A method for calculating the adsorption energy of MOF materials during the interfacial polymerization process to prepare composite films.

Abstract

The present application belongs to the field of high performance membrane material, and particularly relates to a method for calculating the force between MOF material as an additive and two-phase monomers in the process of interfacial polymerization reaction by using computer simulation. The method comprises the following steps: determining the types of monomers in the water phase and the organic phase in the interfacial polymerization system; constructing the three-dimensional chemical structures of the MOF material, the water phase monomers and the organic phase monomers respectively; optimizing the chemical structures of each component by using Materials Studio software; obtaining the functional group and electron orbital information according to the chemical structure, determining the adsorption site, and selecting the adsorption theoretical model; performing density functional theory (DFT) simulation calculation by using Materials Studio software, and obtaining the binding energy of each adsorption model and the distance between the atoms of the intermolecular interaction of each component after the system is balanced. The present application has important guiding significance for improving the interfacial polymerization reaction process and preparing high performance separation membranes.

Description

Technical Field

[0001] This invention belongs to the field of high-performance membrane materials. Specifically, it relates to a method for using computer simulation of the interaction forces between MOF materials as additives and two-phase monomers during interfacial polymerization. Background Technology

[0002] With the depletion of water resources, the demand for pure water is becoming increasingly urgent. Membrane separation technology is a green and energy-saving technology that has been widely applied in various fields such as wastewater treatment, seawater desalination, biomedicine, and gas separation. The most common preparation method for commercial nanofiltration and reverse osmosis membranes is interfacial polymerization. In the interfacial polymerization process, aqueous monomers diffuse into the organic solvent and react with organic monomers at the water-organic phase interface to form a desalination separation layer. The most commonly used aqueous monomers include piperazine (PIP), m-phenylenediamine (MPD), and their derivatives; the most commonly used organic monomers include trimesoyl chloride (TMC) and its derivatives. The resulting desalination separation layer is collectively referred to as a polyamide (PA) layer.

[0003] Most research focuses on improving membrane separation performance through methods such as designing new monomers, introducing intermediate layers, and adding nanomaterials. It is well known that nanomaterials, as additives in interfacial polymerization reactions, play a crucial role in the selective and permeability regulation of nanofiltration and reverse osmosis membranes. Among them, metal-organic frameworks (MOFs) are a class of organic-inorganic hybrid crystalline nanomaterials formed by the coordination of organic ligands with metal ions or metal clusters. Due to their inherent advantages, such as high porosity, designable structures, controllable pore size, and strong affinity with polymer matrices, they are widely used in the preparation of nanofiltration and reverse osmosis membranes. For example, typical MOF materials such as UiO-66, MIL-101, and HKUST-1 have become excellent additives for improving membrane permeate flux, optimizing water transport pathways, and preparing high-performance nanofiltration / reverse osmosis membranes. However, the regulatory mechanism of MOF materials on interfacial polymerization reactions and their influence on the structural characteristics of the PA separation layer remain unclear.

[0004] In this invention, MOF (Metal-Oxide-Flavored Fragrance) is selected as the nano-additive. The adsorption energy between the two-phase monomers and the nano-additive is calculated using DFT simulation to investigate its impact on the PA layer structure of the membrane. After multiple theoretical model selections and simulation parameter optimizations, the energy value between the MOF material and the two-phase monomers can be quantified by calculating the adsorption energy using the DMol3 module. Furthermore, the relationship between the calculated energy value and scanning electron microscopy (SEM) measurements can be established between the nanostructure of the PA layer surface and the adsorption energy. This method has guiding significance for predicting and designing the surface structure of nanofiltration / reverse osmosis membranes, shortening the experimental cycle, and reducing experimental costs. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for simulating the interaction forces between MOF materials and two-phase monomers during interfacial polymerization using Materials Studio software and DFT density functional theory. This method explores the thermodynamic influence of MOF materials as additives on the interfacial polymerization reaction during the formation of composite membrane separation layers from a fundamental perspective, thereby expanding our understanding of the interfacial polymerization mechanism of high-performance separation membranes. Using a combination of simulation and experimental methods, an adsorption model of MOF materials and two-phase monomers was established, obtaining the interaction forces between MOF and monomers, as well as the spacing between interacting atoms in the molecules. This provides new theoretical guidance for preparing polyamide layers with different structures based on MOF materials as additives through interfacial polymerization.

