CN115124677B

CN115124677B - Meltable metallic organic framework material and covalent organic framework material, and preparation methods and uses thereof

Info

Publication number: CN115124677B
Application number: CN202210748788.9A
Authority: CN
Inventors: 万重庆; 辜小玲; 李国强
Original assignee: Capital Normal University
Current assignee: Capital Normal University
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2023-09-26
Anticipated expiration: 2042-06-28
Also published as: CN115124677A

Abstract

The invention discloses a meltable metal organic framework material, a covalent organic framework material, a preparation method and application thereof. The glassy state a is prepared by modification of the metal organic framework material and the covalent organic framework material by an internal salt structure R and by the introduction of a Bronsted acid _g MOF-R.HA and a _g The COF-R.HA material can be heated and melted at medium and low temperatures, so that the melting processing of the material is realized, and the unavoidable grain boundary problem in the processing process of the polycrystalline material is overcome. The MOF/COF material after melt processing has the characteristics of a glass structure, is favorable for obtaining a high-conductivity and planar two-dimensional material, and expands the application of the material in different fields including proton or lithium ion conduction.

Description

Meltable metallic organic framework material and covalent organic framework material, and preparation methods and uses thereof

Technical Field

The invention relates to the field of advanced material processing, in particular to an inner salt structure modified covalent organic framework material, a preparation method and application thereof, and more particularly relates to a glassy material prepared by low-temperature hot melting and low-temperature processing of an ionic liquid functionalized metal organic framework material and a covalent organic framework material.

Background

As porous crystalline materials, metal organic framework materials (MOF, metal organic framework) and covalent organic framework materials (COF, covalent Organic Framework) have large surface areas, customizable pore sizes, ligand modifiable properties, and tunable three-dimensional channels, and are widely used in the fields of gas adsorption and storage, separation, catalysis, sensing, conduction, and the like. At present, many industrial practical problems are faced in applications, such as that the materials exist in powder form and cannot form films or fibers with high mechanical strength. Generally, high-pressure granules, interfacial polymerization, vacuum filtration and other methods are used for molding metal organic frame materials and covalent organic frame material powder, but these treatment methods significantly reduce the performance of the materials, and cannot realize large-scale preparation of COF/MOF film materials with defects and strong mechanical properties. To overcome these disadvantages, reasonThe solution is that the metal organic frame material and the covalent organic frame material can be melted before the thermal decomposition temperature, the liquid COF/MOF is cast and molded, and then the COF/MOF glass is obtained through quenching. However, there are only a few nitrogen-containing heterocyclic ligands and divalent metals Zn in MOF materials ²⁺ Or Co ²⁺ ZIFs formed by ion coordination can be melted by heat, and the decomposition temperature of the COF material is often lower than the melting temperature of the COF material, so that the COF material is decomposed without melting when being heated, and a liquid COF material cannot be obtained, which greatly limits the COF/MOF material.

Attempts have been made to modify COF materials, for example in document Accumulation of Glassy Poly (ethylene oxide) Anchored in a Covalent Organic Framework as a Solid-State Li ⁺ Electroyte, gen Zhang et al, J.am.chem.Soc.2019,141,1227-1234, in which a bottom-up self-assembly process is reported in which 3-molecule, 6-molecule and 9-molecule polymeric polyethylene oxide (PEO) chains are introduced into the interior space of a two-dimensional COF, the accumulated PEO chains being highly dynamic and glassy, rapid transport being achieved by their segmental motion to dissolve lithium ions. However, the surface modification is only carried out on the COF framework material, the COFs melting is not realized by the increased PEO chains, and the pure thermal melting of the COF material is not reported yet; in addition, the use of inorganic porous films in the glassy state after conversion for efficient separation of gases is disclosed in the prior art Coordination Polymer Glasses with Lava and Healing Ability for High-Performance Gas Sieving, jie Li et al (Angew. Chem. Int. Ed.10.1002/anie. 202102047), and Liquid, glass and amorphous solid states of coordination polymers and metal-organic frameworks, T.D Bennett et al (Nat. Reviews doi. Org/10.1038/s 41578-018-0054-3) by facilitating melting of coordination polymers Coordination Polymer (CP) or metal-organic framework (MOF) by simple heating or hot pressing methods. These results are limited to only nitrogen-containing heterocyclic ligands and divalent metals Zn ²⁺ 、Co ²⁺ The ionic coordination of CP or MOF has not been reported for the most stable, most abundant thermal melting of carboxylic acid ligand-based compounds in this family.

