulating and hard. XAES analysis has been reported as a method for determining the hybridization state of carbon atoms in different carbon nanomaterials. In this method, the degree of separation between the most positive maximum and the most negative minimum of first derivative of carbon KLL Auger peaks is defined as the D parameter34. Importantly, the D parameter has been shown to vary linearly with the sp2 / sp3ratio. Auger C KLL spectra were recorded for the various carbon nanomaterials and are provided in the form of their first derivatives in Fig. 15. In order to establish a calibration plot for sp2content as a function of the D parameter, graphite and polyethylene were selected as standards corresponding to 100% sp2and 100% sp3materials, respectively. The D value for graphite was evaluated experimentally at 19 eV, whereas the D value for polyethylene was 12.7 eV. Experimental D values of 15.2, 15.5 and 16.4 eV were obtained from the first derivative Auger spectra of the carbon nanospheres (sample a), carbon nanorods (sample b) and carbon honeycomb-like graphene-like layered structure (sample c) respectively. Hybridization ratios of sp2 / sp3carbon were calculated by assuming a linear dependence on the D parameter and experimental values obtained or graphite and polyethylene. These values, presented in Table 5 correspond to sp2contents ranging from 40 to 60%, with the carbon lamellar structure having the highest sp2hybridization content.

[0134] Table 5. D parameter and sp2value for all carbon nanostructures.

[0135] XPS analyses indicate that essentially all carbon-carbon bonding within the obtained nanomaterials is sp2in nature. Auger spectroscopy, on the other hand, indicates lower sp2contents, on the order of 40-60 %. Infrared spectroscopy, (Fig. 16) spectra of the carbon nanomaterials exhibit a band at 1650 cm1which can be attributed to aromatic C=C stretching shown. The only other features in the I R spectra can be attributed water (at 3300 cm1), which is the solvent used to disperse the carbon nanomaterials and CO2 (g) (2368 cm1).

[0136] The micellar sample of b was characterized by polarized optical microscopy (POM) since it was supposed to have some cylindrical structures in the sample. Jang et al31in their research noted that cylindrical micelles showed birefringent orientation in the POM image because of their disordered arrangement. This analysis is not working on the sample a since it’s a dilute solution and has high amount of hexane as shown in the phase diagram. The POM image is shown in Fig. 17. The polarization of polarized light was changed by the anisotropic refractive index of the structure and showed birefringent striations on the POM image that is related to undulations of cylindrical micelles. This result confirms the accuracy of the cited phase diagram as a reference although the micellar system in our work and reference is slightly different.3.7 Discussion

[0137] TEM analysis revealed that the carbon nanomaterials have a hollow structure with different sizes between 5 nm to 12 nm. The relation between micelle structure and carbon nanomaterials shapes are logical since the micelle sizes are around the 4 nm and phase diagram predicted the shape of micelles. Based on the electron diffraction, the carbon nanospheres and carbon nanorods showed an amorphous pattern but carbon nanolayers showed the highly ordered and periodic pattern consistent with multilayers placed at different angles. The XPS analysis showed that prepared carbon nanostructures have carbon-carbon double bond and sp2sites in the aromatic rings.3.8 Reproducibility

[0138] Except of repeating the result of polymerization synthesizes with micellar solution (AOT- Cu (OTf)2(aq) - Hexane) for three times, the preparation of this micellar solution was repeated with new copper salt to explore the reproducibility of process in terms of carbon nanomaterials morphology and features in the chemical characterization. The copper (II) fluoride (CUF2) was used in the solution of AOT and hexane as a new copper salt. The micellar solutions (AOT- CuF2(aq)- Hexane) were prepared in the same spots of the phase composition and used for the polymerization synthesis. The different shapes of carbon nanomaterials are shown in Fig. 18.Conclusions

[0139] This relationship between the shape of micellar templates and the final shape of synthesized carbon nanomaterials confirms the function of the micellar template as a novel method of producing carbon nanomaterialswith the desired shape.Example 2 - Supporting Information for Example 1Synthesis carbon monomer (butadiyne)

[0140] In a round-bottom flask, copper (I) chloride (500 mg, 0.005 mol) was dispersed in acetone (10 mL). Tetramethylethylenediamine (TMEDA, 0.25 ml) was added and the mixture was purged with nitrogen and stirred for 30 minutes. After 30 min, the solid material settled resulting blue-green solution containing the CuCI-TMEDA complex, which was used as a catalyst in the reaction. CuCI-TMEDA catalyst was added by syringe in 5-mL portions to a solution of acetone (30 mL) and trimethylsilylacetylene (5 g, 50 mmol) and oxygen stream was passed through the reaction. Since after adding the CuCI-TMEDA catalyst the temperature increased, after adding 75% of catalyst the temperature reached to 35°C. In this temperature range, an ice / water bath was used to control the temperature. Then, the remaining catalyst was added, and the temperature was maintained at 25- 30°C for 2.5 hours. When the reaction was completed, there was no evidence of condensation of trimethylsilylacetylene in cold trap, then the stirring and oxygenation were stopped. The acetone was removed with a rotary evaporator, and ether (15 mL) was added to the residue. The resulting solution was shaken and washed with hydrochloric acid (3 M) in a separatory funnel and, after phase separation, the aqueous phase was washed with ether (3x15ml). The organic phases were combined and washed with saturated aqueous sodium chloride (5ml), dried over MgSO4, and evaporated with a rotary evaporator to remove all solvent to dryness. Then hot methanol (40 mL) and aqueous hydrochloric acid 3M (4mL) were added to the solid residue and the solution was filtered to remove all colored insoluble impurities. Water was added dropwise to the filtrate solution to appear the recrystallized materials. Finally, the solution was cooled in the ice and crystalline bis (trimethylsilyl) butadiyne was collected. The material was washed with 50 mL of a water / methanol mixture (1 :1) and air-dried to provide the bis (trimethylsilyl) butadiyne in a pure form (Scheme 2).

[0141] Scheme 2. Reaction scheme of oxidative coupling using CuCI-TMEDAExample 3 -Room-Temperature, Solution-Phase Synthesis of Few-Layer Twisted Graphene

[0142] An approach based on the templated transformation of metastable alkyne-rich derivatives, herein called [n]ynes, was used for the production of twisted multilayer graphene.

[0143] This method possesses several advantages, including easy access to the precursors, low energy input required to initiate the process and control over the size and shape of the resulting carbon nanostructure. However, the highly exothermic transformation of [n]ynes mostly yields amorphous graphitic materials with a relatively large number of structural defects. This is a serious drawback as well-defined structures exhibiting a precise set of properties are needed for many of the targeted applications.

