Screening method of gas production chemical binder based on crystal face coating effect

Abstract

The invention discloses a method for screening a gas production medicine binder based on a crystal face coating effect, which comprises the following steps of: optimizing molecular crystal structure data of an energetic compound in a gas production medicine formula, determining a main crystal face of a molecular crystal, obtaining super-crystal face structure data, calculating a super-crystal face solvent contactable area, and obtaining amorphous crystal face structure data of a binder solution. The method comprises the following steps: optimizing an amorphous super-crystal surface unit cell structure of a binder solution, obtaining a binder-crystal surface coated unit cell structure, calculating the comprehensive adsorption energy of each crystal surface of an energetic compound to the binder, and screening the binder with the best coating effect required by a gas production medicine formula according to the comprehensive adsorption energy to finish screening. The screening efficiency of an existing screening mode is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of computational energetic material chemistry and relates to a screening method for binders of gas-generating propellants based on crystal face coating effects. Background Art

[0002] In recent years, the Chinese automotive industry has developed rapidly. Automotive airbags are the last line of defense for safety. The gas generator is one of the key components in the airbag. The gas-generating propellant inside it can be instantly ignited, generating a large amount of gas to fill the airbag and thus reducing the damage caused by collisions.

[0003] The composition of the gas-generating propellant includes a fuel, an oxidizer, a binder, a burning rate regulator, etc. Among them, the binder mainly serves to bind the pharmaceutical agents and also has functions such as passivation and plasticization. Selecting a suitable binder can effectively help the main components of the gas-generating propellant to form, improve the strength and safety of the pharmaceutical agent. The correct selection of the binder during the pharmaceutical production process can help optimize the production process, improve the production quality of the gas-generating propellant particles, and enhance the production efficiency.

[0004] However, currently, the screening of binders in the gas-generating propellant formula is only based on traditional experience and is only screened within the range of binders that have been used. The formula design is blind and lacks scientific data guidance. In addition, the screening of binders based on experience can only select the best binder after a large number of test samples are prepared and analyzed and tested. The R & D cost is high, and there are also risks of combustion and explosion during the test process. Blind selection of binders easily increases the safety and quality risks during the test production process. Summary of the Invention

[0005] The purpose of the present invention is to provide a screening method for binders of gas-generating propellants based on crystal face coating effects, which effectively improves the screening efficiency of the existing screening methods.

[0006] The technical solution adopted by the present invention is a screening method for binders of gas-generating propellants based on crystal face coating effects, including: optimizing the molecular crystal structure data of energetic compounds in the gas-generating propellant formula, determining the main crystal face of the molecular crystal, obtaining the super crystal face structure data, calculating the solvent-accessible area of the super crystal face, obtaining the amorphous crystal face structure data of the binder solution, optimizing the super crystal face unit cell structure of the amorphous state of the binder solution, obtaining the binder-crystal face coating unit cell structure, calculating the comprehensive adsorption energy of each crystal face of the energetic compound for the binder, and screening out the binder with the best coating effect required for the gas-generating propellant formula according to the comprehensive adsorption energy to complete the screening.

[0007] The characteristics of the present invention also lie in that

[0008] Specifically, it is implemented according to the following steps:

[0009] Step 1: Adopt the molecular mechanics method based on the force field, and optimize the molecular crystal structure data of the energetic compounds in the gas-generating propellant formula according to the preset parameters to obtain the optimized molecular crystal structure data of the energetic compounds;

[0010] Step 2: Use the molecular mechanics method based on the force field to calculate the theoretical crystal morphology of the optimized molecular crystal of the energetic compound, obtain the crystal surface related parameters of the molecular crystal, and determine the main crystal plane;

[0011] The crystal morphology calculation parameters include the force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model. The crystal surface related parameters include the Miller indices of the crystal plane, the crystal plane area, and the crystal plane area ratio. The main crystal plane is the crystal plane with a crystal plane area ratio greater than 1%;

[0012] Step 3: Cut the crystal structure of the energetic compound optimized in Step 1 according to the Miller indices of the main crystal plane obtained in Step 2 to obtain the main crystal plane with thickness. Expand the main crystal plane by a certain multiple in the U-axis and V-axis directions to obtain the super crystal plane structure data, and calculate the solvent accessible area S of the super crystal plane;

[0013] Step 4: Obtain the molecular structure data of the binder. Adopt the molecular mechanics method based on the force field, and establish an amorphous cell model of the binder solution according to the lengths of the super crystal plane in the U-axis and V-axis directions obtained in Step 3, the concentration of the binder solution required by the process, and the calculation parameters of the amorphous state modeling to obtain the amorphous cell structure data of the solution. Cut the amorphous cell of the binder solution according to the Miller indices of the (0 0 1) crystal plane to obtain the amorphous crystal plane structure data of the binder solution with a thickness of one cell length in the C-axis direction;

[0014] Step 5: Add a vacuum layer on the super crystal plane of the energetic compound main crystal plane obtained in Step 3 to obtain the super crystal plane cell structure of the energetic compound. Optimize the super crystal plane cell structure of the energetic compound according to the molecular mechanics calculation parameters to obtain the super crystal plane energy E surf-E ; Add a vacuum layer on the super crystal plane of the amorphous state of the binder solution obtained in Step 4 to obtain the super crystal plane cell structure of the amorphous state of the binder solution. Optimize the super crystal plane cell structure of the amorphous state of the binder solution according to the molecular mechanics calculation parameters to obtain the super crystal plane energy E surf-B ;

[0015] Step 6: Take the supercell of the main crystal plane of the energetic compound obtained in Step 3 as the first layer, and take the crystal plane of the amorphous state of the binder solution obtained in Step 4 as the second layer. There is a vacuum layer between the two crystal planes, and an additional vacuum layer is added above the second crystal plane to obtain a binder-crystal coated unit cell structure. According to the molecular dynamics calculation parameters, use the force field-based molecular dynamics method to simulate the kinetic process of the binder coating the energetic compound at the temperature of the gas-generating propellant manufacturing process, and obtain the energy E of the binder-crystal coated unit cell system ;

[0016] Step 7: Substitute the E surf-E and E surf-B obtained in Step 5 and the E system obtained in Step 6 into the calculation formula E interface = E system -(E surf-E + E surf-B ), calculate the interfacial energy E interface required for the binder to coat the crystal plane of the energetic compound. When E interfac is positive, it indicates that the binder needs to absorb energy to coat the crystal plane of the energetic compound. When E interface is negative, it indicates that the binder needs to release energy to coat the crystal plane of the energetic compound. Calculate the comprehensive adsorption energy E int of each crystal plane of the energetic compound for the binder according to the following formula:

[0017]

[0018] In the formula, E INT ——Comprehensive adsorption energy, unit n——Number of main crystal planes of the energetic compound; ——Interfacial energy of the i-th main crystal plane of the energetic compound, unit kcal / mol; S i ——Solvent accessible area S of the supercell of the interfacial energy of the i-th main crystal plane of the energetic compound, unit P i ——Proportion of the crystal plane area of the i-th main crystal plane of the energetic compound;

[0019] E INT The smaller the value, the better the adsorption effect. Screen the binder with the best coating effect required for the gas-generating propellant formula according to the adsorption effect reflected by E INT .