There is therefore still a need to develop new methods of MOF/COF materials that can be hot melted. Therefore, the application provides the MOF/COF material modified by the inner salt structure, which can realize low-temperature hot melting in the middle, thereby opening up a new processing path of the MOF/COF material, overcoming the defect of difficult processing of MOF/COF powder and expanding the application of the MOF/COF material in separation and purification, proton conduction and lithium ion conduction. Realizes the large-scale preparation of MOF/COF film materials with flexibility, no defects and strong mechanical processing property.

Disclosure of Invention

To solve the above problems, the present application provides a MOF or COF material which is meltable at a medium and low temperature, which is prepared by first synthesizing a metal organic framework material or a covalent organic framework material (MOF/COF-DHz-R) having an internal salt structure modification, and then incorporating a different kind of Bronsted acid (HA) into the MOF/COF-DHz-R, and further preparing the glass body a by heat quenching _g MOF-R.HA or a _g COF-DHz-R.HA, the material can be used for embedding and loading fast ion conductive materials and substances (harmful substances and medicines), and the solvent activation material can be used for preparing membrane materials with separation and purification effects.

According to one aspect of the present invention, it is an object of the present invention to provide an internal salt structure modified covalent organic framework material consisting of C ₃ Symmetrical aldehyde monomers and C modified with an internal salt structure R ₂ Symmetrical hydrazide monomers (DHz-R) are obtained by Schiff base condensation reactions, wherein C ₃ Symmetrical aldehyde monomers and C modified with an internal salt structure R ₂ The molar ratio of symmetrical hydrazide monomers was 2:3.

Wherein the C ₃ The symmetrical aldehyde monomers are selected from the compounds shown below:

the C modified with an internal salt structure R ₂ The symmetrical hydrazide monomer is selected from the compounds shown below：

Wherein R is selected from the following structures:

wherein n is an integer of 2, 3, 4 or 5;

preferably, when R is selected fromWhen n is an integer of 3, 4 or 5;

preferably, when R is selected from When n is an integer of 3 or 4.

According to another aspect of the present invention, it is another object of the present invention to provide a meltable material prepared from the internal salt structure modified covalent organic framework material structure, the meltable material being prepared by reacting the internal salt structure modified covalent organic framework material with a bronsted acid (HA), wherein the bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethanesulfonimide (TFSA), phosphoric acid (H ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of the following.

Preferably, in the preparation of the fusible material with the covalent organic framework modified by the inner salt structure, the covalent organic framework material with the inner salt structure and the Bronsted acid (HA) are ground until the covalent organic framework material and the Bronsted acid (HA) are uniformly mixed, then the mixture is heated at a medium temperature of 100-250 ℃ for 30-40 min to obtain a melt, and then the melt is cooled and quenched to prepare the glassy product, wherein the molar ratio of the covalent organic framework material with the inner salt structure to the HA is 1:1-1:10, and is preferably 1:1.

According to yet another aspect of the present invention, it is a further object of the present invention to provide a method for preparing the internal salt structure modified covalent organic framework material, the method comprising the steps of:

(1) Preparation of C2 symmetrical hydrazide monomer (DHz-R) modified with inner salt structure R:

the C2 symmetrical amino/imidazole/pyridyl modified hydrazide monomer (DHz) is utilized to carry out ring opening reaction with sultone/dicyano vinyl acid lactone, or amino/imidazole/pyridyl modified hydrazide precursor (DHz) is utilized to carry out substitution and dealcoholization reaction with different alkyl bromocarboxylic acid esters, thus obtaining C modified with an inner salt structure R ₂ Symmetrical hydrazide monomer (DHz-R);

(2) Preparation of inner salt structure modified covalent organic framework COF material:

c modified with inner salt structure R obtained in step (1) ₂ Symmetrical hydrazide monomers (DHz-R) and corresponding C ₃ Placing symmetrical aldehyde monomers in a mixed solvent, adding a protonic acid catalyst, ultrasonically mixing, vacuumizing, sealing a reaction system, reacting for 3-8 days at 120-130 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain precipitation, cleaning the precipitation, drying and activating to obtain the covalent organic framework COF material (COF-DHz-R) with modified inner salt structure.

Preferably, in step (1), the C modified with an internal salt structure R ₂ The symmetrical hydrazide monomer is selected from the compounds shown below:

preferably, the corresponding inner salt having the R structure in step (1) is selected from the group consisting of inner sulfamate, inner aminocarboxylic acid, inner aminodicyanovinyl acid, inner imidazole sulfonate, inner imidazole carboxylate, inner imidazole dicyanovinyl acid, inner pyridine sulfonate, inner pyridine carboxylate, inner pyridine dicyanovinyl acid

Further preferably, in step (1), R is selected from the following structures:

wherein n is an integer of 2, 3, 4 or 5;

preferably, when R is selected fromWhen n is an integer of 3, 4 or 5;

Preferably, when R is selected fromWhen n is an integer of 3, 4 or 5;

preferably, when R is selected from When n is an integer of 3 or 4.