[0144] Herein, metastable polyynes were prepared through copper-catalyzed acetylene (or butadiyne) polymerization at the interface of a lamellar phase, confining the precursors into a two-dimensional template where it underwent rapid transformation into highly crystalline few-layer, twisted graphene (mostly bi- and trilayer) in very good yield. Moreover, this process is conducted at room temperature without the need of an external stimulus, making this method of graphene production very environmentally friendly. Interestingly, Moire patterns can be observed in several of the graphene sheets studied by electron microscopy, indicating a high degree of order between the graphene sheets.Experimental MethodMaterials

[0145] Sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and copper (II) triflate (Cu(OTf)2) were purchased from Sigma- Aldrich Canada Co. All solvents including hexane (99.9%) and methanol (99.9%) were purchased from Fisher Scientific. Transmission electron microscopy (TEM) grids (nickel) were purchased from Ted Pella Inc.

[0146] The 1 ,4-bis(trimethylsilyl)butadiyne monomer was synthesized following a method reported by Jones, G. E.; Kendrick, D. A.; Holmes, A. B. 1 ,4-BIS(TRIMETHYLSILYL)BUTA-1 , 3-DIYNE. Org. Synth. 1987, 65, 52.Preparation of the self-assembled surfactant template

[0147] Sodium dioctyl sulfosuccinate (AOT), hexane and water were mixed in appropriate molar ratios to obtain the lamellar phase of the self-assembled surfactant. Specifically, AOT (1 .65 g) was first dissolved in hexane (5 g) to form the organic phase. To this, 0.92 g of an 7x1 O'3M aqueous solution of Cu(OTf)2was added and the mixture was stirred for 10 minutes at room temperature. The copper salt, although not required for the template preparation, is added to the aqueous phase to provide the Cu2+ions required for the Glaser-Hay polymerization.PolymerizationButadiene monomer

[0148] 1 , 4-Bis(trimethylsilyl)butadiyne (50 mg, 0.00026 mol) and potassium fluoride (KF, 30 mg, 0.0005 mol) were added to the lamellar template solution and the resulting mixture was stirred for 3 hours at room temperature and atmospheric pressure. After 3 hours, the solution was centrifuged to separate the particles that were formed from the polymerization and subsequent decomposition of polyynes through crosslinking reactions. Residual AOT waseliminated from the solid product through centrifugation at 5000 rpm for 20 minutes at room temperature, followed by redispersion in methanol. This process was repeated for a total of five centrifugation / redispersion cycles. The synthesis produced 10 mg of purified product which corresponds to a yield of over 80%. monomer

[0149] The prepared lamellar template solution was placed in a sealed reactor (Buchiglas “Miniclave Steel”). Acetylene gas was introduced to reach a pressure of 10 psi. The reaction was allowed to proceed at room temperature for 3 hours under gentle stirring using a magnetic stirrer. At the end of the polymerization reaction, the solution was centrifugated to isolate the solid product. Residual surfactant was removed by repeated cycles of redispersion in the methanol and centrifugation as described above.Characterization methodsTransmission electron mi<

[0150] The solid products isolated after polymerization were dispersed in methanol. A drop of the suspension was deposited on carbon-coated nickel TEM grids for transmission electron microscopy (TEM) and electron diffraction measurements with a JEOL J EM-210Oplus TEM operating at 80 kV equipped with a Gatan OneView 4k camera.

[0151] Samples for X-ray photoelectron spectroscopy (XPS) analysis were prepared by depositing a few drops of a suspension of the isolated product in methanol on small pieces of a silicon wafer. XPS spectra were acquired with a Physical Electronics PHI 5600-ci instrument (Eden Prairie, MN, USA) using an achromatic aluminum X-ray source (Al Ka = 1486.6 eV), without charge compensation. The scan area was 0.5 mm2with a collecting angle of 45° relative to the surface normal. The curve fitting procedure of the components underlying the C1s peaks was performed by means of a least-square minimization procedure employing Gaussian-Lorentzian functions and a Shirley-type background, and the reference was set to the carbon (C1s) peak at 285.0 eV.Small-anqie X-i

[0152] Samples of the surfactant template were introduced into a quartz capillary for SAXS analysis. Scattering profiles were collected with Bruker AXS Nanostar system, equipped with a Microfocus Copper Anode at 45 kV / 0.65 mA, MONTAL OPTICS and a VANTEC 2000 2D detector.

[0153] The scattered intensities, after solvent subtraction, were treated with Primus GNOM 3.0 programs from ATSAS 2.3 software to determine the pair distance distribution function.Results and discussionSynthesis of few-layer graphene

[0154] The polymerization of acetylene and butadiyne was carried out in the ternary system composed of water- Cu+2, AOT and hexane. Although the complete phase diagram for this exact system has not yet been reported in the literature, compositions for the formation of the lamellar phase were determined from the analogous Cu (AOT)2 / water / isooctane system investigated by Lisiecki et al. (I. Lisiecki, P. Andre, A. Filankembo, C. Petit, J. Tanori, T. Gulik-Krzywicki, B. W. Ninham, and M. P. Pileni J. Phys. Chem. B 1999, 103, 9176-9189.) Furthermore, the pair distance distribution function obtained from small-angle X-ray scattering (see Example 4) confirm the lamellar structure of the surfactant template with a periodicity of 2-3 nm. In the case of 1 , 4-bis(trimethy Isi lyl)butad iy ne, potassium fluoride had to be added to the reaction mixture to remove the trimethylsilyl protecting groups. Although the use of this monomer involves the addition of a supplementary reactant, it has the advantage of being easy to weigh as it is a solid, unlike gaseous acetylene whose quantity added to the reaction cannot be accurately determined as easily.

[0155] The proposed mechanism for the formation of carbon nanomaterials from simple alkyne-based compound begins with the copper catalysed Glaser-Hay polymerization to yield oligo- and / or polyynes that undergo rapid decomposition to form TFLG as presented in Scheme 3. Unlike other methods used to prepare carbon materials from alkyne-rich molecules that lead to ill-defined and / or amorphous carbon materials, this strategy yield to remarkably well- ordered materials. In the special case of reaction within the self-assembled surfactant template, it is believed that reaction occurs at the interface between the aqueous and organic phases, since this is where the Cu2+catalyst is located, as illustrated in Figure 19.(unstable)Spontaneous graphitization at rtTwisted few-layer graphene (TFLG)Scheme 3 - Reaction scheme of Glaser-Hay polymerization of (a)butadiene, (b) acetylene.

