Method for forming a graphene film

Abstract

The present invention relates to a method for forming a graphene film, the graphene film produced thereby, and uses thereof. The method for forming a graphene film includes coating a polymeric graphene precursor on a substrate. The method includes irradiating the polymeric graphene precursor coated on the substrate with a pulsed high-intensity light source emitting at two or more wavelengths for a pulse duration of less than one second, thereby converting the polymeric graphene precursor into a graphene film.

Description

[Technical Field]

[0001] This disclosure relates to a method for forming a graphene film. This application claims priority to U.S. Provisional Patent Application No. 63 / 262,656, filed on 18 October 2021, the entire disclosure of which is incorporated herein by reference. [Background technology]

[0002] Graphene is sp 2 Graphene is a nanomaterial with a two-dimensional honeycomb lattice of hybridized carbon atoms. Graphene possesses many unique properties, including high electrical conductivity, high thermal conductivity, good mechanical properties, a large surface area, excellent chemical properties, and good biocompatibility. All of these properties make graphene an ideal candidate for potential applications in nanoelectronics, energy storage, biosensing, catalysts, nanocomposites, and pharmaceuticals, among others. There are three main forms of graphene materials used today: graphene oxide, reduced graphene oxide, and pure (pristine) monolayer and multilayer graphene. Of all forms of graphene, pure graphene possesses the best of the aforementioned properties.

[0003] Numerous graphene preparation methods have been reported in the literature. These methods can be broadly classified into top-down and bottom-up approaches. In the top-down approach, graphene is prepared by mechanical exfoliation, chemical exfoliation of graphite and graphite oxide, laser exfoliation of graphite, chemical reduction of graphene oxide, electrochemical reduction of graphene oxide, photothermal reduction of GO, and photodecomposition of various precursors using a flash lamp. In the bottom-up approach, graphene is produced via solution-based chemical synthesis, solvothermal synthesis, chemical deposition on various substrates such as metal catalysts including copper, ruthenium, and nickel, epitaxial growth on SiC, laser-induced epitaxial growth, and arc discharge.

[0004] Most of the methods described above, with the exception of electrochemical reduction and CVD approaches, are not scalable to large-scale production. Most of them are extremely energy-intensive, require operation under harsh conditions, are expensive, and are very slow to implement. [Overview of the project]

[0005] The present invention provides a method for forming a graphene film. The method includes coating a polymer graphene precursor onto a substrate. The method also includes converting the polymer graphene precursor coated on the substrate into a graphene film by irradiating it with a pulsed high-intensity light source emitting at two or more wavelengths for a pulse duration of less than one second.

[0006] The present invention provides a method for forming a graphene film. The method involves coating a polymer graphene precursor onto a substrate containing carbon fibers, carbon mesh, carbon cloth, carbon composite material, graphene composite material, graphene, carbon film, or a combination thereof. The polymer graphene precursor and the substrate have different chemical compositions. The method also involves irradiating the polymer graphene precursor coated on the substrate with a pulsed high-intensity light source emitting at two or more wavelengths for a pulse duration of less than one second to convert the polymer graphene precursor into a graphene film.

[0007] The present invention provides a graphene film formed by the method of the present invention. The graphene film may be patterned or unpatterned. The present invention provides electrochemical energy storage devices, electromagnetic shielding materials, chemical or biological sensors, post-CMOS nanoelectronic devices, thermal shielding materials, structural composites, filters, or combinations thereof, comprising a graphene film formed by the method of the present invention.

[0008] Various embodiments of the method of the present invention may have advantages over other methods for forming graphene films. For example, in various embodiments, the method of the present invention can be implemented at lower temperatures than other methods, enabling the formation of graphene films on heat-sensitive materials. In various embodiments, rapid thermal decomposition of the polymer graphene precursor can reduce, minimize, or avoid oxidation of the resulting graphene film. In various embodiments, the method can form graphene films with similar or better thermal, electrical, and / or mechanical stability compared to graphene films formed by other methods. In various embodiments, the method of the present invention overcomes the limitations and drawbacks of conventional methods for producing graphene with respect to energy budget, throughput, scalability, and / or versatility of the precursor.

[0009] In various embodiments, the method of the present invention can form graphene without a catalyst or catalyst substrate. In various embodiments, the method of the present invention can be carried out under room temperature, pressure, and humidity conditions. In various embodiments, the method of the present invention can perform the entire pyrolysis process within a microsecond timeframe, or even within a millisecond timeframe, depending on the number of pulses applied, thus providing a much higher throughput compared to other methods for producing graphene. In various embodiments, the method of the present invention does not require harmful or polluting chemicals, extremely high power or mechanical force, or excessive pressure, thus providing a safer and more environmentally friendly alternative to conventional methods for producing graphene. In various embodiments, the method of the present invention can synthesize graphene in a single irradiation step, thus providing a simpler alternative to conventional methods for producing graphene. In various embodiments, the method of the present invention uses less energy to operate the flash lamp and its control electronics than other methods, thus providing a less energy-intensive alternative to conventional methods for producing graphene. In various embodiments, the method of the present invention is a less expensive alternative to conventional methods for producing graphene, as it can be carried out using a simple apparatus equipped with a flash lamp or other suitable radiation source such as a high-intensity light-emitting diode that can be operated under ambient conditions that do not require a vacuum or extreme environment for operation. In various embodiments, the method of the present invention is a more scalable alternative to conventional methods for producing graphene, as it can be operated in a roll-to-roll format that enables extremely high throughput and large-area graphene material in a relatively short time, such as a few minutes, depending on the length of the substrate. In various embodiments, the method of the present invention can produce graphene on a wide range of substrates, including metals (stainless steel, copper, nickel, aluminum, gold, etc.), semiconductors (silicon, silicon carbide, gallium arsenide, indium gallium arsenide, aluminum gallium arsenide wafers, etc.), plastics (polyimide, polyaramid, polyester, etc.), or combinations thereof. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows schemes for preparing graphene by photothermal decomposition of a precursor thin film under ambient conditions, according to various embodiments. [Figure 2A] Figure 2A shows examples of precursor materials in various forms. [Figure 2B] Figure 2B shows examples of precursor materials in various forms. [Figure 2C] Figure 2C shows examples of precursor materials in various forms. [Figure 2D] Figure 2D shows various methods for synthesizing polybenzoxazines. [Figure 3] Figure 3 shows various processing schemes for the photothermal decomposition of unpatterned precursor films and their conversion to graphene composites. [Figure 4] Figure 4 shows various methods for converting benzoxazine monomers into polybenzoxazines by curing. [Figure 5] Figure 5 shows various processing schemes for the cyclization of polyacrylonitrile, the photothermal decomposition of unpatterned cyclized polyacrylonitrile precursor films, and their conversion to graphene composites. [Figure 6] Figure 6 shows various processing schemes for the photothermal decomposition of pure carbon fibers and their conversion to graphene composite materials. [Figure 7] Figure 7 shows processing sequences for photothermal decomposition treatment to obtain patterned pure graphene in various embodiments. [Figure 8] Figure 8 shows processing sequences for photothermal decomposition treatment to obtain screen-printed graphene composites in various embodiments. [Figure 9A] Figure 9A shows the emission spectra of PulseForge® tools in response to pulse voltage in various configurations. [Figure 9B]Figure 9B shows the absorption spectra of glass substrates, benzoxazine monomers, and cured poly(benzoxazine) films in various configurations. [Figure 9C] Figure 9C shows temperature-time profiles obtained from cured poly(benzoxazine) films photothermally decomposed using low-power processes in various configurations. [Figure 9D] Figure 9D shows temperature-time profiles obtained from cured poly(benzoxazine) films photothermally decomposed using high-power processes in various configurations. [Figure 9E] Figure 9E shows the FTIR spectra of benzoxazine monomer, poly(benzoxazine), and photothermally produced graphene composites in various embodiments. [Figure 9F] Figure 9F shows the TGA profiles of poly(benzoxazine), graphene composites, and carbon fibers in various embodiments. [Figure 10A] Figure 10A shows optical images of the cured precursor film in various configurations. [Figure 10B] Figure 10B shows optical images of graphene / carbon fiber composites in various embodiments. [Figure 10C] Figure 10C shows SEM images of graphene / carbon fiber composites in various configurations. [Figure 10D] Figure 10D shows SEM images of graphene / carbon fiber composites in various configurations. [Figure 11A] Figure 11A shows optical images of pure fine mesh carbon fibers of 1K, plain weave, and 228.6 mm thickness in various configurations. [Figure 11B] Figure 11B shows optical images of a single layer of polybenzoxazine precursor film on pure fine mesh carbon fibers of 1K, plain weave, 228.6 mm thickness, and of carbon fiber / graphene composite materials obtained after thermal decomposition, in various embodiments. [Figure 11C]Figure 11C shows optical images of two layers of polybenzoxazine precursor film on pure fine mesh carbon fibers of 1K, plain weave, 228.6 mm thickness, and of carbon fiber / graphene composite materials obtained after thermal decomposition, in various embodiments. [Figure 11D] Figure 11D shows SEM images of the composite material shown in Figure 11C in various configurations. [Figure 12A] Figure 12A shows the Raman spectra of carbon fibers and graphene / carbon fiber composites in various embodiments. [Figure 12B] Figure 12B shows the X-ray diffraction patterns of graphene / carbon fiber composites in various embodiments. [Figure 12C] Figure 12C shows XPS spectra of graphene / carbon fiber composites in various configurations. [Figure 13A] Figure 13A shows images of graphene / carbon composites obtained by low-power pulse modulation processing under various conditions. [Figure 13B] Figure 13B shows images of graphene / carbon composites obtained by high-power pulse modulation processing in various configurations. [Figure 13C] Figure 13C shows images of graphene / carbon composites obtained by high-power pulse modulation processing under various conditions. [Figure 13D] Figure 13D shows the Raman spectra of graphene / carbon composites obtained by low-power and high-power pulse modulation processing in various embodiments. [Figure 14A] Figure 14A shows transmission electron microscope images of graphene / carbon fiber composites in various configurations. [Figure 14B] Figure 14B shows transmission electron microscope images of graphene / carbon fiber composites in various configurations. [Figure 14C] Figure 14C shows transmission electron microscope images of amorphous carbon in various forms. [Figure 15A] Figure 15A shows SEM images of thermoset imprinted features in various forms. [Figure 15B]Figure 15B shows SEM images of graphene features obtained by photothermal decomposition of the features shown in Figure 15A, under various configurations. [Figure 15C] Figure 15C shows SEM images of enlarged vias of the features shown in Figure 15B, in various configurations. [Figure 15D] Figure 15D shows SEM images of enlarged vias of the features shown in Figure 15B, in various configurations. [Figure 16] Figure 16 shows the Raman spectra of imprinted and thermoset structures in various embodiments, as well as the graphene characteristics derived from them during photothermal decomposition in air. [Figure 17] Figure 17 shows optical images of graphene / carbon fiber composites obtained from alternating laminated coatings, two subsequent coatings, and photothermal decomposition of cyclized polyacrylonitrile after thermal decomposition, in various configurations. [Figures 18A-18F] Figures 18A to 18F show SEM images of graphene / carbon fiber composites obtained from alternating laminated coatings, followed by two more coatings, and photothermal decomposition of cyclized polyacrylonitrile after thermal decomposition, in various configurations. [Figure 19] Figure 19 shows the FTIR spectra of polyacrylonitrile (before cyclization) and cyclized polyacrylonitrile membranes in various configurations. [Figure 20A] Figure 20A shows the Raman spectra of graphene / carbon fiber composites obtained from alternating laminated coatings in various configurations, followed by two and three coatings, and photothermal decomposition of cured poly(flange epoxy) after thermal decomposition (with the precursor film coated on a carbon fiber substrate). [Figure 20B] Figure 20B shows the Raman spectra of graphene / carbon fiber composites obtained from alternating laminated coatings in various configurations, followed by two and three coatings, and photothermal decomposition of cured poly(flange epoxy) after thermal decomposition (the precursor film was coated on a stainless steel substrate). [Figure 21A]Figure 21A shows optical images of dimensionally stable polyimide / graphene composite electrode structures obtained from photothermal decomposition in air of screen-printed and thermocured cyclized polyacrylonitrile electrode structures in various embodiments. [Figure 21B] Figure 21B shows Raman spectra of dimensionally stable polyimide / graphene composite electrode structures obtained from photothermal decomposition in air of screen-printed and thermocured cyclized polyacrylonitrile electrode structures in various embodiments. [Figure 22A] Figure 22A shows optical images of unheated pure carbon fiber fabrics in various configurations. [Figure 22B] Figure 22B shows optical images of carbon fiber fabrics that have been photothermally decomposed in various ways. [Figure 23A] Figure 23A shows the FTIR spectra of pure carbon fiber fabrics in various configurations. [Figure 23B] Figure 23B shows the Raman spectra of pure carbon fiber fabric and photothermally decomposed pure carbon fiber fabric in response to xenon flash lamp pulse output in various configurations. [Figure 24A] Figure 24A shows low-magnification SEM images of MnO2-deposited PPGs under various conditions. [Figure 24B] Figure 24B shows low-magnification SEM images of MnO2-deposited PPGs under various conditions. [Figure 24C] Figure 24C shows high-magnification SEM images of MnO2-deposited PPGs under various conditions. [Figure 24D] Figure 24D shows a comparison of Raman spectra of MnO2-deposited PPG and PPG under various configurations. [Figure 24E] Figure 24E shows XRD profiles of PPG and the corresponding MnO2 deposited on PPG in various embodiments. [Figure 24F] Figure 24F shows XPS analysis of MnO2 deposited on PPG under various conditions. [Figure 25A]Figure 25A shows the CV curves at 50 mV / s for PPGs prepared with different output pulses and CFs under various configurations. [Figure 25B] Figure 25B shows the CV curves of PPG from PBz at different scanning speeds in various embodiments. [Figure 25C] Figure 25C shows the GCD profiles of the manufactured devices at different current densities in various embodiments. [Figure 25D] Figure 25D shows Nyquist plots of PPG at frequencies from 10⁴ to 0.1 Hz under various configurations. [Figure 26A] Figure 26A shows the CV curves at various scanning speeds for symmetric devices prepared using MnO2 deposited on PPG, according to various embodiments. [Figure 26B] Figure 26B shows GCD profiles at various current densities for symmetric devices prepared using MnO2 deposited on PPG, according to various embodiments. [Figure 26C] Figure 26C shows the capacitance (F / g) of symmetric devices prepared using MnO2 deposited on PPG, depending on the current density, in various configurations. [Figure 27A] Figure 27A shows Lagoon plots of symmetric devices prepared using MnO2 deposited on PPG in various embodiments. [Figure 27B] Figure 27B demonstrates the device's operation by using three devices connected in series to light an LED in various configurations. [Figure 28A] Figure 28A shows a photograph (top left) of the experimental setup for EMI shielding measurement, including a programmable network analyzer, waveguide, and sample holder assembly; a photograph (bottom left) showing close-ups of the sample holder assembly in various configurations; a photograph (center) showing close-ups of the sample holder in various configurations; and a photograph (right) showing the sample inside the sample holder in various configurations. [Figure 28B]Figure 28B shows schematic diagrams (left) showing front views of samples placed in a sample holder in various configurations, and schematic diagrams (right) showing side views of the sample arrangement in the sample holder. [Figure 29] Figure 29 shows the SE-to-frequency (SE) shielding effect of various two-layer graphene / carbon fiber composite materials, illustrating their multiband (C-band, X-band, and Ku-band) EMI shielding effects. [Figure 30] Figure 30 shows the UV absorption spectra of capton under various conditions. [Figure 31A] Figure 31A shows optical images of PANI on CF (left) and PANI-induced graphene on CF (right) in various configurations. [Figure 31B] Figure 31B shows the TGA profiles of PANI, PANI-derived graphene, and pure CF in various embodiments. [Figure 31C] Figure 31C shows the Raman spectra of pure CF (top), PANI-derived graphene on CF (center), and PANI produced by conventional carbonization at 1000°C (bottom) in various embodiments. [Figure 32A] Figure 32A shows SEM images of electrochemically deposited PANI in various configurations. [Figure 32B] Figure 32B shows SEM images of graphene photothermally produced from PANI under various conditions. [Figure 32C] Figure 32C shows the C1s spectra of graphene photothermally produced from PANI under various conditions. [Figure 33A] Figure 33A shows the CV curves of PANI-derived graphene and CF in 0.5 M sodium sulfate at 50 mV / s under various configurations. [Figure 33B] Figure 33B shows the CV curves of PANI-derived graphene in 1M sulfuric acid at various scanning speeds (10mV / s to 100mV / s) under various configurations. [Figure 33C] Figure 33C shows the GCD curves of PANI-induced graphene at various current densities under various configurations. [Figure 34]Figure 34 shows schematic diagrams of various types of spectacle side arms with energy storage capabilities, formed from polyaniline on carbon fibers. [Figure 35A] Figure 35A shows screen-printed LED circuits containing a cPAN precursor in various configurations. [Figure 35B] Figure 35B shows LED graphene circuits obtained from the photothermal decomposition of screen-printed cPAN precursors in various configurations. [Figure 35C] Figure 35C demonstrates the successful integration of a white light LED into the graphene circuit of Figure 35B, driven by an external power supply, using graphene wiring with a sheet resistance of 100-200 Ω / sq in various embodiments. [Modes for carrying out the invention]