More preferably, the corresponding inner salt of the R structure is selected from APS (inner salt of aminopropanesulfonic acid, n=3), ABS (inner salt of aminobutanesulfonic acid, n=4), MIMPS (inner salt of imidazolium propane sulfonic acid, n=3) and MIMBS (inner salt of imidazolium butane sulfonic acid, n=4).

Preferably, said C in step (2) ₃ The symmetrical aldehyde monomers are selected from the compounds shown below:

preferably, the mixed solvent in the step (2) is mesitylene and 1, 4-dioxane in a volume ratio of 9:1 or o-dichlorobenzene and n-butanol in a volume ratio of 1:1.

Preferably, the protonic acid catalyst in step (2) is trifluoroacetic acid or an aqueous acetic acid solution.

According to still another aspect of the present invention, it is still another object of the present invention to provide a method for preparing the meltable material having the internal salt structure-modified covalent organic framework structure, the method comprising the steps of:

taking a certain amount of covalent organic framework COF material (COF-DHz-R) modified by inner salt structure, grinding to be fluffy, quantitatively transferring different kinds of Bronsted acids (HA), continuously grinding until the materials are uniformly mixed, heating at a medium temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching to obtain a glassy product a _g COF-DHz-R·HA。

Preferably, the molar ratio of COF-DHz-R material to bronsted acid (HA) is between 1:1 and 1:10, preferably 1:1; the heating temperature is 100-160 ℃; the heating time is 1-5min.

Preferably, the bronsted acid (HA) is methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethanesulfonimide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of the following.

According to one aspect of the present invention, it is an object of the present invention to provide an internal salt structure modified Metal organic framework material formed into a porous MOF material by coordination bonds of Metal ions (M) or Metal clusters (Metal clusters) and internal salt modified dicarboxylic acid organic ligands (L-R);

wherein the metal M is a transition metal ion of 3 to 4 valences selected from Fe, cr, zr, ti or Hf, for example, may be selected from Fe ³⁺ 、Cr ³⁺ 、Zr ⁴⁺ Ti or Hf ⁴⁺ ；

The metal cluster is selected from [ M ] ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、 [MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ] ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ 、Ti ⁴⁺ Or Hf ⁴⁺ UiO-66/67/68 (Zr) or UiO-66/67/68 (Ti) or UiO-66/67/68 (Hf)).

Wherein the dicarboxylic acid organic ligand L-R is selected from the compounds shown below:

preferably, when R is selected fromWhen n is an integer of 3, 4 or 5;

Preferably, when R is selected fromWhen n is an integer of 3 or 4.

More preferably, the corresponding inner salt of the R structure is selected from APS (inner salt of aminopropanesulfonic acid, n=3), ABS (inner salt of aminobutanesulfonic acid, n=4), MPPS (inner salt of pyridylpropanesulfonic acid, n=3).

According to another aspect of the present invention, it is another object of the present invention to provide a meltable material (MOF-r·ha) having the internal salt structure-modified metal-organic framework structure, which is prepared by reacting the internal salt structure-modified metal-organic framework material with a bronsted acid (HA), wherein the bronsted acid is selected from the group consisting of: methanesulfonic acid (MSA), ethanesulfonic acid (ESA), trifluoromethanesulfonic acid (TFA), bistrifluoromethanesulfonic acidImide (TFSA), phosphoric acid (H) ₃ PO ₄ ) Sulfuric acid (H) ₂ SO ₄ ) Any one of the following.

Preferably, in the preparation of the meltable material with the internal salt structure modified metal organic framework material, the internal salt structure modified metal organic framework material and the bronsted acid (HA) are ground until the internal salt structure modified metal organic framework material and the bronsted acid (HA) are uniformly mixed, then heated at a medium temperature of 100-250 ℃ for 30-40 min to obtain a melt, and then cooled and quenched to obtain a glassy product, wherein the molar ratio of the ligand L-R to the HA in the internal salt structure modified MOF framework material is between 1:3 and 1:10, and is preferably 1:4.