[0006] This invention is achieved by providing a method for calculating the adsorption energy of MOF materials during the interfacial polymerization reaction to prepare composite films, comprising the following steps:

[0007] (1) Determine the types of monomers in the aqueous and organic phases of the interfacial polymerization system;

[0008] (2) Construct the three-dimensional chemical structures of MOF materials, aqueous monomers and organic monomers respectively;

[0009] (3) The chemical structure of each component was optimized using Materials Studio software;

[0010] (4) Obtain information on functional groups and electronic orbitals based on chemical structure, determine adsorption sites, and select adsorption theoretical models;

[0011] (5) Density functional theory (DFT) simulation calculations were performed using Materials Studio software. After the system was in equilibrium, the interatomic spacing of the molecular interactions of each component in each adsorption model was obtained.

[0012] The most common preparation method for commercial nanofiltration and reverse osmosis membranes is interfacial polymerization. The most commonly used aqueous monomers include piperazine (PIP), m-phenylenediamine (MPD) and its derivatives, as well as other polyamines; the most commonly used organic monomers include trimesoyl chloride (TMC) and its derivatives, as well as other polyacrylamide chlorides. The desalination separation layer formed by the interfacial polymerization of these two monomers is collectively referred to as a polyamide (PA) layer. Therefore, the two phases of the interfacial polymerization reaction described in this invention are: water as the aqueous solvent; n-hexane as the organic solvent; one of the following aqueous monomers: piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, β-cyclodextrin, p-phenylenediamine, m-phenylenediamine, trimesoyl chloride, and diaminotoluene; and one of the following organic monomers: trimesoyl chloride, terephthaloyl chloride, isophthaloyl chloride, succinic acid trichloroethylene chloride, glutaryl chloride, and glutaryl chloride.

[0013] To simulate the interaction between MOF materials and monomers, it is first necessary to construct the chemical structures of MOF and two-phase monomers. Specifically, the three-dimensional chemical structure of the two-phase monomers is constructed based on molecular charge, spatial atomic coordinates, molecular bond lengths, and bond angles. The three-dimensional chemical structure is then constructed by retrieving the CIF file of the MOF from the CCDC crystal structure database.

[0014] To more accurately simulate the interaction between MOF materials and monomers, the chemical structures of the MOF and the two-phase monomers need to be optimized to reach the lowest energy value. Specifically, Materials Studio software is used to optimize the chemical structures of the MOF material, aqueous monomers, and organic monomers. The selected calculation module can be one of CASTEP, DFTB+, DMol3, Forcite, and Gaussian. Based on density functional theory (DFT), the configuration of each molecule is optimized and the lowest energy value is calculated.

[0015] The interaction between MOFs and two-phase monomers is based on various intermolecular forces. To calculate the adsorption energy and intermolecular distance, it is necessary to obtain information on functional groups and electronic orbitals based on the chemical structure, determine the adsorption sites, and then select a possible adsorption theoretical model. This adsorption theoretical model can be one or more of the following: molecular frontier orbital theory, Lewis acid-base theory, proton theory, and the "π-π" interaction theory between benzene ring-containing structures. These theoretical models may coexist, or only one may be the dominant interaction force; therefore, multiple models can be used for calculations. As a demonstration example, this invention only uses the Lewis acid-base theory as an example of the calculation method, but this method is also applicable to other theoretical models.

[0016] During the calculation process, the calculation module can be any one of CASTEP, DFTB+, DMol3, Forcite, and Gaussian. Each module's accuracy is suitable for calculating the interaction between MOFs and two-phase monomers, and the calculation process employs density functional theory (DFT). To better illustrate the implementation effect and facilitate comparison of different embodiments, this invention uses the DMol3 calculation module for demonstration. In the process of using Materials Studio software to perform density functional theory (DFT) simulations to calculate the binding energy of each adsorption model, an optimized convergence tolerance of 10 was used to achieve or meet the required calculation accuracy. -4 Ha (energy), 2×10 -5 Ha, 1×10 -5 One of Ha; the maximum force of optimization is One of them; the minimum displacement required for optimization is One of the following; the optional functional theory is either the local density approximation functional or the generalized gradient approximation functional; the exchange correlation function is one of PW91, BP, PBE, BLYP, VWN, or BOP; the integration accuracy is one of Coarse, Medium, or Fine; check the box to use the solvation model.