[0011] The following references some aspects of the subject matter of this disclosure, with examples partially shown in the accompanying drawings. The subject matter disclosed is described in conjunction with the enumerated claims, but the subject matter illustrated is not intended to limit the claims to the subject matter disclosed.

[0012] The drawings generally illustrate various aspects of the present invention, not as limitations. Throughout this specification, values ​​expressed in range form should be flexibly interpreted to include not only the numerical values ​​explicitly listed as limits to the range, but also all individual numerical values ​​or subranges contained within that range, as if each numerical value and subrange were explicitly listed. For example, the range "approximately 0.1% to approximately 5%" or "approximately 0.1% to approximately 5%" should be interpreted to include not only approximately 0.1% to approximately 5%, but also the individual values ​​within the indicated range (e.g., 1%, 2%, 3%, and 4%) and subranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%). The notation "approximately X to Y" is equivalent to "approximately X to approximately Y" unless otherwise indicated. Similarly, the notation "approximately X, Y, or approximately Z" is equivalent to "approximately X, approximately Y, or approximately Z" unless otherwise indicated.

[0013] In this specification, the term “one” is used to include one or more unless the context explicitly indicates otherwise. The term “or” is used to mean non-exclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” is synonymous with “A, B, or A and B.” It should also be understood that any expressions or terms used herein, unless otherwise defined, are for illustrative purposes only and not for limitation. The use of section headings is intended to aid in the reading of this specification and should not be interpreted as limiting, and the information related to a section heading may be located inside or outside that particular section.

[0014] In the methods described herein, the operations may be performed in any order without departing from the principles of the invention, unless the temporal or operational order is explicitly stated. Furthermore, the specified operations may be performed simultaneously unless the language of the claim explicitly states that they are to be performed separately. For example, the operation of a claim to perform X and the operation of a claim to perform Y may be performed simultaneously within a single operation, and the processing therefrom falls within the scope of the processing of the claim.

[0015] As used herein, the term “approximately” may allow for some degree of variability in a value or range, for example, within 10%, 5%, or 1% of the limits of the described value or range, and includes the exact described value or range.

[0016] As used herein, the term “substantially” means the majority or most of the total, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. As used herein, the term “substantially absent” can mean that the material is absent or present in such small amounts that the amount of the material present does not affect the material properties of the composition containing that material, and the material is present in amounts of about 0% to about 5% by weight, about 0% to about 1% by weight, about 5% or less by weight, about 5% or less by weight and about 4.5% or more by weight, or 4% by weight, 3.5% by weight, 3% by weight, 2.5% by weight, 2, 1% by weight, 1% by weight, 0.9% by weight, 0.8% by weight, 0.7% by weight, 0.6% by weight, 0.5% by weight, 0.4% by weight, 0.3% by weight, 0.2% by weight, 0.1% by weight, 0.01% by weight, or about 0.001% or less by weight, or about 0% by weight.

[0017] As used herein, the term "polymer" refers to a molecule having at least one repeating unit, and may include copolymers. [Method for forming graphene films] Various aspects of the present invention provide a method for forming a graphene film. The method includes coating a polymer graphene precursor onto a substrate. The method also includes irradiating the polymer graphene precursor coated on the substrate with a pulsed high-intensity light source that emits light at two or more wavelengths and has a pulse duration of less than one second. This irradiation converts the polymer graphene precursor into a graphene film. This irradiation can form a graphene film by thermally decomposing the polymer graphene precursor.

[0018] The formed graphene film may be a composite graphene film or a non-composite graphene film. The formed graphene film may include a substrate so that the formed graphene film is coated onto the substrate. The substrate may be any suitable material, such as a heat-sensitive material or a non-heat-sensitive material. The substrate and the polymer graphene precursor may have the same chemical composition. The substrate and the polymer graphene precursor may have different chemical compositions. The substrate and the graphene film formed on the substrate may have different chemical compositions. The substrate may be a material other than a graphene film or a polymer graphene film precursor.

[0019] Irradiation includes irradiating a polymer graphene precursor coated on a substrate. Irradiation may include irradiating the polymer graphene precursor or both the polymer graphene precursor and the substrate. Irradiation of the substrate may or may not cause a change in the substrate. In various embodiments, irradiation of the substrate may convert the substrate into a graphene-containing material. In various embodiments, irradiation of the substrate does not convert the substrate into a graphene-containing material. Irradiation of the polymer graphene precursor may be carried out in air, an inert gas, or any suitable gas. Irradiation of the polymer graphene precursor may be carried out in the atmosphere.

[0020] Irradiation may include irradiating and / or maintaining the polymer graphene precursor at temperatures below 100°C, for example, 0°C to 99°C, 10°C to 50°C, 20°C to 30°C, below 100°C and 0°C, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or above 95°C. Irradiation may include irradiating the polymer graphene precursor at room temperature or ambient temperature. Irradiation may include substantially maintaining the pre-irradiation temperature of the polymer graphene precursor throughout the irradiation. Irradiation may include raising the temperature of the polymer graphene precursor to 10°C or less, 2°C or less, 0°C or less, or 100°C or less and 0.001°C, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95°C or higher relative to the pre-irradiation temperature of the precursor film. The method may include localizing light absorption in the precursor film such that the temperature rise of the polymer graphene precursor is below a desired limit. By localizing light absorption in the precursor film during photothermal treatment, the treatment can be carried out at ambient temperature, making it possible to prepare high-quality graphene and graphene composites on any substrate, including heat-sensitive substrates, without the need for a catalyst. Various aspects of the method of the present invention can leave the substrate undamaged, relative to the state of the coating and the substrate before irradiation. By enabling the formation of a graphene film without damaging the substrate, the method allows for the individual selection of polymer graphene precursors and substrates, providing advantages when preparing graphene materials on any substrate.

[0021] The light source may be any suitable light source that induces graphene formation from the polymer graphene precursor described herein. The light source may be any suitable light source having an emission band that overlaps with the absorption band of the polymer graphene precursor. The light source may include a xenon flash lamp, a halogen flash lamp, a light-emitting diode, two or more light-emitting diodes, or a combination thereof. The light source may include a xenon flash lamp or be a xenon flash lamp. The light source may include an emission wavelength that overlaps with the absorption wavelength of the polymer graphene precursor. The light source may include emission wavelengths in the range of 100nm to 2000nm, 300nm to 800nm, 400nm to 600nm, or 2000nm or less and within the range of 100nm, 150, 200, 250, 300, 350, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1200, 1400, 1600, or 1800nm ​​or more.

[0022] The pulse duration of the light source during irradiation can be shorter than the thermal equilibrium time of the polymer graphene precursor so that the temperature rise of the polymer graphene precursor during irradiation is small, minimal, or zero. The pulse duration can be any appropriate pulse duration such as 1 to 999 milliseconds, 200 to 900 milliseconds, 400 to 800 milliseconds, or 999 milliseconds or less and 1 millisecond, 2 milliseconds, 5, 10, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 milliseconds or more.

[0023] The light source may have any suitable intensity during irradiation, such as 100V to 2000V, 400V to 700V, or below 2000V and 100V, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, or 1900V or above. The light source may have an energy density per pulse of 0.1 J / cm 2 ~100 J / cm 2 、 1 J / cm 2 ~10 J / cm 2 、 2 J / cm 2 ~9 J / cm 2 、 or an energy density per pulse of 100 J / cm 2 or less and 0.1 J / cm 2 、 0.5、 1、 2、 3、 4、 5、 6、 7、 8、 9、 10、 12、 14、 16、 18、 20、 25、 30、 35、 40、 45、 50、 55、 60、 65、 70、 75、 80、 85、 90、 or 95 J / cm 2 or above. The light source may have a total area density of 10 J / cm 2 ~1000 J / cm 2 、 30 J / cm 2 ~200 J / cm 2 、 or a total area density of 1000 J / cm 2 or less and 10 J / cm 2 、 20、 30、 40、 50、 60、 70、 80、 90、 100、 110、 120、 130、 140、 150、 160、 170、 180、 190、 200、 250、 300、 400、 500、 600、 700、 800、 or 900 J / cm 2 or above.

[0024] The light source may have any suitable pulse frequency, such as 0.001Hz to 1000Hz, 0.1Hz to 10Hz, 0.5Hz to 1Hz, or 1000Hz or less and 0.1Hz, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 2, 2.5, 3, 4, 5, 6, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 80, 100, 150, 200, 250, 300, 400, 600, 800, or 900Hz or higher. Irradiation may include any appropriate number of pulses from the light source, such as 5 to 1000 pulses, 10 to 40 pulses, or 1000 pulses or less, and 5 pulses, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 140, 160, 180, 200, 250, 300, 400, 500, 600, 700, 800, or 900 pulses or more.

[0025] The coating of polymer graphene precursor onto a substrate can be carried out by any suitable means. For example, coating a substrate with polymer graphene precursor may include using printing, offset printing, inkjet printing, transfer printing, aerosol jet printing, microcontact printing, embossing, nanoimprint lithography, photolithography, electron beam lithography, ion beam lithography, or a combination thereof. The method may include curing the polymer graphene precursor coating by thermal curing, photocuring or UV curing, or a combination thereof, to form a cured polymer graphene precursor film. Irradiation may include irradiating the cured film. In other embodiments, the method may not include curing, and irradiation may include irradiating an uncured polymer graphene precursor coating.