[0020] The molecular crystal structure data includes the unit cell length, unit cell orientation, and the original fractional coordinates of all atoms within the molecular crystal. The preset parameters include the force field model, system energy convergence criterion, atomic force convergence criterion, maximum atomic displacement parameter, atomic charge model, electrostatic potential model, and van der Waals force model. The optimized molecular crystal structure data includes the optimized unit cell length, optimized unit cell orientation, and the optimized fractional coordinates of all atoms within the molecular crystal;

[0021] The selection of the force field model includes COMPASS, COMPASS II, Dreiding, Universal, cvff. The system energy convergence criterion is 2.0×10 -5 ~1.0×10 -3 kcal mol -1 , and the atomic force convergence criterion The maximum atomic displacement convergence criterion The selection of the atomic charge model includes the QEq model, Gasteiger model, and force field specified model. The selection of the electrostatic potential model includes the Ewald model, PPPM model, atomic model, and group model. The selection of the van der Waals force model includes the Ewald model, atomic model, and group model.

[0022] The supercell face structure data includes the lengths of the face in the U and V axis directions and the fractional coordinates of all atoms in the face. The value range of the thickness of the main crystal face of the energetic compound in step 3 is 1 to 5 times the unit cell length in the direction perpendicular to the face, and the main crystal face is enlarged 2 to 10 times in the U and V axis directions.

[0023] The molecular structure data of the binder includes the fractional coordinates of all atoms in the binder molecule; the calculation parameters for amorphous state modeling include density, crystal system, unit cell length, force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model; the solution amorphous state unit cell structure data includes all unit cell lengths, unit cell orientations, and the fractional coordinates of all atoms; the solution amorphous state face structure data includes the lengths of the face in the U and V axis directions and the fractional coordinates of all atoms in the face;

[0024] The value range of the calculation parameters for amorphous state modeling in step 4 is as follows: the density is 0.1~2.0g cm -1 ; the selection of the crystal system includes cubic crystal system, orthorhombic crystal system, and tetragonal crystal system.

[0025] The molecular mechanics calculation parameters include force field model, system energy convergence criterion, atomic force convergence criterion, maximum atomic displacement parameter, atomic charge model, electrostatic potential model, and van der Waals force model;

[0026] The value range of the thickness of the vacuum layer added on the supercell of the main crystal face of the energetic compound in step 5 is

[0027]

[0028] The parameters of molecular dynamics calculation include step size, duration, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model. The value ranges of the parameters of molecular dynamics calculation are as follows: the step size ranges from 0.1 to 2.0 fs, the duration ranges from 1 to 1000 ps, the ensemble is the NVT ensemble, and the selection of the heat bath model includes the VelocityScale model, Nose model, Andersen model, and Berendsen model.

[0029] The value range of the vacuum layer thickness between the two layers of crystal planes in Step 6 is The value range of the increased vacuum layer thickness above the second layer of crystal plane is

[0030] The beneficial effects of the present invention are as follows:

[0031] 1) The screening method of the gas-generating propellant binder based on the crystal plane coating effect of the present invention can be used in the initial stage of the gas-generating propellant formulation design to screen out the best binder suitable for the corresponding gas-generating propellant formulation based on scientific and accurate data, reduce the R & D cost, improve the R & D efficiency, and shorten the R & D cycle;

[0032] 2) The screening method of the present invention expands the binder screening range to new binders that have not been applied yet by calculating the interfacial energy during the adsorption process between the surface of the energetic compound molecular crystal and the binder, reducing the R & D risk brought by the new formulation;

[0033] 3) The screening method of the present invention can not only be used to screen the best binder, but also screen out process parameters such as the best binder solution concentration and the best binder ratio based on the calculation of the interfacial energy, providing a basis for the gas-generating propellant formulation design. Description of the Drawings

[0034] Figure 1 is the flowchart for establishing the model of the nitroguanidine (1 1 1) crystal plane adsorbing PVA solution in Example 1;

[0035] Figure 2 is the schematic diagram of the initial state of the nitroguanidine (1 1 1) supercrystal plane adsorbing PVC in Example 1;

[0036] Figure 3 is the schematic diagram of the final state of the nitroguanidine (1 1 1) supercrystal plane adsorbing PVC in Example 1;

[0037] Figure 4 is the model diagram of the phenolic resin solution established according to the 8×10 supercrystal plane of the guanidine nitrate (2 0 0) crystal plane in Example 2. Detailed Embodiments

[0038] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] Example 1

[0040] This example provides a screening method for the binder of gas-generating propellant based on the crystal face coating effect. In this example, the energetic compound is nitroguanidine, and the binders are polyvinyl alcohol (PVA) and polyvinyl chloride (PVC) for comparison. The schematic diagram of the process of establishing the model of the (1 1 0) crystal face of nitroguanidine adsorbed with PVA solution in this example is as Figure 1 shown. This method includes the following steps:

[0041] Step 1: Obtain the molecular crystal structure data of the energetic compound nitroguanidine Using the molecular mechanics method based on the force field, the optimized molecular crystal structure data of the energetic compound are obtained according to the preset parameters.

[0042] The molecular crystal structure data include the unit cell length, unit cell direction, and the original fractional coordinates of all atoms in the molecular crystal. The preset parameters include the force field model, system energy convergence criterion, atomic force convergence criterion, maximum atomic displacement parameter, atomic charge model, electrostatic potential model, and van der Waals force model; the optimized molecular crystal structure data include the optimized unit cell length, optimized unit cell direction, and the optimized fractional coordinates of all atoms in the molecular crystal.

