Methods for analyzing the structure of a substance

Abstract

This provides a simple structural analysis method that can contribute to elucidating the correlation between structural properties. [Solution] A method for analyzing the structure of a material, comprising the steps of: a computer performing structural optimization of an analytical model having multiple conjugated planar structures; calculating the interplanar distance between any conjugated planar structure of the analytical model after the structural optimization and the other conjugated planar structures; and calculating the distribution of the interplanar distances obtained by the interplanar distance calculation.

Description

Technical Field

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[0001] The present invention relates to a method for a computer to analyze the structure of a substance using an analysis model.

Background Art

[0002] Conventionally, research has been underway to elucidate the structure-property correlations of various substances, and various methods have been utilized as methods for obtaining the structure information of substances. For example, analysis of the structure information of substances has been advanced by utilizing X-ray scattering methods such as small-angle X-ray scattering (SAXS) and medium-angle X-ray scattering (MAXS). For example, cases where the small-angle X-ray scattering method has been utilized to clarify the structure-property correlations of substances such as styrene-butadiene rubber have been reported (Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to further promote the elucidation of the structure-property correlations of various substances, a simpler method is required compared to conventional structure analysis methods. The present invention has been made in view of the above circumstances, and an object thereof is to provide a simple structure analysis method that can contribute to the elucidation of structure-property correlations.

Means for Solving the Problems

[0005] The gist of the present invention is as follows [1] to [5]. [1] A method for analyzing the structure of a substance, The computer performs the following steps: optimizes the structure of an analytical model having multiple conjugated surface structures; calculates the inter-surface distance between any conjugated surface structure of the analytical model after the structural optimization and the other conjugated surface structures; and calculates the distribution of the inter-surface distances obtained from the inter-surface distance calculation. A method for analyzing the structure of a substance. [2] The process includes the steps of: calculating the normal angle between the normal of an arbitrary conjugate system surface structure and the normal of another conjugate system surface structure in the analytical model for which the above structural optimization has been performed; and calculating the distribution of the normal angles obtained from the above normal angle calculation. A method for analyzing the structure of the substance described in [1]. [3] A method for analyzing the structure of a substance as described in [1] or [2], wherein the analytical model described above is an analytical model having multiple planar structures of a cyclic conjugated system. [4] A method for analyzing the structure of a substance, as described in any of [1] to [3], used for analyzing the relationship between the structure and physical properties of a substance. [5] A method for analyzing the structure of any of the substances described in [1] to [4], used in a method for analyzing the correlation between an adhesive and the physical properties of the above-mentioned adhesive. [Effects of the Invention]

[0006] According to the present invention, a simple structural analysis method can be provided.

[0007] Specifically, the present invention provides a simple analysis method that can replace conventional structural analysis methods when elucidating structural property correlations.

[0008] In detail, according to one embodiment of the present invention, structural analysis can be performed by a simpler method compared to, for example, performing structural analysis using X-ray scattering methods such as small-angle X-ray scattering (SAXS). According to one embodiment of the present invention, it is excellent in that it can promote the elucidation of structural-physical-property relationships of various materials and contribute to the establishment of design guidelines for various materials. [Brief explanation of the drawing]

[0009] [Figure 1] This flowchart shows an example of the processing procedure for an analysis method according to one embodiment of the present invention. [Figure 2] This figure shows an example of an analytical model used in the analytical method according to one embodiment of the present invention. [Figure 3] This figure illustrates an example of an analysis method relating to one embodiment of the present invention. [Figure 4] This figure illustrates an example of an analysis method relating to one embodiment of the present invention. [Figure 5] This figure shows the measurement results of small-angle X-ray scattering (SAXS) related to one embodiment of the present invention. [Figure 6] This figure illustrates an example of an analysis method relating to one embodiment of the present invention. [Figure 7] This figure illustrates an example of an analysis method relating to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] In this specification, "x and / or y (where x, y are any configuration)" means at least one of x and y, and can mean x only, y only, or x and y.

[0011] An analysis method according to one embodiment of the present invention (hereinafter sometimes referred to as "this analysis method") is a method for analyzing the structure of a material, characterized in that a computer performs the steps of: optimizing the structure of an analysis model having a plurality of conjugated planar structures; calculating the interplanar distance between any conjugated planar structure of the analysis model on which the structural optimization calculation has been performed and other conjugated planar structures; and calculating the distribution of the interplanar distances.

