System and method for mesophase pitch structure control and composition analysis using magnetic field

Abstract

The disclosed embodiments may include a material having a composition that includes a mesophase pitch material that comprises from about 5.0% to 95.0% and at least one of about Ts < lt >, about Ts < lt >, about Ts < lt >, about Ts < lt >, about Ts < lt >, about Ts < lt >, and about Ts < lt >; the mesophase pitch material has a viscosity of about 0.01 to 102 Pascal seconds (Pa.s) in a temperature range of T < = 475 DEG C, where Ts > = 150 DEG C, at least a portion of the mesophase pitch material may be oriented by a magnetic field having an intensity of about 0.25 to 6.0 Tesla. The portion of the mesophase pitch material may have an average molecular spacing of about 3.4 to 3.7 angstroms and an average molecular size of about 1 to 3 nanometers (nm).

Description

Technical Field

[0001] This application relates to systems and methods for controlling the structure and analyzing the composition of mesophase pitch using magnetic fields. Background Art

[0002] Molecules in heavy hydrocarbon feeds (e.g., bottoms column effluent streams, steam cracker tars, vacuum residua, etc.) typically include polycyclic aromatic compounds with small side groups. Isotropic pitch can be separated from these heavy feeds via pyrolysis and / or various separations such as solvent extraction, distillation, etc. Isotropic pitch rich in disordered heavy hydrocarbons can be converted to ordered "mesophase" pitch (discotic nematic phase) via thermal and / or catalytic pathways, which can be further assisted by solvent extraction. Pitch pyrolysis is an energy-intensive process, and there is a search for new cost-effective ways to control the mesophase transition rate and subsequent texturing.

[0003] Therefore, there is still a need for improved systems and methods for mesophase structure control and composition analysis using other methods (e.g., magnetic fields). Summary of the Invention

[0004] The disclosed embodiments may include a material. The material may include a composition comprising a mesophase pitch material, the mesophase pitch material accounting for about 5.0% to 95.0% and having a viscosity of about 0.01 to 10 s , s , 2 , s , , s ,

[0005] , , s ,

[0004] , 2 ,

[0003] , , Pascal seconds (Pa·s) within a temperature range of about T 2 where T s ≥ 150 °C, where T s represents the softening point of the pitch. At least a portion of the mesophase pitch material can be aligned by a magnetic field having an intensity of about 0.25 to 6.0 Tesla (T). The portion of the mesophase pitch material can have an average molecular spacing of about 3.4 to 3.7 angstroms (Å) in the stacking direction and an average molecular size of about 1 to 3 nanometers (nm) in the lateral direction.

[0005] The disclosed embodiments may include a method for controlling the orientation of mesogenic molecules in a composition. The method may include providing a composition comprising a mesophase pitch material, the mesophase pitch material accounting for about 5.0% to 100.0% and having a viscosity of about 0.01 to 10 s within a temperature range of about T 2 Pa·s, where T [[ID=3,2]] s≥150 °C. The method can include applying a magnetic field of about 0.25 to 6.0 T to the composition, thereby causing at least a portion of the mesophase pitch material to be oriented through the magnetic field in about 0.1 seconds to 10 4 seconds. The portion of the mesophase pitch material can include a plurality of mesophase droplets having a minimum droplet diameter of about 50 nm.

[0006] The disclosed embodiments can include a pitch material. The material can include a composition containing a mesophase pitch material that accounts for about 5.0% to 95.0% and has a viscosity of about 0.01 to 10 2 Pa·s (e.g., above the softening point of the pitch). At least a portion of the mesophase pitch material can be oriented through the magnetic field in the presence of a magnetic field of about 0.5 to 2.0 T, at a temperature of about T s <T ≤ 450 °C and in about 0.1 seconds to 50 minutes, where T s ≥150 °C.

[0007] These and other features and attributes of the present disclosure, as well as their advantageous applications and / or uses, will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To assist those of ordinary skill in the relevant art in making and using the subject matter herein, reference is made to the accompanying drawings, in which:

[0009] Figure 1A-1B Shows, according to certain embodiments of the disclosed technology, the orientation of mesophase pitch using a magnetic field, (A) where the director of the discotic mesogen is oriented in the XY plane (field along the z-axis), and (B) by rotating the sample or the magnetic field to obtain a unique average director orientation (along X or -X).

[0010] Figure 2A-2C Shows, according to certain embodiments of the disclosed technology, (A) the size (diameter) of mesophase pitch droplets required for orientation in different magnetic fields as a function of magnetic anisotropy (aromaticity), (B) the time scale for orientation of 4-ring aromatic materials (e.g., benzophenanthrene) above the threshold size of the droplets at different viscosities, and (C) a comparison of the orientation time scales for 4-ring and 7-ring materials.

[0011] Figure 3A Provides a flow chart for producing isotropic pitch from SOP2 tar feed according to certain embodiments of the disclosed technology.

[0012] Figure 3B-3DOptical micrographs of asphalt samples pyrolyzed at 400°C for 30 min (3B), 60 min (3C), and 90 min (3D) at room temperature are provided (top: cross-polarized light image; bottom: corresponding fluorescence image).

[0013] Figures 4A-4D Different scenarios are illustrated according to certain embodiments of the disclosed technology, wherein (A) during pyrolysis, when the size of the mesophase droplets is larger than the threshold volume required for thermal fluctuations, and (BD) in a pre-prepared mesophase system, by heating to a temperature higher than that of isotropic or mesophase. g To achieve magnetic orientation control of the asphalt system.

[0014] Figure 5A-5G The following are shown: (A) Sample preparation of SOP2 tar material with or without a magnetic field according to certain embodiments of the disclosed technology; (B) 2D scattering pattern of isotropic powder material as received; (CD) from... Figure 5A X-ray scattering pattern of the sample, (E) intensity distribution of scattering data relative to scattering vector q, (F) polarized light micrograph of the original material upon receipt, depicting an isotropic phase surrounded by an epoxy sealant, and (G) material after heating at 400°C for 30 minutes resulting in approximately 20% mesophase content, depicting liquid crystal mesophase droplets surrounded by isotropic material.

[0015] Figures 6A-6F The following are shown: (A) magnetic orientation experiments of samples (i) and (ii) according to certain embodiments of the disclosed technology in a 6 T magnetic field; (BE) the corresponding 2D X-ray data; and (F) high-angle reflection q ~ 1.8 Å at 6 T after samples were isothermally annealed at 300 °C for 30 min and subsequently annealed at 400 °C for 10 min, 30 min, and 60 min, respectively. -1 Room temperature data for the azimuth intensity distribution.

[0016] Figures 7A-7G The following are shown: (A) magnetic orientation experiments of samples (i) and (ii) according to certain embodiments of the disclosed technology in a 1 T magnetic field; (BE) corresponding 2D X-ray data (30 min at 300 °C, 30 min at 400 °C, 60 min at 400 °C, and 90 min at 1 T); (F) intensity plotted relative to the scattering vector q; and (G) high-angle reflections q ~ 1.8 Å after isothermal annealing of the pure sample at 1 T and the sample at 300 °C for 0 min to 30 min followed by isothermal annealing at 400 °C for 30 min and 60 min at 400 °C. -1 Room temperature data for azimuth intensity distribution.

[0017] Figures 8A-8COptical micrographs of unoriented mesophase pitch samples under different sample rotations are provided according to certain embodiments of the disclosed technology.

[0018] Figures 9A-9C Cross-polarized light micrographs of magnetically oriented mesophase pitch samples obtained with respect to cross-polarized light under different sample orientations, according to certain embodiments of the disclosed technique, are provided. Arrows indicate the direction of the magnetic field relative to the sample orientation.

[0019] Figure 10 The 2D X-ray scattering pattern obtained at room temperature is shown, demonstrating the rapid response of the mesophase pitch material under a 6 T magnetic field. First, two sets of mesophase samples were prepared by heat-treating the original pitch at a higher temperature in the absence of a magnetic field. The first set of samples was prepared by isothermal holding at 300 °C for 30 minutes. The second set was prepared by isothermal heating at 300 °C for 30 minutes, followed by isothermal heating at 400 °C for another 30 minutes. After sample preparation, the two sets of samples were placed in a 6 T magnetic field at 400 °C for 1 minute and 5 minutes, respectively.