[0017] The advantages and positive effects of this invention are:

[0018] To address the unclear interaction between nano-additives and two-phase monomers in the interfacial polymerization process for nanofiltration / reverse osmosis membranes, this invention employs computer simulation. Using Materials Studio software for DFT calculations, the adsorption configuration between the two-phase monomers and MOF materials was established. By matching suitable adsorption theories and models, the simulation calculations can accurately predict the impact of nano-additives on the interfacial polymerization reaction. This calculation method exhibits good universality. Unlike previous kinetic calculation methods, the calculation method described in this invention has higher accuracy from thermodynamic and quantum mechanical perspectives, accurately quantifying the interaction forces between monomers and MOF materials. Based on the above simulation results, the influence of MOF additives on the morphology and structure of the PA layer during the interfacial polymerization reaction can be analyzed. Attached Figure Description

[0019] Figure 1 Hydrogen bonds between free H in Zr-OC and N in PIP in UiO-66;

[0020] Figure 2 C and [H2PIP] in Zr-OC in UiO-66 2+ Hydrogen bonds between H atoms;

[0021] Figure 3 Hydrogen bonds between C in Zr-OC and free H in TMC in UiO-66;

[0022] Figure 4 Surface morphology of polyamide separation layer prepared by interfacial polymerization of UiO-66 in an aqueous solvent containing piperazine (PIP);

[0023] Figure 5 Add UiO-66 to compounds containing protonated piperazine ([H2PIP)). 2+ Surface morphology of polyamide separation layer prepared by interfacial polymerization reaction in aqueous solvent;

[0024] Figure 6 The surface morphology of the polyamide separation layer prepared by interfacial polymerization of UiO-66 in an organic solvent containing trimesoyl chloride (TMC);

[0025] Figure 7 The hydrogen bond between the C of Cr-OC and the free H of terephthaloyl chloride in MIL-101;

[0026] Figure 8 The hydrogen bonds between the free H of Cr-OC and the N of piperazine in MIL-101;

[0027] Figure 9 The hydrogen bond between the C of Cr-OC and the free H of glutaryl chloride in MIL-101;

[0028] Figure 10 The hydrogen bond between the free H of Cu-OC and the N of 2-methylpiperazine in HKUST-1;

[0029] Figure 11 The hydrogen bond between the C of Cu-OC in HKUST-1 and the free H of terephthaloyl chloride;

[0030] Figure 12 The hydrogen bond between the free H of Cu-OC in HKUST-1 and the N of diaminotoluene;

[0031] Figure 13 Hydrogen bonds between the free H of Zn-OC and the N of m-phenylenediamine in MOF-5;

[0032] Figure 14 The hydrogen bond between the free H of Zn-OC in MOF-5 and the N of 2-methylpiperazine;

[0033] Figure 15 The hydrogen bond between the C of Zn-OC in MOF-5 and the free H of terephthaloyl chloride. Detailed Implementation

[0034] Example 1

[0035] Piperazine (PIP) was selected as the aqueous monomer, and UiO-66 was selected as the nano-additive for simulation calculations. The CIF file of UiO-66 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Zr-OC in UiO-66 and the N of PIP. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software, obtaining the adsorption configuration of UiO-66 and piperazine in a stable equilibrium state. Parameter settings in the DMol3 module: the spin polarization density function was calculated using the Perdew Wang 1991 (PW91) exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 10. -4 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effect in the piperazine and UiO-66 adsorption models. For example... Figure 1 As shown, the adsorption energy between piperazine and UiO-66 is -39.476 kcal / mol, and the interaction distance is... Experimental verification showed that the prepared membrane surface exhibited a granular structure. Figure 4 ).