[0026] The polymer graphene precursor on the substrate may include a patterned polymer graphene precursor; that is, the polymer graphene precursor can be patterned. The patterning may be introduced into the film after the film has been applied to the substrate, or it may be introduced into the film simultaneously with the application of the film to the substrate. The patterned film of the polymer graphene precursor can be formed by any suitable method such as printing, offset printing, inkjet printing, transfer printing, aerosol jet printing, microcontact printing, or a combination thereof. The patterned film of the polymer graphene precursor can be formed by embossing, nanoimprint lithography, or a combination thereof. The patterned film of the polymer graphene precursor can be formed by photolithography, electron beam lithography, or ion beam lithography.

[0027] Polymer graphene precursors can be any suitable polymer precursors that form graphene films under the irradiation conditions described herein. For example, polymer graphene precursors may include polymers containing disubstituted benzenes, benzenes substituted with one or more chromophores, polycyclic aromatic rings, or combinations thereof. Polymer graphene precursors may include polymers containing nitroaniline, aniline, nitrophenol, biphenyl (e.g., two conjugated benzene rings), nitrobenzene, benzaldehyde, acetophenone, pyrene, pentacene, anthracene, tetracene, or combinations thereof. Polymer graphene precursors may include polymers selected from resols, pyrene pitch oligomers, cyclized polyacrylonitriles, polyaniline, carbon fibers, thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and epoxy, and combinations thereof. Polymer graphene precursors may include polymers selected from poly(3-phenyl-2,4-dihydro-1,3-benzoxazine), poly(phenylbenzoxazine), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine), poly(furanylbenzoxazine), poly(phenol-co-formaldehyde), resol, oligomers of pyrene pitch, cyclized polyacrylonitrile, pure carbon fibers, polyaniline, thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and bis-phenol-A furfuryl diglycidyl ether, and combinations thereof. In various embodiments, polymer graphene precursors include polyaniline. In various embodiments, polymer graphene precursors include polyaniline. Polymer graphene precursors are irradiated to form graphene films with reduced or zero requirements for high-temperature crosslinking or curing. For example, such irradiation may be carried out (e.g., maintained) at room temperature or below 30°C, 35°C, 40°C, 45°C, or 50°C. In various embodiments, the polymer graphene precursor contains polyaniline, and the resulting graphene film is a porous graphene film.

[0028] Polymer graphene precursors may have absorption bands that overlap with the emission band of a pulsed light source. Polymer graphene precursors may have absorption bands in the ranges of 100nm to 2000nm, 300nm to 800nm, 400nm to 600nm, or below 2000nm and above, including 100nm, 150, 200, 250, 300, 350, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1200, 1400, 1600, or above 1800nm.

[0029] The substrate can be any suitable substrate. The substrate may include plastic, metal, cloth, woven fabric, carbon, or a combination thereof. A carbon-containing substrate may include carbon fibers, carbon mesh, carbon cloth, carbon composites, graphene composites, graphene, carbon films, or a combination thereof. In various embodiments, a carbon-containing substrate may form graphite, graphene, or a combination thereof during irradiation. In other embodiments, a carbon-containing substrate may remain unchanged during irradiation. Alternatively, a carbon-containing substrate may be converted into a material other than graphite and / or graphene.

[0030] A graphene film may have an electrical conductivity of at least 150 S / cm, for example, 150-5000 S / cm, 150 S / cm-1000 S / cm, 150-500 S / cm, or 5000 S / cm or less and 150 S / cm, 160, 170, 180, 190, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 550, 600, 650, 700, 750, 800, 900, 1000, 1250, 1500, 1750, 2000, 2500, 3000, or 3500 S / cm or more.

[0031] The graphene film is determined by Raman spectroscopy, at 1350 cm². -1 A distinctive disordered band (D band) with a peak nearby, and 1582 cm-1 The ratio to the characteristic graphite band (G band) with a peak nearby may be less than 1. Graphene films are determined by Raman spectroscopy, at 2700 cm². -1 A distinctive 2D band with a peak nearby, and a 1582 cm² suitable for a single Lorentz function. -1 The ratio to the characteristic graphite band (G band) with a peak nearby may be less than 1.

[0032] Irradiation may include pulsed output modulation. The method may include adjusting the fine structure of the graphene film using pulsed output modulation. [Graphene film] Various aspects of the present invention provide graphene films formed by the method of the present invention. The graphene film may be a graphene film coated on a substrate as described herein. The graphene film may be a patterned graphene film or an unpatterned graphene film.

[0033] [Devices containing graphene films] Various aspects of the present invention provide electrochemical energy storage devices, electromagnetic shielding materials, chemical or biological sensors, post-CMOS nanoelectronic devices, thermal shielding materials, structural composites, filters, or combinations thereof, including graphene films formed by the method of the present invention. For example, graphene films formed by this method can find applications in electrochemical energy storage devices as electrodes in supercapacitors and batteries, electromagnetic interference and electromagnetic pulse shielding structures as shielding materials, chemical and biological sensors as electrodes, flexible electronics as electrodes and sensors, post-CMOS nanoelectronic devices as interconnects, thermal applications as heat shielding materials in hypersonic and electronics, structural composites, filtration as filters for water and biological formulations, and in eyeglasses such as eyeglass side arms that can store electrochemical energy and be used in laser projection applications. Various aspects of the present invention provide graphene derived from the photothermal decomposition of exemplary screen-printed precursor materials such as cPAN and / or poly(BZ), which are coated on flexible polyimide and intended for printing and flexible electronics applications.

[0034] [Examples] Various aspects of the present invention can be better understood by referring to the following examples provided for illustrative purposes. The present invention is not limited to the examples shown herein.

[0035] A method for rapidly and efficiently preparing graphene by photothermal decomposition of precursor thin films in a millisecond timeframe under ambient conditions includes using high-intensity pulsed light from a xenon flash lamp operating in room-temperature air to photothermal decompose unpatterned graphene precursor films, printed graphene precursor films, and imprinted graphene precursor films.

[0036] Figure 1 shows the processing scheme. By localizing light absorption in the precursor film during photothermal treatment, the process can be carried out at ambient temperature, making it possible to prepare high-quality graphene and graphene composites over a large area on any substrate, including heat-sensitive substrates, without the need for catalysts. The use of patterned films deposited using screen printing or additives directly yields two-dimensionally patterned graphene material. Nanoimprint patterning of the precursor film before photothermal processing can directly yield a designed three-dimensional surface with features ranging from nanoscale to microscale dimensions. This process produces high-quality pure graphene and graphene composites, depending on the initial precursor.

[0037] If the radiation source is pulsed for a duration (on the order of milliseconds) shorter than the thermal equilibrium time between the preceramic polymer and the substrate, the precursor film can be rapidly heated and thermally decomposed before it can transfer significant energy to the substrate. Ideal thermal decomposition conditions depend on the precursor film, its absorption cross-section, film thickness, substrate type, and the type / content of any additives. The exposure energy delivered to the sample can be adjusted by varying the discharge voltage and pulse duration. The ability to independently adjust the pulse duration and intensity provides independent control over both the output and energy delivered to the sample. The choice of using a xenon flash lamp source instead of a laser for photoprocessing offers several advantages, including reduced cost and complexity, improved efficiency in converting electrical energy to light, and scalability for large-area processing without rasterizing.

[0038] Polymer graphene precursors have an absorption profile that overlaps with a portion of the emission spectrum of a xenon flash lamp with a peak intensity in 400–600 nm. The n-π* (R band) is the most relevant electronic transition corresponding to this wavelength region, and materials having a portion that can be excited by radiation within a significant portion of the xenon flash lamp emission spectrum will inevitably be well thermally decomposed when irradiated with pulses of sufficient intensity and power density. While the use of a xenon flash lamp is emphasized here, other broadband, high-intensity pulse sources can also be used to photothermally decompose suitable precursors. Examples of suitable precursors include disubstituted benzenes such as nitroaniline, nitrophenol, and biphenyl (with two conjugated aromatic rings), benzenes substituted with chromophores such as nitrobenzene, benzaldehyde, acetophenone, nitrobenzene, and biphenyl, and materials containing polynuclear aromatic compounds with high aromatic content such as pyrene, pentacene, anthracene, and tetracene. Selected representative examples of precursor resins shown in Figures 2A to 2C include, but are not limited to, poly(3-phenyl-2,4-dihydro-1,3-benzoxazine) or poly(phenylbenzoxazine) (I), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine) or poly(furanylbenzoxazine) (II), poly(phenol-co-formaldehyde) or resol (III), oligomers of pyrene pitch (IV), cyclized polyacrylonitrile (V), polyaniline, and thermosetting resin networks formed from blends and crosslinks of polybenzoxazine with epoxy such as furfuryl diglycidyl ether of bisphenol-A (in the figures, R2 is bisphenol-A and epoxy is diglycidyl ether of bisphenol-A) and flange epoxy (VI). Other examples include pure carbon fibers and / or polyaniline (e.g., structure-(phenyl-NH) n Examples include having - and having a phenyl ring bonding affinity of 1,4 (para) in the polymer backbone.

[0039] Conventional methods, with the exception of electrochemical reduction and CVD approaches, are not scalable to large-scale production. Most of them are extremely energy-intensive, operate under harsh conditions, are expensive, and are very slow to execute. Various embodiments of the present invention overcome all these drawbacks by using a high-intensity pulsed xenon flash lamp in air under ambient conditions of room temperature and atmospheric pressure to thermally decompose a suitable precursor in milliseconds. The millisecond duration of the radiation pulse is shorter than the thermal equilibrium time of the precursor, enabling the thermal decomposition of the precursor and the formation of high-quality graphene before significant energy transfer to the substrate, making this process unparalleled suitable for graphene preparation on or adjacent to heat-sensitive materials. Rapid precursor thermal decomposition and phase transformation during flash lamp treatment limit the oxidation of the resulting graphene, even in air.

[0040] (Example 1) Synthesis of exemplary precursor materials (benzoxazine monomer and polyaniline) Benzooxazine monomers can be synthesized via a one-pot chemical reaction using bisphenol A, aniline, and paraformaldehyde in a molar ratio of 1:2:4, as shown in Figure 2D. Bisphenol A and aniline are introduced into a two-necked round-bottom flask fitted with a reflux condenser, and the resulting solution is stirred at room temperature for 30 minutes to ensure homogeneous mixing. The temperature of the mixture is then reduced to 5°C using an ice bath, and then a dispersion of stoichiometric amounts of paraformaldehyde dispersion in dioxane is added dropwise to the bisphenol A and aniline reaction mixture. The resulting reaction mixture is then heated in a silicone oil bath at 60°C for 1 hour, followed by further heating at 120°C for 5 hours with constant stirring and reflux. The conversion of the reagents to benzooxazine monomers is confirmed by the color change of the reaction solution from milky white to clear orange. The residual dioxane solvent can be removed from the benzooxazine monomer by heating the product mixture at 130°C for 2 hours, and then the product is cooled to room temperature to obtain pure benzooxazine monomers. This pure benzoxazine monomer can be used directly without further treatment. The reaction yield is 90%.

[0041] Polyaniline (PANI) was electrochemically grown (electrodeposited) onto a conductive carbon fiber substrate using three electrodes configured as described in various literatures: a carbon fiber as the working electrode, a platinum wire as the counter electrode, and Ag / AgCl as the reference electrode. The electrodes were immersed in an aqueous solution containing 0.3 M aniline and 1 M HCl as the electrolyte. A constant current of 10 mA was applied for 10 minutes to uniformly grow PANI on the carbon fiber. After deposition, the PANI on the CF was thoroughly washed with deionized water to remove excess electrolyte, and then dried at 100°C for 1 hour.

[0042] (Example 2) Photothermal decomposition treatment of exemplary unpatterned precursor film material Figures 3-5 are schematic diagrams of treatment sequences for photothermal decomposition of two exemplary unpatterned precursor films, polybenzoxazine and cycloadelliptic polyacrylonitrile, coated on carbon fibers. Figure 6 shows a treatment scheme for photothermal decomposition of pure carbon fibers. For use in photothermal treatment, a solution of the precursor material in a suitable solvent and an appropriate concentration are first prepared. With respect to the exemplary precursor material of benzoxazine, and a blend of benzoxazine and epoxy precursor material, the solution is prepared in dioxane at a concentration of 1.0 g / mL. Figure 5 shows the photothermal treatment sequence of cycloadelliptic polyacrylonitrile (another exemplary precursor material). For use in photothermal treatment, a solution of polyacrylonitrile in dimethylformamide and an appropriate concentration are first prepared.

[0043] The processing sequence for unpatterned films begins with coating both sides of a suitable substrate, e.g., a carbon fiber substrate (10 cm × 10 cm), with a thickness of 5–8 microns using a Meyer rod (#20), drying at room temperature, and then thermal curing for 24 hours in a nitrogen-filled oven maintained at 220°C. Curing crosslinks the precursor monomers, converting them into the corresponding polymers, as shown in Figure 4 for the crosslinking of benzoxazine monomers to exemplary polybenzoxazine precursors.