[0020] Figure 11A-11D The following are shown according to certain embodiments of the disclosed technology: (A) a composite material having mesophase pitch, (B) droplets of mesophase pitch with their disk-shaped directional vectors oriented perpendicular to the applied magnetic field, and (CD) uniaxial orientation of the directional vectors when the magnet (or sample) is rotated.

[0021] Figure 12 A composite material containing carbon nanotubes (CNTs) and mesophase pitch according to certain embodiments of the disclosed technology is shown.

[0022] Figures 13A-13B The following are illustrated combined approaches to obtaining highly oriented thin film samples by using surface-induced orientation in combination with magnetic orientation according to certain embodiments of the disclosed technology, (A) when the mesomorph is oriented in a plane relative to the surface, and (B) using additional surface constraints.

[0023] Figures 14A-14B The diagram shows (A) a 2D X-ray scattering pattern measured at room temperature according to certain embodiments of the disclosed technique, and (B) a pattern for scattering at ~1.8 Å. -1 Gaussian fitting of the azimuth intensity distribution of high-angle reflections.

[0024] Figures 15A-15B Provided, according to certain embodiments of the disclosed technology, (A) oriented mass as a function of depth (vertical axis) for different annealing times (horizontal axis), and (B) a bulk mesophase fraction estimated by expression (3) for different heights along the capillary.

[0025] Figure 16 Examples of schemes for inducing the orientation of mesophase molecules in an article (e.g., fiber) during extrusion or 3D printing, according to certain embodiments of the disclosed technology, are shown. Invention Details

[0027] Molecules in heavy hydrocarbon feedstocks (e.g., main column bottoms, steam cracker tar, vacuum residue, etc.) typically include polycyclic aromatic compounds with small side groups. Isotropic pitch can be separated from these heavy feedstocks via pyrolysis and / or various separation methods such as solvent extraction, distillation, etc. At the glass transition temperature (T0...) g Above, isotropic asphalt flows like a liquid, becomes more viscous at lower temperatures, and at T... g The material then transitions to a glassy state. Disk-shaped mesophases can form during thermal or catalytic (or thermo-catalytic) treatments due to chemical and structural transformations occurring within the material. Chemical transformations can include chain (side group) cleavage, condensation, cyclization (ring closure), and / or dehydrogenation reactions, resulting in more condensed aromatic molecules. Increased planarity and aromaticity generally lead to higher mesocrystalline (liquid crystal) properties in these materials. Concurrently with these chemical reactions, degassing of volatiles and reaction products leads to an increase in the overall viscosity of the system at constant temperatures during pyrolysis. The increased mesocrystalline content and removal of low-boiling components due to the chemical reactions result in phase separation of mesocrystalline and non-mesocrystalline molecules into an isotropic phase, which self-assembles to form an ordered liquid crystal disk-shaped nematic mesophase, primarily mediated by aromatic-aromatic π-π interactions and spatial interactions. The isotropic-nematic phase transition temperature (Ti) in asphalt during heat treatment is [not specified in the original text]. IN It depends on the extent of the chemical reaction (chemical strength). In heat treatment (e.g., above the material's softening point T), s During the isothermal immersion, T IN The increase in solubility parameter is due to the continuous variation in the composition of asphalt, namely the increase in the number density of larger and planar aromatic (more mesocrystalline) molecules, and the favorable intermolecular interactions (cohesive energy density).

[0028] When isotropic materials are at T 热解 When the pyrolysis occurs, the transparency transition temperature (i.e., the temperature at which the nematic phase transforms into an isotropic liquid, and therefore the finite order parameter becomes zero) T C =T 热解At this point, the mesophase droplets can be observed first using a cross-polarized light microscope. When the material transforms into a nematic state, the mesophase droplets can couple to and orient themselves with an external magnetic field, and the timescale of orientation can be further aided by the lower viscosity of the surrounding isotropic medium. However, since the viscosity of the material increases with pyrolysis time at the orientation temperature, this will slow down the kinetics of magnetic orientation. However, the increase in aromaticity with time (thermal intensity) leads to an increase in the magnetic anisotropy of the system, which reduces the timescale of magnetic orientation, thus resulting in an effect that is conducive to accelerating orientation. Therefore, the orientation kinetics of mesophase pitch are determined by the balance between these two effects. When T C =T 热解 Intermediate phase droplets appear at times, but as the chemical process proceeds, the transparency temperature T of those droplets decreases. C As the molecular weight increases, the T phase continues to increase; therefore, the earlier the intermediate phase forms, the higher the T value. C The higher the proportion of magnetically registered intermediate phase, the better. Therefore, in-situ magnetic orientation procedures during the pyrolysis of isotropic bitumen may be more suitable for obtaining a higher proportion of magnetically registered intermediate phase.

[0029] During pyrolysis, newly formed mesophase droplets become oriented with the magnetic field when their size exceeds a threshold size defined by magnetic anisotropy and field strength. Thus, during droplet nucleation and growth, they are oriented by the magnetic field and continue to maintain their orientation while increasing in size due to further growth. However, this effect also depends on the composition of the material; for example, if a material with a high mesophase content has an achievable transparency temperature, rapid orientation of the composition can be achieved by cooling across the isotropic-nematic phase transition temperature. If the transparency temperature cannot be reached, and if the system has a sufficiently low viscosity (e.g., 1–10 Pa·s) at a higher temperature well above the softening point, mesophase orientation can be achieved on a reasonably rapid timescale (e.g., seconds to minutes). The mesophase transition kinetics (which in turn depend on the composition of the pitch) play a crucial role in the magnetic orientation timescale.

[0030] The properties (e.g., mechanical, electrical, or thermal) of carbon fibers or other carbon materials based on mesophase pitch are ultimately determined by the texture of the microstructure domains and the size of the graphite domains, the former being primarily determined by the mesocrystalline orientation due to spinneret geometry or processing conditions (temperature or inert gas injection). Therefore, controlling the microstructure of the precursor mesophase pitch material during processing allows for enhanced properties of the carbon materials formed from it. To this end, controlling the mesophase director orientation in the bulk is a necessary step in defining the material properties for a given application. Therefore, a method for measuring the mesophase content in the bulk is needed to define the pitch product specifications before and after the manufacturing process.

[0031] Isotropic pitch rich in disordered heavy hydrocarbons can be transformed into ordered "mesophase" pitch (disc-shaped nematic phase) via thermal and / or catalytic pathways, which can be further aided by solvent extraction. Pitch pyrolysis is an energy-intensive process, and new cost-effective approaches are being sought to control the mesophase transformation rate and subsequent texturing. Mesophase pitch produced via melt spinning as spun green fiber (spun mesophase pitch fiber prior to further processing) undergoes additional steps, such as stabilization and carbonization, followed by a final graphitization step to achieve structural properties in the form of high-modulus, high-strength carbon fibers. This final step can be carried out at high temperatures (e.g., >2000°C) to form carbon fibers, thereby obtaining high-performance properties.

[0032] For pitch-based carbon fibers or other pitch-based carbon composites, properties (e.g., mechanical, electrical, thermal, etc.) are determined by the mesophase content in the precursor material, the crystallite size of the graphite domains, and their geometry (fiber texture) within the resulting carbon fibers. The properties (e.g., mechanical, electrical, or thermal) of mesophase-based carbon fibers are ultimately determined by the microdomain texture and graphite domain size, the former primarily determined by the mesocrystalline orientation in the spun nascent fibers due to spinneret geometry or processing conditions (e.g., temperature or inert gas injection). Therefore, the subsequent graphite structure and morphology are strongly correlated with the molecular orientation obtained in the raw carbon material prior to high-temperature processing. Irregular and random spatial arrangements of the mesophase domains can lead to small grain sizes and structural defects (including void formation or microporosity in the final carbon material), thus degrading performance. Mesophase-pitch carbon fibers also suffer from reduced tensile strength compared to polyacrylonitrile (PAN)-based carbon fibers due to their high crystallinity and graphite orientation. Typically, when extruding nascent fibers, temperature and spinneret geometry are frequently altered to modulate the fiber texture. This helps optimize the tensile strength of carbon fibers but compromises the mechanical modulus (or thermal and electrical properties) for various applications. Therefore, there is a strong need for new methods to control the internal morphology of fibers or other carbon products, thereby modulating the structure and physical properties of various carbon forms.