[0043] In this example, the force field model is selected as COMPASS II, the system energy convergence criterion is 2×10 -5 kcal / mol, the force convergence criterion the internal pressure convergence criterion is 0.001 GPa, and the atomic displacement convergence criterion The atomic charge model is the force field-specified model, the intermolecular electrostatic potential selects the Ewald model, and the van der Waals force selects the Atom based model to obtain the optimized crystal structure data of the nitroguanidine molecule.

[0044] Step 2: According to the crystal morphology calculation parameters, use the molecular mechanics method based on the force field to calculate the theoretical crystal morphology of the optimized nitroguanidine molecular crystal, obtain the relevant parameters of the crystal surface, and determine the main crystal face of the nitroguanidine molecular crystal.

[0045] The crystal morphology calculation parameters include the force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model. The relevant parameters of the crystal surface include the Miller index of the crystal face, the crystal face area, and the crystal face area ratio. The main crystal face is the crystal face with a crystal face area ratio greater than 1%.

[0046] In this embodiment, the force field model selects COMPASS II, the atomic charge model is the force field specified model, the intermolecular electrostatic potential selects the Ewald model, the van der Waals force selects the Atom based model, and the main crystal planes of the nitroguanidine molecular crystal are (2 2 0), (0 4 0), (1 1 -1), and (1 1 1), and the proportion of the crystal plane area is 61.12%, 13.74%, 10.23%, and 10.23% respectively.

[0047] Step 3: Cut the crystal structure of the energetic compound optimized in Step 1 according to the Miller indices of the 4 main crystal planes obtained in Step 2 to obtain the main crystal plane structure data with a thickness of 3 unit cell lengths. Expand the main crystal plane by a certain multiple in the U-axis and V-axis directions to obtain the super crystal plane structure data, and calculate the solvent-accessible area S of the super crystal plane.

[0048] The super crystal plane structure data includes the lengths of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane.

[0049] In this embodiment, the main crystal plane size, expansion multiple, super crystal plane size, and solvent-accessible area of the super crystal plane of the nitroguanidine molecular crystal are listed in Table 1.

[0050] Table 1 Main crystal plane, super crystal plane size and accessible solvent area of nitroguanidine molecular crystal

[0051]

[0052] Step 4: Obtain the molecular structure data of the binders PVA and PVC. Using the molecular mechanics method based on the force field, establish an amorphous cell model of the binder solution according to the lengths of the super crystal plane in the U-axis and V-axis directions obtained in Step 3, the concentration of the binder solution required by the process, and the calculation parameters of the amorphous state modeling to obtain the amorphous cell structure data of the solution. Cut the amorphous cell of the binder solution according to the Miller index of (0 01) to obtain the amorphous plane structure data of the binder solution with a thickness of one unit cell length in the C-axis direction.

[0053] The molecular structure data of the binder includes the fractional coordinates of all atoms in the binder molecule; the calculation parameters of the amorphous state modeling include density, crystal system, unit cell length, force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model; the amorphous cell structure data of the solution includes all unit cell lengths, unit cell directions, and the fractional coordinates of all atoms; the amorphous plane structure data of the solution includes the lengths of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane.

[0054] In this embodiment, the amorphous cell structure parameters corresponding to the (2 2 0) super crystal plane are α = β = γ = 90°; The structural parameters of the amorphous cell of the solution corresponding to the (1 1 -1) super crystal plane are α = β = γ = 90°; The process requires that the mass ratio of the solute to the solvent of the binder solution is 1:4. The solvent of the PVA solution is water, and the solvent of the PVC solution is ether; The amorphous cell of the solution is an orthorhombic system, and the solution density is 0.8 g / cm 3 , the process temperature is 353 K, the force field model is selected as COMPASS II, the atomic charge model is the force field specified model, the intermolecular electrostatic potential is selected as the Ewald model, and the van der Waals force is selected as the Atom based model.

[0055] Step 5. Add a vacuum layer with a thickness on the super crystal plane of the nitroguanidine main crystal plane obtained in Step 3 to obtain the super crystal plane cell structure of nitroguanidine, optimize the super crystal plane cell structure of nitroguanidine, and obtain the super crystal plane energy E of nitroguanidine surf-E ; Add a vacuum layer with a thickness on the super crystal plane of the amorphous state of the PVA and PVC solutions obtained in Step 4 to obtain the super crystal plane cell structure of the amorphous state of the PVA and PVC solutions, and optimize the super crystal plane cell structure of the amorphous state of the PVA and PVC solutions according to the molecular mechanics calculation parameters to obtain the super crystal plane energy E of the amorphous state of the PVA and PVC solutions surf-B .

[0056] The molecular mechanics calculation parameters include the force field model, the system energy convergence criterion, the atomic force convergence criterion, the maximum atomic displacement parameter, the atomic charge model, the electrostatic potential model, and the van der Waals force model.

[0057] In this embodiment, the force field model is selected as COMPASS II, and the system energy convergence criterion is 1×10 -3 kcal / mol, the force convergence criterion The internal pressure convergence criterion is 0.5 GPa, and the atomic displacement convergence criterion The atomic charge model is the force field specified model, the intermolecular electrostatic potential is selected as the Ewald model, and the van der Waals force is selected as the Atom based model.

[0058] Step 6. Take the super crystal plane of the nitroguanidine main crystal plane obtained in Step 3 as the first layer, and the super crystal plane of the amorphous state of the PVA and PVC solutions as the second layer. There is a vacuum layer with a thickness between the two crystal planes, and then add a vacuum layer with a thickness above the second layer crystal plane to obtain the binder-crystal plane coated cell structure. According to the molecular dynamics calculation parameters, use the force field-based molecular dynamics method to simulate the kinetic process of the binder coating the energetic compound at the production temperature of the gas generating agent to obtain the energy E of the binder-crystal plane coated cell system , asFigure 2 and Figure 3 are the initial and final states of the process of PVC adsorbed on the (111) supercrystal plane of nitroguanidine, respectively.

[0059] The molecular dynamics calculation parameters include step size, duration, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model.

[0060] In this embodiment, the molecular dynamics simulation step size is 1 fs, the simulation duration is 200 ps, the simulation temperature is 353 K, the NVT ensemble and the Velocity Scale heat bath model are selected, the COMPASS II force field model is chosen, the atomic charge model is the force field specified model, the Ewald model is selected for the intermolecular electrostatic potential, and the Atom based model is chosen for the van der Waals force.