[0044] Next, the unpatterned and patterned films are photothermally decomposed using a xenon flash lamp from a PulseForge 1300 tool (Novacentrix PulseForge® 1300 xenon lamp system, Austin, Texas, USA). The dried and crosslinked PCP films on each substrate are first loaded onto a stainless steel chuck positioned below the center of the tool's xenon flash lamp. The lamp needs to be positioned 15 mm above the sample to ensure a uniform energy distribution within the irradiated PCP film. It is important to control the rate and mechanism by which organic matter and solvents in the PCP film are removed as gaseous products during the precursor's thermal decomposition conversion to ensure uniform densification, prevent impurity residue, and / or the formation of gas-generating defects such as pores. For this purpose, first, 5.3 J / cm² is applied. 2 The sample needs to be irradiated with 20 pulses (frequency 0.5 Hz, pulse length 800 μs, and voltage 540 V) of area energy density to volatilize any residual solvent and low molecular weight components remaining in the film after thermal curing in a vacuum oven. Next, 8.2 J / cm 2 The samples need to be irradiated with high-power pulses (1.0 Hz frequency, 800 μs pulse length, and 620 V voltage) with an area energy density of 20 to thermally decompose them.

[0045] The photothermal treatment of PANI on CF was carried out in two steps, similar to that of the polybenzoxazine-based system. The PANI on CF was crosslinked during carbonization, enabling photothermal treatment without the need for high-temperature crosslinking, making the treatment more sustainable and reducing energy consumption. The sample was initially treated at 2.6 J / cm². 2 The organic residue is removed by 10 pulses of low-energy radiation (400V, 800μs, 1Hz frequency), followed by 8.91 J / cm². 2 PANI was completely converted to graphene by being irradiated with 10 pulses at a high energy dose of (630V, 800μs, 1Hz frequency).

[0046] (Example 3) Photothermal decomposition treatment of exemplary patterned precursor film material The processing sequence for the patterned film (Figure 7) includes soft lithography imprint patterning of a suitable polymer film coated on a suitable substrate, including silicon wafers and stainless steel foil, using a fluorinated solvent-permeable patterned poly(dimethylsiloxane) stamp while simultaneously curing the film at a suitable temperature. The cured film is then subjected to photothermal decomposition in air using a high-intensity xenon flash lamp to obtain a catalyst-free patterned graphene structure. The photothermal decomposition conditions are 5.3 J / cm² for the cured sample. 2This involved irradiation with 70 pulses (1.0 Hz frequency, 500 μs pulse length, and 540 V voltage) of area energy density. Fluorination of the stamp ensures a smooth release of the stamp at the end of the imprinting process without damaging the imprinted features. Thermal curing at 220°C in a nitrogen-supplied oven results in a structurally stable structure against photothermal decomposition in air at temperatures up to 1500°C. Structures of various shapes, including lines, holes, and trenches, and length scales ranging from nanometers to millimeters, can be easily realized in minutes using this technique. Suitable precursor polymers have absorption spectra with peak values ​​that overlap with the emission spectrum of a xenon flash lamp, and these include polybenzoxazines and phenol-formaldehyde resins.

[0047] (Example 4) Photothermal decomposition treatment of exemplary screen-printed precursor film material Figure 8 shows the processing sequence for a screen-printed film, which includes dispensing an appropriate amount of neat viscous solution of the precursor film onto a screen placed on a suitable high-temperature substrate such as a polyimide film, and printing the image of the screen onto the substrate by applying force to pass the solution through the screen. Next, the film is thermally cured for 24 hours at an appropriate temperature (220°C for polybenzoxazine) in a nitrogen-supplied oven. For poly(acrylonitrile) precursors, the screen-printed film is first cured at 150°C in an air-supplied oven, and then the sample is heated overnight at 250°C to cyclize the linear polyacrylonitrile. Thermal curing of the screen-printed precursor film of polybenzoxazine at 220°C and cyclization of polyacrylonitrile at 250°C result in a structurally stable structure against photothermal decomposition in air at temperatures up to 1500°C.

[0048] Next, the cured or cyclized precursor film is subjected to photothermal decomposition in air to convert it into a graphene structure without the use of a catalyst. The photothermal decomposition treatment conditions are 2.5 J / cm². 2The curing method involved irradiating the cured sample with 20 pulses (1.0 Hz frequency, 500 μs pulse length, and 490 V voltage) at a surface energy density of . Photothermal decomposition using such low-power pulses allows for the preservation of the structural integrity of the screen-printed features, otherwise the features may be damaged.

[0049] (Example 5) Material properties of exemplary unpatterned precursor polybenzoxazine and graphene / carbon fiber composites derived from photothermal decomposition Polybenzoxazine is a polymer with moderate char yield and an absorbance spectrum that overlaps with the maximum intensity of the xenon lamp emission spectrum (Figures 9A and 9B). UV / Vis / NIR absorption spectra of polybenzoxazine films coated on stainless steel substrates were collected in reflectance mode over the wavelength range of 200 nm to 1200 nm using a Lambda-1050 UV / Vis / NIR spectrophotometer (Perkin-Elmer, Boston, Massachusetts, USA). Measurements were performed after spin-coating samples onto glass substrates. Upon photothermal decomposition, the films could reach temperatures exceeding 1530°C and 2040°C depending on pulse output modulation (Figures 9C and 9D). Structural changes in the films in response to the treatment were monitored using IR spectroscopy. Infrared absorption spectra of samples were collected using a Frontier 1300 attenuated total reflectance Fourier transform infrared spectrometer (Perkin-Elmer, Boston, Massachusetts, USA) over a wavelength range of 3200–500 cm⁻¹. -1 The samples were obtained within the specified range. The samples consisted of powder from a composite material scraped off a carbon fiber substrate after thermal decomposition. The FTIR spectra were obtained at 941 cm⁻¹. -1 and 1491cm -1The disappearance of the monomer oxazine ring and the trisubstituted benzoxazine at the peak confirmed the complete conversion of the benzoxazine monomer to the polymer and the thermal curing of the polymer (Figure 9E). The absence of structure in the composite spectrum confirmed that the precursor material was completely thermally decomposed and converted to a carbonaceous composite (Figure 9E). Thermogravimetric analysis was performed using a Q50TA instrument at a temperature range of 25–700°C at 10°C / min in a nitrogen atmosphere. Thermogravimetric analysis confirmed the conversion of polybenzoxazine to a carbonaceous composite (Figure 9F).

[0050] The surface morphology of the sample was analyzed using field emission scanning electron microscopes (FEI Magellan 400 XHR SEM and FEI Helios Dual Beam FIB SEM). High-resolution transmission electron microscopy (HRTEM) analysis of the sample was performed using a JEOL JEM-2200 OFS energy-filtered transmission electron microscope with a 200kV acceleration voltage. The sample consisted of powder of graphene composite material scraped from a carbon fiber substrate after thermal decomposition. Phase order and phase transformation of the composite material were investigated using Raman spectroscopy. Raman spectra of the sample were recorded at room temperature using a ThermoScientific DXR Smart Raman spectrometer (ThermoFisher Scientific, Waltham, Massachusetts, USA) with an excitation laser wavelength of 633 nm, a laser power of 5 mW, a spot diameter of 3.1 μm, and a sample exposure of 5 seconds. Figures 10A to 10D show optical images of cured poly(benzoxazine) on carbon fiber cloth (Figure 10A), and SEM images of the composite material obtained from the photothermal decomposition of cured poly(benzoxazine) (Figures 10C and 10D). Figures 11A to 11C show optical images of pure carbon fiber fabric (Figure 11A), a carbon fiber / graphene composite material obtained after a single layer of precursor film and thermal decomposition (Figure 11B), and a carbon fiber / graphene composite material with a thickness of 1093 μm obtained after a double layer of precursor film and thermal decomposition (Figure 11C). Figure 11D shows an SEM image of the composite material in Figure 11C. The composite material has a microporous surface morphology. The Raman spectrum obtained for the photothermal decomposition sample is 1582 cm⁻¹.-1 (Graphite, G-band) and 1350cm -1 A characteristic graphite band is observed near (disorder, D band) (Figure 12A). The ratio of the intensity of the D band to the G band (I D / I G The ratio is a good measure of the quality of graphite carbon in the sample. D / I G The ratio is 0.46. Since this ratio is less than 1, the sample exhibits a high degree of regularity and is a high-graphite phase. 2700 cm² -1 The nearby peak (2D band) is an overtone of the D band, which is also characteristic of graphite, specifically the graphitic ordering of free carbon along the free axis. The ability to fit this peak to a single Lorentz peak indicates the presence of high-quality graphene in the sample. Furthermore, the size of this peak relative to the G peak is a good indicator of the number of graphene layers present in the sample. 2D / I G The ratio is 0.64, which suggests the presence of several layers of graphene in the sample.

[0051] The X-ray diffraction pattern reveals that the composite material is highly ordered (Figure 12B). The crystallinity of the photothermally induced graphene composite was determined using an X-ray diffractometer (PANanalytical X'Pert X-ray diffractometer) with CuKαα radiation at a wavelength of 1.54 Å at a voltage of 45 kV and a current of 40 mA. X-ray photoelectron spectroscopy (XPS) of the graphene composite was performed using a Physical Electronics Versa Probe II instrument equipped with a monochromatic Alkα X-ray source (hν = 1486.6 eV) and a concentric hemisphere analyzer. All peaks were corrected using a reference C1s spectrum at 284.5 eV. The XPS spectrum shows the presence of C1s at a binding energy of 284.5 eV, which is characteristic of the sp² structure of graphene and graphite. 2 It shows hybridized carbon (Figure 12C). Furthermore, XPS shows that the atomic composition of the composite material is 99.1% C and 0.9% O, suggesting that it is a pure carbonaceous composite material.

[0052] Figures 13A–13D show pulsed power modulation and phase ordering of graphene / carbon composite microstructures. Low-power processing results in complete carbonization, leading to low-quality graphene composites with significant defects and high porosity. High-power processing is associated with reduced defects, decreased porosity, and higher quality graphene. The spectrum obtained from high-power pulse processing is shown below. D / I G It is 0.46, and the I of the spectrum obtained by high-power pulse processing 2D / I G It is 0.65, and the I of the spectrum obtained by low-power pulse processing D / I G It is 1.29, and the I of the spectrum obtained by low-power pulse processing 2D / I G The value was 0.57. For low-power pulse processing, the value was 106 J / cm². 2 This corresponds to a total area energy density of 5.3 J / cm² per pulse. 2 Twenty pulses (0.5 Hz, 800 μs pulse length, and 540 V voltage) with the area energy density were used. For high-power pulse processing, the area energy density was 164 J / cm². 2 This corresponds to a total area energy density of 8.2 J / cm² per pulse. 2 Twenty pulses (1.0 Hz, 800 μs pulse length, and 620 V voltage) were used to measure the area energy density.

[0053] The microstructure of the composite material was investigated using transmission electron microscopy. The presence of graphene in the composite material was further confirmed by a hexagonal lattice with a D spacing of approximately 0.33 nm, obtained by Fourier transform (Figures 14A-14C). In contrast, TEM of amorphous carbon (Figure 14C) showed no structure of any kind.

[0054] (Example 6) Material properties of exemplary patterned precursor polybenzoxazine and graphene / carbon fiber composites derived from photothermal decomposition Figures 15A–15D show SEM images of imprinted and thermoset structures, as well as graphene features obtained from those structures during photothermal decomposition in air. Figures 15B–15D show dimensionally stable graphene features, including lines, square holes, and trenches, with patterned features decorated with graphene flakes and platelets (gray). When the size of a feature is smaller than the size of the graphene flakes and platelets, a portion of the imprinted feature is covered by the graphene flakes and platelets.

[0055] Figure 16 shows 175 J / cm². 2 2.5 J / cm² per pulse corresponds to the total area energy density. 2 The area energy density was 210 J / cm² for 70 pulses (1.0 Hz, 500 μs pulse length, and 520 V voltage). 2 3 J / cm² per pulse corresponds to the total area energy density. 2 The Raman spectra of imprinted and thermoset structures, as well as graphene features obtained from those structures during photothermal decomposition in air, are shown, depending on the irradiation pulse energy density, when using 70 pulses (1.0 Hz, 500 μs pulse length, and 560 V voltage) of area energy density. Non-thermal decomposition samples were not photothermally treated. The spectra obtained for photothermal decomposition samples are shown at 1582 cm⁻¹. -1 (Graphite, G-band) and 1350cm -1 A characteristic graphite band is observed near the (disordered, D band). The ratio of the intensity of the D band to the G band is 210 J / cm². 2 The total pulse energy density for the sample thermally decomposed was less than 1, indicating that the sample has a high degree of structural order and high graphite phase quality. The ratio of D-band intensity to G-band intensity was 170 J / cm². 2 In the sample thermally decomposed at the total pulse energy density, the value was greater than 1, indicating that the sample has a high degree of structural disorder and low graphite phase quality. Furthermore, the photothermal decomposition of the sample was 2700 cm³. -1A 2D peak is present nearby, which is also characteristic of graphite, specifically the graphitic ordering of free carbon along the free axis. The fact that this peak can be fitted to a single Lorentz peak indicates the presence of high-quality graphene in these samples. 210 J / cm 2 In samples photothermally decomposed with pulses, a ratio of 2D peaks to G peaks of less than 1 suggests the presence of several layers of graphene in the sample. The quality of the resulting graphene improves with increasing pulse power density used for the thermal decomposition of the precursor film. In contrast, non-thermally decomposed samples lack 2D peaks and have very broad D peaks and poorly defined G peaks.