[0033] In typical systems and methods used for orientation control, mesophase molecules tend to orient themselves along the flow direction, or when subjected to an external field (e.g., a magnetic field) or a surface field (surface-induced orientation). Because mesophase pitch materials are inherently highly aromatic, the high magnetic anisotropy, combined with the lower viscosity provided by high temperatures, can be advantageously used to orient the mesophase material to low-intensity magnetic fields. Hydrocarbon feedstocks already containing a significant fraction of polynuclear aromatic compounds can provide a faster response in low-intensity magnetic fields (e.g., ≤1 Tesla) during mesophase formation or when subjected to a magnetic field after mesophase formation.

[0034] Therefore, embodiments of this disclosure can provide control over the orientation of the mesophase within a bitumen material by applying a magnetic field during the mesophase formation process or when the bitumen is in its molten state. Embodiments of this disclosure can provide control over the ordering, orientation, morphology (texture), and / or domain size of the mesophase itself, which can affect the properties of the final carbon products.

[0035] For example, embodiments of this disclosure focus on using magnetic fields to control the orientational ordering of the mesophase during phase transitions in mesophase pitch materials or other carbon products (e.g., composites). Furthermore, magnetic field patterns can also be used to control the geometrical orientation of mesophase structural domains or droplets in fibers or composites with high fidelity, where, in the latter case, the mesophase forms a minority (filler) or a majority (matrix phase). Composites may also include CNT / mesophase pitch composites, matrix materials with CNTs, or other high aspect ratio carbon materials. In thin film geometry, the simultaneous application of magnetic fields, along with the surface anchoring effect of discoid molecules in the pitch, can be used to generate highly oriented mesophase precursors to produce large graphite flakes (2D materials) or bands. Therefore, when applied to melt fiber spinning or 3D printing of mesophase pitch, magnetic field-induced structural control of the mesophase pitch using permanent magnets or electromagnets can provide additional processing for carbon fiber texturing, which can transform into larger and highly oriented graphite structural domains in the resulting carbon material after high-temperature treatment (e.g., stabilization, carbonization, graphitization). The strong anisotropic ordering or texturing of various forms of mesophase pitch at reasonable timescales opens up the possibility of manufacturing advanced carbon products with higher performance properties, such as lithium-ion battery anodes and graphite materials. Furthermore, embodiments of this disclosure demonstrate a novel approach to quantifying the mesophase content in bulk materials by orienting mesophase structural domains (droplets) under a magnetic field.

[0036] Mesophase pitch contains large aromatic disk-shaped molecules and exhibits weak diamagnetism, with the easy magnetization axis located in the aromatic ring plane. Therefore, when thermodynamic ( Under certain conditions (grain size) and kinetics (lower viscosity enables a faster response), these disk-like systems are expected to orient in the presence of an external magnetic field (B), and the applied field (B) is higher than the threshold field required to observe the orientation of mesophase droplets (or portions) on a practical timescale (seconds to minutes). Typically, the kinetics of mesophase formation in bitumen are a slow process, and when isotropic bitumen undergoes pyrolysis, it can take several hours to form approximately 50% mesophase content. However, embodiments of this disclosure provide a bitumen composition that forms a mesophase in less than about 30 minutes at higher temperatures (e.g., 400°C), which is beneficial for in-situ pyrolysis under a magnetic field. Furthermore, embodiments of this disclosure provide a scenario where the starting bitumen material contains a significant fraction of mesocrystalline molecules, whose driven orientation occurs over a time period of seconds to minutes, depending on operating conditions (e.g., temperature, viscosity, magnetic field strength, and aromatic size).

[0037] Thermodynamic conditions are given as follows:

[0038] (Equation 1)

[0039] in It is diamagnetic anisotropy (parallel direction) and vertical direction (The difference between diamagnetic susceptibility).

[0040] With the size of the liquid crystal domain (e.g., droplet size or radius) Increase, for a given The magnetic field strength required for orientation decreases (as shown below for...) Figure 2A (As discussed further). When magnetic energy Exceeding thermal energy At this time, the material (e.g., a droplet) is oriented in the field. The threshold volume is given by the following equation:

[0041] (Equation 2)

[0042] For a given And B, the time required for the magnetic orientation of the mesophase droplet (greater than critical volume) Viscosity depends on temperature dependence. .

[0043] (Equation 3)

[0044] Therefore, the directional kinetics depend on the temperature-dependent viscosity of the mesophase pitch (as shown below for...). Figure 2B (As discussed further). Once the mesophase droplet size exceeds the threshold size, the orientation timescale of a given field intensity... Regardless of the droplet volume or size, the condition is that the viscosity of the surrounding medium remains constant. However, this is not the case for mesophase asphalt formation, where volatiles escape at higher temperatures in addition to reaction products. Furthermore, chemical reactions can also lead to an increase in molecular weight. Both of these effects increase the viscosity of isotropic and anisotropic materials. Therefore, the rapid mesophase formation kinetics can be used for the purposes of applying this method.

[0045] Before disclosing and describing the methods and apparatus of the present invention, it should be understood that, unless otherwise stated, the invention is not limited to specific compounds, components, compositions, reactants, reaction conditions, linkers, ligands, or the like, as these can be varied unless otherwise specified. It should also be understood that the various terms used herein are for describing particular embodiments only and are not intended to be limiting.

[0046] For the purposes of this disclosure, the following definitions shall apply:

[0047] The terms "a" and "the" as used in this article are understood to encompass both plural and singular forms.

[0048] All values ​​in the detailed description modified by "about" or "approximately" relative to the indicated value take into account experimental errors and variations expected by those skilled in the art. In some cases, the use of "about" or "approximately" may include a deviation of ±10% from the indicated value. Detailed Implementation

[0049] Example

[0050] This disclosure evaluates systems and methods for controlling molecular orientation in mesophase pitch materials by applying a magnetic field.

[0051] Control of mesophase pitch texture

[0052] There are two methods to achieve texture control in mesophase pitch. First, during high-temperature mesophase synthesis, in-situ orientation during pyrolysis occurs, where once the mesophase droplet size exceeds a threshold size, the droplets orient themselves with a direction vector perpendicular to the magnetic axis. Therefore, the aromatic ring plane can be oriented parallel to the field direction (z-axis), while the optical axis can be perpendicular to the applied field axis (xy-plane), as... Figure 1A-1BAs shown in Figure 1A, a magnetic field orients mesophase pitch materials, where the mesocrystalline director of the disk-shaped structures is oriented in the xy plane (along the z-axis field). Therefore, degeneracy exists related to the orientation of the disk-shaped director. Figure 1B shows that a unique average director orientation (along X or -X) can be obtained by rotating the pitch sample or the magnetic field, thus achieving texture control. By rotating the sample in a static magnetic field, molecular layers can be uniaxially oriented relative to the field direction. If the mesophase formation kinetics are faster and homogeneous nucleation occurs, in-situ orientation during pyrolysis can allow for the orientation of higher concentrations of the mesophase, thus orienting almost all droplets. This method can be used in applications requiring highly oriented mesophase materials.

[0053] Secondly, when the material is heated to a temperature higher than that of the isotropic portion (T... g，各向同性 ) or intermediate phase (T) g，中间相 Orientation of mesophase pitch can be achieved at temperatures higher than its glass transition temperature, depending on the volume fraction of each phase in the mesophase pitch material. The magnetic orientation time can vary depending on the droplet size (or mesophase content) and the viscosity of the material (Equation 3). If the main phase is isotropic, then if the material is heated above its softening point T... s In this case, the mesophase droplets orient themselves, and the kinetics will be faster compared to the case where the mesophase forms the main phase. Due to the higher aromaticity of mesocrystalline materials and molecular order, the mesophase portion has a higher viscosity than the isotropic portion. Therefore, the orientation of the pre-formed mesophase and the isotropic portion forming the continuous phase can provide a faster rate of mesophase structure control for applications requiring high-throughput processing.

[0054] Mesophase formation kinetics in asphalt

[0055] Typically, the kinetics of mesophase formation in pitch systems are quite slow during pyrolysis at higher temperatures (e.g., 400°C). Therefore, to achieve a high mesophase content (e.g., greater than about 50% by volume), isotropic materials must undergo pyrolysis for several hours, which can be energy-intensive. In addition to processing steps, the mesophase transformation rate also depends on the composition of the original feedstock. Longer heat treatment can also result in higher molecular weight materials, which can lead to higher viscosity. This can also adversely affect magnetic orientation kinetics (e.g., some regions may be unoriented) or require a strong magnetic field (e.g., greater than about 2T) to apply uniform orientation to the material.