According to another aspect of the present invention, it is another object of the present invention to provide a method for preparing the internal salt structure modified metal organic framework material (MOF-R), the method comprising the steps of:

(1) Preparation of inner salt structure modified dicarboxylic acid organic ligand L-R

The corresponding reaction precursor amino/pyridyl modified dicarboxylic acid organic ligand and sultone/dicyanovinyl lactone are subjected to ring opening reaction, or the amino/pyridyl modified dicarboxylic acid organic ligand and different alkyl bromocarboxylate are subjected to substitution and dealcoholization reaction, so that dicarboxylic acid organic ligand (L-R) modified with an inner salt structure R is obtained;

(2) Preparation of inner salt structure modified metal organic framework MOF-R material:

placing the inner salt modified dicarboxylic acid organic ligand (L-R) and the Metal salt corresponding to the Metal (M) or the Metal cluster (Metal cluster) in an N, N-Dimethylformamide (DMF) solvent, adding a protonic acid regulator, ultrasonically mixing, reacting in a polytetrafluoroethylene lining reaction kettle at the temperature of 80-180 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain reaction precipitate, and cleaning, drying and activating the precipitate to obtain the porous MOF-R material with the inner salt modified structure.

Preferably, the ratio of the organic ligand (L-R) to the metal salt in step (2) is 1:1.

Preferably, in step (2), the protic acid modifier is preferably 75 equivalents of acetic acid based on 1 equivalent of the metal salt.

Preferably, the metal M in step (2) is a transition metal ion of 3 to 4 valences selected from Fe, cr, zr or Hf, and may be selected from Fe, for example ³⁺ 、Cr ³⁺ 、Zr ⁴⁺ Or Hf ⁴⁺ ；

The metal cluster is selected from [ M ] ₃ (μ ₃ -O/OH)(COO) ₆ ](M＝Fe ³⁺ ，Cr ³⁺ ，MiL-101，MiL-100)、 [MO ₄ (OH) ₂ ](M＝Al ³⁺ DUT-5) and [ M ] ₆ O ₄ (μ ₃ -OH) ₄ ](M＝Zr ⁴⁺ Or Hf ⁴⁺ UiO-66 (Zr) or UiO-66 (Hf)).

Preferably, the dicarboxylic acid organic ligand L-R in step (1) is selected from the compounds shown below:

preferably, when R is selected fromWhen n is an integer of 3, 4 or 5;

preferably, when R is selected fromWhen n is an integer of 3 or 4.

According to another aspect of the present invention, it is another object of the present invention to provide a method for preparing the meltable material having the internal salt structure-modified metal-organic framework structure, the method comprising the steps of:

taking a certain amount of MOF-R material, grinding the MOF-R material in a mortar until the powder is fluffy, quantitatively transferring Bronsted acid (HA), transferring the Bronsted acid (HA) into the mortar, continuously grinding until the MOF-R material is uniformly and completely mixed, and controlling the temperature to be between 100 and 250 DEG C Heating for 30-40 min to obtain melt, cooling and quenching to obtain glassy product a _g MOF-R·HA。

Preferably, by controlling the amount of acid to be different to control the melting point of the sample, MOF-r.ha having different melting points is obtained, wherein the molar ratio of dicarboxylic acid organic ligand L-R to HA in the MOF-R is between 1:3 and 1:10, preferably 1:4 is selected; the heating temperature is 100-160 ℃.

According to another aspect of the present invention, it is another object of the present invention to provide the fusible material of the COF or metal organic framework material MOF having the covalent organic framework structure modified by the inner salt structure as an ion conductive material (e.g., H ⁺ 、Li ⁺ 、Na ⁺ 、K ⁺ Etc.), optical devices, multifunctional glasses, gas adsorption separation membranes, etc.

Compared with the prior art, the invention has the beneficial effects that:

the MOF-R.HA material modified by the ionic liquid can be heated and melted at medium and low temperature to form a glassy state a _g The MOF-R.HA material HAs the advantages of uniformity, continuity, no defect and light transmission, is favorable for the application of the MOF of the metal organic framework material on ion conductive materials, and can be used as a novel optical device material.

According to the invention, binary ionic liquid is introduced into the metal organic framework, so that the melt processing of MOFs (metal organic frameworks) materials, such as film material preparation and material molding, can be promoted, and the characteristics of main and guest materials can be recovered by removing guest molecules, so that the application requirements of adsorption, separation and the like of the pore materials can be met.

The covalent organic framework material synthesized by the invention belongs to beta-ketoenamine COF, and can maintain chemical stability in strong acid, strong alkali and different solvents.