[0012] From the perspective of further promoting research to elucidate the structure-property correlation and establish new guidelines for structural design, the inventors have intensively studied a simple method that can replace the conventional structural analysis method. In the process of repeated such studies, the inventors focused on the inter-plane distance of the analysis model having a surface structure of a conjugate system that constitutes a stable arrangement, among the analysis methods using an analysis model by CAE (Computer Aided Engineering), and found that a simple analysis method that can replace the conventional structural analysis method can be provided by obtaining the distribution information of the inter-plane distance.

[0013] For example, the inventors obtained a new finding that the distribution of the inter-plane distance of the surface structure of the conjugate system in the above analysis model coincides with the peak of the three-dimensional structure obtained by the X-ray scattering method or the like of the actual object corresponding to the analysis model. Specifically, the inventors have found that, for example, the peak of the three-dimensional structure (scattering region derived from benzene ring) shown in the profile obtained by the analysis of phenolic resin using the small-angle X-ray scattering method (SAXS) coincides with the information obtained by the distribution calculation of the inter-plane distance obtained by this analysis method. And since the peak area of the three-dimensional structure of phenolic resin using the small-angle X-ray scattering method (SAXS) is correlated with the adhesive strength, and the adhesive strength tends to increase as the peak area increases, based on the information obtained by the inter-plane distance distribution calculation by this analysis method, the correlation analysis between the structure of phenolic resin and the adhesive strength, etc. can be easily performed. In addition to the small-angle X-ray scattering method (SAXS), the present invention can be effectively utilized as a simple analysis method that can replace, for example, X-ray analysis methods (XRD) such as wide-angle X-ray scattering method (WAXS) and ultrasmall-angle X-ray scattering method (USAXS), and Raman analysis method, etc., and various structure correlation analyses can be easily performed.

[0014] Hereinafter, the embodiments of the present invention will be described in more detail.

[0015] FIG. 1 is a flowchart showing an example of the main processing procedure of this analysis method. This analysis method includes a step S1 of optimizing the structure of an analysis model having a plurality of conjugated surface structures, a step S2 of calculating the surface-to-surface distance between an arbitrary conjugated surface structure of the analysis model for which the above structure optimization calculation has been performed and another conjugated surface structure, and a step S3 of calculating the distribution of the above surface-to-surface distances. Note that this analysis method is not limited to the content of this flowchart.

[0016] Each step shown in FIG. 1 is executed by a computer. The computer is the same as those used in conventional CAE (Computer Aided Engineering). This analysis method is usually executed by software and hardware cooperating to execute a processing routine stored in advance in an information processing device such as a personal computer provided with an arithmetic processing unit (CPU), ROM, working memory, a storage device such as a magnetic disk, an input device such as a keyboard and a mouse, a display device such as a display, etc.

[0017] <Step S1> This analysis method includes a step S1 in which a computer performs a structure optimization calculation of an analysis model having a plurality of conjugated surface structures.

[0018] The analysis model in this analysis method is, like a known analysis model, an analysis model composed of a plurality of unit elements that can be numerically analyzed by a computer in a virtual model creation area, and is created according to a known method.

[0019] The analysis model includes a predetermined atomic model or molecular model and is created in an arbitrary model creation area. The arbitrary model creation area is the entire area where periodic boundary conditions are defined, or a partial area having an arbitrary shape extracted from the area where periodic boundary conditions are defined, or a partial area having an arbitrary shape extracted from a space where periodic boundary conditions are not defined, etc.

[0020] The analytical model used in this analysis method only needs to contain information about the types of atoms constituting the planar structure of the conjugated system and information about the positional relationships between those atoms, so that it can be processed by a computer. It can be created using commercially available model creation software, with the necessary parameters set as appropriate.

[0021] This analytical method uses an analytical model that has multiple conjugated planar structures. A conjugated planar structure refers to a planar structure formed by a group of conjugated atoms, and a planar structure formed by a group of conjugated atoms and atoms bonded to it. A conjugated system is a system in which two or more multiple bonds are conjugated. The π electrons in the multiple bonds interact and are delocalized via single bonds. A conjugated planar structure is, for example, a structure in which double bonds and / or triple bonds are connected by single bonds, atoms with lone pairs of electrons, or atoms with empty p orbitals.

[0022] Specifically, examples include isoprene, butadiene, chloroprene, and monocyclic, fused, and polycyclic structures such as benzene. Specifically, examples include fused structures such as naphthalene, anthracene, tetracene, pentacene, phenanthrene, pyrene, chrysene, perylene, and coronene, and polycyclic structures such as biphenyl, terphenyl, tetraphenyl, binaphthyl, and bianthranil.