[0056] like Figure 2A-2C As shown, larger aromaticity and mesophase droplet size affect the thermodynamics of orientation, while orientation kinetics depend on the material viscosity at the operating temperature. Specifically, Figure 2A The threshold size (diameter) of the mesophase pitch droplets required for orientation in different magnetic fields is shown as a function of magnetic anisotropy (aromaticity). Figure 2B The benzo[a]phenanthrene system (i.e., quaternary aromatic compounds) at different viscosities is shown. Approximately 10 -4 The timescale of magnetic orientation is above the droplet threshold size (dimensionless SI units). As shown in the figure, in the presence of a magnetic field with an intensity of approximately 0.25 to 6.0 T (e.g., approximately 1.0 T, 2.0 T, 3.0 T, 4.0 T, 5.0 T, etc.), when heated to above the softening point of the mesophase pitch material, it can have a magnetic orientation timescale of approximately 0.1 to 10. 2 Viscosities between Pa.s (e.g., between about 0.25 and 50 Pa.s) are used to achieve orientation. As discussed herein, mesophase pitch materials can be heated to about T when subjected to a magnetic field to achieve proper orientation. s < T ≤ 475℃ (e.g., about 200℃ to 475℃, or about 300℃ to 475℃). Furthermore, as discussed herein, the sample is heated above its softening point (T). s For example, at least higher than T s Temperatures of approximately 20°C to 150°C can help achieve a greater degree of orientation. Figure 2C A comparison of the orientation timescales of 4-membered aromatic rings and 7-membered aromatic rings is provided.

[0057] Mesophase pitch materials

[0058] This disclosure provides material compositions that already contain a majority of aromatic molecules with mesocrystalline properties, allowing for orientation at lower temperatures and / or shorter times. Figure 3A A flowchart is provided for the production of this bitumen material, specifically isotropic bitumen from SOP2 tar feed. As shown, the SOP2 tar feed, prepared by steam cracking, is heat-treated at 25°C for 2 hours under a constant hydrogen flow at 250 psi pressure to remove light molecules, and the liquid is collected in a separation tank (KO). The liquid bottom stream retained in the autoclave (with a yield of approximately 82%) is filtered simultaneously with heat using a 2.5-micron filter to remove the coke fraction, which is found to be approximately 2%. The filtered liquid bottom stream is then deasphalted with n-heptane to remove DAO (deasphalted oil). The insoluble fraction is isotropic bitumen. The total yield of the final product is approximately 40%. The resulting bitumen has a softening point T of approximately 275°C. s And approximately 78% micro carbon residue test (MCRT). In some embodiments, the MCRT can be greater than approximately 40%.

[0059] The raw bitumen material obtained by the above method exhibits a birefringent droplet appearance upon heat treatment, indicating the formation of an intermediate phase within the material. Because the intermediate phase is optically birefringent, reflected cross-polarized light is used to highlight the intermediate phase region from the isotropic portion. Furthermore, fluorescence imaging is used here to quantify the intermediate phase content. The π-π interactions between adjacent planar aromatic molecules in the intermediate phase enable energy transfer, intermolecular or intramolecular charge transfer, leading to fluorescence quenching and thus producing a high-contrast image, which significantly simplifies the segmentation and quantification of the two phases. A standard pixel-intensity thresholding algorithm is used to segment the fluorescence image to calculate the area fraction of the intermediate phase present in the sample. Cross-polarized light images are acquired using a waveplate (a specific type of birefringent crystal), shifting the phase of the polarized light components by approximately 532 nm, known as a full-waveplate, which significantly enhances image contrast and makes all phases uniquely visible, such as... Figure 3B-3D As shown. In cross-polarized grayscale images, the isotropic phase appears as a lighter gray, while the epoxy-filled areas appear as dark gray, and the mesophase areas appear brighter. Simultaneously, due to the addition of dye, fluorescence imaging depicts the epoxy as brighter (high fluorescence), the isotropic phase as gray, and the mesophase (which quenches most of its emission due to its high disk-like order) as darker. Figure 3B-3D The instructions indicate that at a selected temperature of 400°C, the mesophase content increases from 20%, 27%, and 35% for different heat treatment times of 30 minutes, 60 minutes, and 90 minutes, respectively.

[0060] The prepared untreated (isotropic) powder exhibits a high angle d(002) reflection of approximately 3.5 Å (as shown below for... Figure 5A-5G As discussed further), this is due to the typical scattering peak position seen in mesophase pitch due to the stacking of planar aromatic molecules, which have a higher C / H ratio and therefore higher aromaticity and / or planar properties (disc-like). Polarization optical microscopy measurements ( Figure 5F The birefringence domains in the original material are very weak, indicating a lack of strong intermediate phase ordering in the system. At the softening point of 300℃ (T... s After annealing at temperatures above 275℃, a small-angle peak at 2 nm (originating from the average separation between molecules) is significant. The higher intensity in the original powder material likely originates from the scattering contrast due to porosity, which is evident above T0. s It disappears after annealing. The original material may lack strong orientational order and long-range order, possibly due to the deasphalting step using n-heptane, which may lead to structural freezing. Therefore, it is possible to obtain [order] at temperatures higher than the material's [temperature]. s The increased orderliness after annealing.

[0061] Magnetic orientation control of asphalt systems

[0062] Figures 4A-4D It provides different scenarios in which magnetic orientation control of the bituminous system can be achieved. Figure 4A This illustrates that during pyrolysis, when the size of the mesophase droplets exceeds the threshold volume required to overcome thermal fluctuations, the droplets will orient themselves. (As shown...) Figure 4B-4D As shown, the pre-fabricated mesophase system can be heated to a temperature higher than that of isotropic or mesophase systems. g Orientation is required. The timescale for orientation depends on temperature-dependent viscosity and the composition of the material (diamagnetic anisotropy or aromatic size). These experiments need to be conducted under inert conditions or in a vacuum.

[0063] like Figures 4A-4D As shown, there are different ways to orient mesophase pitch using this method. One approach is to heat the material to a higher temperature (e.g., about 400°C) using a reasonable isotropic rate (e.g., 0.5°C / min to 20°C / min). Another approach is to isothermally heat-soak the material at a higher temperature (e.g., 350°C or higher) while subjecting it to a magnetic field, which allows for the magnetic orientation of the mesophase droplets formed during the chemical reaction. Thus, this method provides chemical and simultaneous control over the orientation of the director of the mesophase formed over time. Therefore, the latter approach allows for the orientation of a higher fraction of the mesophase material (>50%) using a magnetic field over a short period of time.

[0064] Results & Analysis of Mesophase Pitch Materials

[0065] Figure 5A-5G The data obtained by analyzing the aforementioned bitumen materials are shown, such as for Figure 3A As stated above. Figure 5A Experimental procedures are provided for preparing samples for magnetic orientation studies. Sample (i) is isothermally heated at 300°C for 30 minutes, followed by isothermally heated at 400°C for 30 minutes to produce sample (ii) (in the absence and presence of a magnetic field). Figure 5B 2D scattering patterns of the isotropic powder materials received in their original state are provided. The random morphology of these samples is evident in the powder scattering patterns. Figure 5C Figures D and D provide 2D X-ray scattering patterns for samples (i) and (ii). After heating the samples, corresponding to... Stacking distances d(002) ~ 3.5 Å in q ~ 1.8 Å -1 The characteristic reflection intensity increases at q ~ 0.35 Å, while the indication is in the range of q ~ 0.35 Å. -1 The mid-angle peak of the average lateral spacing at (~2nm) is clear and distinct. Figure 5E The intensity curves of the scattering data relative to the scattering vector q are provided. Figure 5F and 5G The materials were provided as they were received. Figure 5F) and materials heated at 400°C for 30 minutes resulting in a mesophase content of approximately 20% ( Figure 5G Polarized light photomicrographs. Figure 5B-5G The data provided was obtained in the absence of a magnetic field.