[0156] As shown below, the polymerization of acetylene and butadiyne within the lamellar template leads to the formation of crystalline twisted multilayer graphene in 80% yield (for the reaction with 1 ,4-bis(trimethylsilyl)butadiyne as the monomer). This result suggests that the two-dimensional preorganization of the polyyne chains within the template allows for concerted addition reactions across neighbouring chains to produce graphene sheets. In addition, at the AOT / water / hexane ratios employed to obtain the lamellar phase, the aqueous phase can be estimated to occupy only about 10% of the total volume. The polymerization and subsequent polyyne decomposition can therefore beassumed to take place in a confined two-dimensional space.

[0157] Once the reaction is over, the TFLG is isolated using five cycles of centrifugation / redispersion in methanol to ensure the total removal of the excess surfactant.X-ray photoelectron and Raman spectroscopies

[0158] The high resolution XPS spectrum of the C1s signal is presented in Example 4. Deconvolution reveals a primary spectral component (74%) at a binding energy of 284.6 eV, corresponding to carbon-carbon double bonds. Two additional, less intense, signals are observed at 286.2 and 288.6 eV and can be attributed to carbon atoms bonded to oxygen, through single or double bonds, respectively. It is important to note that signals at these two positions are also observed in XPS spectra of the silicon wafer and therefore do not definitively indicate the presence of oxygen within the samples.Transmission electron microscopy and electron diffraction measurements

[0159] Representative transmission electron microscopy (TEM) images of nanomaterials obtained by the polymerization of acetylene and butadiyne within the surfactant template are presented in Figure 20. Additional TEM images are provided in Example 4. Although the exact morphology varies from one particle to another, all of the nanostructures share several common characteristics. In all cases, TEM images show a layered structure, with lateral dimensions on the order of 200 to 500 nm. Furthermore, the TEM images exhibit periodic striations or hashtag motifs that are reminiscent of interference, or Moire, patterns obtained from the overlay of two similar periodic layers that are translationally shifted or rotated, one with respect to the other. In the specific case of twisted bilayer graphene, Moire patterns have been previously observed by both HRTEM and scanning tunnelling microscopy.

[0160] The electron diffraction patterns presented in Figure 20 provide more conclusive evidence that the carbon nanomaterials are in fact composed of twisted graphene multilayers. As shown in Figure 21, the diffraction patterns can be indexed with the hexagonal lattice of graphene with the characteristic d-ioo spacing of 2.13 A. The electron diffraction patterns furthermore show the presence of layers at three distinct orientations. Taking the pattern outlined in blue as a reference, a second pattern, highlighted in red, is observed at a twist angle of 30°. In addition, the blue pattern shows clear doubling of the 0220, 2200, 2200 and 0220 diffraction spots, indicating the presence of a third orientation with a twist angle of about 3° with respect to the reference.

[0161] While it is striking that the two samples presented in Figure 20 exhibit almost identical electron diffraction patterns, despite being prepared from different monomers, is important to note that other diffraction patterns are observed. Examples are provided in Example 4. Of particular interest is the pattern presented in Figure 22. This sample was obtained by the polymerization of acetylene, and, in fact, was imaged from the same TEM grid as the sample presented in Figure 20A. Despite being obtained from the same synthesis, the diffraction patterns of the two samples differ. Both exhibit well-defined diffraction spots characteristic of graphene layers, but the relative orientation of the superimposed reciprocal lattices is different. Rather than twist angles of 30° and 3°, as observed in Figure 21 A, the diffraction pattern of the sample presented in Figure 22 indicates a twist angle of 12°.

[0162] As mentioned above, twisted graphene bilayers exhibit characteristic Moire patterns than can be observed in TEM or STM images. Furthermore, the angle of rotation (0) between the two layers is related to the periodicity of the Moire pattern (d) by the following relation:where a is the atomic lattice constant of graphene, equal to 0.246 nm.

[0163] According to equation 1 , twist angles of 3°, 12° and 30° will result in Moire periodicities of 4.7, 1.2 and 0.48 nm, respectively. The hashtag patterns visible in Figures 20A and 22A have periodicities of 23 and 20 nm, respectively. Rather than a hashtag pattern, the TEM image of the structure shown in Figure 20B exhibits clear striations with a periodicity of 8 nm. Other sample TEM images provided in Example 4 show striations with periodicities that vary between 4 - 10 nm. Clearly, the relationship between the periodicities observed in the TEM images and the twist angles evaluated from electron diffraction does not follow equation 1 . This is perhaps the result of the multilayer nature of the samples.Conclusion

[0164] Polymerization of acetylene and butadiyne with the lamellar phase of a self-assembled surfactant leads to the formation of twisted graphene multilayers with lateral dimensions on the order of 200-500 nm. Electron diffraction measurements indicate that individual layers are composed of crystalline graphene. In most cases, electron diffraction further reveals a well-defined twist angle between the layers within a multilayer stack. The exact angle of rotation, however, can vary from one sample to another. TEM images of the twisted graphene multilayers exhibit periodic striations and hashtag motifs Moire pattern. However, a clear correlation between these patterns and the twist angles determined by electron diffraction has yet to be established.Example 4 - Supporting Information for Example 3

[0165] We provide below more information on the material produced at Example 3.TEM and FFT measurment of prepared twisted graphene

[0166] The TEM image (zoom out) of grid for prepared twisted graphene is shown in the Figure 23.

[0167] The d-spacing values from HRTEM images were determinded using inverted FFT image after selecting specific diffraction spot in the FFT image (Figure 24). This transformation identified easily the inter-spacings clean from other interference and with enhanced contrast. Obtaining the d-spacing is more accurate as it involves directly measuring the distance. This can be achieved by drawing a straight line on the inverted FFT image. The choosen white points are correspond to the selected section of the related TEM image. The d-spacing values for the HRTEM images are presented in the Table 6.T able 6. D spacing measurement of the TEM images.SAXS result

[0168] Characterizing lamellar phase using Small-Angle X-ray Scattering (SAXS) analysis is a powerful approach that unveils intricate details about the structural and morphological features of these nanoscale assemblies in solution. The SAXS technique employs X-rays to probe the scattering behavior of lamellar phase providing valuable information about their size and shape. The X-rays interact with the electrons in the micelle sample, causing scattering. The scattered X-rays are detected at various angles. The scattered X-rays produce a scattering pattern, representing the intensity (I) of scattered X-rays as a function of the scattering vector (q) or the scattering angle (20). The scattering vector (q) is a measure of the momentum transfer and is defined as q = 4TT sin (9) / A, where 7 the X-ray wavelength and 9 is the scattering angle.

