Modeling method for ultrafine diamond nanowire functionalization

Abstract

The invention discloses a superfine diamond nanowire functionalization modeling method which comprises the following steps: establishing a functional group molecular model, and calculating a functional group space coordinate transformation parameter equation; establishing a periodic unit cell model of the superfine diamond nanowire; establishing a superfine diamond nanowire model, and transforming atomic coordinates of the superfine diamond nanowire model to an original point; selecting a functionalized area on the superfine diamond nanowire model, selecting random functionalization sites through random numbers, and excluding adjacent functionalization sites; calculating a coordinate transformation matrix based on the functionalization sites to obtain corresponding functional group molecule coordinates; and integrating topological information of the functionalized superfine diamond nanowire model. According to the method, the surface functional groups of the diamond nanowires are accurately positioned and controlled, quantitative research of the functional groups on the performance of one-dimensional nanomaterials and quantitative research of the functionalized one-dimensional nanomaterials on the performance of modified materials are facilitated, and the intrinsic mechanism of the micro scale is analyzed.

Description

Technical Field

[0001] The invention relates to the field of low-dimensional nano material modeling and atomic scale simulation, and in particular to a modeling method for functionalization of ultrafine diamond nanothreads. Background Art

[0002] Low-dimensional nanomaterials, especially carbon nanomaterials, have shown great application potential in the fields of microelectronics, aerospace, civil engineering, national defense, etc. due to their unique structure and excellent physical and chemical properties. Nanowires, as an important one-dimensional nanomaterial, are not only an important component unit of advanced nanodevices, but also can be used as additive phases to greatly enhance or regulate the properties of traditional materials, such as mechanical, thermal and electrical properties. In order to further improve the performance of one-dimensional nanomaterials or to exert their excellent performance as additive phases, functionalization is a commonly used modification strategy. For the application of nano additive phases, one-dimensional nanomaterials modified by functionalization can effectively avoid their aggregation due to surface effects, and at the same time can strengthen their interface strength with the matrix material or reduce the interface thermal resistance, thereby better exerting the performance of the nano additive phase.

[0003] At present, researchers have introduced a variety of functional group types into one-dimensional nanomaterials, such as methyl (-CH3), ethyl (-C2H5), phenyl (-C6H5), etc. However, due to the random positions of functional groups in different one-dimensional nanomaterials and differences in functionalization during the experiment, it is difficult to conduct quantitative research on the effects of functional groups on the performance of one-dimensional nanomaterials, and the effects of functionalized one-dimensional nanomaterials on the performance of modified materials from an experimental perspective. Atomic-scale simulation, starting from the nanoscale model, can effectively make up for this deficiency and analyze the intrinsic mechanism at the microscale. The primary challenge of atomic-scale simulation is the controllable modeling of one-dimensional nanomaterials. Although there are atomic-scale simulations to explore the performance of functionalized one-dimensional nanomaterials, the selection of functional group sites for different works is usually manually and randomly selected, which makes it difficult to standardize the comparison and explore the effects of functional groups. Therefore, it is very necessary to establish a standardized controllable modeling method for the functionalization of one-dimensional nanomaterials. Summary of the invention

[0004] In view of the lack of controllable modeling methods for functionalization of existing one-dimensional carbon nanomaterials, the present invention provides a modeling method for functionalization of ultrafine diamond nanowires. The specific technical scheme is as follows:

[0005] A modeling method for functionalization of ultrafine diamond nanowires, comprising the following steps:

[0006] S1: Establish a functional group molecular model, and establish the rotation matrix, translation matrix and spatial coordinate transformation parameter equation of the orientation factor according to the coordinates of the functional group model;

[0007] S2: establishing a periodic unit cell model of the ultrafine diamond nanowire, and numbering the carbon atoms and hydrogen atoms in the unit cell model in a clockwise direction;

[0008] S3: Based on the principal coordinate direction of the periodic unit cell model of the ultrafine diamond nanowire, the length of the diamond nanowire is pre-set, an ultrafine diamond nanowire model of the required length is established, and the carbon and hydrogen atomic coordinates of the ultrafine diamond nanowire model are respectively placed into two arrays; then the bottom center of the ultrafine diamond nanowire model is transformed to the origin of the coordinate system, and the length direction is along the principal coordinate direction of the coordinate system;

[0009] S4: Based on the converted carbon atom coordinates of the ultrafine diamond nanowire model, the site area for adding functional groups and the ratio of the number of functional groups are set, while excluding unreasonable functional group addition sites, and finally integrating all carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model to obtain the topological information of the overall functionalization model.