[0066] Surprisingly, when a 6T magnetic field is present, compared to T... s When the sample was heat-treated at 300°C (under N2) at a temperature 25°C higher than the surrounding material, mesophase orientation was observed, as discussed further below. It is speculated that the less ordered mesophase (with weak birefringence) formed during the solvent deasphalting step can evolve into a well-ordered mesophase at thermal equilibrium above the glass transition temperature. Furthermore, X-ray scattering can be used to measure the liquid crystal order and orientation of submicron droplets, which are difficult to discern under an optical microscope. When heated to a temperature much higher than the surrounding material... g or T s (T s At ~275°C, these submicron droplets are able to orient themselves along the field (pointing vector or mesophase droplet magnetic poles perpendicular to the magnetic field axis). Therefore, the original starting material is expected to possess a significant portion of mesocrystalline properties (or planar aromatic properties). However, due to solvent treatment, the material is less ordered and becomes more ordered at higher temperatures. As the material forms mesophase droplets, they orient themselves in the field when the droplet size exceeds the threshold size specified in Equation 2. Furthermore, higher temperatures enhance the mesophase formation kinetics of this material. Thus, hydrocarbon materials with a higher fraction of mesocrystalline properties result in a faster mesophase formation rate, and therefore faster orientation control at lower magnetic fields (e.g., 1 T to 2 T) can be achieved at higher temperatures (e.g., 375°C or 400°C), where the orientation timescale is faster than reported in the prior art.

[0067] The reduced viscosity and faster chemical transformation rate (leading to the formation of more planar and aggregated disk-shaped mesocrystalline structures) improved orientation kinetics at higher temperatures (e.g., around 400 °C). This was observed in the range q–1.8 Å. -1 The intensity of the π-π stacked reflection increases over time, consistent with the formation of more disk-shaped mesocrysts and enhanced kinetics at 400 °C. The strong orientation of the liquid crystal phase is also reflected at approximately 0.35 Å. -1 The anisotropic reflection of the small-angle peak at q (the transverse intermolecular distance is about 2 nm) is due to the disk-like nature of the molecules.

[0068] Figures 6A-6FThe orientation of the mesophase material in the presence of a magnetic field is shown, particularly the orientation of samples (i) and (ii) in a 6T magnetic field. The samples were first annealed at 300°C for 30 minutes at 6T (sample label i), followed by heating to 400°C and isothermal annealing for 10 minutes, 30 minutes, and 60 minutes, respectively. The corresponding 2D X-ray data are shown in [reference needed]. Figure 6B-6E As shown in the image. Figure 6F Provided at approximately 1.8 Å at 6T. -1 The azimuth intensity distribution under high-angle reflection is shown. With increasing processing temperature, stronger orientation is observed, as reflected by the decrease in the full width at half maximum (FWHM) of the reflections from the π-π stack. Furthermore, the background intensity due to the unoriented structure decreases with increasing processing temperature. Notably, q ~ 0.35 Å is orthogonal to the π-π stack reflections. -1 (Spacing ~2 nm) shows improved ordering with increasing temperature and time. At 400 °C, the intensity of π-π stacked reflections also increases slightly with increasing processing time. All this data indicates that pyrolysis leads to a greater content of mesophase, resulting in an increase in the clusters of mesophase oriented in a field defined by the magnetic anisotropy of the material.

[0069] Figures 7A-7G The orientation of the mesophase material in the presence of a magnetic field is shown, particularly the orientation of samples (i) and (ii) in a 1T magnetic field. Figure 7A As shown, the sample was first annealed at 300℃ for 30 minutes at 1T (sample label i), then heated to 400℃ and isothermally annealed for 0 minutes, 30 minutes, 60 minutes, and 90 minutes respectively. The corresponding 2D X-ray data are shown in... Figures 7B-7E As shown in the image. Figure 7F The intensity is provided for plotting against the scattering vector q. Figure 7G Provided at approximately 1.8 Å at 1T. -1 The azimuth intensity distribution under high-angle reflection is shown in the diagram. The sample annealed at 300°C did not show orientation within 30 minutes of processing. However, at higher temperatures, a stronger orientation of the structure was observed with processing time, consistent with processing at 6T, but with a much smaller field strength of 1T. This demonstrates the feasibility of controlling the structure of mesophase pitch even under small magnetic field strengths, which can be generated by permanent magnets or electromagnets. Furthermore, Figure 7G The decrease in background intensity in the azimuth distribution indicates that the fraction of the oriented intermediate phase increases over time, which also stems from the increase in the fraction of the intermediate phase as the chemical reaction proceeds.

[0070] like Figures 7A-7BAs shown, magnetic orientation experiments conducted at lower field strengths (1T) did not reveal significant mesophase orientation in the material at 300°C (for 30 minutes). However, at higher temperatures, strong orientation of the mesophase with the field was observed, which could be attributed to three main factors: (i) lower viscosity at higher temperatures; (ii) increased droplet size at higher temperatures, exceeding the threshold volume required for coupling with a 1T field; and (iii) chemical reactions that could increase aromaticity (diamagnetic anisotropy) to a considerable extent. Another possibility is the generation of more mesocrystalline material at higher temperatures for a short period (e.g., 5–10 minutes at approximately 425°C or 450°C), followed by cooling to lower temperatures to induce orientation (e.g., at approximately 350°C). Alternatively, viscosity could be adjusted by adding solvent or deasphalted oil fraction (DAO) retained during processing steps to enhance the ordering kinetics at lower temperatures when a considerable amount of mesocrystalline material (e.g., between approximately 40–90%) is present in the system. The strong orientation observed at a field strength of 1T can indicate when this new material composition can be used for structural control of mesophase pitch fibers or when it can be used in composite applications.

[0071] The magnetic response of the mesophase pitch material was also illustrated by polarized light microscopy measurements performed at room temperature, such as... Figures 8A-8C As shown in 9A-9C. Figures 8A-8C Optical micrographs of unoriented mesophase pitch samples (used as control samples here) are provided. The samples were prepared by heating to 300°C and holding for 30 minutes, followed by isothermal heating at 400°C for 30 minutes. Figures 8A to 8C The sample is at 45 degrees relative to the cross polarizer o Incremental rotation. As expected, heat treatment without a magnetic field did not reveal a global orientation of the mesophase spheres. The optical texture of the droplets resembled the previously reported molecular orientation. However, when subjected to a magnetic field, strong optical anisotropy of the droplets was observed, such as... Figures 9A-9C As shown. Figures 9A-9C Optical micrographs of magnetically oriented mesophase pitch samples are provided. Samples were prepared by heating to 300°C and holding for 30 minutes in the presence of a 6T magnetic field, followed by isothermal heating at 400°C for 30 minutes, and then cooling to room temperature. Figures 9A to 9C The sample is rotated relative to the cross-polarizer, indicating the direction of the magnetic field applied to the sample. Clearly, the mesocrystalline orientation is largely uniform compared to the unoriented sample, as evidenced by the uniform color and angle-dependent optical anisotropy. Figures 9A-9CAs shown, the main portion of the mesophase droplets is oriented by an external field determined by the magnetic anisotropy of the disk-shaped mesocrystalline material. Furthermore, the data indicate that, in contrast to the typical bipolar texture of nematic liquid crystal droplets, the molecular orientation within most droplets is uniform. This is likely due to the strong coupling between the mesophase droplets and the magnetic field, which overcomes the elastic distortion caused by the droplet curvature and the anchoring energy of the mesocrystalline material at the interphase locations. Because the orientation of the disk-shaped director vector is degenerate perpendicular to the magnetic field axis (Fig. 1A), the observation direction of some droplets in the image will be along the mesocrystalline director vector; therefore, no birefringence variation is observed in some droplets. Thus, the data suggest that almost all mesophase pitch droplets are oriented with a director vector perpendicular to the field axis, and no obvious bipolar texture is observed in the oriented mesophase droplets.

[0072] Applying permanent magnets to a suspension of mesophase pitch droplets or particles can magnetically orient them to induce unique anisotropic properties in the material. The droplets can be configured to orient themselves along the direction of the magnetic field, either when the magnetic field is applied statically or when the magnet or sample is rotated.

[0073] like Figure 10 As shown, two sets of samples (each with two samples) were prepared in the absence of a magnetic field to measure orientation dynamics. The first set of samples was prepared by isothermally heating the prepared bitumen material at 300 °C for 30 minutes. The second set of samples was prepared by a two-step heat treatment. First, the prepared material was isothermally heated at 300 °C for 30 minutes, and then pyrolyzed at 400 °C for 30 minutes to generate more mesophase. After this temperature treatment, both sets of samples showed random orientation of mesophase structural domains, which was evident in the 2D X-ray patterns. The first set of samples was then heated to 400 °C at a heating rate of 20 °C / min, with one sample isothermally held at this temperature for 1 minute and the second sample isothermally held for 5 minutes. After this procedure, the samples were cooled to room temperature, and the X-ray scattering patterns were measured. For these short timescales (e.g., 1 minute), both samples showed similar degrees of orientation. The second group of samples also underwent similar experimental procedures, and they showed strong orientation even after a 1-minute isothermal immersion at 400°C, indicating that orientation can be achieved on a short timescale (e.g., <1 minute).