[0056] (Example 7) Material properties of graphene / carbon fiber composite derived from photothermal decomposition of exemplary unpatterned precursor (cyclized polyacrylonitrile) Cyclized polyacrylonitrile has an absorbance spectrum that overlaps with the maximum intensity of the xenon lamp emission spectrum, whereas linear polyacrylonitrile does not. This explains why cyclized polyacrylonitrile is readily thermally decomposed by a xenon flash, while its linear morphology is not. Figure 17 shows optical images of the graphene / carbon fiber composite obtained from the photothermal decomposition of the cyclized polyacrylonitrile film after a single coating and thermal decomposition following the alternating laminate coating. The surface morphology of the composite was examined using a scanning electron microscope. Figures 18A to 18F show SEM images of the graphene / carbon fiber composite obtained from the photothermal decomposition of the cyclized polyacrylonitrile film after a single coating and thermal decomposition following the alternating laminate coating. The composite has a microporous surface morphology. Structural changes in the film during the cyclization process were observed using IR spectroscopy (Figure 19). From the FTIR spectrum, the 2245 cm⁻¹ of the cyclized polyacrylonitrile spectrum was observed. -1 Disappearance of the nitrile group C≡N peak at 1596 cm⁻¹ -1 The appearance of the C=N peak at 1257 cm, and at 1257 cm. -1The appearance of a CN single bond peak at 1 confirms the completion of the cyclization reaction of polyacrylonitrile. The absence of structure in the spectrum of the composite obtained from thermal decomposition confirms that the precursor material was completely thermally decomposed and converted into a carbonaceous composite.

[0057] Using Raman spectroscopy, the phase ordering and phase transformation of composite materials were investigated according to the type of substrate (carbon fiber and stainless steel). From the Raman spectra of composite materials obtained for both carbon fiber and stainless steel substrates (Figures 20A and 20B), the phase order of 2650 cm⁻¹ was investigated. -1 The presence of a 2D peak at 1350cm -1 Disorderly band and 1550cm -1 The ratio of intensity to graphite bands in I is slightly lower than 1, especially after one alternating lamination coating on a carbon fiber substrate and after thermal decomposition. D / I G Considering the fact that it is a ratio, it can be confirmed that the composite material contains graphene of fairly good quality. For the composite material obtained on a stainless steel substrate, 1350 cm³ -1 Disorderly band and 1550cm -1 The ratio of the intensity to the graphite band at 1.0 is slightly greater than 1.0, which likely suggests that the stainless steel substrate is less efficient than carbon fiber in forming high-quality graphene. The fact that the 2D peaks obtained from both substrates can be fitted to a single Lorentz peak indicates the presence of high-quality graphene in the sample. The size of this peak relative to the G peak is also a good measure of the number of graphene layers present in the sample. The ratio of the 2D peak to the G peak is slightly less than 1 in the samples obtained from both substrates, which suggests the presence of several layers of graphene in the sample.

[0058] (Example 8) Material properties of exemplary screen-printed precursor cyclized polyacrylonitrile and graphene / carbon fiber composite derived from its photothermolysis Figures 21A and 21B show optical images (Figure 21A) and Raman spectra (Figure 21B) of dimensionally stable polyimide / graphene composite electrode structures obtained from photothermal decomposition in air of screen-printed and thermocured cyclized polyacrylonitrile electrode structures. D / I G It is 0.63, and the I of the spectrum obtained by high-power pulse processing 2D / I G The value was 0.71. In the photothermal treatment, the value was 50 J / cm². 2 This corresponds to a total area energy density of 2.5 J / cm² per pulse. 2 Twenty pulses (1.0 Hz, 500 μs pulse length, and 490 V voltage) of the area energy density were used. The Raman spectrum obtained from this sample was 1582 cm⁻¹. -1 (Graphite, G-band) and 1350cm -1 A characteristic graphite band is observed near (disorder, D band) (Figure 21B). The ratio of the intensity of the D band to the G band (I D / I G The ratio is a good measure of the quality of graphite carbon in the sample. D / I G The ratio is 0.63. Since this ratio is less than 1, the sample exhibits a high degree of regularity and is a high-graphite phase. 2700 cm² -1 The nearby peak (2D band) is an overtone of the D band, which is also characteristic of graphite, specifically the graphitic ordering of free carbon along the free axis. The ability to fit this peak to a single Lorentz peak indicates the presence of high-quality graphene in the sample. Furthermore, the size of this peak relative to the G peak is a good indicator of the number of graphene layers present in the sample. 2D / I G A ratio of 0.71 suggests the presence of several layers of graphene in the sample. The sheet resistance of the graphene composite is 0.25 Ω·cm.

[0059] (Example 9) Material properties of graphene / carbon fiber composite obtained from photothermal decomposition of exemplary precursors (carbon fiber and polyaniline) The pure carbon fiber consists of graphite and has an absorption spectrum that well overlaps with the emission spectrum of a xenon flash lamp. It has a rather short radiation decay length. Therefore, by irradiating with a high-intensity flash lamp, it can be exfoliated to graphene layers. The surface morphology of the graphene / carbon fiber composite material thus obtained was examined with a scanning electron microscope. Figures 22A and 22B show SEM images of non-thermally decomposed pure carbon fiber (A) and photo-thermally decomposed carbon fiber (B). Figure 23A shows the FTIR spectrum of the pure carbon fiber. Since there is no structure in the spectrum of the pure carbon fiber cloth, it was confirmed that the precursor material consists only of pure carbon. Raman spectroscopy was used to investigate the phase order and phase transformation of the carbon fiber during photo-thermal decomposition.

[0060] Figure 23B shows the Raman spectra of the pure carbon fiber fabric and the photo-thermally decomposed pure carbon fiber fabric in response to the pulse output of the xenon flash lamp. The photo-thermal treatment was carried out as follows: (1) 540 - 640 V: 20 pulses (0.5 Hz, 800 μs pulse length, and 540 V voltage) with an area energy density of 5.3 J / cm 2 per pulse corresponding to a total area energy density of 106 J / cm 2 , and then 20 pulses (1.0 Hz, 800 μs pulse length, and 640 V voltage) with an area energy density of 8.5 J / cm 2 per pulse corresponding to a total area energy density of 170 J / cm 2 , (2) 540 - 620 V: 20 pulses (0.5 Hz, 800 μs pulse length, and 540 V voltage) with an area energy density of 5.3 J / cm 2 per pulse corresponding to a total area energy density of 106 J / cm 2 , and then 20 pulses (1.0 Hz, 800 μs pulse length, and 620 V voltage) with an area energy density of 8.2 J / cm 2 per pulse corresponding to a total area energy density of 164 J / cm 2 , (3) 20 pulses with an area energy density of 5.3 J / cm 2 per pulse corresponding to a total area energy density of 106 J / cm 2The area energy density was measured using 20 pulses (0.5 Hz, 800 μs pulse length, and 540 V voltage), followed by 158 J / cm². 2 7.9 J / cm² per pulse corresponds to the total area energy density. 2 Area energy density of 20 pulses (1.0 Hz, 800 μs pulse length, and 600 V voltage). From the spectrum, 1582 cm⁻¹ -1 (Graphite, G-band) and 1350cm -1 Characteristic graphite bands near (disorder, D band), and 2650 cm -1 Considering the presence of nearby 2D bands, the formation of high-quality graphene from the photothermal decomposition of pure carbon fibers is confirmed. In the photothermal decomposition sample, I D / I G A ratio of less than 1 indicates high structural order in the graphene sample. The I of the sample was obtained by photothermal decomposition using 540-620V treatment. D / I G The ratio is 2.02. This treatment is 106 J / cm². 2 5.3 J / cm² per pulse corresponds to the total area energy density. 2 The area energy density was obtained from 20 pulses (0.5 Hz repetition rate, 800 μs pulse length, and 540 V voltage), then 164 J / cm². 2 8.2 J / cm² per pulse corresponds to the total area energy density. 2This was performed by irradiating the samples with 20 pulses (1.0 Hz, 800 μs pulse length, and 620 V voltage) of area energy density. Furthermore, the ability to fit the 2D peak in the photothermally decomposed samples to a single Lorentz peak indicates the presence of high-quality graphene in these samples. The size of this peak relative to the G peak is also a good measure of the number of graphene layers present in the sample. A ratio of 0.62 for the 2D peak to the G peak indicates the presence of several layers of graphene in these photothermally decomposed samples. In contrast, the pure, undecomposed samples lacked a 2D peak and instead had broad, indistinct D and G peaks, suggesting the absence of graphene and lack of structural order in the samples. The sheet resistance of the samples photothermally decomposed at 540–620 V was 0.02 Ω·cm, indicating that this composite has good conductivity.

[0061] Polyaniline has an absorbance spectrum in the 500 nm–700 nm region, which closely matches the emission spectrum of a xenon flash lamp. This enabled the photothermal conversion of PANI to graphene. Figure 31A shows optical images of PANI and derived graphene. The green color of the precursor film was an indicator of the emeraldine form of PANI, and the gray color of the photothermally treated film was an indicator of the conversion from PANI to carbonaceous material. The conversion from PANI to carbon was confirmed by TGA, as no mass loss was observed, as shown in Figure 31B.

[0062] The carbon quality was investigated using Raman spectroscopy. The presence of D-bands, G-bands, and 2D-bands, as shown in Figure 31C, is representative of the graphite structure described above. 8.91 J / cm 2The ratio of D-band pairs to G-band pairs at the input energy is approximately 0.35, which indicates the presence of graphite with fewer defects in its structure. The 2D band indicates the ordering of graphite along the free axis. In the case of PANI-derived graphene, the presence of the 2D band, along with the 2D-band to G-band ratio of less than 1, indicates the formation of multi-layer graphene, such as polybenzoxazine-derived graphene. Interestingly, PANI carbonized conventionally at 1000°C exhibits diffused D and G bands representative of amorphous carbon. Therefore, it can be said that the temperature accessed during the photothermal treatment in milliseconds is higher than 1000°C, resulting in the formation of high-quality graphene. Morphological investigation of the obtained graphene was performed using SEM. The electrochemically deposited PANI exhibited a rod-like morphology as shown in Figure 32A. Photothermal treatment of PANI resulted in the formation of a porous network of graphene (Figure 32B). This macroporous morphology is highly beneficial for the transport of electrolytes that allow access to the bulk material. Furthermore, the fibrous structure of graphene enhances the interaction between the electrode and electrolyte, resulting in excellent electrochemical performance. XPS was performed to determine the chemical composition of PANI-induced graphene. As shown in Figure 32C, an asymmetric peak centered at 284.5 eV was observed, which is in good agreement with the findings from the Raman data. 2 The presence of hybrid graphite-like carbon was confirmed. Furthermore, the proportions of carbon and oxygen atoms were estimated to be 98% and 2%, respectively, suggesting that graphene is composed almost entirely of carbon, even if the processing was carried out in air.

[0063] (Example 10) Applications in electrochemical energy storage The electrochemical energy application of graphene / carbon fiber composites obtained via photothermal decomposition of exemplary polybenzoxazine precursor materials was demonstrated on a previously observed sample coated with MnO2. MnO2 is an attractive candidate for supercapacitor electrodes due to its abundant availability, low cost, high electrochemical performance, and environmental inertness. Unfortunately, its low conductivity results in insufficient cycleability and low rate capability in electrochemical energy storage devices prepared using it. Combining MnO2 with carbonaceous materials such as graphene is a viable strategy to overcome the aforementioned limitations. However, the production of high-quality graphene in a scalable manner presents many challenges. Various aspects of the present invention overcome these challenges, enabling the production of high-quality graphene in milliseconds under ambient conditions in a scalable manner.

[0064] The processing scheme for depositing MnO2pm graphene composites first involves UV-ozone treatment of both sides of the graphene composite formed on a carbon fiber substrate for 5 minutes to oxidize the surface and thereby increase its hydrophilicity. Next, MnO2 is deposited on the graphene composite using a three-electrode configuration in which graphene on the carbon fiber is used as the working electrode, and Pt wire and Ag / AgCl are used as the counter electrode and reference electrode, respectively. MnO2 is deposited on the graphene composite by immersing the three electrodes in an electrolyte containing aqueous solutions of 50 mM manganese II acetate and 100 mM sodium sulfate, and performing cyclic voltammetry measurements in the potential range of 0 to 1.4 V at a scanning speed of 50 mV / s. To investigate the effect of the amount of MnO2 on the electrochemical performance, the number of deposition cycles is varied between 5 and 15 cycles. Following MnO2 deposition, the electrode surfaces are thoroughly washed with DI water and then dried in a vacuum furnace at 100°C for 2 hours. The mass of the deposited MnO2 is calculated using a weighing balance with an accuracy of 0.01 mg.