[0010] Furthermore, the step S4 comprises:

[0011] S41: selecting a pseudo-functionalized region according to simulation requirements; storing the carbon and hydrogen atom coordinates of the pseudo-functionalized region into a functionalized region carbon atom array and a corresponding hydrogen atom array;

[0012] S42: Calculating the total number of functional groups to be added according to the functionalization ratio and the total number of carbon atoms in the functionalizable region;

[0013] S43: controlling a random number seed, obtaining a random number according to an array of carbon atoms in a region that can be functionalized, and extracting the carbon atom coordinates corresponding to the random number as a random site for functionalization;

[0014] S44: According to the quadrant where the random site is located, based on the coordinates of the random site, the angle of the random site relative to the origin of the coordinate system is calculated, and based on the spatial coordinate transformation parameter equation of S1, the rotation matrix, translation matrix and orientation factor corresponding to the spatial coordinate transformation are calculated;

[0015] S45: Based on the topological file of the functional group model, the functional group topological information of the random site is obtained through the rotation matrix, translation matrix and orientation factor of the coordinate transformation, stored in the functional group matrix, and numbered the functional group;

[0016] S46: According to the serial numbers of the random site coordinates and the serial number marking rules of the carbon atoms of the ultrafine diamond nanowires, adjacent carbon atoms in the same carbon ring and carbon atoms in adjacent carbon rings are found and removed to avoid the concentration of functional groups;

[0017] S47: updating the array of carbon atoms in the region that can be functionalized, and at the same time removing the hydrogen atoms corresponding to the removed carbon atoms, updating the corresponding hydrogen atom array, and returning to S43; until all random sites that can be functionalized are determined;

[0018] S5: According to the array of all random sites of the functional group, the carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model are integrated to obtain the topological information of the overall functionalization model, including the coordinates, types, serial numbers and corresponding molecular serial number information of the atoms.

[0019] Furthermore, the S2 specifically includes the following sub-steps:

[0020] S21: generating a periodic unit cell model of ultrafine diamond nanowires, and exporting the periodic unit cell model into a coordinate file and a crystal information file;

[0021] S22: Based on the coordinate file and crystal information file of the periodic unit cell model, the coordinate information and boundary information of the periodic unit cell model are obtained, and the carbon atoms and hydrogen atoms in the periodic unit cell model are numbered clockwise, and stored separately in two arrays.

[0022] The beneficial effects of the present invention are as follows:

[0023] The modeling method of the present invention realizes the precise positioning and control of the functional groups on the surface of diamond nanowires by standardizing the functional groups and their coordinate transformation, molecular modeling and controllable random selection of functionalization sites, and excluding high-energy sites of concentrated functionalization. It is helpful to carry out quantitative research on the effects of functional groups on the performance of one-dimensional nanomaterials and the effects of functionalized one-dimensional nanomaterials on the performance of modified materials, and to analyze the intrinsic mechanism at the microscopic scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of a modeling method for functionalizing ultrafine diamond nanowires according to an embodiment of the present invention.

[0025] Figure 2 Schematic diagram of the periodic unit cell model and functional group model of ultrafine diamond nanowires.

[0026] Figure 3 Schematic diagram of the region where functional groups are added in an embodiment of the present invention.

[0027] Figure 4 Schematic diagram of exclusion points for adding functional groups in an embodiment of the present invention, where green indicates exclusion points.

[0028] Figure 5 A schematic diagram of the functionalized structure of ultrafine diamond nanowires modeled in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] like Figure 1 As shown, the modeling method for functionalization of ultrafine diamond nanowires of the present invention includes two steps: creation and coordinate transformation of functional groups, and functionalization of ultrafine diamond nanowires. All input files in this embodiment are compiled and run in Matlab.