[0074] Figure 11A-11D A composite material with mesophase pitch is shown. The orientation of the disk-shaped mesocrystalline direction is random. (Example: ...) Figure 11AAs shown, when the mesophase is mixed with a polymerizable monomer system, the mesophase pitch droplets can be made from a single mesophase or a mesophase containing some isotropic phases. Both are different compositions of matter. If epoxy resin is then added, the epoxy resin can be cured before the mesophase is oriented because the isotropic phase still exists, which will give a sufficiently low viscosity for the mesophase droplets to cure at higher temperatures (>T). s Under a magnetic field, the material can be reoriented. However, if the material initially contains 100% mesophase droplets, the droplets should be oriented before the polymerizable monomer is cured to prepare the composite material; otherwise, the mesophase material may not be reoriented in the cured epoxy. For this embodiment, the mesophase can be oriented at a lower temperature (e.g., room temperature) using a low-intensity magnetic field provided by the low viscosity of the surrounding medium (e.g., monomer solvent).

[0075] like Figure 11B As shown, when a magnetic field is applied at high temperature (above the softening point of the matrix or isotropic phase), the droplet aligns along the field, and its magnetic poles lie in a plane perpendicular to the direction of the magnetic field. Figure 11C-11D As shown, when the magnet (or sample) is rotated, the uniaxial orientation of the pointer satisfies the energy condition consistent with the magnetic anisotropy of the disk-shaped mesocrystal in the mesophase pitch.

[0076] To achieve faster orientation rates of mesophase domains or droplets along a magnetic field, the mesophase can have an average intermolecular spacing between about 3.4 and 3.7 Å (e.g., about 3.4 Å, about 3.5 Å, about 3.6 Å, about 3.7 Å) and an average molecular size (polycyclic aromatic compounds) between about 1 and 3 nm (e.g., about 1.0 nm, about 1.5 nm, about 2.0 nm, about 2.5 nm, about 3.0 nm). When the size of the mesophase domains or droplets formed by mesocrystalline properties is equal to or greater than a threshold size (e.g., 50 nm), the droplets can be rapidly oriented with an applied magnetic field, such as an applied magnetic field of about 0.1 to 10 nm. 4 Seconds (e.g., about 0.01 to 60 minutes, or about 0.01 to 30 minutes). In some embodiments, when the mesophase droplet reaches about 50 nm, the droplet can spontaneously orient itself with the applied magnetic field.

[0077] Furthermore, when the sample is subjected to a magnetic field, pyrolysis can occur at high temperatures (T). s < T 热解 The reaction is carried out at ≤475℃. This results in the formation of more mesocrystalline material, which depends on the reaction kinetics, which are a function of temperature. Subsequently, the thermodynamic transition temperature (T0) of the mesophase, which is composed of temperature-dependent viscosity, is used. 各向同性-向列相 ≥T 热解The kinetics determine mesocrystalline diffusion, nucleation, and subsequent growth into mesophase droplets. When all these conditions are met, the number density of mesophase droplets (i.e., the mesophase content) increases with time. In such cases... Figure 14B In one implementation shown, for T 热解 = 400℃, exhibiting a time-dependent relationship of mesophase content. Additionally, when materials containing a high amount of mesophase (e.g., approximately 25-50% mesophase) are subjected to a magnetic field and the temperature is at T... s <T 热解 Within the temperature range of ≤475°C (the timescale depends on the operating temperature and the chemical composition of the material under consideration), the use of the material can lead to faster orientation of the mesophase droplets. The orientation rate also depends on the magnetic anisotropy (the number of aromatic rings in the disk) and the applied field strength. For example, the higher the field strength and the higher the temperature, the faster the orientation of the mesophase can be achieved.

[0078] In composite systems ( Figure 11B-11C The mesophase bitumen fraction can be between about 20-100% by volume, wherein for the highest mesophase content, the suspension medium / matrix should have an achievable softening point, preferably close to (or less than) the softening point of the mesophase bitumen. When the mesophase content is very high (e.g., greater than about 60%), the reorientation kinetics of the mesophase structural domains (or droplets) within the medium depend only on the operating temperature (diamagnetic anisotropy) of the given composition. The field strength (B) in Equation 3 needs to be much higher than the softening point (or solid-liquid crystal transition temperature) of the mesophase, so that the viscosity is low enough for the director to reorient. However, if the mesophase pitch contains a high fraction of isotropic structural domains (e.g., greater than about 50%), once the isotropic pitch component is above its softening point, the lower viscosity imparted by the isotropic pitch matrix surrounding the mesophase material provides a sufficiently low viscosity for droplet reorientation, where the magnetic poles are perpendicular to the field axis.

[0079] The suspension medium can be a polymer resin / monomer (with or without other additives) or isotropic pitch as a solvent. The polymer resin should have a sufficiently low viscosity at the operating temperature to allow the mesophase pitch particles to orient themselves over a short timescale, and upon achieving orientation, it should be rapidly cured / polymerized to lock the particle orientation. It is possible that such a composite material of raw mesophase particles (uncarbonized) and cured resin may have significantly improved properties than pure polymers for certain non-load-bearing applications. However, for high performance, the mesophase particles may need to be graphitized to achieve high stiffness. The mesophase particles can be heat-treated (stabilized, carbonized, or graphitized) before embedding in the resin, resulting in a carbon-polymer composite material with unique anisotropic properties. Graphite particles obtained from mesophase pitch can also be incorporated into isotropic pitch materials, and after the magnetic orientation of the graphite crystal particles (utilizing their crystalline magnetic anisotropy), the matrix isotropic material can be oxidatively stabilized to lock the orientation of the graphite particles. Further heat treatment can produce carbon-carbon materials with unique anisotropic mechanical, electrical, or thermal properties. It is also possible to 3D print carbon products using a resin suspension containing mesophase pitch droplets while simultaneously subjecting them to a magnetic field at the nozzle, to obtain structures with adjustable morphologies defined by the orientation of the magnetic field lines. In a solvent / polymer suspension, droplets can be magnetically oriented and allowed to coalesce and deposit into sheet-like structures upon solvent evaporation. These structures can be graphitized to obtain larger graphite sheets for use as coatings, reinforcing layers, etc.

[0080] CNT-containing mesophase bitumen materials

[0081] As discussed in this paper, magnetic control can be implemented in other systems, such as mesophase pitch containing CNTs. CNTs also exhibit significant magnetic susceptibility anisotropy, Δχ≈10 -5 emu mol -1 If CNTs can be dispersed in a thermally induced mesophase pitch, the composite material can form two coexisting nematic states (e.g., with a CNT loading of about 3%): one formed by the mesophase pitch and the other by CNTs (once above a critical concentration). At lower CNT concentrations (e.g., below about 1%), the orientation of the CNTs will be controlled by interfacial energy (anchoring condition for the disk-like mesoporosis between the CNTs) and the magnetic anisotropy of the mesophase pitch. Because at higher concentrations (e.g., above about 3%), CNTs can also cause collective anisotropy, the orientation can be determined by the collective diamagnetic anisotropy of the CNTs and mesoporosis, as well as the anchoring effect for a given field strength. Therefore, the orientation control of CNTs can be achieved by applying an external field, such as... Figure 12As shown, a composite material containing CNTs and mesophase pitch is presented. This material will be in a nematic liquid crystal material at a softening point greater than that of the liquid crystal matrix. The orientation of the CNTs depends on the concentration and anchoring effect of the mesophase molecules at the CNT interface. After high-temperature heat treatment and orientation under a strong magnetic field, the size of the graphite domains and the orientation of the graphite basal planes in these carbonaceous pitch materials may be enhanced, leading to improved mechanical properties.