[0061] Step 7: Substitute E surf-E and E surf-B obtained in step 5 and E system obtained in step 6 into the calculation formula E interface = E system -(E surf-E + E surf-B ) to calculate the interfacial energy E interface required for the binder to coat the energetic compound crystal plane. When E interfac is positive, it indicates that the binder needs to absorb energy to coat the energetic compound crystal plane. When E interface is negative, it indicates that the binder needs to release energy to coat the energetic compound crystal plane. The comprehensive adsorption energy E int of each crystal plane of the energetic compound for the binder is calculated according to the following formula:

[0062]

[0063] In the formula,

[0064] E INT ——Comprehensive adsorption energy, unit

[0065] n——The number of main crystal planes of the energetic compound;

[0066] ——The interfacial energy of the i-th main crystal plane of the energetic compound, unit kcal / mol;

[0067] S i ——The solvent-accessible area S of the supercrystal plane of the interfacial energy of the i-th main crystal plane of the energetic compound, unit

[0068]

[0069] P i——The proportion of the crystal plane area of the i-th main crystal plane of the energetic compound.

[0070] E INT The smaller the value, the better the adsorption effect. According to E INT The binder with the best coating effect required for the gas-generating propellant formula is screened according to the adsorption effect reflected.

[0071] In this example, the adsorption energies of the binders PVA and PVC on the surface of nitroguanidine are listed in Table 2. The comprehensive adsorption energy of nitroguanidine for PVA is less than its comprehensive adsorption energy for PVC. Therefore, PVA is more suitable as a binder in the nitroguanidine-based gas-generating propellant formula.

[0072] Table 2 Surface energy, solution energy and adsorption energy of nitroguanidine adsorbed on PVA and PVC models

[0073]

[0074]

[0075] Example 2

[0076] This example provides a screening method for a gas-generating propellant binder based on the crystal plane coating effect. In this example, the energetic compound is guanidine nitrate, and the binders are polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and phenolic resin for comparison. The method includes the following steps:

[0077] Step 1: Obtain the molecular crystal structure data of the energetic compound guanidine nitrate (a = 12.69, b = 7.27, c = 3.63, α = γ = 90°, β = 120.85°), and use the molecular mechanics method based on the force field to optimize the obtained molecular crystal structure data according to the preset parameters.

[0078] The molecular crystal structure data includes the unit cell length, unit cell direction, and the original fractional coordinates of all atoms in the molecular crystal. The preset parameters include the force field model, system energy convergence criterion, atomic force convergence criterion, maximum atomic displacement parameter, atomic charge model, electrostatic potential model, and van der Waals force model; the optimized molecular crystal structure data includes the optimized unit cell length, optimized unit cell direction, and the optimized fractional coordinates of all atoms in the molecular crystal.

[0079] In this example, the force field model is selected as COMPASS II, the system energy convergence criterion is 2×10 -5 kcal / mol, the force convergence criterion The internal pressure convergence criterion is 0.001 GPa, and the atomic displacement convergence criterion The atomic charge model specifies the model for the force field. The Ewald model is selected for the intermolecular electrostatic potential, and the Atom based model is selected for the van der Waals force, obtaining the optimized crystal structure data of nitroguanidine molecules.

[0080] Step 2: According to the crystal morphology calculation parameters, use the molecular mechanics method based on the force field to calculate the theoretical crystal morphology of the optimized guanidine nitrate molecule crystal, obtain the relevant parameters of the crystal surface, and determine the main crystal planes of the guanidine nitrate molecule crystal.

[0081] The crystal morphology calculation parameters include the force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model. The relevant parameters of the crystal surface include the Miller indices of the crystal plane, the area of the crystal plane, and the proportion of the crystal plane area. The main crystal planes are the crystal planes with a crystal plane area proportion greater than 1%.

[0082] In this embodiment, the COMPASS II force field model is selected. The atomic charge model is the force field specified model. The Ewald model is selected for the intermolecular electrostatic potential, and the Atom based model is selected for the van der Waals force. The main crystal planes of the guanidine nitrate molecule crystal are (1 1 0), (-1 1 0), (0 0 1), (0 0 -1), (2 0 0), (-2 0 0), (2 0 -1), (-2 0 1). The proportions of the crystal plane areas are 23.80%, 23.80%, 14.70%, 14.70%, 5.70%, 5.70%, 5.09%, 5.09% respectively. (1 1 0) and (-1 1 0) are symmetry planes, and the rest are in pairs similar to each other.

[0083] Step 3: Cut the crystal structure of the energetic compound optimized in Step 1 according to the Miller indices of the 8 main crystal planes obtained in Step 2 to obtain the main crystal plane structure data with a thickness of 3 unit cell lengths. Expand the main crystal plane by a certain multiple in the U-axis and V-axis directions to obtain the super crystal plane structure data, and calculate the solvent-accessible area S of the super crystal plane.

[0084] The super crystal plane structure data includes the lengths of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane.

[0085] In this embodiment, the molecular weight of the binder phenolic resin is relatively large. To make the modeling size reasonable, the area of the guanidine nitrate super crystal plane in the phenolic resin adsorption model is four times that of the guanidine nitrate super crystal plane in other models. The sizes of the main crystal planes, expansion multiples, super crystal plane sizes, and solvent-accessible areas of the guanidine nitrate molecule crystal are listed in Table 3.

[0086] Table 3 Sizes of the main crystal planes and super crystal planes of the guanidine nitrate molecule crystal and the accessible solvent area

[0087]

[0088] Step 4: Obtain the molecular structure data of binders PVA, PVC, and phenolic resin. Using the molecular mechanics method based on the force field, establish an amorphous cell model of the binder solution according to the lengths of the supercell plane in the U-axis and V-axis directions, the concentration of the binder solution required by the process, and the calculation parameters for amorphous state modeling, and obtain the structural data of the amorphous cell of the solution. Cut the amorphous cell of the binder solution according to the Miller index of the (0 0 1) crystal plane to obtain the structural data of the amorphous plane of the binder solution with a thickness of one cell length in the C-axis direction.

[0089] The molecular structure data of the binder includes the fractional coordinates of all atoms in the binder molecule; the calculation parameters for amorphous state modeling include density, crystal system, cell length, force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model; the structural data of the amorphous cell of the solution includes all cell lengths, cell directions, and the fractional coordinates of all atoms; the structural data of the amorphous plane of the solution includes the lengths of the plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the plane.