[0169] The scattering curves can be converted to a Pair Distance Distribution Function (PDDF) which is a histogram of p(r) (probability) as a function of r (distance). The p(r) function expresses the distribution of distances of separation between all possible pairs of scattering atoms within the particle. The characteristic form of the p(r) vs. r graph provides details about the fundamental geometry of the scattered lamellar phase. The l(q) plots for micelle sample is shown in Fig 26. The pair distance distribution function p(r) corresponding to l(q) data are shown in Fig 27. In a lamellar micelle system, it can typically observe one or more peaks in the SAXS pattern. These peaks correspond to the repeating structural units within the lamellar phase.XPS result

[0170] The XPS high resolution analysis of carbon atoms shown in Figures 26 and 27. The position of the carbon 1s signal indicates that the majority (74%) of carbon atoms in the samples are bonded to other carbon atoms. As shown in Figure 28, the highest energy peak appears at 284.6 eV, meaning that most of the carbon-carbon bonds are double bonds. The other smaller peaks at 286.2 and 288.6 eV correspond to the carbon atoms with one bond and two bonds to oxygen, respectively. The oxygen containing bands are from the silicon wafer. Always there are inevitable carbon-oxygen bond on the silicon wafer which cannot be removed.

[0171] Table 7. Results of the XPS high resolution of prepared graphene.[001 72] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.REFERENCES