[0065] Figures 24A, 24B, and 24C show SEM images of MnO2 deposited on graphene composites at various magnifications. Figure 24A confirms conformal deposition of MnO2 on the graphene composite, and Figure 24C shows the floral structure of the deposited MnO2. This floral structure enhances the interaction between the electrolyte and MnO2 due to its high surface area. Furthermore, the macropores in the composite provide an easy pathway for the transport of the electrolyte to the bulk material, thus making these MnO2 / graphene composites promising candidates for electrochemical energy storage applications. The deposited MnO2 structure was further investigated using Raman, XRD, and XPS, as shown in Figures 24D–24F. The Raman spectrum shown in Figure 24D, along with the graphene peak, a characteristic peak of the Mn-O lattice, at 570 and 650 cm⁻¹ -1 Two additional peaks are shown. The peak at 36.9° in XRD confirms the formation of partially crystallized alpha-MnO2 resulting from electrochemical deposition. Elemental analysis performed using XPS is shown in Figure 24F, and Mn(Mn 2p Mn 2s Mn 3s ), O 1s and C 1s This indicates the presence of MnO2 and supports the successful deposition of MnO2.

[0066] All electrochemical characterization and performance tests of graphene composites derived from the photothermal decomposition of exemplary polybenzoxazine precursors were performed using a CHI660E electrochemical workstation (CH Instruments, Austin, Texas) under ambient conditions. Cyclic voltammetry, charge-discharge testing, and electrochemical impedance spectroscopy were performed using three electrode systems. Here, the photothermally produced graphene composite coated with MnO2 was used as the working electrode, a Pt wire as the counter electrode, and Ag / AgCl as the reference electrode. These measurements were performed in an electrolyte containing an aqueous solution of 0.5 M Na2SO4. The performance of a symmetric device using MnO2-deposited graphene on both electrodes, along with a separator made from cellulose filter paper pre-soaked in 0.5 M Na2SO4, was also investigated.

[0067] Graphene's high porosity and high electrical conductivity, along with the lack of binders in graphene composites, make the latter an ideal supercapacitor electrode. Therefore, photothermally generated graphene on MnO2-coated carbon fiber cloth was evaluated as a supercapacitor electrode using cyclic voltammetry (CV), and its constant current charge-discharge (GCD) was investigated. CV was performed in the potential range of 0–1.0 V using a 0.5 M Na₂SO₄ aqueous solution. Graphene photothermally induced from exemplary polybenzoxazine precursors, as well as bare graphite-like carbon fibers, exhibited pseudo-rectangular CV curves at 50 mV / s (Figures 25A–25D), showing EDLC behavior. The capacitance obtained from the area under the CV curve was 3.6 mF / cm² for graphene produced with high-power and low-power pulses, respectively. 2 and 1.5 mF / cm 2The superior performance of high-power pulsed samples compared to low-power samples can be attributed to their superior conductivity, higher porosity, and higher degree of graphitization, all of which facilitated ion adsorption on their surface and facilitated charge transport. Thus, all other electrochemical analyses were performed on graphene prepared using high-power pulses. CV was performed at various scanning speeds to determine the charge transport capability of graphene. The charge transport capability maintained a pseudo-rectangular shape up to 2 V / s, demonstrating excellent charge propagation through the bulk of the material. This was further verified using GCD, where the sample maintained an isosceles triangular charge-discharge profile even at very high current densities. Furthermore, even after an eightfold increase in current density, the capacitance value decreased by only 9%, thus demonstrating the good rate characteristics of the graphene-based supercapacitor. 3.6 mF / cm 2 The resulting area capacitance is one of the highest values ​​reported for graphene-based microsupercapacitors. In summary, these results demonstrate the potential utility of photothermally produced graphene for carbon fiber woven EDLC-type microsupercapacitor applications.

[0068] Figures 26A to 26C show the electrochemical performance test results (Figure 26A) obtained at various scanning speeds for a symmetric device prepared using MnO2 deposited on a graphene composite derived from the photothermal decomposition of an exemplary polybenzoxazine precursor, as well as the GCD profile of the device at different current densities (Figure 26B) and the capacitance (F / g) depending on the current density (Figure 26C).

[0069] Figure 27A shows a Ragone plot of a symmetric device prepared using MnO2 deposited on a graphene composite obtained from the photothermal decomposition of an exemplary precursor of polybenzoxazine. Figure 27B shows a demonstration of three supercapacitor devices connected in series to light an LED. The supercapacitors were fabricated using electrodes prepared with MnO2 deposited on a graphene composite derived from the photothermal decomposition of an exemplary precursor of polybenzoxazine.

[0070] The electrochemical properties of photothermally induced graphene from PANI were determined considering its macroporosity, high conductivity, and fibrous structure. Cyclic voltammetry (CV) and constant current charge-discharge (GCD) tests were performed using a three-electrode system, similar to those employed for exemplary polybenzoxazine-induced graphene. Graphene from PANI on CF was used as the working electrode, Pt as the counter electrode, and Ag / AgCl as the reference electrode. Electrochemical measurements were performed in a 0.5 M Na2SO4 (sodium sulfate) salt aqueous solution and a 1 M H2SO4 (sulfuric acid) electrolyte. CV was performed for both CF and PANI-induced graphene on CF in the potential range of 0–0.8 V at 50 mV / s. Both exhibited a pseudo-rectangular shape, showing ideal EDLC-type behavior (Figure 33A). The capacitance obtained from the area under the curve was 22.4 mF / cm² for both PANI-induced graphene and CF, respectively. 2 and 1.5 mF / cm 2 The capacity of PANI-derived graphene was superior to that of polybenzoxazine-derived graphene. The superior performance of PANI-derived graphene is mainly due to its high porosity, fibrous structure, and excellent conductivity, which facilitate the adsorption and transport of ions across the bulk of the material. Interestingly, the capacity of PANI-derived graphene was 100 mF / cm at 10 mV / s when the capacity was evaluated in an acidic electrolyte (1 M H2SO4). 2 The capacity increased (Figure 33B). The significant increase in capacity in the acidic electrolyte may be due to the pseudocapacitive effect of oxygen functional groups present in graphene. To verify the findings from cyclic voltammetry, GCD was also performed in the potential range of 0–0.8V at various current densities, as shown in Figure 33C. The sample maintained its isosceles triangular shape even at a very high current density of 40mA. In this sample, 185mF / cm² was obtained at 5mA. 2A capacitance of 0.5 is obtained, which is one of the highest capacitance values ​​reported for a graphene-based supercapacitor. Furthermore, the device retains over 60% of its capacitance at a current density of 40 mA, which suggests good interfacial contact between graphene and CF, excellent conductivity, and easy access to the bulk material. These findings indicate that the performance of the device can be significantly improved, as demonstrated, by controlling its morphology, which is an area that has not been studied to date.

[0071] An exemplary application of graphene photothermally fabricated from polyaniline on carbon fibers is a spectacle side arm that can store electrochemical energy and be used for laser projection applications. The extremely high energy storage capacity and mechanical stability enabled by the carbon fiber / graphene composite material offer significant advantages for custom applications. Figure 34 shows a schematic image of the spectacle side arm frame with proposed dimensions. The fabrication of the device involves generating a large-area graphene film on an area of ​​15 cm × 15 cm, appropriately laser-cutting the graphene film, and assembling the films in series or parallel configurations with a solid electrolyte between the positive and negative electrodes of each cell to achieve the desired energy output.

[0072] (Example 11) Applications in electromagnetic interference shielding Graphene / carbon fiber composites derived from the photothermal decomposition of polybenzoxazine, an exemplary precursor material, were evaluated for electromagnetic interference (EMI) shielding applications.

[0073] Electromagnetic parameter characteristics and EMI shielding performance testing of graphene composites derived from the photothermal decomposition of polybenzoxazine, an exemplary precursor. The EMI shielding effectiveness of graphene / carbon fiber composites was measured using an Agilent Technologies vector network analyzer (VNA) series E5061B, in accordance with ASTM D4935-99. Samples were cut to fit the required shape and dimensions of the analyzer sample holder. Thickness measurements were performed using a digital micrometer.

[0074] Sample density was calculated from experimental measurements of volume and mass. Material parameters of the composite (dielectric constant, conductivity, and permeability) were extracted from EMI shielding measurements of the composite across three frequency bands investigated: the C-band, X-band, and Ku-band, covering the frequency range of 5 GHz to 18 GHz.

[0075] The measurement of the electromagnetic properties of the composite material involved a four-step process. After loading the sample into the sample holder, the experimental apparatus setup, including the VNA and waveguide, was calibrated, and then the scattering parameters of the sample were measured. Next, the experimentally measured scattering parameters were modeled and simulated. By fitting the model to the measured S-parameters, the dielectric constant (ε), permeability (μ), and conductivity (σ) of the composite material were easily extracted.

[0076] Figure 28A shows a photograph (top left) of the experimental setup for EMI shielding measurement, including a programmable network analyzer, waveguides, and sample holder assembly; a photograph (bottom left) showing close-ups of the sample holder assembly in various configurations; a photograph (center) showing close-ups of the sample holder in various configurations; and a photograph (right) showing samples within the sample holder in various configurations. The setup includes an Agilent Technologies programmable VNA (Vector Network Analyzer) Series E5061B, its cables, and three different sets of waveguides (WR137, WR90, and WR62) with operating frequency ranges of 5–8 GHz, 8–12 GHz, and 12–18 GHz. Each of these setups was calibrated and used according to the Transmission-Reflection-Length (TRL) method. The sample holders were configured to enable EMI shielding measurements for each operating frequency band. These sample holders were designed to minimize the sensitivity of the measurement to variations in sample size. Figure 28B shows a schematic diagram (left) showing a front view of the sample placed in the sample holder, and a schematic diagram (right) showing a side view of the sample arrangement in the sample holder. This setup was able to measure EMI shielding effects up to 120 dB.

[0077] A composite material sample was inserted into the center of a rectangular waveguide, and the complex reflection and transmission coefficients of the waveguide with and without the sample were measured using a VNA. The measurement results for the waveguide without the sample were used as calibration to eliminate the coaxial influence on the rectangular waveguide adapter. The effective material parameters of the composite material (dielectric constant (ε), permeability (μ), and conductivity (σ)) were extracted by simulating the reflection and transmission of the waveguide with the sample, fitting the simulation results to the measurement results, and using material parameters as fitting parameters. For samples with latent anisotropy parameters, measurements and simulations were performed for two different polarizations of the incident wave (i.e., the TE mode and TM mode of the waveguide). Next, the shielding properties (i.e., shielding effect, absorption, and reflection) for different thicknesses of the composite material were calculated from the extracted material parameters. The material model of the composite material was refined using the measured material parameters, and potential approaches to increase shielding effectiveness were identified.

[0078] Figure 29 shows the EMI shielding performance of a 400 μm thick, two-layer graphene / carbon fiber composite. This result indicates that the graphene / carbon fiber composite provided over 80 dB of EMI shielding across multiple bands, namely the C-band, X-band, and Ku-band frequencies. Recognizing that decibels are logarithmic, an 80 dB EMI shielding effect indicates that more than 99.99999% of the incident radiation is attenuated by this composite.

[0079] (Example 12) Application of various embodiments of the present invention in printed flexible electronic devices Graphene derived from the photothermal decomposition of cPAN and poly(BZ) coatings, exemplary precursor materials screen-printed onto flexible polyimide films, was evaluated for applications in printed flexible electronic devices.

[0080] Figures 35A to 35C demonstrate a graphene LED circuit used to illuminate a white light LED device. Figure 35A shows a screen-printed trace of an exemplary precursor, cPAN, on a flexible polyimide substrate. Figure 35B shows the graphene trace of the LED circuit realized from the photothermal decomposition of the screen-printed cPAN precursor in Figure 35A. Figure 35C demonstrates the successful integration of a white light LED device onto the graphene trace and the actual illumination of the LED device driven by an external power supply.

[0081] (Example 13) Physical characteristics and device performance indicators Table 1 summarizes the physical properties and device performance indicators of graphene composites according to various embodiments of the present invention. Compared to equivalent products processed by conventional methods, the graphene composites according to various embodiments of the present invention have the following characteristics: D / I G As indicated by the ratio (<1.0), it is of much higher quality, has much better properties in terms of its morphology as indicated by its very large porosity, and has a lower sheet resistance (0.15 Ω·cm for carbon fiber / graphene composites). In contrast, graphene composites produced by laser carbonization have been reported to have a sheet resistance of 21-33 Ω·cm, which is about 140-220 times greater than the sheet resistance of various embodiments of the present invention. Polyimide / graphene composites of various embodiments of the present invention have good conductivity (150 S / m). Furthermore, composites of various embodiments of the present invention have high area capacitance (3 mF / cm²) when used as micro-supercapacitor electrodes. 2 As demonstrated by its multiband (C-band, X-band, and Ku-band) EMI shielding performance exceeding 80 dB, it exhibits improved performance compared to conventional composite materials obtained by thermal decomposition.

[0082] [Table 1-1]

[0083] [Table 1-2]

[0084] Numerous graphene preparation methods have been reported in the literature. These methods can be broadly classified into top-down and bottom-up approaches. In the top-down approach, graphene is prepared by mechanical exfoliation, chemical exfoliation of graphite and graphite oxides, laser exfoliation of graphite, chemical reduction of graphene oxide, electrochemical reduction of graphene oxide, photothermal reduction of GO and photodegradation of various precursors using a flash lamp, as well as direct CO2 laser carbonization of polymer precursors having absorption spectra that significantly overlap with the emission wavelengths of lasers in the short range of 9.4 μm to 10.6 μm, which occur exclusively in the mid-infrared (IR) band. In the bottom-up approach, graphene is produced via solution-based chemical synthesis, solvothermal synthesis, chemical deposition on various substrates such as metal catalysts (copper, ruthenium, nickel), epitaxial growth on SiC, laser-induced epitaxial growth, and arc discharge.