[0036] Example 2

[0037] Selected protonated piperazine [H2PIP] 2+ As an aqueous monomer, UiO-66 was used as a nano-additive in simulation calculations. The CIF file of UiO-66 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure. UiO-66 and [H2PIP] were analyzed using Materials Studio software. 2+ Molecular mapping was performed. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structures, functional group and electronic orbital information were obtained, and the adsorption sites were determined to be C and [H2PIP] of Zr-OC in UiO-66. 2+The hydrogen bonds between H atoms were determined using Lewis acid-base theory as the theoretical model. The adsorption energy of the system was simulated using the DFT method in the DMol3 module of Materials Studio software, yielding a stable equilibrium state between UiO-66 and the piperazine hydrolysis product ([H2PIP)). 2+ The adsorption configuration of ) was determined. Parameter settings in the DMol3 module: Spin polarization density function calculations for geometry optimization and energy calculations were performed using the Perdew Wang 1991 (PW91) exchange correlation function and the generalized gradient approximation (GGA). DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets were used to describe atomic orbitals. The optimized convergence tolerance was 10. -4 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effects of the PIP and UiO-66 adsorption models. For example... Figure 2 As shown, [H2PIP] 2+ The adsorption energy between UiO-66 and UiO-66 is -196.366 kcal / mol, and the interaction distance is [missing information]. Experimental verification showed that the prepared membrane surface exhibited a ridge-like structure. Figure 5 ).

[0038] Example 3

[0039] Tristyrene chloride was selected as the organic phase monomer, and UiO-66 was selected as the nano-additive for simulation calculations. The CIF file of UiO-66 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure. The molecules of UiO-66 and tristyrene chloride were plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the C of Zr-OC in UiO-66 and the free H of TMC. The Lewis acid-base theory was selected as the theoretical model. The adsorption energy was simulated using the DFT of the DMol3 module in Materials Studio software to obtain the adsorption configuration of UiO-66 and tristyrene chloride molecules in a stable equilibrium state. Parameter settings in the DMol3 module: the spin polarization density function was calculated using the Perdew Wang 1991 (PW91) exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets were used to describe atomic orbitals. The optimized convergence tolerance was 10. -4 Ha (energy) (maximum force) and (Minimum displacement). The solvation effect of the adsorption model for trimesoyl chloride and UiO-66 was treated using COSMO in hexane solvent with a dielectric constant of 1.89. (e.g.) Figure 3 As shown, the adsorption energy between pyromellitic methyl chloride and UiO-66 is -26.387 kcal / mol, and the interaction distance is [missing information]. Experimental verification showed that the prepared membrane surface exhibited a granular structure. Figure 6 ).

[0040] Example 4

[0041] Terephthalic acid chloride (TECC) was selected as the organic phase monomer, and MIL-101 was used as the nano-additive for simulation calculations. The CIF file of MIL-101 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure. The molecules of MIL-101 and TECC were plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the C of Cr-OC in MIL-101 and the free H of TECC. The Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software, obtaining the adsorption configuration of MIL-101 and TECC molecules in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the PBE exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 2 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). The solvation effect of the MIL-101 and terephthalic acid chloride adsorption model was treated using COSMO in hexane solvent with a dielectric constant of 1.89. (e.g.) Figure 7 As shown, the interatomic distance between MIL-101 and terephthaloyl chloride is (>Example 3: Therefore, based on Example 3, it is predicted that the surface morphology of the prepared film will exhibit a granular structure.

[0042] Example 5

[0043] Piperazine was selected as the aqueous monomer, and MIL-101 was used as the nano-additive for simulation calculations. The CIF file of MIL-101 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Cr-OC in MIL-101 and the N of piperazine. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software, obtaining the adsorption configuration of MIL-101 and piperazine in a stable equilibrium state. Parameter settings in the DMol3 module: the spin polarization density function was calculated using the BLYP exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. The dual numerical polarization (DNP) basis set was used to describe atomic orbitals. The optimized convergence tolerance is 2×10 -5 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effects of piperazine and MIL-101 adsorption models. For example... Figure 8 As shown, the interatomic distance between MIL-101 and piperazine is (>Example 1:) Therefore, based on Example 1, it is predicted that the surface morphology of the prepared membrane will exhibit a ridge-like structure.