[0173] The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety. These documents include, but are not limited to, the following:(1) Choudhary, N.; Hwang, S.; Choi, W. Carbon Nanomaterials: A Review. In Handbook of Nanomaterials Properties,' Springer Berlin Heidelberg, 2014; pp 709-769. https: / / doi.org / 10.1007 / 978-3-642-31107-9_37.(2) Wang, Y.; Hu, A. Carbon Quantum Dots: Synthesis, Properties and Applications. J. Mater. Chem. C 2014, 2 (34), 6921-6939. https: / / doi.org / 10.1039 / c4tc00988f.(3) Wu, T.; Ao, Y.; Wang, P.; Wang, C. Carbon Quantum Dots: Synthesis and Applications. Cailiao Daobao / Materials Rev. 2016, 30 (7), 30-35. https: / / doi.Org / 10.11896 / j.issn.1005-023X.2016.013.005.(4) Chan, M. H.; Liu, R. S. Carbon Nitride Quantum Dots and Their Applications. In Phosphors, Up Conversion Nano Particles, Quantum Dots and Their Applications,' 2016; Vol. 2, pp 485-502. https: / / doi.org / 10.1007 / 978-981-10- 1590-8 J 7.(5) Peng, H.; Travas-Sejdic, J. Simple Aqueous Solution Route to Luminescent Carbogenic Dots from Carbohydrates. Chem. Mater. 2009, 21 (23), 5563-5565. https: / / doi.org / 10.1021 / cm901593y.(6) Liu, S.; Tian, J.; Wang, L; Zhang, Y.; Qin, X.; Luo, Y.; Asiri, A. M.; Al-Youbi, A. O.; Sun, X. Hydrothermal Treatment of Grass: A Low-Cost, Green Route to Nitrogen-Doped, Carbon-Rich, Photoluminescent Polymer Nanodots as an Effective Fluorescent Sensing Platform for Label-Free Detection of Cu(ll) Ions. Adv. Mater. 2012, 24 (15), 2037-2041 . https: / / doi.Org / 10.1002 / adma.201200164.(7) Sahu, S.; Behera, B.; Maiti, T. K.; Mohapatra, S. Simple One-Step Synthesis of Highly Luminescent Carbon Dots from Orange Juice: Application as Excellent Bio-Imaging Agents. Chem. Commun. 2012, 48 (70), 8835-8837. https: / / doi.Org / 10.1039 / c2cc33796g.(8) Hsu, P. C.; Shih, Z. Y.; Lee, C. H.; Chang, H. T. Synthesis and Analytical Applications of Photoluminescent Carbon Nanodots. Green Chem. 2012, 14 (4), 917-920. https: / / doi.org / 10.1039 / c2gc16451e.(9) Ozin, G. G. A.; Arsenault, A. Nanochemistry: A Chemical Approach to Nanomateriais,' Royal Society of Chemistry, 2015.(10) Gu, Z.-G. G.; Li, D.-J. J.; Zheng, C.; Kang, Y.; Woll, C.; Zhang, J. MOF-Templated Synthesis of Ultrasmall Photoluminescent Carbon-Nanodot Arrays for Optical Applications. Angew. Chemie - int. Ed. 2017, 56 (24), 6853— 6858. https: / / d0i.0rg / l 0.1002 / an ie.201702162.(11) Soares, S. F.; Fernandes, T.; Daniel-Da-Silva, A. L; Trindade, T. The Controlled Synthesis of Complex Hollow Nanostructures and Prospective Applications. Proceedings of the Royai Society A: Mathematical, Physical and Engineering Sciences. Royal Society Publishing 2019. https: / / doi.org / 10.1098 / rspa.2018.0677.(12) Wang, J.; Liu, G.; Leung, K.; Loffroy, R.; Lu, P.-X.; J. Wang, Y. Opportunities and Challenges of Fluorescent Carbon Dots in Translational Optical Imaging. Curr. Pharm. Des. 2015, 21 (37), 5401-5416. https: / / doi.org / 10.2174 / 1381612821666150917093232.(13) Wan, M. M.; Wei, Z. Z.; Zhang, Z. Z.; Zhang, L. L; Huang, K.; Yang, Y. Studies on Nanostructures of Conducting Polymers via Self-Assembly Method. In Synthetic Metals,' 2003; Vol. 135-136, pp 175-176. https: / / d0i.0rg / l 0.1016 / S0379-6779(02)00563-5.(14) Wang, Z.-G. G.; Ding, B. DNA-Based Self-Assembly for Functional Nanomateriais. Adv. Mater. 2013, 25 (28), 3905-3914. https: / / d0i.0rg / l 0.1002 / adma.201301450.(15) Zhang, X.; Manohar, S. K. Polyaniline Nanofibers: Chemical Synthesis Using Surfactants. Chem. Commun. 2004, No. 20, 2360-2361. https: / / doi.org / 10.1039 / b409309g.(16) Huang, L; Wang, Z.; Wang, H.; Cheng, X.; Mitra, A.; Yan, Y. Polyaniline Nanowires by Electropolymerization from Liquid Crystalline Phases. J. Mater. Chem. 2002, 12 (2), 388-391. https: / / doi.org / 10.1039 / b107499g.(17) Jang, J.; Yoon, H. Facile Fabrication of Polypyrrole Nanotubes Using Reverse Microemulsion Polymerization. Chem. Commun. 2003, 3 (6), 720-721. https: / / doi.org / 10.1039 / b211716a.(18) Zhang, X.; Lee, J.-S.; Lee, G. S.; Cha, D.-K.; Kim, M. J.; Yang, D. J.; Manohar, S. K. Chemical Synthesis of PEDOT Nanotubes. Macromolecules 2006, 39 (2), 470-472. https: / / doi.org / 10.1021 / ma051975c.(19) Hopwood, J. D.; Mann, S. Synthesis of Barium Sulfate Nanoparticles and Nanofilaments in Reverse Micelles and Microemulsions. Chem. Mater. 1997, 9 (8), 1819-1828. https: / / doi.org / 10.1021 / cm970113q.(20) Shi, H.; Qi, L; Ma, J.; Cheng, H. Polymer-Directed Synthesis of Penniform BaW04 Nanostructures in ReverseMicelles. J. Am. Chem. Soc. 2003, 125 (12), 3450-3451. https: / / doi.org / 10.1021 / ja029958f.(21) Kumar, S.; Singh, V.; Aggarwal, S.; Kumar Mandal, U. Synthesis of 1-Dimensional Polyaniline Nanofibers by Reverse Microemulsion. Colloid Polym. Sci. 2009, 287 (9), 1107-1110. https: / / doi.org / 10.1007 / s00396-009-2078-0.(22) Lin, C. H.; Chang, J. H.; Yeh, Y. Q.; Wu, S. H.; Liu, Y. H.; Mou, C. Y. Formation of Hollow Silica Nanospheres by Reverse Microemulsion. Nanoscale 2015, 7 (21), 9614-9626. https: / / doi.org / 10.1039 / c5nr01395j.(23) Rajapantulu, A.; Bandyopadhyaya, R. Formation of Gold Nanoparticles in Water-in-Oil Microemulsions:Experiment, Mechanism, and Simulation. Langmuir 2021 , 37 (22), 6623-6631. https: / / doi.org / 10.1021 / acs.langmuir.1c00084.(24) Jones, G. E.; Kendrick, D. A.; Holmes, A. B. 1 ,4-BIS(TRIMETHYLSILYL)BUTA-1, 3-DIYNE. Org. Synth. 1987, 65, 52. https: / / doi.org / 10.15227 / orgsyn.065.0052.(25) Lisiecki, I.; Andre, P.; Filankembo, A.; Petit, C.; Tanori, J.; Gulik-Krzywicki, T.; Ninham, B. W.; Pileni, M. P. Mesostructured Fluids. 1. Cu(AOT)2-H2O-lsooctane in Oil Rich Regions. J. Phys. Chem. B 1999, 103 (43), 9168— 91 5. https: / / doi.Org / 10.1021 / jp991242s.