[0082] Droplet texture analysis

[0083] Due to differences in molecular orientation leading to discontinuities (pointing towards the vector) at the domain interfaces, defects or misalignments may appear in birefringent regions of liquid crystal (LC) systems, including mesophase droplets. The droplet morphology in LCs is determined by curvature strain and three Frank elastic constants (K0, K0, K0, K0). 11 K 22 and K 33 The quadratic function of ) determines the resistance that captures the intermediate phase relative unfolding, torsion, and bending deformation modes. For the intermediate phase system, the predicted K 33 >K 11 Furthermore, the K33 / K11 ratio can be reduced by introducing alkoxy side groups. The overall texture observed in each sample may also be influenced by droplet coalescence and molecular mobility (viscosity). Shear effects acting on the system during pyrolysis (volatile formation) can also affect the texture in these systems. Due to the diamagnetic anisotropy of the mesophase formed by disk-shaped mesomorphs with directional vectors pointing perpendicular to the molecular plane when mesophase pitch droplets are subjected to an external magnetic field (above a threshold), the layer plane should be oriented in the direction of the field – such that the magnetic poles (singularity regions in the mesophase droplets) are degenerately oriented in a plane perpendicular to the applied field. When the sample is heated to a temperature above the glass transition temperature T of the isotropic surrounding material. g This is expected when the softening point is above that of the mesophase droplets. The orientation of the disk-shaped mesocrystalline material in a magnetic field during pyrolysis can significantly reduce the elastic deformation imparted by the droplet interface once the droplets come into contact, thereby increasing the rate of droplet coalescence. This could have implications for material processing (e.g., carbon fiber production) with varying mesophase contents.

[0084] When subjected to concurrent fields (shear field, surface orientation, and magnetic field) during material processing, the droplet texture analysis of different feed materials in the presence of an external magnetic field has a potential impact on molecular orientation. For example... Figures 13A-13B As shown, the surface-induced orientation of disk-shaped mesoporosis can be combined with the application of a magnetic field to obtain large domain orientations in thin and thick films on supporting and sandwich films. Figure 13A As shown, if the mesomorph is oriented in a plane relative to the surface, a magnetic field can be used to induce a stronger orientation in thin or thicker films. Additionally, as... Figure 13BAs shown, surface constraints can also achieve stronger orientation. Magnetic orientation can force the disk-shaped mesocrystalline interface to orient along the field (the larger molecular axis). Furthermore, if the surface forces favor in-plane orientation, they can lead to even stronger in-plane orientation. If the disks are oriented perpendicular to the substrate interface, and if the substrate interface remains parallel to the field direction during orientation processing, a unique orientation of the disk-shaped directores of the mesophase pitch parallel to the field axis can be obtained. Subsequent heat treatments (e.g., oxidation, carbonization, and graphitization) can lead to an increase in the size of the graphite domains in the film, making these materials potentially usable for electrode or other composite material applications.

[0085] Estimation of the oriented mesophase fraction in asphalt using magnetic orientation

[0086] The mesophase fraction in bitumen can be estimated using reflective polarized light microscopy by estimating the area fraction covered by birefringent droplets or regions. Samples can be prepared by embedding them in an epoxy matrix and polishing them to obtain a mirror-smooth surface to enhance image contrast (to minimize scattering under reflection). While this surface measurement technique is industry standard, the approach to estimating the mesophase content in the bulk is not straightforward. Embodiments of this disclosure use the magnetic orientation of bitumen to estimate the mesophase fraction by the intensity contribution due to the orientation and non-orientation fractions and the peak width of reflections from molecular stacking (d(002)).

[0087] In some implementations, achieving a higher mesophase content (e.g., about 30% to 60%) Figure 14B Applying a magnetic field allows for the measurement of the bulk mesophase fraction using X-ray scattering. In such instances, isotropic portions may still exist, but the intermolecular distances are not far from the mesophase, thus allowing for bulk measurements of the mesophase content. In some embodiments, this method can also be used to measure the oriented fraction of the mesophase or the mesophase formation rate, for example, at higher temperatures (T0). s <T 热解 When pyrolyzing asphalt materials at ≤475℃, the pre-formed mesophase asphalt can be estimated for bulk mesophase content when oriented by a strong magnetic field.

[0088] Magnetically oriented samples are used for data fitting purposes. Figure 14A These are 2D data of oriented mesophase samples, which are further analyzed to obtain... Figure 14B The diagram shows the relative intensity azimuth.

[0089] Figure 14B The angular distribution of wide-angle reflections is shown, corresponding to the range of q to 1.8 Å. -1 The intermediate phase ordering peak below is modeled as the sum of Gaussian and constant components according to the following equation:

[0090] (Equation 4)

[0091] The constant C is the background scattering intensity caused by the random-oriented mesophase or isotropic structural domains (which have a more closely spaced intermolecular distance than the mesophase due to their higher aromaticity).

[0092] The contribution from the oriented or non-oriented portions should be proportional to the integral intensity of all orientations in q. The following equation can be used to estimate the contribution due to the random orientation structural domains (where I...). random Indicate I 无规 ).

[0093] (Equation 5)

[0094] The orientation is partly generated by the face-to-face correlation of the disk. For a "perfect" orientation, scattering will be a circle extending around the equator, unlike a nematic, where a perfect orientation would give a single orientation to the nematic director. Conversely, if it is in the width... A "belt" with a constant strength A can be calculated in spherical coordinates using the following method (where I...). oriented Indicate I 取向 "in radians" indicates that radians are used.

[0095]

[0096] (in degrees) (Equation 6)

[0097] (Equation 7)

[0098] The intermediate phase fraction can therefore be calculated as follows (where f meso f 中间相 ):

[0099] (Equation 8)

[0100] for Figure 14B The data shown, the intermediate phase fraction is calculated as follows: , and f 中间相 It was approximately 0.27, or approximately 27%. The mesophase fraction was found to vary along the length of the capillary during pyrolysis, with a larger mesophase content obtained towards the bottom of the capillary, such as... Figures 15A-15BAs shown. This may be due to the higher density of the mesophase material compared to the isotropic part. This approach can also be extended to shear-oriented (spun) mesophase pitch fibers to estimate the fraction of the mesophase oriented along the fiber axis in the as-spun fiber, as well as the changes due to further upstream high-temperature processing (such as carbonization and graphitization).

[0101] Figure 15A The orientation quality is provided as a function of the depth (vertical axis) in the direction of the magnetic field axis for a given annealing time (horizontal axis). Figure 15B The bulk mesophase fraction estimated by Equation 8 (above) is shown for different heights along the capillary. The highest mesophase content is observed near the bottom of the capillary. The data points represented by stars indicate the bulk mesophase content obtained by measurement with cross-polarized light microscopy, where the samples were prepared in a high-temperature oven operating in a N2 atmosphere, so the sample preparation conditions for the subsequent samples are different.

[0102] Mesophase Orientation Applications

[0103] Figure 16 Examples of schemes for inducing the orientation of mesophase molecules in articles (such as fibers) during different applications, such as extrusion or 3D printing, are provided. As shown, a magnet (with a north pole (N) and a south pole (S)) can be configured at the spinneret exit or output point of an extruder. Thus, when an asphalt filament containing mesophase molecules exits the extruder or spinneret (for example, air flows in a direction perpendicular to the extrusion direction), the orientation of the mesophase molecules can be achieved in the presence of an applied magnetic field.

[0104] Additional Embodiments <00004​​​​​​​​​​​​oriented through the magnetic field within seconds.

[0107] Embodiment 3. The material according to any one of Embodiments 1-2, wherein the portion of the mesophase pitch material is oriented through the magnetic field within about 0.01 to 30 minutes of applying the magnetic field.

[0108] Embodiment 4. The material according to any one of Embodiments 1-3, wherein the microcarbon residue test (MCRT) of the material is greater than about 40%.

[0109] Embodiment 5. The material according to any one of Embodiments 1-4, wherein the composition further comprises a matrix phase and a plurality of mesophase droplets suspended in the matrix phase, and wherein the plurality of mesophase droplets are configured to be oriented through the magnetic field, wherein the magnetic field is applied statically, by rotating a central magnetic field, or by rotating the material.

[0110] Embodiment 6. The material according to any one of Embodiments 1-5, wherein the composition further comprises one or more of a carbon / carbon composite material, a carbon / polymer composite material, a carbon nanotube (CNT) composite material, or a combination thereof.

[0111] Embodiment 7. A lithium-ion battery anode comprising the material according to any one of Embodiments 1-6.

[0112] Embodiment 8. The material according to any one of Embodiments 1-7, wherein the composition has a molecular weight of about 200 to 2000 g / mol.