[0023] The analytical model used in this analysis method is not particularly limited as long as it has a conjugated planar structure, but for example, one having a cyclic conjugated planar structure is preferred. Furthermore, the analytical model in this analysis method may be an analytical model corresponding to an adhesive having multiple conjugated surface structures, and more specifically, it may be an analytical model corresponding to a phenolic resin having multiple conjugated surface structures. More specifically, examples include resol-type phenolic resins having multiple conjugated surface structures.

[0024] Optimization calculations are performed as appropriate using known methods. Specifically, for example, the energy of the constructed analytical model is determined, and calculations are performed to move atoms and electrons in a more stable direction based on the energy gradient. By performing optimization calculations, the three-dimensional structure in which each atomic model constituting the analytical model exists stably is determined.

[0025] Optimization calculations are performed as appropriate by known methods, such as first-principles calculations. Examples of first-principles calculations include computational methods that use only the atomic number as an input parameter and make abject predictions of physical mechanisms, etc., based on quantum mechanics (first principles), which is the fundamental law of matter at the atomic and nanoscale levels. The total energy and electron energy band structure of a model containing atoms with known atomic numbers and spatial coordinates are determined, the forces acting on the atoms are calculated from the total energy values, and the structure is optimized.

[0026] Specifically, although not limited to the following, general first-principles calculation procedures described in literature such as "Hiroyuki Kageshima, Basic Lectures on First-Principles Calculation Methods I, Applied Physics, Vol. 75, No. 10, p. 1258 (2006)" can be applied, and these calculation procedures can be executed using a predetermined program.

[0027] <Step S2> This analysis method includes step S2, in which a computer calculates the inter-plane distance between any conjugate system surface structure and other conjugate system surface structures in the analysis model. Specifically, for example, first the surface structures constituting the analysis model are identified. Next, the three-dimensional coordinates of each surface structure constituting the analysis model are calculated, and the inter-plane distance is calculated based on these three-dimensional coordinates. Specifically, although not limited to the following, for example, the centroid coordinates are calculated from the three-dimensional coordinates of the surface structure of the conjugated system that constitutes the analytical model, and the straight-line distance between the centroid coordinates of any conjugated system surface structure and the surface structure of another conjugated system is calculated.

[0028] The inter-plane distance calculation in this analysis method can be appropriately set according to the analysis target and purpose. For example, it can be a calculation targeting the surface structures of all conjugated systems constituting the analysis model, or a calculation targeting the surface structures of some conjugated systems.

[0029] <Step S3> This analysis method includes Step S3 in which a computer performs distribution calculation of the inter-plane distances obtained by the above inter-plane distance calculation. For example, calculate the frequency for each predetermined inter-plane distance interval. Specifically, but not limited to the following, for example, steps of setting a plurality of intervals step by step, such as an interval where the inter-plane distance is equal to or greater than a1 and less than a2 (a1 < a2), an interval where it is equal to or greater than a2 and less than a3 (a2 < a3), an interval where it is equal to or greater than a3 and less than a4 (a3 < a4), and steps of calculating the frequency corresponding to each interval can be mentioned.

[0030] The setting of the inter-plane distance intervals is not limited to the above, and can be appropriately set according to the analysis target and purpose. For example, at least two or more intervals can be set within the range of the minimum value and the maximum value of each inter-plane distance obtained by the inter-plane distance calculation in Step S2, and the frequency in each interval can be calculated. Also, for example, but not limited to the following, for example, intervals of 10 to 30, intervals of 15 to 20 can be set.

[0031] In Steps S2 and S3, for example, ranks can be determined for the surface structures (P2, P3, P4...) of other conjugated systems with respect to the surface structure (P1) of an arbitrary conjugated system, and calculations can be performed only on the surface structures of conjugated systems within a predetermined rank. For example, ranks can be determined according to the distance from the surface structure (P1) of an arbitrary conjugated system, and the distances to the surface structures of conjugated systems within a predetermined rank can be calculated. Specifically, for example, the order of the surface structures of other conjugated systems can be determined in ascending order of the inter-plane distance from the surface structure (P1) of an arbitrary conjugated system (P2 < P3 < P4...), and the inter-plane distances to the surface structures of conjugated systems within an arbitrary rank can be calculated. Or, those that satisfy the condition that the inter-plane distance between the surface structure (P1) of an arbitrary conjugated system and the surface structures (P2, P3, P4...) of other conjugated systems is within or less than a specific value can be used as the calculation targets.