(26) Schrettl, S.; Stefaniu, C.; Schwieger, C.; Pasche, G.; Oveisi, E.; Fontana, Y.; Morral, A. F. I.; Reguera, J.; Petraglia, R.; Corminboeuf, C.; Brezesinski, G.; Frauenrath, H. Functional Carbon Nanosheets Prepared from Hexayne Amphiphile Monolayers at Room Temperature. Nat. Chem. 2014, 6 (6), 468-476. https: / / doi.org / 10.1038 / nchem.1939.(27) Alvarez, E.; Garcia-Rio, L; Mejuto, J. C.; Navaza, J. M.; Perez-Juste, J. Effects of Temperature on the Conductivity of AOT / lsooctane / Water Microemulsions. Influence of Salts. J. Chem. Eng. Data 1999, 44 (4), 850-853. https: / / d0i.0rg / l 0.1021 / je9900575.(28) Lisiecki, I.; Andre, P.; Filankembo, A.; Petit, C.; Tanori, J.; Gulik-Krzywicki, T.; Ninham, B. W.; Pileni, M. P. Mesostructured Fluids. 2. Microstructure and Supra-Aggregation. J. Phys. Chem. B 1999, 103 (43), 9176-9189. https: / / d0i.0rg / l 0.1021 / jp991243k.(29) Nagarajan, R. Molecular Packing Parameter and Surfactant Self-Assembly: The Neglected Role of the Surfactant Tail. Langmuir 2002, 78 (1), 31-38. https: / / doi.org / 10.1021 / la010831y.(30) Lombardo, D.; Kiselev, M. A.; Magazu, S.; Calandra, P. Amphiphiles Self-Assembly: Basic Concepts and Future Perspectives of Supramolecular Approaches. Advances in Condensed Matter Physics. 2015. https: / / doi.org / 10.1155 / 2015 / 151683.(31) Jang, J.; Yoon, H. Formation Mechanism of Conducting Polypyrrole Nanotubes in Reverse Micelle Systems. Langmuir 2005, 21 (24), 11484-11489. https: / / doi.org / 10.1021 / la051447u.(32) Lesiak, B.; Kbver, L; Toth, J.; Zemek, J.; Jiricek, P.; Kromka, A.; Rangam, N. C Sp 2 / Sp 3 Hybridisations in Carbon Nanomaterials - XPS and (X)AES Study. Appl. Surf. Sci. 2018, 452, 223-231. https: / / d0i.0rg / l 0.1016 / j.apsusc.2O18.04.269.(33) Robertson, J. Diamond-like Amorphous Carbon. Mater. Sci. Eng. R Reports 2002, 37 (4-6), 129-281.https: / / doi.Org / 10.1016 / s0927-796x(02)00005-0.(34) Lee, S. Y.; Lyu, J.; Kang, S.; Lu, S. J.; Bielawski, C. W. Ascertaining the Carbon Hybridization States of Synthetic Polymers with X-Ray Induced Auger Electron Spectroscopy. J. Phys. Chem. C 2018, 122 (22), 11855-11861. https: / / doi.org / 10.1021 / acs.jpcc.8b02217.(35) Ferrari, A.; Robertson, J. Interpretation of Raman Spectra of Disordered and Amorphous Carbon. Phys. Rev. B - Condens. Mater Mater. Phys. 2000, 61 (20), 14095-14107. https: / / doi.org / 10.1103 / PhysRevB.61.14095.(36) Tuinstra, F.; Koenig, J. Raman Spectrum of Graphite. J. Chem. Phys. 1970, 53 (3), 1126-1130. https: / / doi.Org / 10.1063 / 1.1674108.(37) Lespade, P.; Al-Jishi, R.; Dresselhaus, M. S. Model for Raman Scattering from Incompletely Graphitized Carbons. Carbon N. Y. 1982, 20 (5), 427-431. https: / / doi.org / 10.1016 / 0008-6223(82)90043-4.(38) Coleman, J. N.; Lotya, M.; O’Neill, A.; Bergin, S. D.; King, P. J.; Khan, LL; Young, K.; Gaucher, A.; De, S.; Smith, R. J.; Shvets, I. V.; Arora, S. K.; Stanton, G.; Kim, H.-Y.; Lee, K.; Kim, G. T.; Duesberg, G. S.; Hallam, T.; Boland, J. J.; Wang, J. J.; et al. Two-Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials, Science 2011 , 331 , 568.(39) Y. Zhang, L. Zhang, C. Zhou, Acc. Chem. Res. 2013, 46, 2329-2339.(40) Agarwal, V.; Zetterlund, P. B. Chem. Eng. J. 2021 , 405, 127018.KR20180059617ACN102674316BKR101956920B1US9440857B2Cortez et al. CVD synthesis of graphene from acetylene catalyzed by a reduced CuO thin film deposited on SiO2 substrates, J. Chil. Chem. Soc. vol.60 no.2 Concepcion jun. 2015, D0l:10.4067 / S0717-97072015000200010Gutierrez-Cruz et al. A review of top-down and bottom-up synthesis methods for the production of graphene, graphene oxide and reduced graphene oxide, Journal of Materials Science volume 57, pages 14543-14578 (2022)Levesque et al. Layered graphitic materials from a molecular precursor, Chemical Science 2014, 5, 831 .Schrettl et al. Functional carbon nanosheets prepared from hexayne amphiphile monolayers at room temperature, Nature Chem. 2014, 6, 468-476.Jayswal et al. Synthesis of Fluorescent carbon nanoparticles by dispersion polymerization of acetylene, Nanoscale Adv. 2023, 5, 337-343.Sun, X.; Lei, Y., Fluorescent carbon dots and their sensing applications. TrAC Trends in Analytical Chemistry 2017, 89, 163-180.Lim, S. Y.; Shen, W.; Gao, Z., Carbon quantum dots and their applications. Chemical Society Reviews 2015, 44 (1), 362-381.Zheng, F.; Liang, L; Gao, Y.; Sukamto, J. H.; Aardahl, C. L, Carbon nanotube synthesis using mesoporous silica templates. Nano Letters 2002, 2 (7), 729-732.Lv, R.; Cao, C.; Zhai, H.; Wang, D.; Liu, S.; Zhu, H., Growth and characterization of single-crystal ZnSe nanorods via surfactant soft-template method. Solid state communications 2004, 130 (3-4), 241-245.Walker, L. M.; Kuntz, D. M., Wormlike micelles as a template for polymerization. Current Opinion in Colloid & Interface Science 2007, 12 (3), 101-105.Bao, Y.; Wang, T.; Kang, Q.; Shi, C.; Ma, J., Micelle-template synthesis of hollow silica spheres for improving water vapor permeability of waterborne polyurethane membrane. Scientific reports 2017, 7, 46638Leong, Y. S.; Candau, F., Inverse microemulsion polymerization. The Journal of Physical Chemistry 1982, 86 (13), 2269-2271.Hay, A. S., Oxidative coupling of acetylenes. 111 . The Journal of Organic Chemistry 1962, 27 (9), 3320-3321.Chernick, E. T.; Tykwinski, R. R., Carbon-rich nanostructures: the conversion of acetylenes into materials. Journal of Physical Organic Chemistry 2013, 26 (9), 742-749.Kikhney, A. G.; Svergun, D. I., A practical guide to small angle X-ray scattering (SAXS) of flexible and intrinsically disordered proteins. FEBS letters 2015, 589 (19), 2570-2577.Chang, C. C., Auger electron spectroscopy. Surface Science 1971 , 25 (1), 53-79.Graphite exfoliation using ball-milling (ACS Appl. Eng. Mater. 