[0085] Flash lamps have been used in the past to prepare graphene, but the precursors used in these preparation methods are different from the precursors in the various embodiments of the present invention. Furthermore, the low I obtained using the methods shown in the various embodiments of the present invention D / I G The quality of graphene shown (see Table 1) is far superior to that reported in the aforementioned literature. Furthermore, there are clear differences in the methods by which the radiation field is modulated and applied in the various embodiments of the present invention compared to those reported in the literature.

[0086] Of all the methods described above for fabricating graphene, direct CO2 laser carbonization based on laser flash photothermal decomposition is most closely related to xenon flash lamp photothermal decomposition in various embodiments of the present invention. Photonic processing using a xenon flash lamp source having an emission spectrum extending in the wavelength range of 200 nm to 1000 nm offers several advantages over CO2 lasers, namely, reduced cost and complexity, improved efficiency in converting electrical energy to light, scalability to large-area processing, and broadband illumination overlapping the near-ultraviolet (UV), visible, and near-infrared (IR) regions of the electromagnetic spectrum, encompassing a much broader selection of potential precursor materials having portions that can undergo photothermal and photochemical conversion mediated by valence electron transitions, molecular vibrations, phonon / lattice vibrations, and molecular rotations under flash photon pulse illumination. The energy of a single photon within the 300 to 400 nm wavelength range of the emission band of a xenon flash lamp, corresponding to 4.1 eV to 3.1 eV, is sufficient to directly cleave some of the bonds in the precursor polymer. The combination of photo-induced bond cleavage and lattice vibration induction in the precursor polymer ultimately leads to efficient photothermal decomposition, carbonization, and graphitization.

[0087] In contrast, the emission of CO2 lasers used in the carbonization of polymer precursors has an emission spectrum with wavelengths in a fairly short band of 9.4 μm to 10.6 μm, occurring exclusively in the mid-infrared (IR) band. This limits the suitable material pool to materials that are active only in the mid-infrared (IR) range, and therefore limited to materials that can only undergo photothermal conversion mediated by molecular vibrations and phonon / lattice vibrations. The energy of a single photon in the 9.4 μm to 10.6 μm emission wavelength band of the CO2 laser, corresponding to 0.12 eV to 0.13 eV, is insufficient to directly cleave any bonds in the precursor polymer. Therefore, CO2 laser radiation induces phonons in the precursor polymer, leading to bond dissociation, photothermal decomposition, carbonization, and graphitization.

[0088] A good example of the subtle distinction between the photothermal and photochemical basis of xenon flash lamp photothermal decomposition and laser photothermal decomposition is illustrated by the absorption spectrum of Kapton. Kapton is a polyimide substrate commonly used in printed electronic equipment and flexible circuit boards due to its excellent properties, namely high oxidation stability, high mechanical strength, high modulus of elasticity, excellent electrical and optical properties, and excellent chemical resistance. Kapton exhibits a broad UV absorption band in the 180–400 nm UV region (Figure 30), which allows for effective absorption of all common excimer and exciplex laser wavelengths, including 193, 248, 308, and 351 nm, thus enabling its use in ablation research and applications. Polyimides are not the only organic polymers with this type of absorption property. In fact, organic polymers strongly absorb ultraviolet light, allowing for efficient excimer laser ablation of these materials.

[0089] Generally, the mechanism of laser ablation is thought to be primarily photothermal, with only slight photochemical characteristics. Kapton is 40 mJ / cm² in the near-ultraviolet (UV) region, which does not form graphene. 2 Although it undergoes excimer laser-induced ablation exceeding the laser fluence threshold, it is carbonized into graphene when irradiated with a high-intensity continuous wave or pulsed CO2 laser in the 9.4 μm and 10.6 μm frequency bands in the mid-infrared (IR) region. However, under irradiation with a high-intensity xenon flash lamp on a precursor such as cyclized polyacrylonitrile, the precursor's absorption spectrum has a peak that overlaps with the emission spectrum of the xenon flash lamp in the near-UV region. As shown in Figures 21A and 21B, the precursor is photothermally decomposed into graphene, and Kapton is not affected at all.

[0090] The screen-printed features of the precursor film in Figures 21A and 21B are 0.63 I D / I G Ratio and 0.71 I 2D / I GAs shown by the ratio, while high-quality multi-layer graphene was converted, it is equally important that the aperture regions of the Kapton substrate not coated with the precursor film were not ablated or photothermally decomposed during the process and did not become graphene. There are differences between photothermally decomposition treatment with a high-intensity pulsed xenon flash lamp and photothermal treatment with a high-intensity CO2 laser in various embodiments of the present invention, as well as differences between photothermal treatment with a high-intensity pulsed xenon flash lamp and photothermal treatment with an excimer laser in various embodiments of the present invention. In other words, photothermally decomposition with a xenon flash lamp can convert a suitable precursor into high-quality graphene in the mid-ultraviolet (UV) band, while an excimer laser can only ablate the precursor film without converting it into graphene. Furthermore, while CO2 laser photothermal treatment can carbonize kapton into graphene within the short wavelength band of 9.4 μm to 10.6 μm, it cannot do so outside this narrow band of the electromagnetic spectrum, which limits its applicability to only a few precursor materials that have reasonable absorption in the mid-infrared (IR) region of the spectrum. Xenon flash lamp photothermal treatment, which utilizes a broad wavelength source spanning the near-UV (ultraviolet), visible, and even near-infrared (IR) regions of the spectrum, can select and carbonize a wider range of absorbing precursors within the aforementioned bands into graphene than CO2 laser-based photothermal treatment. Another drawback of CO2 laser-based photothermal treatment is that its IR emission wavelength hinders its use in high-resolution applications.

[0091] Furthermore, it should be emphasized that photothermally graphitizing a suitable precursor after coating it is an additive process in which the substrate itself is not damaged and the precursor and substrate can be selected independently. Independent selection of the precursor offers advantages in tuning the properties of graphene material on any substrate. In contrast, CO2 laser graphitization of polymer films is subtractive, etching / damaging the substrate, and the substrate itself is converted into graphene, thus not allowing independent selection of the substrate and precursor.

[0092] The terms and expressions used are for illustrative purposes only, not limitation, and in using such terms and expressions, there is no intention to exclude any equivalents of the illustrated and described features or any part thereof, and various modifications are possible within the scope of the embodiments of the invention. Accordingly, although the invention is specifically disclosed by certain embodiments and optional features, modifications and variations of the concepts disclosed herein may be used by those skilled in the art, and such modifications and variations are also within the scope of the embodiments of the invention.

[0093] (Examples) The following exemplary embodiments are provided. The numbering of the exemplary embodiments should not be interpreted as indicating a level of importance.

[0094] Embodiment 1 is a method for forming a graphene film, Coating a polymer graphene precursor onto a substrate, The present invention provides a method for converting the polymer graphene precursor, which is coated on the substrate, into a graphene film by irradiating it with a pulsed high-intensity light source that emits light at two or more wavelengths for a pulse duration of less than one second using the pulsed high-intensity light source that emits light at two or more wavelengths.

[0095] Embodiment 2 provides the method of Embodiment 1, wherein the graphene film is a graphene composite film. Embodiment 3 provides the method of Embodiment 1 or 2, wherein the graphene film is a non-composite graphene film.

[0096] Embodiment 4 provides the method according to any one of Embodiments 1 to 3, wherein the polymer graphene precursor and the substrate have different chemical compositions. Embodiment 5 provides a method according to any one of Embodiments 1 to 4, wherein the irradiation includes irradiating the polymer graphene precursor and the substrate.

[0097] Embodiment 6 provides a method according to any one of Embodiments 1 to 5, wherein the irradiation of the polymer graphene precursor and the substrate does not convert the substrate into a graphene-containing material.

[0098] Embodiment 7 provides the method according to any one of Embodiments 1 to 6, wherein the light source includes an emission wavelength in the range of 100 nm to 2000 nm. Embodiment 8 provides the method according to any one of Embodiments 1 to 7, wherein the light source includes an emission wavelength in the range of 300 nm to 800 nm.

[0099] Embodiment 9 provides the method according to any one of Embodiments 1 to 8, wherein the light source includes an emission wavelength in the range of 400 nm to 600 nm. Embodiment 10 provides a method according to any one of Embodiments 1 to 9, wherein the pulse duration is shorter than the thermal equilibrium time of the polymer graphene precursor.

[0100] Embodiment 11 provides a method according to any one of Embodiments 1 to 10, wherein the pulse duration is 1 to 999 milliseconds. Embodiment 12 provides a method according to any one of Embodiments 1 to 11, wherein the pulse duration is 200 to 900 milliseconds.

[0101] Embodiment 13 provides a method according to any one of Embodiments 1 to 12, wherein the pulse duration is 400 to 800 milliseconds. Embodiment 14 provides the method according to any one of Embodiments 1 to 13, wherein the light source has an intensity of 100V to 2000V.

[0102] Embodiment 15 provides a method according to any one of Embodiments 1 to 14, wherein the light source has an intensity of 400V to 700V. Embodiment 16 provides the method according to any one of Embodiments 1 to 15, wherein the light source has a pulse frequency of 0.001 Hz to 1000 Hz.

[0103] Embodiment 17 provides a method according to any one of Embodiments 1 to 16, wherein the light source has a pulse frequency of 0.1 Hz to 10 Hz. Embodiment 18 provides a method according to any one of Embodiments 1 to 17, wherein the light source has a pulse frequency of 0.5 Hz to 1 Hz.

[0104] Embodiment 19 is a light source with a density of 0.1 J / cm². 2 ~100J / cm 2 The present invention provides a method according to any one of embodiments 1 to 18, having an energy density per pulse. Embodiment 20 is a light source with a power output of 1 J / cm². 2 ~10J / cm 2 The present invention provides a method according to any one of embodiments 1 to 19, having an energy density per pulse.

[0105] Embodiment 21 is a light source with a density of 2 J / cm². 2 ~9J / cm 2 The present invention provides a method according to any one of embodiments 1 to 20, having an energy density per pulse. Embodiment 22 is a light source with a flux of 30 J / cm². 2 ~200J / cm 2 The present invention provides a method according to any one of embodiments 1 to 21, having a total surface density of

[0106] Embodiment 23 provides a method according to any one of Embodiments 1 to 22, wherein the irradiation includes 5 to 1000 pulses of the light source. Embodiment 24 provides a method according to any one of Embodiments 1 to 23, wherein the irradiation includes 10 to 40 pulses of the light source.

[0107] Embodiment 25 provides a method according to any one of Embodiments 1 to 24, wherein the polymer graphene precursor is thermally decomposed by irradiation. Embodiment 26 provides a method according to any one of Embodiments 1 to 25, wherein coating the polymer graphene precursor onto the substrate includes using printing, offset printing, inkjet printing, transfer printing, aerosol jet printing, microcontact printing, embossing, nanoimprint lithography, photolithography, electron beam lithography, ion beam lithography, or a combination thereof.

[0108] Embodiment 27 provides a method according to any one of Embodiments 1 to 26, wherein the polymer graphene precursor on the substrate comprises a patterned polymer graphene precursor.

[0109] Embodiment 28 provides the method of Embodiment 27, which further comprises coating the substrate with the polymer graphene precursor and then patterning the polymer graphene precursor coating to form the patterned polymer graphene precursor coating on the substrate.

[0110] Embodiment 29 provides a method according to any one of Embodiments 27 to 28, comprising coating the patterned polymer graphene precursor onto the substrate. Embodiment 30 provides a method according to any one of Embodiments 27 to 29, wherein coating the substrate with the polymer graphene precursor is performed by printing, offset printing, inkjet printing, transfer printing, aerosol jet printing, microcontact printing, or a combination thereof, to form the patterned polymer graphene precursor coated on the substrate.

[0111] Embodiment 31 provides a method according to any one of Embodiments 27 to 30, wherein coating the polymer graphene film on the substrate is performed by using embossing, nanoimprint lithography, or a combination thereof to form the patterned polymer graphene precursor coated on the substrate.

[0112] Embodiment 32 provides a method according to any one of Embodiments 27 to 31, wherein coating the polymer graphene film on the substrate is performed by using photolithography, electron beam lithography, or ion beam lithography to form the patterned polymer graphene precursor coated on the substrate.

[0113] Embodiment 33 provides a method according to any one of Embodiments 1 to 32, wherein the polymer graphene precursor comprises a polymer containing a disubstituted benzene, a benzene substituted with one or more chromophores, a polycyclic aromatic ring, or a combination thereof.

[0114] Embodiment 34 provides the method according to any one of Embodiments 1 to 33, wherein the polymer graphene precursor comprises a polymer containing nitroaniline, aniline, nitrophenol, biphenyl, nitrobenzene, benzaldehyde, acetophenone, pyrene, pentacene, anthracene, tetracene, or a combination thereof.

[0115] Embodiment 35 provides a method according to any one of Embodiments 1 to 34, wherein the polymer graphene precursor comprises a polymer selected from resol, pyrene pitch oligomers, cyclized polyacrylonitrile, carbon fibers, polyaniline, a thermosetting resin network formed from a blend and crosslinking of polybenzoxazine and epoxy, and combinations thereof.