[0090] In this embodiment, the structural parameters of the amorphous cell of the PVA solution corresponding to the (11 0) supercell plane are α = β = γ = 90°, and the structural parameters of the amorphous cell of the phenolic resin solution are α = β = γ = 90°; the structural parameters of the amorphous cell of the PVC solution corresponding to the (2 0 0) supercell plane are α = β = γ = 90°, and the structural parameters of the amorphous cell of the phenolic resin solution are α = β = γ = 90°; the process requires a mass ratio of solute to solvent in the binder solution of 1:4, where the solvent of the PVA solution is water, the solvent of the PVC solution is ether, and the solvent of the phenolic resin is ethanol; the amorphous cell of the solution is an orthorhombic crystal system, and the solution density is 0.8 g / cm 3 , the process temperature is 353 K, the force field model is selected as COMPASS II, the atomic charge model is the force field specified model, the intermolecular electrostatic potential is selected as the Ewald model, and the van der Waals force is selected as the Atom based model.

[0091] Step 5: Add a vacuum layer with a thickness of on the supercell plane of the guanidine nitrate main crystal plane obtained in Step 3 to obtain the supercell crystal structure of guanidine nitrate, optimize the supercell crystal structure of guanidine nitrate, and obtain the supercell energy E surf-E ; add a vacuum layer with a thickness of The vacuum layer is obtained to obtain the supercrystal plane cell structure in the amorphous state of the PVA and PVC solutions. According to the molecular mechanics calculation parameters, the supercrystal plane cell structure in the amorphous state of the PVA, PVC, and phenolic resin solutions is optimized to obtain the supercrystal plane energy E of the PVA, PVC, and phenolic resin solutions in the amorphous state surf-B .

[0092] The molecular mechanics calculation parameters include force field model, system energy convergence criterion, atomic force convergence criterion, maximum atomic displacement parameter, atomic charge model, electrostatic potential model, and van der Waals force model.

[0093] In this embodiment, the force field model is selected as COMPASS II, and the system energy convergence criterion is 1×10 -3 kcal / mol, the force convergence criterion The internal pressure convergence criterion is 0.5 GPa, and the atomic displacement convergence criterion The atomic charge model is the force field specified model, the intermolecular electrostatic potential selects the Ewald model, and the van der Waals force selects the Atom based model.

[0094] Step 6: Take the supercrystal plane of the guanidine nitrate main crystal plane obtained in step 3 as the first layer, and the supercrystal planes of the PVA, PVC, and phenolic resin solutions in the amorphous state as the second layer. There is a thickness of the vacuum layer between the two crystal planes. Then, add another thickness of the vacuum layer above the second crystal plane to obtain the binder-crystal plane coated cell structure. As Figure 4 shown is the phenolic resin solution model established based on the 8×10 supercrystal plane of the guanidine nitrate (2 0 0) crystal plane. According to the molecular dynamics calculation parameters, the molecular dynamics method based on the force field is used to simulate the kinetic process of the binder coating the energetic compound at the temperature of the gas generating propellant manufacturing process, and the energy E of the binder-crystal plane coated cell is obtained system .

[0095] The molecular dynamics calculation parameters include step size, duration, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model;

[0096] In this embodiment, the molecular dynamics simulation step size is 1 fs, the simulation duration is 200 ps, the simulation temperature is 353 K, the NVT ensemble and the Velocity Scale heat bath model are selected, the force field model is selected as COMPASS II, the atomic charge model is the force field specified model, the intermolecular electrostatic potential selects the Ewald model, and the van der Waals force selects the Atom based model.

[0097] Step 7: Combine the E surf-E and E surf-B obtained in step 5 with the E system, substitute into the calculation formula E interface = E system -(E surf-E + E surf-B ) to calculate the interfacial energy E interface required for the binder to coat the crystal plane of the energetic compound. When E interface is positive, it indicates that the binder needs to absorb energy to coat the crystal plane of the energetic compound. When E interface is negative, it indicates that the binder needs to release energy to coat the crystal plane of the energetic compound. Calculate the comprehensive adsorption energy E int of each crystal plane of the energetic compound for the binder according to the following formula:

[0098]

[0099] In the formula,

[0100] E INT ——Comprehensive adsorption energy, unit

[0101] n——The number of main crystal planes of the energetic compound;

[0102] ——The interfacial energy of the i-th main crystal plane of the energetic compound, unit kcal / mol;

[0103] S i ——The solvent-accessible area S of the supercrystal plane of the interfacial energy of the i-th main crystal plane of the energetic compound, unit

[0104]

[0105] P i ——The proportion of the crystal plane area of the i-th main crystal plane of the energetic compound.

[0106] E INT The smaller the value, the better the adsorption effect. Select the binder with the best coating effect required for the gas-generating agent formula according to the adsorption effect reflected by E INT .

[0107] In this example, the adsorption energies of binders PVA, PVC, and phenolic resin on the surface of guanidine nitrate are listed in Table 4. Only 4 main crystal planes are listed in the table, and the theoretical solvent-accessible areas S i of the other four symmetric planes and the interfacial energy are the same. Judging from the data in the table, the comprehensive adsorption energy of guanidine nitrate for PVA is the smallest, which is The adsorption effect is the best, and the adsorption capacity for phenolic resin is stronger than that for PVC. PVA is more suitable as a binder in the formula of guanidine nitrate-based gas-generating agent. Since heat absorption is required during the adsorption process, the process temperature needs to be increased. Comparing the comprehensive adsorption energy of nitroguanidine for PVA and PVC in Example 1, nitroguanidine is more likely to adsorb PVC than guanidine nitrate, and the coating effect of PVC on nitroguanidine is stronger than that of PVA on guanidine nitrate. In the working condition where the binder component cannot be replaced, a more suitable gas-generating agent can be replaced.

[0108] Table 4 Surface energy, solution energy and adsorption energy of the models of guanidine nitrate adsorbing PVA, PVC and phenolic resin

[0109]

[0110] In the actual production of gas-generating agents, when using the wet mixing granulation - tableting process and the fluidized granulation - tableting process to manufacture gas-generating agents, PVA is often selected as the binder for both nitroguanidine-based gas-generating agents and guanidine nitrate-based gas-generating agents. It is dissolved in water to prepare solutions with different concentrations to suit different processes. The solution preparation process is simple, water as a solvent is safe and environmentally friendly, the coating effect of the prepared gas-generating agent particles is good, the particle consistency is high, and it is easy to tablet, so it is widely used in gas-generating agents.