2023, 1, 2304-2314).Few-layer graphene synthesis from expanded polystyrene waste (ACS Omega 2020, 5, 4075-4082).Few-layer graphene synthesis through pyrolysis of biopolymers (Nanomaterials 2022, 12, 657).Few-layer graphene from waste biomass (Scientific Reports, 2017, 7, 15239).Few-layer graphene from liquid-phase graphite exfoliation (Scientific Reports, 2018, 8, 9766).Carr, Stephen; Massatt, Daniel; Fang, Shiang; Cazeaux, Paul; Luskin, Mitchell; Kaxiras, Efthimios (17 February 2017). "Twistronics: Manipulating the electronic properties of two-dimensional layered structures through their twist angle". Physical Review B. 95 (7).Jarillo-Herrero, Pablo; Kaxiras, Efthimios; Taniguchi, Takashi; Watanabe, Kenji; Fang, Shiang; Fatemi, Valla; Cao, Yuan (2018-03-06). "Magic-angle graphene superlattices: a new platform for unconventional superconductivity". Nature. 556 (7699): 43-50.Gibney Elizabeth (2019-01-02). "How 'magic angle' graphene is stirring up physics". Nature. 565 (7737): 15-18.Tritsaris, Georgios A.; Carr, Stephen; Zhu, Ziyan; Xie, Yiqi; Torrisi, Steven B.; Tang, Jing; Mattheakis, Marios; Larson,Daniel; Kaxiras, Efthimios (2020-01-30). "Electronic structure calculations of twisted multi-layer graphene superlattices". 2D Materials. 7 (3): 035028.Li, Guohong; Luican, A.; Lopes dos Santos, J. M. B.; Castro Neto, A. H.; Reina, A.; Kong, J.; Andrei, E. Y. (February 2010). "Observation of Van Hove singularities in twisted graphene layers". Nature Physics. 6 (2): 109-113.Suarez Morell, E.; Correa, J. D.; Vargas, P.; Pacheco, M.; Barticevic, Z. (13 September 2010). "Flat bands in slightly twisted bilayer graphene: Tight-binding calculations". Physical Review B. 82 (12): 121407.Bistritzer, Rafi; MacDonald, Allan H. (26 July 2011). "Moire bands in twisted double-layer graphene". Proceedings of the National Academy of Sciences. 108 (30): 12233-12237.Cao, Yuan; Fatemi, Valla; Fang, Shiang; Watanabe, Kenji; Taniguchi, Takashi; Kaxiras, Efthimios; Jarillo-Herrero, Pablo (5 March 2018). "Unconventional superconductivity in magic-angle graphene superlattices". Nature. 556 (7699): 43-50.Princeton University, "Experiments explore the mysteries of 'magic' angle superconductors”. Phys.org. 2019-07-31.Ishikawa, Interfacial Atomic Structure of Twisted Few-Layer Graphene, Interfacial Atomic Structure of Twisted FewLayer Graphene, Scientific Reports volume 6, Article number: 21273 (2016).Wang, Thermal transport in twisted few-layer graphene, 2017 Chinese Phys. B 26 116503.Song, Observation of Chirality Transfer in Twisted Few-Layer Graphene, ACS Nano 2024, 18, 27, 17578-17585.The rise of graphene, Geim, A. K.; Novoselov, K. S., Nature Materials (2007), 6(3), 183-191Graphene: Status and Prospects, Geim, A. K. Science (Washington, DC, United States) (2009), 324(5934), 1530-1534A roadmap for graphene, Novoselov, K. S.; Fal'ko, V. I.; Colombo, L; Gellert, P. R.; Schwab, M. G.; Kim, K.Nature (London, United Kingdom) (2012), 490(7419), 192-200Honeycomb Carbon: A Review of Graphene, Allen, Matthew J.; Tung, Vincent C.; Kaner, Richard B.Chemical Reviews (Washington, DC, United States) (2010), 110(1), 132-145Graphene: The New Two-Dimensional Nanomaterial, Rao, C. N. R.; Sood, A. K.; Subrahmanyam, K. S.; Govindaraj, A. Angewandte Chemie, International Edition (2009), 48(42), 7752-7777A new twist in graphene research: Twisted graphene, Umesha Mogera a, 1 , Giridhar U. Kulkarni, Carbon 156 (2020) 470e487Recent Advances in Twisted Structures of Flatland Materials and Crafting Moire Superlattices Ghulam Abbas, Yu Li,* Huide Wang, Wen-Xing Zhang, Cong Wang, and Han Zhang Adv. Funct. Mater. 2020, 30, 2000878Graphene bilayers with a twist, Eva Y. Andrei 1 B and Allan H. MacDonald2, Nature Materials | VOL 19 | December 2020 | 1265-1275Twisted Bilayer Graphene: A Journey Through Recent Advances and Future Perspectives, R. Ajay Rakkesh,* P. N.Blessy Rebecca, T. B. Naveen, D. Durgalakshmi, and S. Balakumar, Part. Part. Syst. Charact. 2024, 41 , 2300125Unconventional superconductivity in magic-angle graphene superlattices Yuan Cao1 , Valla Fatemil , Shiang Fang2, Kenji Watanabe3, Takashi Taniguchi3, Efthimios Kaxiras2,4 & Pablo Jarillo-Herrerol 5 a p r i l 2 0 1 8 | VO L 5 5 6 | N AT U R E | 4 31Fabrication Strategies of Twisted Bilayer Graphenes and Their Unique Properties Le Cai and Gui Yu Adv. Mater. 2021 , 33, 20049741Towards wafer-size graphene layers by atmospheric pressure graphitization of silicon carbide Konstantin V, et al. NATURE MATERIALS j VOL 8 j MARCH 2009 203Twisting Bilayer Graphene Superlattices Chun-Chieh Lu, I Yung-Chang Lin, I Zheng Liu, J Chao-Hui Yeh, I Kazu Suenaga.J and Po-Wen Chiuf,* ACS Nana VOL. 7 ’ NO. 3 ’ 2587-2594 ’ 2013Raman Spectroscopy Study of Rotated Double-Layer Graphene: Misorientation-Angle Dependence of Electronic Structure, Kwanpyo Kim et al., PRL 108, 246103 (2012)Superlattice structures in twisted bilayers of folded graphene Hennrik Schmidt et al. NATURE COMMUNICATIONS | 5:5742 | DOI: 10.1038 / ncomms6742 |www.nature.com / naturecommunicationsLisiecki, I., Andre, P., Filankembo, A., C. P.-T. J. of & 1999, Mesostructured fluids. 2. Microstructure and supraaggregation. ACS PublicationsLisiecki, P et al., The Journal of Physical Chemistry B:1999' ACS Publications.Carbon-rich nanostructures: the conversion of acetylenes into materials, Erin T. Chernicka and Rik R. Tykwinskia J. Phys. Org. Chem. 2013, 26 742-749Twisting Bilayer Graphene Superlattices Chun-Chieh Lu, J Yung-Chang Lin, J Zheng Liu, J Chao-Hui Yeh, J Kazu Suenaga.J and Po-Wen Chiu ACS Nano VOL. 7 ' NO. 3 ’ 2587-2594 ’ 2013High-Precision Twist-Controlled Bilayer and Trilayer Graphene Xu-Dong Chen , Wei Xin , Wen-Shuai Jiang , Zhi-Bo Liu ,* Yongsheng Chen , and Jian-Guo Tian * Adv. Mater. 2016, 28, 2563-2570Monolayers of graphite rotated by a defined angle: hexagonal superstructures by STM. H. Beyer, M. Muller, Th. Schimmel, Appl. Phys. A 68, 163-166 (1999)Structural analysis of multilayer graphene via atomic moire interferometry, David L. Miller et al., PHYSICAL REVIEW B 81 , 125427 _2010_The structure of suspended graphene sheets, Jannik C. Meyer et al., Vol 446| 1 March 2007| doi: 10.1038 / nature05545