[0032] <Other steps> In addition to the above steps S1 to S3, etc., this analysis method may include any arbitrary steps. For example, this analysis method may include a step of calculating the angle between the normal vectors of the surface structures of any conjugate system and the normal vectors of the surface structures of other conjugate systems in the analysis model where structural optimization has been performed, and a step of calculating the distribution of the angles between the normal vectors obtained by the above calculation of the angles between the normal vectors. Specifically, for example, first, a normal vector is calculated based on the three-dimensional coordinates of the surface structure of the conjugate system. The normal vector is a vector perpendicular to the plane. Next, the angle formed by the normal vector of the surface structure of the conjugate system and the normal vector of the surface structure of another conjugate system is calculated.

[0033] In addition, in the step of calculating the angle between the normal vectors, for example, rankings may be determined for the surface structures of other conjugate systems (P2, P3, P4...) with respect to the surface structure of any conjugate system (P1), and the calculation may be targeted only at the surface structures of conjugate systems within a predetermined ranking. For example, rankings may be determined according to the distance from the surface structure of any conjugate system (P1), and the angle between the normal vectors with the surface structures of conjugate systems within a predetermined ranking may be calculated. Specifically, for example, the order of the surface structures of other conjugate systems may be determined in ascending order of the surface-to-surface distance from the surface structure of any conjugate system (P1) (P2 < P3 < P4...), and the angle between the normal vectors with the surface structures of conjugate systems within an arbitrary ranking may be calculated. Alternatively, those that satisfy the condition that the surface-to-surface distance between the surface structures of other conjugate systems (P2, P3, P4...) with respect to the surface structure of any conjugate system (P1) is within or less than a specific value may be targeted for calculation.

[0034] In addition, for example, this may include a step of comparing the distribution information obtained by calculating the distribution of surface-to-surface distances in the analysis model with the structural analysis information measured using the actual object corresponding to the analysis model. The structural information measured using the actual object is the measurement information obtained by structural analysis using the actual object corresponding to the analysis model. Specifically, for example, it is a profile obtained by structural analysis using an X-ray scattering method such as the small-angle X-ray scattering method (SAXS).

[0035] <Structural-Physical Correlation Analysis> This analysis method is suitably used to analyze the correlation between the structure and physical properties of a material. For example, this method allows for the analysis of the correlation between structure and physical properties based on information obtained from the calculation of the distribution of interplane distances. For instance, as mentioned above, using the analysis of a phenolic resin (resol type) by small-angle X-ray scattering (SAXS) as an example, the peak area of ​​the three-dimensional structure (scattering region derived from the benzene ring) shown in the SAXS profile correlates with adhesive strength, with the adhesive strength increasing as the peak area increases. Since the information obtained from the interplane distance distribution calculation obtained by this analysis method tends to coincide with the said peak area, the correlation with physical properties (adhesive strength) can be analyzed based on the interplane distance distribution calculation. From this viewpoint, this analysis method is suitably used, for example, to analyze the correlation between adhesives such as phenolic adhesives and the physical properties of the aforementioned adhesives. Furthermore, this analysis method is not limited to the above, and can also be suitably used, for example, in methods for analyzing the structural-physical property correlation of various rubber materials and resin materials.

[0036] <Simulation Method> This analysis method may include, for example, a step of creating a dataset that includes the inter-plane distance and / or inter-normal angle of the analysis model as explanatory variables. Alternatively, it may include a step of creating a dataset that uses the inter-plane distance and / or inter-normal angle of the analysis model as explanatory variables and includes physical properties such as adhesive force as the objective variable. In one embodiment of the present invention, it can also be suitably implemented as a simulation method that includes the step of performing machine learning based on the aforementioned dataset and constructing a material property prediction model.

[0037] <Structural analysis device for analyzing the structure of materials> Furthermore, one embodiment of the present invention is a structural analysis device that analyzes the structure of a material using software that performs each of the above steps. Specifically, for example, this is a structural analysis device that analyzes the structure of a material using software that performs the steps of: optimizing the structure of an analysis model having multiple conjugated planar structures; calculating the interplanar distance between any conjugated planar structure of the analysis model on which the structural optimization calculation has been performed and other conjugated planar structures; and calculating the distribution of the interplanar distances. [Examples]

[0038] Next, the present invention will be described based on examples. However, the present invention is not limited to these examples.

[0039] The substance analyzed in this embodiment is a resol-type phenolic resin. First, based on the above phenolic resin, an optimized three-dimensional analysis model was created using commercially available analysis model creation software (Gaussian09w) based on first-principles calculations (Figure 2).

[0040] Next, the planar structure P (six-membered ring) included in the three-dimensional analysis model was identified (Figure 3), and the interplanar distance of this planar structure P was calculated. Specifically, using Python (including numpy, pandas, etc.), an ID was assigned to each atom constituting the three-dimensional analysis model, and for each structural unit (six-membered ring) to be analyzed, an ID was assigned indicating which structural unit each atom belongs to. Based on the structural unit ID and three-dimensional coordinates, the centroid coordinates of the structural unit were calculated. Then, the distance from the centroid coordinates of any structural unit to the centroid coordinates of other structural units was calculated. The pairs of unit IDs for which the distances were calculated were recorded.