[0111] Example 3

[0112] This example provides a screening method for the binder of gas-generating agent based on the crystal plane coating effect, including: optimizing the molecular crystal structure data of the energetic compound in the gas-generating agent formula, determining the main crystal plane of the molecular crystal, obtaining the super crystal plane structure data, calculating the solvent-accessible area of the super crystal plane, obtaining the amorphous crystal plane structure data of the binder solution, optimizing the super crystal plane unit cell structure of the amorphous state of the binder solution, obtaining the binder-crystal plane coating unit cell structure, calculating the comprehensive adsorption energy of each crystal plane of the energetic compound for the binder, and screening out the binder with the best coating effect required for the gas-generating agent formula according to the comprehensive adsorption energy to complete the screening.

[0113] Specifically, it is implemented according to the following steps:

[0114] Step 1: Using the molecular mechanics method based on the force field, and optimizing the molecular crystal structure data of the energetic compound in the gas-generating agent formula according to the preset parameters to obtain the optimized molecular crystal structure data of the energetic compound;

[0115] The force field model selection is Universal, cvff, the system energy convergence standard is 1.0×10 -3 kcal mol -1 , the atomic force convergence standard The maximum atomic displacement convergence standard The Gasteiger model is selected for the atomic charge model, the PPPM model is selected for the electrostatic potential model, and the atomic model is selected for the van der Waals force model.

[0116] Step 2: Use the force field-based molecular mechanics method to calculate the theoretical crystal morphology of the optimized energetic compound molecular crystal, obtain the crystal surface related parameters of the molecular crystal, and determine the main crystal plane of the molecular crystal;

[0117] Step 3: Cut the crystal structure of the energetic compound optimized in Step 1 according to the Miller indices of the crystal plane of the main crystal plane obtained in Step 2 to obtain the main crystal plane with thickness. Expand the main crystal plane by a certain multiple in the U-axis and V-axis directions to obtain the super crystal plane structure data, and calculate the solvent-accessible area S of the super crystal plane;

[0118] The super crystal plane structure data includes the lengths of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane. The thickness of the main crystal plane of the energetic compound in Step 3 ranges from 1 times the unit cell length in the direction perpendicular to the crystal plane, and the main crystal plane is expanded 2 times in the U-axis and V-axis directions.

[0119] Step 4: Obtain the molecular structure data of the binder. Use the force field-based molecular mechanics method to establish an amorphous cell model of the binder solution according to the lengths of the super crystal plane in the U-axis and V-axis directions obtained in Step 3, the concentration of the binder solution required by the process, and the calculation parameters of the amorphous state modeling, obtain the cell structure data of the solution amorphous state, and cut the amorphous cell of the binder solution according to the Miller indices of the crystal plane (0 0 1) to obtain the amorphous surface structure data of the binder solution with a thickness of one unit cell length in the C-axis direction;

[0120] The calculation parameter values for the amorphous state modeling in Step 4 include: the density is 0.1 g cm -1 ; The selection of crystal systems includes cubic crystal system, orthorhombic crystal system, and tetragonal crystal system; The value range of the A-axis unit cell length of the orthorhombic crystal system is The value range of the B-axis unit cell length is The value range of the C-axis unit cell length of the tetragonal crystal system is

[0121] Step 5: Add a vacuum layer with a thickness of to the super crystal plane of the main crystal plane of the energetic compound obtained in Step 3 to obtain the super crystal plane cell structure of the energetic compound. Optimize the super crystal plane cell structure of the energetic compound according to the molecular mechanics calculation parameters to obtain the super crystal plane energy E of the energetic compound surf-E; Add a vacuum layer on the supercrystal plane of the amorphous state of the binder solution obtained in Step 4 to obtain the crystal cell structure of the supercrystal plane of the amorphous state of the binder solution. According to the molecular mechanics calculation parameters, optimize the crystal cell structure of the supercrystal plane of the amorphous state of the binder solution to obtain the energy E of the supercrystal plane of the amorphous state of the binder solution surf-B ;

[0122] Step 6: Take the supercrystal plane of the energetic compound main crystal plane obtained in Step 3 as the first layer, and take the crystal plane of the amorphous state of the binder solution obtained in Step 4 as the second layer. There is a vacuum layer with a thickness of between the two crystal planes. Then add another vacuum layer with a thickness of above the second crystal plane to obtain the binder-crystal plane coated crystal cell structure. According to the molecular dynamics calculation parameters, use the molecular dynamics method based on the force field to simulate the kinetic process of the binder coating the energetic compound at the temperature of the gas-generating propellant manufacturing process to obtain the energy E of the binder-crystal plane coated crystal cell system ;

[0123] The molecular dynamics calculation parameters include step size, duration, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model. The values of the molecular dynamics calculation parameters are as follows: the step size ranges from 0.1 fs, the duration ranges from 1 ps, the ensemble is the NVT ensemble, and the Nose model is selected for the heat bath model

[0124] Step 7: Substitute the E surf-E and E surf-B obtained in Step 5 and the E system obtained in Step 6 into the calculation formula E interface = E system -(E surf-E + E surf-B ) to calculate the interfacial energy E interface required for the binder to coat the energetic compound crystal plane. When E interfac is positive, it means that the binder needs to absorb energy to coat the energetic compound crystal plane. When E interface is negative, it means that the binder needs to release energy to coat the energetic compound crystal plane. Calculate the comprehensive adsorption energy E int of each crystal plane of the energetic compound to the binder according to the following formula

[0125]

[0126] E INT The smaller the value, the better the adsorption effect. Screen the binder with the best coating effect required for the gas-generating propellant formula according to the adsorption effect reflected by E INT

[0127] Example 4

[0128] ​This embodiment provides a screening method for the binder of gas-generating propellant based on the crystal plane coating effect, including: specifically implemented according to the following steps:

[0129] Step 1: Use the molecular mechanics method based on the force field, and optimize the molecular crystal structure data of the energetic compound in the gas-generating propellant formula according to the preset parameters to obtain the optimized molecular crystal structure data of the energetic compound;

[0130] The cvff force field model is selected, and the system energy convergence criterion is 2.0×10 -4 kcal mol -1 , and the atomic force convergence criterion The maximum atomic displacement convergence criterion The QEq model is selected for the atomic charge model, the atomic model is selected for the electrostatic potential model, and the atomic model is selected for the van der Waals force model.