[0116] Embodiment 36 provides a method according to any one of Embodiments 1 to 35, wherein the polymer graphene precursor comprises a polymer selected from poly(3-phenyl-2,4-dihydro-1,3-benzoxazine), poly(phenylbenzoxazine), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine), poly(furanylbenzoxazine), poly(phenol-co-formaldehyde), resol, oligomers of pyrene pitch, cyclized polyacrylonitrile, pure carbon fiber, polyaniline, a thermosetting resin network formed from a blend and crosslinking of polybenzoxazine and bis-phenol-A furfuryl diglycidyl ether, and combinations thereof.

[0117] Embodiment 37 provides a method according to any one of Embodiments 1 to 36, wherein the absorption band of the polymer graphene precursor overlaps with the emission band of the pulsed light source. Embodiment 38 provides the method according to any one of Embodiments 1 to 37, wherein the polymer graphene precursor has an absorption band in the range of 100 nm to 2000 nm.

[0118] Embodiment 39 provides the method according to any one of Embodiments 1 to 38, wherein the polymer graphene precursor has an absorption band in the range of 300 nm to 800 nm. Embodiment 40 provides a method according to any one of Embodiments 1 to 39, wherein the polymer graphene precursor has an absorption band in the range of 400 nm to 600 nm.

[0119] Embodiment 41 provides a method according to any one of Embodiments 1 to 40, wherein the substrate includes plastic, metal, cloth, woven fabric, or a combination thereof. Embodiment 42 provides the method according to any one of Embodiments 1 to 41, wherein the substrate contains carbon.

[0120] Embodiment 43 provides the method according to Embodiment 42, wherein the substrate includes carbon fibers. Embodiment 44 provides the method according to Embodiment 42 or 43, wherein the substrate includes a carbon mesh.

[0121] Embodiment 45 provides a method according to any one of Embodiments 42 to 44, wherein the substrate includes a carbon cloth. Embodiment 46 provides a method according to any one of Embodiments 42 to 45, wherein the substrate includes a carbon composite material.

[0122] Embodiment 47 provides a method according to any one of embodiments 42 to 46, wherein the substrate includes a graphene composite material. Embodiment 48 provides a method according to any one of embodiments 42 to 47, wherein the substrate includes graphene.

[0123] Embodiment 49 provides a method according to any one of Embodiments 42 to 48, wherein the substrate includes a carbon film. Embodiment 50 provides a method according to any one of Embodiments 1 to 49, wherein the light source includes a xenon flash lamp.

[0124] Embodiment 51 provides the method according to any one of Embodiments 1 to 50, wherein the light source includes a halogen flash lamp. Embodiment 52 provides a method according to any one of Embodiments 1 to 51, wherein the light source includes a light-emitting diode.

[0125] Embodiment 53 provides a method according to any one of Embodiments 1 to 52, wherein the light source includes one or more light-emitting diodes. Embodiment 54 provides a method according to any one of Embodiments 1 to 53, wherein the irradiation includes irradiating the polymer graphene precursor coated on the substrate in air.

[0126] Embodiment 55 provides a method according to any one of Embodiments 1 to 54, wherein the irradiation includes irradiating the polymer graphene precursor at a temperature of less than 100°C. Embodiment 56 provides a method according to any one of Embodiments 1 to 55, wherein the irradiation includes maintaining the polymer graphene precursor at a temperature of less than 100°C.

[0127] Embodiment 57 provides a method according to any one of Embodiments 1 to 56, wherein the irradiation includes irradiating the polymer graphene precursor at room temperature. Embodiment 58 provides a method according to any one of Embodiments 1 to 57, wherein the irradiation includes substantially maintaining the pre-irradiation temperature of the polymer graphene precursor throughout the entire irradiation.

[0128] Embodiment 59 provides a method according to any one of Embodiments 1 to 58, wherein the irradiation includes raising the temperature of the polymer graphene precursor by 10°C or less. Embodiment 60 provides a method according to any one of Embodiments 1 to 59, wherein the irradiation includes raising the temperature of the polymer graphene precursor by 2°C or less.

[0129] Embodiment 61 provides the method according to any one of Embodiments 1 to 60, wherein the graphene film has an electrical conductivity of at least 150 S / m. Embodiment 62 is a graphene film whose thickness is determined by Raman spectroscopy, 1350 cm². -1 A distinctive disordered band (D band) with a peak nearby, and 1582 cm -1 The present invention provides a method according to any one of embodiments 1 to 61, wherein the ratio to a characteristic graphite band (G band) having a peak nearby is less than 1.

[0130] Embodiment 63 is a graphene film having a thickness of 2700 cm² determined by Raman spectroscopy. -1 A distinctive 2D band with a peak nearby, and a 1582 cm² suitable for a single Lorentz function. -1 The present invention provides a method according to any one of embodiments 1 to 62, wherein the ratio to a characteristic graphite band (G band) having a peak nearby is less than 1.

[0131] Embodiment 64 provides a method according to any one of Embodiments 1 to 63, wherein the irradiation includes localizing light absorption with respect to the precursor film such that the temperature of the polymer graphene precursor rises by 10°C or less during the irradiation relative to the temperature of the precursor film before irradiation.

[0132] Embodiment 65 provides a method according to any one of Embodiments 1 to 64, wherein the method does not damage the substrate in relation to the state of the coating and the substrate before irradiation. Embodiment 66 provides a method according to any one of Embodiments 1 to 65, wherein the irradiation includes pulse output modulation.

[0133] Embodiment 67 provides the method according to Embodiment 66, which includes adjusting the microstructure of the graphene film using the pulse output modulation. Embodiment 68 provides a graphene film formed by the method described in any one of Embodiments 1 to 67.

[0134] Embodiment 69 provides a patterned graphene film manufactured by the method described in any one of Embodiments 1 to 67. Embodiment 70 provides an electrochemical energy storage device, an electromagnetic shielding material, a chemical or biological sensor, a post-CMOS nanoelectronic device, a thermal shielding material, a structural composite, a filter, or a combination thereof, which includes a graphene film formed by the method described in any one of Embodiments 1 to 67.

[0135] Embodiment 71 is a method for forming a graphene film, A polymer graphene precursor is coated onto a substrate containing carbon fibers, carbon mesh, carbon cloth, carbon composite material, graphene composite material, graphene, carbon film, or a combination thereof, wherein the polymer graphene precursor and the substrate have different chemical compositions, and The present invention provides a method for converting the polymer graphene precursor, which is coated on the substrate, into a graphene film by irradiating it with a pulsed high-intensity light source that emits light at two or more wavelengths for a pulse duration of less than one second using the pulsed high-intensity light source that emits light at two or more wavelengths.

[0136] Embodiment 71 provides graphene films, electrochemical energy storage devices, electromagnetic shielding materials, chemical or biological sensors, post-CMOS nanoelectronic devices, thermal shielding materials, structural composites, filters, or any combination of embodiments 1 to 70 configured optionally so that all enumerated elements or options are available for use or selection.

Claims

1. A method for forming a graphene film, A polymer graphene precursor is coated onto a substrate, wherein the polymer graphene precursor is coated onto a substrate that includes plastic, metal, cloth, woven fabric, or a combination thereof. A method comprising converting the polymer graphene precursor coated on the substrate into a graphene film by irradiating it with a pulsed high-intensity light source that emits light at two or more wavelengths for a pulse duration of less than one second.

2. The method according to claim 1, wherein the composition of the polymer graphene precursor is different from the composition of the substrate.

3. The method according to claim 1, wherein the light source includes emission wavelengths in the range of 100 nm to 2000 nm.

4. The pulse duration is 200 to 900 milliseconds, the light source has an intensity of 100 V to 2000 V, the light source has a pulse frequency of 0.1 Hz to 10 Hz, and the light source has an intensity of 0.1 J / cm². ２ ~100 J / cm ２ The light source has an energy density per pulse of 10 J / cm². ２ ~1000 J / cm ２ The method according to claim 1, having a total surface density.

5. The method according to claim 1, wherein coating the polymer graphene precursor onto the substrate includes using printing, offset printing, inkjet printing, transfer printing, aerosol jet printing, microcontact printing, embossing, nanoimprint lithography, photolithography, electron beam lithography, ion beam lithography, or a combination thereof.

6. The method according to claim 1, wherein the polymer graphene precursor on the substrate comprises a patterned polymer graphene precursor.

7. The method according to claim 1, wherein the polymer graphene precursor comprises a polymer containing a disubstituted benzene, a benzene substituted with one or more chromophores, a polycyclic aromatic ring, aniline, nitroaniline, nitrophenol, biphenyl, nitrobenzene, benzaldehyde, acetophenone, pyrene, pentacene, anthracene, tetracene, or a combination thereof.

8. The method according to claim 1, wherein the polymer graphene precursor comprises polymers selected from resol, pyrene pitch oligomers, cyclized polyacrylonitrile, carbon fibers, polyaniline, thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and epoxy, poly(3-phenyl-2,4-dihydro-1,3-benzoxazine), poly(phenylbenzoxazine), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine), poly(furanylbenzoxazine), poly(phenol-co-formaldehyde), thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and bis-phenol-A furfuryl diglycidyl ether, and combinations thereof.

9. The method according to claim 1, wherein the absorption band of the polymer graphene precursor overlaps with the emission band of the pulsed high-intensity light source, and the polymer graphene precursor has an absorption band in the range of 400 nm to 600 nm.

10. The method according to claim 1, wherein the substrate includes carbon fiber, carbon mesh, carbon cloth, carbon composite material, graphene composite material, graphene, carbon film, or a combination thereof.

11. The method according to claim 1, wherein the light source includes a xenon flash lamp.

12. The method according to claim 1, wherein the irradiation includes irradiating a polymer graphene precursor coated on the substrate in air at room temperature.

13. The method according to claim 1, wherein the irradiation comprises irradiating and / or maintaining the polymer graphene precursor at a temperature of less than 100°C.

14. The method according to claim 1, wherein the polymer graphene precursor comprises polyaniline.

15. The method according to claim 1, wherein the graphene film has an electrical conductivity of at least 150 S / m.

16. The graphene film is Determined by Raman spectroscopy, 1350 cm －１ A characteristic disordered band (D band) with a peak nearby, and 1582 cm －１ The ratio to a characteristic graphite band (G band) with a peak nearby is less than 1, Determined by Raman spectroscopy, 2700 cm⁻¹ －１ A distinctive 2D band with a peak in the vicinity, and a 1582 cm² band that can be fitted to a single Lorentz function. －１ The ratio to a characteristic graphite band (G band) with a peak nearby is less than 1, or The method according to claim 1, having a combination thereof.

17. A method for forming a graphene film, A polymer graphene precursor is coated onto a substrate containing carbon fibers, carbon mesh, carbon cloth, carbon composite material, graphene composite material, graphene, carbon film, or a combination thereof, wherein the polymer graphene precursor and the substrate have different chemical compositions, and the polymer graphene precursor is A polymer comprising disubstituted benzene, benzene substituted with one or more chromophores, polycyclic aromatic rings, aniline, nitroaniline, nitrophenol, biphenyl, nitrobenzene, benzaldehyde, acetophenone, pyrene, pentacene, anthracene, tetracene, or a combination thereof, or Polymers selected from resol, pyrene pitch oligomers, cycloadjusted polyacrylonitrile, carbon fibers, polyaniline, thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and epoxy, poly(3-phenyl-2,4-dihydro-1,3-benzoxazine), poly(phenylbenzoxazine), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine), poly(furanylbenzoxazine), poly(phenol-co-formaldehyde), thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and bis-phenol-A furfuryl diglycidyl ether, and combinations thereof. Coating with the polymer graphene precursor, and A method comprising converting the polymer graphene precursor coated on the substrate into a graphene film by irradiating it with a pulsed high-intensity light source that emits light at two or more wavelengths for a pulse duration of less than one second.

18. A method for forming a graphene film, This involves coating a substrate with a polymer graphene precursor, Polymers comprising disubstituted benzenes, benzenes substituted with one or more chromophores, polycyclic aromatic rings, aniline, nitroaniline, nitrophenol, biphenyl, nitrobenzene, benzaldehyde, acetophenone, pyrene, pentacene, anthracene, tetracene, or combinations thereof, Polymers selected from resol, pyrene pitch oligomers, cycloadjusted polyacrylonitrile, carbon fibers, polyaniline, thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and epoxy, poly(3-phenyl-2,4-dihydro-1,3-benzoxazine), poly(phenylbenzoxazine), poly(3-furanyl-2,4-dihydro-1,3-benzoxazine), poly(furanylbenzoxazine), poly(phenol-co-formaldehyde), thermosetting resin networks formed from blends and crosslinks of polybenzoxazine and bis-phenol-A furfuryl diglycidyl ether, and combinations thereof. Coating the substrate with the polymer graphene precursor containing the above, A method comprising converting the polymer graphene precursor coated on the substrate into a graphene film by irradiating it with a pulsed high-intensity light source that emits light at two or more wavelengths for a pulse duration of less than one second.

19. The method according to claim 18, wherein the substrate includes a cloth, a woven fabric, carbon fiber, or a combination thereof.

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