[0113] Embodiment 9. A method of controlling the orientation of mesogenic molecules in a composition, the method comprising: providing a composition comprising a mesophase pitch material, the mesophase pitch material comprising from about 5.0% to 100.0% and having a viscosity of about 0.01 to 10 s <in a temperature range of T ≤ 475 °C, where T 2 ≥ 150 °C, and applying a magnetic field of about 0.25 to 6.0 tesla to the composition, thereby causing at least a portion of the mesophase pitch material to be oriented through the magnetic field within about 0.1 second to 10 s <seconds, wherein the portion of the mesophase pitch material comprises a plurality of mesophase droplets having a minimum droplet diameter of about 50 nanometers (nm). 4 s

[0114] Embodiment 10. The method according to Embodiment 9, wherein the magnetic field is about 1.0 tesla, and wherein the magnetic field is applied at a temperature of about T s < T ≤ 475 °C.

[0115] Embodiment 11. The method according to any one of Embodiments 9-10, wherein the portion of the mesophase pitch material is oriented by the magnetic field for about 0.01 to 30 minutes.

[0116] Embodiment 12. The method according to any one of Embodiments 9-11, wherein the microcarbon residue test (MCRT) of the composition is greater than about 40%.

[0117] Embodiment 13. The method according to any one of Embodiments 9-12, wherein applying the magnetic field allows measurement of the bulk mesophase fraction or the oriented mesophase fraction using two-dimensional X-ray scattering.

[0118] Embodiment 14. The method according to any one of Embodiments 9-13, wherein applying the magnetic field allows optimization of the mesophase domains or droplet sizes of the mesophase pitch material.

[0119] Embodiment 15. The method according to any one of Embodiments 9-14, wherein applying the magnetic field is in a shear zone, resulting in control of one or more fibrous properties of the composition.

[0120] Embodiment 16. A material comprising: a composition comprising a mesophase pitch material, the mesophase pitch material comprising from about 5.0% to 95.0% and having a viscosity of about 0.01 to 10 2 pascal seconds (Pa·s), wherein at least a portion of the mesophase pitch material is oriented by the magnetic field in the presence of a magnetic field of about 0.5 tesla to 2.0 tesla at a temperature of about T s <T≤450 °C and within about 0.1 seconds to 50 minutes, where T s ≥150 °C.

[0121] Embodiment 17. The material according to Embodiment, wherein the portion of the mesophase pitch material is oriented by the magnetic field for about 0.01 to 30 minutes.

[0122] Embodiment 18. The material according to any one of Embodiments 16-17, wherein the microcarbon residue test (MCRT) of the material is greater than about 40%.

[0123] Embodiment 19. The material according to any one of Embodiments 16-18, wherein the composition further comprises a matrix phase and a plurality of mesophase droplets suspended in the matrix phase, and wherein the plurality of mesophase droplets are configured to be oriented by the magnetic field, wherein when the magnetic field is applied statically, by rotating the central magnetic field, or by rotating the material.

[0124] Implementation Scheme 20. The material according to any one of Implementation Schemes 16-19, wherein applying the magnetic field and utilizing surface orientation allow for increased molecular ordering of the material, and increased graphite domain size of the material after stabilization, carbonization and graphitization.

[0125] Certain features have been described using a set of upper and lower numerical limits. It is self-evident that a range from any lower limit to any upper limit should be considered, unless otherwise stated. Some lower limits, upper limits, and ranges appear in one or more of the following claims. All numerical values ​​take into account experimental errors and biases that would be expected by someone skilled in the art.

[0126] The various terms have been defined above. If a term used in the claims is not defined above, it should be given the broadest definition possible, as those skilled in the art will know that the term is reflected in at least one printed publication or issued patent. Furthermore, all patents, experimental procedures, and other documents cited in this application are consistent with the present invention and are fully incorporated herein by reference to the extent permitted by all rights.

[0127] The foregoing description of this disclosure illustrates and describes the method. Additionally, exemplary methods are shown and described in this disclosure; however, it should be understood that various other combinations, modifications, and environments may be employed, and the method can be changed or modified within the scope of the concepts expressed herein, commensurate with the foregoing teachings and / or skills or knowledge in the relevant fields.

Claims

1. Materials, including: A composition comprising a mesophase pitch material, said mesophase pitch material being present in an amount of from about 5.0% to 95.0% and having a viscosity of from about 0.01 to 10 s Pascal seconds (Pa·s) in the temperature range of about T 2 <T ≤ 475 °C, where T s ≥ 150 °C, At least a portion of the mesophase bitumen material is oriented by a magnetic field having a strength of about 0.25 to 6.0 Tesla, and The mesophase pitch material has an average intermolecular spacing of about 3.4 to 3.7 angstroms and an average molecular size of about 1 to 3 nanometers (nm).

2. The material of claim 1, wherein the magnetic field is about 1.0 Tesla, and wherein the portion of the mesophase pitch material has a minimum droplet diameter of about 50 nm, and at about T s At temperatures < T≤450℃ and with the magnetic field applied for approximately 0.1 to 10 4 Oriented by the magnetic field within seconds.

3. The material of claim 1, wherein the portion of the mesophase pitch material is oriented by the magnetic field for about 0.01 to 30 minutes after the magnetic field is applied.

4. The material of claim 1, wherein the microcarbon slag test (MCRT) of the material is greater than about 40%.

5. The material of claim 1, wherein the composition further comprises a matrix phase and a plurality of intermediate phase droplets suspended in the matrix phase, and wherein the plurality of intermediate phase droplets are configured to be oriented by the magnetic field, wherein the magnetic field is applied statically, by a rotating central magnetic field, or by rotating the material.

6. The material of claim 1, wherein the composition further comprises one or more of carbon / carbon composite materials, carbon / polymer composite materials, carbon nanotube (CNT) composite materials, or combinations thereof.

7. A lithium-ion battery anode comprising the material of claim 1.

8. The material of claim 1, wherein the composition has a molecular weight of about 200 to 2000 g / mol.

9. A method for controlling the orientation of mesocrystalline molecules in a composition, the method comprising: Provided is a composition comprising a mesophase pitch material, the mesophase pitch material accounting for about 5.0% to 100.0% and having a viscosity of about 0.01 to 10 s Pascal seconds (Pa·s) within a temperature range of about T 2 <T ≤ 475 °C, where T s ≥ 150 °C, and A magnetic field of about 0.25 to 6.0 Tesla is applied to the composition, thereby causing at least a portion of the mesophase pitch material to be in a magnetic field of about 0.1 to 10 Tesla. 4 Oriented by the magnetic field within seconds. The portion of the mesophase pitch material comprises a plurality of mesophase droplets having a minimum droplet diameter of about 50 nanometers (nm).

10. The method of claim 9, wherein the magnetic field is about 1.0 Tesla, and wherein the magnetic field is applied at about T s The experiment was conducted at a temperature of T≤475℃.

11. The method of claim 9, wherein the portion of the mesophase bitumen material is oriented by the magnetic field for about 0.01 to 30 minutes.

12. The method of claim 9, wherein the composition has a microcarbon slag test (MCRT) of more than about 40%.

13. The method of claim 9, wherein applying the magnetic field allows for the measurement of the bulk intermediate phase fraction or the directed intermediate phase fraction using two-dimensional X-ray scattering.

14. The method of claim 9, wherein applying the magnetic field allows for optimization of the mesophase structural domains or droplet size of the mesophase pitch material.

15. The method of claim 9, wherein the magnetic field is applied in a shear zone, resulting in control of one or more fibrous properties of the composition.

16. Materials, including: A composition comprising mesophase bitumen material, wherein the mesophase bitumen material comprises about 5.0% to 95.0% and has a content of about 0.01% to 10%. 2 Viscosity in Pascals Seconds (Pa.s) At least a portion of the mesophase pitch material is oriented through the magnetic field in the presence of a magnetic field of from about 0.5 tesla to 2.0 tesla at a temperature of from about T s <T ≤ 450 °C and within from about 0.1 seconds to 50 minutes, where T s ≥ 150 °C.

17. The material of claim 16, wherein the portion of the mesophase pitch material is oriented by the magnetic field for about 0.01 to 30 minutes.

18. The material of claim 16, wherein the microcarbon slag test (MCRT) of the material is greater than about 40%.

19. The material of claim 16, wherein the composition further comprises a matrix phase and a plurality of intermediate phase droplets suspended in the matrix phase, and wherein the plurality of intermediate phase droplets are configured to be oriented by the magnetic field, wherein the magnetic field is applied statically, by a rotating central magnetic field, or by rotating the material.

20. The material of claim 16, wherein applying the magnetic field, together with utilizing surface orientation, allows for increased molecular order of the material and the size of the graphite domains of the material after graphitization.

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