[0131] Step 2: Use the molecular mechanics method based on the force field to calculate the theoretical crystal morphology of the optimized energetic compound molecular crystal, obtain the crystal surface related parameters of the molecular crystal, and determine the main crystal plane of the molecular crystal;

[0132] The crystal morphology calculation parameters include the force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model. The crystal surface related parameters include the Miller index of the crystal plane, the crystal plane area, and the crystal plane area ratio. The main crystal plane is the crystal plane with a crystal plane area ratio greater than 1%;

[0133] Step 3: Cut the crystal structure of the energetic compound optimized in Step 1 according to the Miller index of the main crystal plane obtained in Step 2 to obtain the main crystal plane with thickness, expand the main crystal plane by a certain multiple in the U-axis and V-axis directions to obtain the super crystal plane structure data, and calculate the super crystal plane solvent accessible area S;

[0134] The super crystal plane structure data includes the lengths of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane. The thickness of the main crystal plane of the energetic compound in Step 3 ranges from 5 times the unit cell length in the direction perpendicular to the crystal plane, and the main crystal plane is expanded 10 times in the U-axis and V-axis directions.

[0135] Step 4: Obtain the molecular structure data of the binder. Use the molecular mechanics method based on the force field to establish an amorphous cell model of the binder solution according to the lengths of the super crystal plane in the U-axis and V-axis directions obtained in Step 3, the concentration of the binder solution required by the process, and the calculation parameters of the amorphous state modeling, obtain the amorphous cell structure data of the solution, and cut the amorphous cell of the binder solution according to the Miller index of (0 0 1) to obtain the amorphous crystal plane structure data of the binder solution with a thickness of one unit cell length in the C-axis direction;

[0136] The values of the calculation parameters for the amorphous state modeling in Step 4 include: the density is 2.0 g / cm -1 ; the selection of crystal systems includes cubic crystal system, orthorhombic crystal system, and tetragonal crystal system; the value range of the lattice parameter of the A-axis of the orthorhombic crystal system is the value range of the lattice parameter of the B-axis is the value range of the lattice parameter of the C-axis of the tetragonal crystal system is

[0137] Step 5: Add a vacuum layer with a thickness of to the supercell surface of the main crystal plane of the energetic compound obtained in Step 3 to obtain the supercell crystal structure of the energetic compound. Optimize the supercell crystal structure of the energetic compound according to the molecular mechanics calculation parameters to obtain the supercell energy E surf-E of the energetic compound; add a vacuum layer to the supercell surface of the amorphous state of the binder solution obtained in Step 4 to obtain the supercell crystal structure of the amorphous state of the binder solution. Optimize the supercell crystal structure of the amorphous state of the binder solution according to the molecular mechanics calculation parameters to obtain the supercell energy E surf-B of the amorphous state of the binder solution;

[0138] Step 6: Use the supercell surface of the main crystal plane of the energetic compound obtained in Step 3 as the first layer, and use the crystal plane of the amorphous state of the binder solution obtained in Step 4 as the second layer. There is a vacuum layer with a thickness of between the two crystal planes. Add another vacuum layer with a thickness of above the second crystal plane to obtain the binder-crystal plane coating crystal structure. According to the molecular dynamics calculation parameters, use the force field-based molecular dynamics method to simulate the kinetic process of the binder coating the energetic compound at the temperature of the gas-generating propellant manufacturing process to obtain the energy E system of the binder-crystal plane coating crystal cell;

[0139] The molecular dynamics calculation parameters include step size, duration, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model. The values of the molecular dynamics calculation parameters include: the step size value range is 2.0 fs, the duration value range is 1000 ps, the ensemble is the NVT ensemble, and the heat bath model selects the Berendsen model.

[0140] Step 7: Substitute E surf-E and E surf-B obtained in Step 5 and E system obtained in Step 6 into the calculation formula E interface = E system - (E surf-E + E surf-B ) to calculate the interfacial energy E interface required for the binder to coat the crystal plane of the energetic compound., E interfac When it is a positive value, it indicates that energy needs to be absorbed for the binder to coat the crystal plane of the energetic compound. E interface When it is a negative value, it indicates that energy needs to be released for the binder to coat the crystal plane of the energetic compound. The comprehensive adsorption energy E of each crystal plane of the energetic compound for the binder is calculated according to the following formula int :

[0141]

[0142] E INT The smaller the value, the better the adsorption effect. According to the adsorption effect reflected by E INT , the binder with the best coating effect required for the gas-generating propellant formula is screened out

[0143] Based on the above analysis, it can be seen that by screening the binder suitable for the energetic main material in the gas-generating propellant formula according to the screening method of the present invention, the screening result is consistent with the binder used in the existing production process, indicating that the screening of the binder suitable for the gas-generating propellant of the present invention is reliable

Claims

1. A method for screening gas generating agent binders based on crystal surface coating effect, characterized in that: include: Optimize the molecular crystal structure data of the energetic compounds in the gas generating agent formula, determine the main crystal plane of the molecular crystal, obtain the supercrystal plane structure data, calculate the supercrystal plane solvent-contactable area, obtain the amorphous crystal plane structure data of the binder solution, optimize the amorphous supercrystal plane unit cell structure of the binder solution, obtain the binder-crystal plane coating unit cell structure, calculate the comprehensive adsorption energy of each crystal plane of the energetic compound on the binder, and screen out the binder with the best coating effect required for the gas generating agent formula based on the comprehensive adsorption energy to complete the screening.

2. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 1, characterized in that: Follow the steps below to implement it: Step 1: using a molecular mechanics method based on force field and optimizing the molecular crystal structure data of the energetic compound in the gas generating agent formulation according to preset parameters to obtain the optimized molecular crystal structure data of the energetic compound; Step 2: using a force field-based molecular mechanics method to calculate the theoretical crystal morphology of the optimized energetic compound molecular crystal, obtain the crystal surface related parameters of the molecular crystal, and determine the main crystal plane of the molecular crystal; The crystal morphology calculation parameters include force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model; the crystal surface related parameters include crystal plane Miller index, crystal plane area, and crystal plane area ratio; the main crystal plane is a crystal plane whose crystal plane area ratio is greater than 1%; Step 3, cutting the crystal structure of the energetic compound obtained by optimizing in step 1 according to the crystal plane Miller index of the main crystal plane obtained in step 2, obtaining a main crystal plane with thickness, expanding the main crystal plane by a certain multiple in the U-axis and V-axis directions, obtaining super-crystal surface structure data, and calculating the super-crystal surface solvent accessible area S; Step 4, obtaining molecular structure data of the binder, using a molecular mechanics method based on force field, establishing an amorphous unit cell model of the binder solution according to the length of the super crystal plane in the U-axis and V-axis directions in step 3, the binder solution concentration required by the process, and the calculation parameters of the amorphous state modeling, obtaining the amorphous unit cell structure data of the solution, cutting the amorphous unit cell of the binder solution according to the crystal plane Miller index of (0 0 1), and obtaining the amorphous crystal plane structure data of the binder solution with a thickness of one unit cell length in the C-axis direction; Step 5: Add a vacuum layer on the supercrystal surface of the main crystal surface of the energetic compound obtained in step 3 to obtain the supercrystal surface unit cell structure of the energetic compound; optimize the supercrystal surface unit cell structure of the energetic compound according to the molecular mechanics calculation parameters to obtain the supercrystal surface energy E of the energetic compound. surf-E ; Add a vacuum layer on the amorphous supercrystal surface of the binder solution obtained in step 4 to obtain the supercrystal surface unit cell structure of the amorphous supercrystal of the binder solution, optimize the supercrystal surface unit cell structure of the amorphous supercrystal of the binder solution according to the molecular mechanics calculation parameters, and obtain the supercrystal surface energy E of the amorphous supercrystal of the binder solution surf-B ; Step 6: The super crystal plane of the main crystal plane of the energetic compound obtained in step 3 is used as the first layer, and the crystal plane of the amorphous state of the binder solution obtained in step 4 is used as the second layer. There is a vacuum layer between the two crystal planes, and a vacuum layer is added above the second crystal plane to obtain a binder-crystal surface coating unit cell structure. According to the molecular dynamics calculation parameters, a force field-based molecular dynamics method is used to simulate the dynamic process of the binder coating the energetic compound at the manufacturing process temperature of the gas generating agent to obtain the energy E of the binder-crystal surface coating unit cell. system ; Step 7: E obtained in step 5 surf-E and E surf-B E obtained in step 6 system , substitute into the calculation formula E interface =E system -(E surf-E +E surf-B ), and the interfacial energy E required for the binder to cover the energetic compound crystal surface is calculated interface , E interfac When it is positive, it means that the binder needs to absorb energy to cover the energetic compound crystal surface, E interface When it is a negative value, it means that the binder needs to release energy to cover the crystal surface of the energetic compound. The comprehensive adsorption energy E of each crystal surface of the energetic compound on the binder can be calculated according to the following formula: int : In the formula, E INT ——Comprehensive adsorption energy, unit n——the number of principal crystal faces of energetic compounds; ——interfacial energy of the i-th principal crystal plane of the energetic compound, in kcal / mol; S i ——Interface energy supersurface solvent accessible area S of the i-th principal crystal surface of energetic compound, unit P i ——The crystal surface area ratio of the i-th principal crystal plane of the energetic compound; E INT The smaller the value, the better the adsorption effect. INT The reflected adsorption effect is used to select the binder with the best coating effect required by the gas generating agent formula.

3. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The molecular crystal structure data include the unit cell length, unit cell direction and the original fractional coordinates of all atoms in the molecular crystal, and the preset parameters include the force field model, the system energy convergence standard, the atomic force convergence standard, the maximum atomic displacement parameter, the atomic charge model, the electrostatic potential model and the van der Waals force model; the optimized molecular crystal structure data include the optimized unit cell length, the optimized unit cell direction and the optimized fractional coordinates of all atoms in the molecular crystal; The force field models include COMPASS, COMPASS II, Dreiding, Universal, and cvff. The system energy convergence standard is 2.0×10 -5 ~1.0×10 -3 kcal mol -1 , atomic force convergence criterion Maximum atomic displacement convergence criterion The options for atomic charge models include QEq model, Gasteiger model, and force field specified model; the options for electrostatic potential models include Ewald model, PPPM model, atom model, and group model; and the options for van der Waals force models include Ewald model, atom model, and group model.

4. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The super crystal plane structure data includes the length of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane. The thickness of the main crystal plane of the energetic compound described in step 3 ranges from 1 to 5 times the length of the unit cell in the direction perpendicular to the crystal plane, and the main crystal plane is enlarged by 2 to 10 times in the U-axis and V-axis directions.

5. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The molecular structure data of the binder include the fractional coordinates of all atoms in the binder molecules; the calculation parameters of amorphous state modeling include density, crystal system, unit cell length, force field model, atomic charge, intermolecular electrostatic potential model, and van der Waals force model; the unit cell structure data of the amorphous state of the solution include all unit cell lengths, unit cell directions, and fractional coordinates of all atoms; the crystal plane structure data of the amorphous state of the solution include the length of the crystal plane in the U-axis and V-axis directions and the fractional coordinates of all atoms in the crystal plane; The values ​​of the calculation parameters of the amorphous state modeling described in step 4 include: density of 0.1 to 2.0 gcm -1 ; The choices of crystal systems include cubic, orthorhombic and tetragonal.

6. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The molecular mechanics calculation parameters include force field model, system energy convergence standard, atomic force convergence standard, maximum atomic displacement parameter, atomic charge model, electrostatic potential model and van der Waals force model.

7. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The thickness of the vacuum layer added on the super-crystal surface of the energetic compound main crystal surface in step 5 has a value range of 8. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The molecular dynamics calculation parameters include step size, time length, temperature, ensemble, heat bath model, force field model, atomic charge model, intermolecular electrostatic potential model, and van der Waals force model. The values ​​of the molecular dynamics calculation parameters include: the step size ranges from 0.1 to 2.0 fs, the time length ranges from 1 to 1000 ps, ​​the ensemble is the NVT ensemble, and the choices of heat bath models include VelocityScale model, Nose model, Andersen model, and Berendsen model.

9. The method for screening gas generating agent binders based on crystal surface coating effect according to claim 2, characterized in that: The thickness of the vacuum layer between the two crystal planes in step 6 is in the range of The thickness of the vacuum layer added above the second crystal plane ranges from

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