[0044] Example 6

[0045] Glutaryl chloride was selected as the organic phase monomer, and MIL-101 was used as the nano-additive for simulation calculations. The CIF file of MIL-101 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the C of Cr-OC in MIL-101 and the free H of glutaryl chloride. The Lewis acid-base theory was selected as the theoretical model. The adsorption energy was simulated using the DFT of the DMol3 module in Materials Studio software to obtain the adsorption configuration of MIL-101 and glutaryl chloride molecules in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the PWC exchange correlation function and the local density approximation (LDA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 2 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). The solvation effect of the MIL-101 and glutaryl chloride molecular adsorption model was treated using COSMO in hexane solvent with a dielectric constant of 1.89. For example... Figure 9 As shown, the interatomic distance between MIL-101 and glutaryl chloride is (>Example 3: Therefore, based on Example 3, it is predicted that the surface morphology of the prepared film will exhibit a granular structure.

[0046] Example 7

[0047] 2-Methylpiperazine was selected as the aqueous monomer, and HKUST-1 was used as the nano-additive for simulation calculations. The CIF file of HKUST-1 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Cu-OC in HKUST-1 and the N of 2-methylpiperazine. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software, obtaining the adsorption configuration of HKUST-1 and 2-methylpiperazine molecules in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the BP exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. The dual numerical polarization (DNP) basis set was used to describe atomic orbitals. The optimized convergence tolerance is 2×10 -5 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effect of the HKUST-1 and 2-methylpiperazine adsorption models. For example... Figure 10 As shown, the interatomic distance between HKUST-1 and 2-methylpiperazine is (>Example 2: Therefore, based on Example 2, it is predicted that the surface morphology of the prepared membrane will exhibit a ridge-like structure.

[0048] Example 8

[0049] Terephthalic acid chloride (TBCC) was selected as the organic phase monomer, and HKUST-1 was used as the nano-additive for simulation calculations. The CIF file of HKUST-1 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the C of Cu-OC in HKUST-1 and the free H of TBCC. The Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DMol3 module of Materials Studio software via DFT, yielding the adsorption configuration of HKUST-1 and TBCC molecules in a stable equilibrium state. Parameter settings in the DMol3 module: the spin polarization density function was calculated using the BOP exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 2 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). The solvation effect of the HKUST-1 adsorption model with terephthalic acid chloride was treated using COSMO in hexane solvent with a dielectric constant of 1.89. (e.g.) Figure 11 As shown, the interatomic distance between HKUST-1 and terephthaloyl chloride is (>Example 3: Therefore, based on Example 3, it is predicted that the surface morphology of the prepared film will exhibit a granular structure.

[0050] Example 9

[0051] Diaminotoluene was selected as the aqueous monomer, and HKUST-1 was used as the nano-additive for simulation calculations. The CIF file of HKUST-1 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Cu-OC in HKUST-1 and the N of diaminotoluene. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software, obtaining the adsorption configuration of HKUST-1 and diaminotoluene molecules in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the PWC exchange correlation function and the local density approximation (LDA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. The dual numerical polarization (DNP) basis set was used to describe atomic orbitals. The optimized convergence tolerance is 1×10 -5 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effect in the HKUST-1 and diaminotoluene adsorption model. For example... Figure 12 As shown, the interatomic distance between HKUST-1 and diaminotoluene is (<Example 2: Therefore, based on Example 2, it is predicted that the surface morphology of the prepared membrane will exhibit a granular structure.

[0052] Example 10

[0053] m-Phenylenediamine was selected as the aqueous monomer, and MOF-5 was used as the nano-additive for simulation calculations. The CIF file of MOF-5 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Zn-OC in MOF-5 and the N of m-Phenylenediamine. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software to obtain the adsorption configuration of MOF-5 and m-Phenylenediamine molecules in a stable equilibrium state. Parameter settings in the DMol3 module: the spin polarization density function was calculated using the Perdew Wang 1991 (PW91) exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 1 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effect in the MOF-5 and m-phenylenediamine adsorption model. For example... Figure 13 As shown, the interatomic distance between MOF-5 and m-phenylenediamine is... (<Example 2: Therefore, based on Example 2, it is predicted that the surface morphology of the prepared membrane will exhibit a granular structure.