Claims

CLAIMS:1 . A method for producing graphene or a hollow carbon nanostructure, such as a hollow sphere, a hollow ellipsoid, or a hollow rod, preferably graphene, a) mixing together water, an organic solvent that is immiscible with water, and a surfactant to prepare a suspension of self-assembled surfactant templates, b) adding a monomer to the suspension, c) polymerizing the monomer to form a polymer on the self-assembled surfactant template, and d) decomposing the polymer into carbon, thereby forming graphene or the hollow carbon nanostructure.

2. The method of claim 1 , wherein step a) comprises dissolving the surfactant in one of i) water and ii) the organic solvent, thereby producing a mixture, and then mixing this mixture with the other of i) water and ii) the organic solvent.

3. The method of claim 2, wherein step a) comprises dissolving the surfactant in the organic solvent, thereby producing a mixture, and then mixing this mixture with water.

4. The method of any one of claims 1 to 3, wherein the surfactant comprises bis(2-ethylhexyl) sulfosuccinate (AOT), preferably is AOT.

5. The method of any one of claims 1 to 4, wherein the organic solvent comprises hexane, preferably is hexane.

6. The method of any one of claims 1 to 5, wherein the mixing in step a) is done by mechanical stirring for e.g., 10 minutes.

7. The method of any one of claims 1 to 6, wherein step a) comprises preparing a solution of the surfactant in one of i) water and ii) the organic solvent, and then adding this solution to the other of i) water and ii) the organic solvent.

8. The method of claim 7, wherein step a) comprises preparing a solution of the surfactant in the organic solvent, and then adding this solution to water9. The method of any one of claims 1 to 8, wherein the self-assembled surfactant templates are spherical, ellipsoidal, cylindrical, or lamellar in shape.

10. The method of claim 9, wherein the self-assembled surfactant templates are lamellar in shape, thereby yielding graphene.11 . The method of any one of claims 1 to 10, further comprising adjusting the proportions of water, surfactant, and organic solvent used at step a) so as to adjust the shape of the self-assembled surfactant templates12. The method of any one of claims 1 to 11 , wherein the monomer is soluble in only one phase selected from i) the organic solvent and i) water, and polymerization of the monomer requires a polymerization reactant that is insoluble the phase in which the monomer is soluble.

13. The method of claim 12, comprising adding the polymerization reactant at step a) or at step b).

14. The method of claim 13, wherein step a) comprises preparing a solution of the polymerization reactant in one of i) water and ii) the organic solvent, and then adding this solution to the other of i) water and ii) the organic solvent.

15. The method of claim 14, wherein step a) comprises preparing a solution of the polymerization reactant in water, and then adding this solution to the organic solvent.

16. The method of any one of claims 1 to 15, wherein the polymer is a polyyne or a polyene.

17. The method of claim 16, wherein the polymer is a polyyne.

18. The method of claim 17, wherein the monomer is an acetylenic monomer, preferably acetylene, butadiyne, hexatriyne, [n]oligoynes where n > 3, silyl-protected acetylene, silyl-protected butadiyne, silyl-protected triyne, silyl-protected [n]oligoynes where n >3, preferably a silyl-protected butadiyne, most preferably 1, 4- bis(trimethylsilyl) butadiyne.

19. The method of claim 16 or 17, wherein the monomer is polymerized into the polyyne at step c) by Glaser coupling, Eglinton reaction, Hay coupling, Cadiot-Chodkiewicz coupling, or palladium-catalyzed alkyne homocoupling.

20. The method of claim 19, wherein the monomer is polymerized at step c) by Eglinton reaction.21 . The method of claim 20, wherein the polymerization reactant is a cupric salt, preferably copper (II) fluoride or copper (II) triflate.

22. The method of claim 16, wherein the polymer is a polyene.

23. The method of claim 22, wherein the monomer isan acetylenic monomer, preferably acetylene, butadiyne, hexatriyne, [n]oligoynes where n > 3, silyl-protected acetylene, silyl-protected butadiyne, silyl-protected triyne, silyl-protected [n]oligoynes where n >3, preferably a silyl-protected butadiyne, most preferably 1 , 4-bis(trimethylsilyl) butadiyne, or a cycloalkene made of alternating single and double carbon-carbon double bond, preferably cyclooctatetraene.

24. The method of claim 22 or 23, wherein the monomer is polymerized into the polyene at step c) by Ziegler-N atta reaction or by Ring opening metathesis (ROMP)25. The method of any one of claims 1 to 24, wherein the decomposing at step d) is spontaneous and step d) is a step of allowing the decomposition to occur.

26. The method of any one of claims 1 to 24, wherein the decomposing is performed by heating the polymer, irradiating the polymer, or adding pressure to the polymer.

27. The method of any one of claims 1 to 26, further comprising after step d) functionalizing the graphene or hollow carbon nanostructure.

28. The method of any one of claims 1 to 27, further comprising isolating and purifying the graphene or hollow carbon nanostructure.

29. Crystalline twisted bilayer or few-layer graphene.

30. The twisted graphene of claim 29, being made of up to 10 stacked graphene layers, preferably up to 5 stacked graphene layers, and more preferably up to 3 stacked graphene layers.31 . The twisted graphene of claim 29 or 30, being made of 2 to 5 stacked graphene layers.

32. The twisted graphene of any one of claims 29 to 31, being highly crystalline.

33. The twisted graphene of any one of claims 29 to 32, being substantially free of amorphous graphene.

34. The twisted graphene of any one of claims 29 to 33, exhibiting, when analyzed by electron diffraction, hexagonal diffraction spots with spacings corresponding to crystalline graphene sheets over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges.

35. The twisted graphene of any one of claims 29 to 34, exhibiting a Moire pattern when observed by transmission electron microscopy (TEM) or high-resolution transmission electron microscopy (HRTEM).

36. The twisted graphene of any one of claims 29 to 35, having a high level of purity, for example being substantially free of atoms other than carbon atoms.

37. The twisted graphene of any one of claims 29 to 36, being substantially free of any other allotrope of carbon.

38. The twisted graphene of any one of claims 29 to 37, appearing as pure graphene when analyzed by Raman spectroscopy39. The twisted graphene of any one of claims 29 to 38, having a Raman spectrum free of peaks attributed to substances other than graphene.

40. The twisted graphene of any one of claims 29 to 39, having a twist angle of between 1 and 45°, preferably between 1 and 30°.41 . The twisted graphene of any one of claims 29 to 40, appearing to be intact over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.

42. The twisted graphene of any one of claims 29 to 41, appearing to be free of holes over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more of its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.

43. The twisted graphene of any one of claims 29 to 42, appearing to be free structural defects over 85% or more, preferably over 90% or more, more preferably over 95% or more, even more preferably over 98% or more its surface, most preferably over substantially the whole of its surface, except at the edges, when observed by TEM.

44. The twisted graphene of any one of claims 29 to 43, having an average width and an average length between about 200 nm and about 1000 nm, preferably between about 200 nm and about 500 nm.

Images