[0041] This embodiment is a three-dimensional analysis model having 13 six-membered rings, and the total number of inter-plane distance measurements is 78 (13C2=78).

[0042] Next, the distribution of inter-plane distances for the plane structure P (six-membered ring) was calculated (Figure 4). Figure 4 is a histogram output of the distribution calculation results, with the horizontal axis showing inter-plane distance and the vertical axis showing frequency. The interval (bin) on the horizontal axis was set to 2 Å.

[0043] Next, small-angle X-ray scattering (SAXS) was performed on resol-type phenolic resins under the following conditions. The results are shown in Figure 5. In Figure 5, the vertical axis represents the scattering intensity, and the horizontal axis represents the scattering vector q. [Measurement conditions for small-angle X-ray scattering (SAXS)] Measurement: BL8S3 (Aichi Synchrotron Radiation Center) ·X-ray wavelength: 0.92Å • Detector: PILATUS 2M Camera length: 240mm • Exposure time: 60 seconds From the two-dimensional data obtained from the SAXS measurement, a one-dimensional SAXS profile is obtained by taking an annular average. In the log-log plot of the scattering vector and scattering intensity of this SAXS profile, peaks appearing in the range of q values ​​from 5 to 30 are fitted with a linear baseline and a pseudo-Voigt function to calculate the peak area of ​​the three-dimensional structure.

number

[0044] In the above formula, q represents the magnitude of the scattering vector, λ represents the wavelength of the incident X-ray, and θ represents the scattering angle.

[0045] As shown in Figures 4 and 5, it was confirmed that the peak of the interplane distance of the planar structure P (six-membered ring) coincides with the peak of the three-dimensional structure obtained by SAXS measurement. This indicates that the analytical method of the present invention can contribute to establishing guidelines for predicting the physical properties of the higher-order structure of a material without actually performing structural analysis (such as SAXS).

[0046] Next, the distribution of the normal angles was calculated (Figure 6). The normal angle of a surface structure P (six-membered ring) is the normal angle formed by the normal vector of the surface structure (indicated by arrows in Figure 3) and the normal vector of any other arbitrary surface structure (indicated by arrows in Figure 3). In Figure 6, the horizontal axis shows the normal angle, and the vertical axis shows the frequency. This embodiment is an analytical model with 13 six-membered rings, and the total number of measured inter-ring angles is 78 (13C2=78).

[0047] Figure 7 shows the relationship between the inter-plane distance and the inter-normal angle of a planar structure P (six-membered ring), with the vertical axis representing the inter-plane distance and the horizontal axis representing the inter-normal angle. By examining the relationship between the inter-plane distance and the inter-normal angle, it can be seen, for example, that the inter-normal angle between six-membered rings that are close together is close to 90 degrees. By examining both the inter-plane distance and the inter-normal angle of six-membered rings, it can be seen that it is possible to contribute to establishing guidelines for predicting the physical properties of the higher-order structure of a material. [Industrial applicability]

[0048] According to the present invention, a simpler structural analysis method can be provided, facilitating the analysis of structural-physical-property correlations and contributing to the establishment of design guidelines for various materials such as adhesives, making it extremely useful.

Claims

1. A method for analyzing the structure of a substance, The computer performs the following steps: optimizes the structure of an analytical model having multiple conjugated surface structures; calculates the inter-surface distance between any conjugated surface structure of the analytical model after the structural optimization and the other conjugated surface structures; and calculates the distribution of the inter-surface distances obtained from the inter-surface distance calculation. A method for analyzing the structure of a substance.

2. The process includes the steps of: calculating the normal angle between the normal of an arbitrary conjugate system surface structure and the normal of another conjugate system surface structure in the analytical model for which the above structural optimization has been performed; and calculating the distribution of the normal angles obtained from the above normal angle calculation. A method for analyzing the structure of the substance described in claim 1.

3. A method for analyzing the structure of a substance according to claim 1 or 2, wherein the analytical model described above is an analytical model having multiple planar structures of a cyclic conjugated system.

4. A method for analyzing the structure of a substance according to claim 1 or 2, used in a method for analyzing the correlation between the structure and physical properties of a substance.

5. A method for analyzing the structure of a substance according to claim 1 or 2, used in a method for analyzing the correlation between an adhesive and the physical properties of the adhesive.

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