[0054] Example 11

[0055] 2-Methylpiperazine was selected as the aqueous monomer, and MOF-5 was used as the nano-additive for simulation calculations. The CIF file of MOF-5 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, and the MOF-5 and 2-methylpiperazine molecules were plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the free H of Zn-OC in MOF-5 and the N of 2-methylpiperazine. Lewis acid-base theory was selected as the theoretical model. The adsorption energy of the system was simulated using the DFT of the DMol3 module in Materials Studio software to obtain the adsorption configuration of MOF-5 and 2-methylpiperazine molecules in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the PBE exchange correlation function and the generalized gradient approximation (GGA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 1 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). A conductor-like shielding model (COSMO) with a dielectric constant of 75.84 was used to handle the solvation effect in the MOF-5 and 2-methylpiperazine adsorption models. For example... Figure 14 As shown, the interatomic distance between MOF-5 and 2-methylpiperazine is (>Example 2: Therefore, based on Example 2, it is predicted that the surface morphology of the prepared membrane will exhibit a ridge-like structure.

[0056] Example 12

[0057] Terephthaloyl chloride was selected as the organic phase monomer, and MOF-5 was used as the nano-additive for simulation calculations. The CIF file of MOF-5 was retrieved from the CCDC crystal structure database to obtain its three-dimensional chemical structure, which was then plotted using Materials Studio software. The chemical structures of each component were optimized using the DMol3 module. Based on the chemical structure, functional group and electronic orbital information were obtained, and the adsorption site was determined to be the hydrogen bond between the C of Zn-OC in MOF-5 and the free H of terephthaloyl chloride. The Lewis acid-base theory was selected as the theoretical model. The adsorption energy was simulated using the DFT of the DMol3 module in Materials Studio software to obtain the adsorption configuration of MOF-5 and terephthaloyl chloride in a stable equilibrium state. Parameter settings in the DMol3 module: Spin polarization density function calculations were performed using the PWC exchange correlation function and the local density approximation (LDA) for geometry optimization and energy calculation. DFT semi-core pseudopots were used for core processing. Dual numerical polarization (DNP) basis sets are used to describe atomic orbitals. The optimized convergence tolerance is 1 × 10⁻⁶. -5 Ha (energy) (maximum force) and (Minimum displacement). The solvation effect of the MOF-5 and terephthalic acid adsorption model was treated using COSMO in hexane solvent with a dielectric constant of 1.89. For example... Figure 15 As shown, the interatomic distance between MOF-5 and terephthaloyl chloride is (>Example 3: Therefore, based on Example 3, it is predicted that the surface morphology of the prepared membrane will exhibit a ridge-like structure.

[0058] Instruction manual attached Figure 1-3 In section 7-15, the types of atoms represented by each color are as follows: O: red; N: dark blue; H: white; C: gray; Zr: cyan. Figure 1-3 ); Cr: pale purple ( Figure 7-9 Cu: orange ( Figure 10-12 Zn: dark gray Figure 13-15 Simulation results show that when MOF is used as an aqueous phase additive, it has a larger adsorption energy with aqueous phase monomers (diamines) (e.g., Example 1: -39.476 kcal / mol); while when MOF is used as an organic phase additive, the interaction between MOF and organic phase monomers (acyl chlorides) is weaker (e.g., Example 3: -26.387 kcal / mol). Based on the simulation results, surface electron microscopy images of the polyamide layer prepared by interfacial polymerization are shown. Figure 4-6The results show that: 1) When nanomaterials are added to the organic phase, the interaction force between the additive and the organic phase monomers is not significant, and because the PA layer is formed near the interface and far from the aqueous phase, the surface of the prepared film basically exhibits the granular morphology of the additive; 2) When nanomaterials are added to the aqueous phase, the interaction force and intermolecular distance between the additive and the aqueous phase monomers change significantly: when the interaction distance meets the following conditions... (Example 2) > Interaction force between the two > (Example 1) When the interaction distance between the aqueous monomer and the MOF additive is relatively short, the surface of the formed PA layer tends to have a granular structure; when the interaction distance satisfies the interaction force between the two > (Example 2) The interaction distance between the aqueous monomer and the MOF additive becomes longer, and the resulting PA layer tends to have a ridge-like structure. Therefore, this invention can simulate the interaction between MOF materials as additives and two-phase monomers and obtain theoretical calculation results, and can be widely used in the morphology prediction of polyamide separation layers prepared by interfacial polymerization reactions.