[0031] Step 1: Functional group modeling and coordinate transformation

[0032] S11: Establish a functional group molecular model according to the requirements and obtain a topology file. The functional group selected in this embodiment is methyl (-CH3), such as Figure 2 As shown, the carbon and hydrogen atoms of the methyl group form a tetrahedron in space.

[0033] S12: Read the methyl topology file and establish the spatial coordinate transformation parameter equations of the rotation matrix, translation matrix and orientation factor according to the coordinates of the functional group model.

[0034] Step 2: Unit cell modeling and data reading of ultrafine diamond nanowires

[0035] S21: Generate a periodic unit cell model of ultrafine diamond nanowires using molecular modeling tools such as Materials Studio or VESTA. Figure 2 As shown, the unit cell model is exported as a .xyz coordinate file and a .cif crystal information file.

[0036] S22: Based on the two topology files in S21, the coordinate information and boundary information of the unit cell model are obtained, and the carbon and hydrogen atoms in the unit cell model are numbered clockwise and stored separately in two arrays.

[0037] In this embodiment, S2 can be implemented by Matlab programming, but can also be implemented by C, python and other programming.

[0038] Step 3: Modeling of ultrafine diamond nanowires

[0039] Based on the principal coordinate direction of the periodic unit cell model of the ultrafine diamond nanowire, the length of the diamond nanowire is pre-set, and the ultrafine diamond nanowire model of the required length is established. The carbon and hydrogen atomic coordinates of the ultrafine diamond nanowire model are placed in two arrays respectively; then the bottom center of the ultrafine diamond nanowire model is transformed to the origin of the coordinate system, and the length direction is along the principal coordinate direction of the coordinate system. The modeled ultrafine diamond nanowire model is shown in the figure below. Figure 3shown.

[0040] Step 4: Functional group site selection

[0041] Based on the converted carbon atom coordinates of the ultrafine diamond nanowire model, the site area and the ratio of the number of functional groups to add functional groups are set, while excluding unreasonable functional group addition sites, and finally integrating all carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model to obtain the topological information of the overall functionalization model. Step 4 is achieved through the following sub-steps:

[0042] S41: selecting a pseudo-functionalized region according to simulation requirements; storing the coordinates of carbon and hydrogen atoms in the pseudo-functionalized region into a carbon atom array and a corresponding hydrogen atom array of a functionalized region;

[0043] S42: Calculating the total number of functional groups to be added according to the functionalization ratio and the total number of carbon atoms in the functionalizable region;

[0044] S43: controlling a random number seed, obtaining a random number according to an array of carbon atoms in a region that can be functionalized, and extracting the carbon atom coordinates corresponding to the random number as a random site for functionalization;

[0045] S44: according to the quadrant where the random site is located, based on the coordinates of the random site, calculating the angle of the random site relative to the origin of the coordinate system, and based on the spatial coordinate transformation parameter equation of step 1, calculating the rotation matrix, translation matrix and orientation factor corresponding to the spatial coordinate transformation;

[0046] S45: Based on the topology file of the functional group model, the functional group topology information of the random site is obtained through the rotation matrix, translation matrix and orientation factor of the coordinate transformation, stored in the functional group matrix, and the functional group is numbered;

[0047] S46: According to the serial number of the random site coordinates and the serial number marking rule of the carbon atoms of the ultrafine diamond nanowire, find and remove adjacent carbon atoms in the same carbon ring and carbon atoms in adjacent carbon rings to avoid the concentration of functional groups. Figure 4 As shown, the positions of the exclusion points of the functional group addition sites are displayed, where the green ones are the exclusion points.

[0048] S47: updating the array of carbon atoms in the region that can be functionalized, and at the same time removing the hydrogen atoms corresponding to the removed carbon atoms, updating the corresponding hydrogen atom array, and returning to S43; until all random sites that can be functionalized are determined.