[0059] This specific embodiment is merely a demonstration of the simulation and calculation methods described in this application and an introduction to the implementation effects. It is not intended to limit the scope of protection of this application. Therefore, all equivalent changes made based on the theories and methods of this application should be covered within the scope of protection of this application.

Claims

1. A method for calculating the adsorption energy of a MOF material during the interfacial polymerization process for preparing a composite membrane, characterized in that, It comprises the following steps: (1) determining the types of monomers in the water phase and the organic phase of the interfacial polymerization system; (2) constructing the three-dimensional chemical structures of the MOF material, the water phase monomer and the organic phase monomer respectively; (3) optimizing the chemical structures of the components by using the Materials Studio software; the chemical structures of the MOF material, the water phase monomer and the organic phase monomer are optimized by using the Materials Studio software, and one of the selected calculation modules is CASTEP, DFTB+, DMol3, Forcite and Gaussian; according to the density functional theory (DFT), the lowest energy value of each molecule is calculated; (4) determining the adsorption sites and selecting the adsorption theoretical model according to the functional group and electron orbital information obtained from the chemical structure; the adsorption sites are determined according to the electrons and electron orbits of the atoms, and a suitable theoretical model is selected; the adsorption theoretical model is one or more of the molecular frontier orbital theoretical model, the Lewis acid-base theoretical model, the proton theoretical model and the "π-π" interaction theoretical model containing a benzene ring structure; (5) performing density functional theory (DFT) simulation calculation by using the Materials Studio software, and obtaining the binding energy of each adsorption model and the distance between the interaction atoms of each component molecule after the system is balanced; the optimized molecular model obtained by the construction method in step (2) and the energy value obtained in step (3) are used to simulate the adsorption energy of the system by DFT by using the Materials Studio software, to obtain the adsorption configuration between the stable equilibrium state MOF material and the water phase monomer and the oil phase monomer and to calculate the distance between the interaction atoms and the adsorption energy of the molecules.

2. The method of claim 1, wherein the method is used for calculating the adsorption energy of a simulated MOF material in the process of interfacial polymerization for preparing a composite membrane. In step (1), the water phase solvent is water; the organic phase solvent is n-hexane; the water phase monomer is one of piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, β-cyclodextrin, p-phenylenediamine, m-phenylenediamine, murexide, and diaminotoluene; and the organic phase monomer is one of murexide, p-phenylenediamine, m-phenylenediamine, butanetriyl chloride, pentanetriyl chloride, and glutaryl chloride.

3. The method of claim 1, wherein the method is used for calculating the adsorption energy of a simulated MOF material in the process of interfacial polymerization for preparing a composite membrane. In step (2), the three-dimensional chemical structure of the two-phase monomer is built according to the molecular charge, spatial atomic coordinates, bond length and bond angle; the CIF file of the MOF is retrieved from the CCDC crystal structure database to construct the three-dimensional chemical structure.

4. The method of claim 1, wherein, Convergence tolerance is 10 when the calculation module is DMol3 -4 Ha, 2 x 10 -5 Ha, 1 x 10 -5 Ha; the maximum force required for optimization is one of Ha; the minimum displacement required for optimization is one of Ha; One of the local density approximation functional and the generalized gradient approximation functional is selected for calculation; one of PW91, BP, PBE, BLYP, VWN and BOP is selected as the exchange correlation function; one of Coarse, Medium and Fine is selected as the calculation integral precision; the DNP basis set is selected and the solvation model is checked to meet the calculation requirements of the solution system.

5. A method for calculating the adsorption energy of a MOF material during the interfacial polymerization process for preparing a composite membrane, characterized in that, The MOF material and the two-phase monomer adsorption energy calculation method according to any one of claims 1-4 is adopted.

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