[0049] Step 5: According to the array of all random sites of the functional group, the carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model are integrated to obtain the topological information of the overall functionalization model, including the coordinates, types, serial numbers and corresponding molecular serial number information of the atoms. The final ultrafine diamond nanowire functionalization structure is as follows: Figure 5 shown.

[0050] After obtaining the topological information of the overall functionalization model, the data file and coordinate file of the functionalized ultrafine diamond nanowire can be output according to the data format requirements, and further displayed or calculated through molecular model visualization software and molecular dynamics simulation software, such as Ovito and VMD.

[0051] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A modeling method for functionalization of ultrafine diamond nanowires, characterized in that: The steps include: S1: Establish a functional group molecular model, and establish the rotation matrix, translation matrix and spatial coordinate transformation parameter equation of the orientation factor according to the coordinates of the functional group model; S2: establishing a periodic unit cell model of the ultrafine diamond nanowire, and numbering the carbon atoms and hydrogen atoms in the unit cell model in a clockwise direction; S3: presetting the length of the diamond nanowire based on the principal coordinate direction of the periodic unit cell model of the ultrafine diamond nanowire, establishing an ultrafine diamond nanowire model of a required length, and placing the carbon and hydrogen atomic coordinates of the ultrafine diamond nanowire model into two arrays respectively; Then the bottom center of the ultrafine diamond nanowire model is transformed to the origin of the coordinate system, and the length direction is along the principal coordinate direction of the coordinate system; S4: Based on the converted carbon atom coordinates of the ultrafine diamond nanowire model, the site area for adding functional groups and the ratio of the number of functional groups are set, while excluding unreasonable functional group addition sites, and finally integrating all carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model to obtain the topological information of the overall functionalization model.

2. The modeling method for functionalization of ultrafine diamond nanowires according to claim 1, characterized in that: The step S4 comprises: S41: selecting a pseudo-functionalized region according to simulation requirements; storing the carbon and hydrogen atom coordinates of the pseudo-functionalized region into a functionalized region carbon atom array and a corresponding hydrogen atom array; S42: Calculating the total number of functional groups to be added according to the functionalization ratio and the total number of carbon atoms in the functionalizable region; S43: controlling a random number seed, obtaining a random number according to an array of carbon atoms in a region that can be functionalized, and extracting the carbon atom coordinates corresponding to the random number as a random site for functionalization; S44: According to the quadrant where the random site is located, based on the coordinates of the random site, the angle of the random site relative to the origin of the coordinate system is calculated, and based on the spatial coordinate transformation parameter equation of S1, the rotation matrix, translation matrix and orientation factor corresponding to the spatial coordinate transformation are calculated; S45: Based on the topological file of the functional group model, the functional group topological information of the random site is obtained through the rotation matrix, translation matrix and orientation factor of the coordinate transformation, stored in the functional group matrix, and numbered the functional group; S46: According to the serial numbers of the random site coordinates and the serial number marking rules of the carbon atoms of the ultrafine diamond nanowires, adjacent carbon atoms in the same carbon ring and carbon atoms in adjacent carbon rings are found and removed to avoid the concentration of functional groups; S47: updating the array of carbon atoms in the region that can be functionalized, and at the same time removing the hydrogen atoms corresponding to the removed carbon atoms, updating the corresponding hydrogen atom array, and returning to S43; until all random sites that can be functionalized are determined; S5: According to the array of all random sites of the functional group, the carbon atom coordinates and hydrogen atom coordinates of the ultrafine diamond nanowire model are integrated to obtain the topological information of the overall functionalization model, including the coordinates, types, serial numbers and corresponding molecular serial number information of the atoms.

3. The modeling method for functionalization of ultrafine diamond nanowires according to claim 1, characterized in that: The S2 specifically includes the following sub-steps: S21: generating a periodic unit cell model of ultrafine diamond nanowires, and exporting the periodic unit cell model into a coordinate file and a crystal information file; S22: Based on the coordinate file and crystal information file of the periodic unit cell model, the coordinate information and boundary information of the periodic unit cell model are obtained, and the carbon atoms and hydrogen atoms in the periodic unit cell model are numbered clockwise, and stored separately in two arrays.

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