According to the invention, an inner salt structure modified hydrazide monomer and an aldehyde group monomer are subjected to Schiff base reaction to prepare beta-ketoenamine COFs, and different kinds of Bronsted acids are introduced into a covalent organic framework material by a grinding impregnation method to prepare the ionic liquid modified COF material. The glass-state COF material formed by heating and melting at a certain temperature has the advantages of uniformity, continuity and no defect, and is beneficial to the further development of covalent organic framework materials in proton conducting and lithium ion conducting materials.

The covalent organic framework material modified by the meltable inner salt structure is designed and synthesized, so that the difficult problem that the COF material is difficult to process is solved, the uniform synthesis is facilitated, the separation membrane with strong processability is realized, and the application of the covalent organic framework material in separation and purification is expanded.

The covalent organic framework material modified by the meltable inner salt structure is designed and synthesized, the unavoidable grain boundary problem of the polycrystalline conductive material is solved, the COF material after the melting processing has enough sites, the high conductivity is facilitated to be obtained, and the application of the covalent organic framework material in proton conductivity and lithium ion conductivity is expanded.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will briefly explain the drawings needed in the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention and that other drawings can be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is an X-ray powder diffraction pattern of the material COF-DHz-APS obtained in example 1.

FIG. 2 is an infrared spectrum of the material COF-DHz-APS obtained in example 1.

FIG. 3 is a schematic diagram of the materials COF-DHz-APS-MSA, COF-DHz-APS-ESA, a obtained in example 3 _g COF-DHz-APS·MSA，a _g X-ray powder diffraction pattern of COF-DHz-APS. ESA.

FIG. 4 is a differential scanning calorimeter of the materials COF-DHz-APS, COF-DHz-APS. MSA obtained in examples 1 and 3.

FIG. 5 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g COF-DHz-APS·MSA， a _g COF-DHz-APS ESA, and SAXS profile of reference polycarbonate, silica glass panel.

FIG. 6 is a material a obtained according to example 3 _g Polarized light microscopy of COF-DHz-APS.MSA.

FIG. 7 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g SEM image of COF-DHz-APS.MSA.

FIG. 8 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g Conductivity map of COF-DHz-APS. MSA.

FIG. 9 is an X-ray powder diffraction pattern of the material COF-DHz-MIMPS obtained in example 2.

FIG. 10 is an infrared spectrum of a material COF-DHz-MIMPS obtained in example 2.

FIG. 11 is an optical micro-mirror photograph of the material COF-DHz-MIMPS.MSA obtained in examples 2 and 4 before and after heating.

FIG. 12 is a material a obtained according to example 4 _g Polarized light microscopy of COF-DHz-MIMPS.MSA.

FIG. 13 is the COF-DHz-MIMPS, a of the materials obtained in examples 2 and 4 _g Conductivity map of COF-DHz-MIMPS-MSA.

FIG. 14 is a diagram of materials UiO-66, uiO-66-APS. MSA, uiO-66-APS. ESA, a according to examples 5-6 _g UiO-66-APS.MSA and a _g Powder X-ray diffraction pattern of UiO-66-APS. ESA.

FIG. 15 is an optical micrograph of the materials UiO-66-APS. MSA and UiO-66-APS. ESA obtained in example 5 according to the present invention before and after heating.

FIG. 16 Material a according to example 5 _g The UIO-66-APS-MSA and the UIO-66-APS-ESA are pictures under the conditions that the polarization microscope performs parallel polarization analysis, and the upper and lower analyzers form an angle of 45 degrees and orthogonal polarization analysis.

FIG. 17 is a diagram of the materials UiO-66-APS. MSA, uiO-66-APS. ESA, a obtained according to examples 5-6 _g UiO-66-APS.MSA and a _g SEM image of UiO-66-APS. ESA.

FIG. 18 is a differential scanning calorimeter of materials UiO-66-APS. MSA and UiO-66-APS. ESA obtained in example 5.

FIG. 19 is a material a obtained according to example 6 _g UiO-66-APS.MSA and a _g Conductivity diagram of UiO-66-APS ESA.

FIG. 20 is a diagram of materials UiO-67, uiO-67-MPPS, uiO-66-MPPS. MSA, a according to examples 7 and 8 _g Powder X-ray diffraction pattern of UiO-66-MPPS.MSA.

FIG. 21 is an optical microscope photograph of the material UiO-67-MPPS.MSA obtained in example 7 before and after heating.

FIG. 22 is a photograph of the material UiO-67-MPPS.MSA obtained in examples 7 and 8 under an optical microscope before and after heating, and under parallel and orthogonal polarization analyses by a polarized light microscope.

FIG. 23 is a diagram of the material UiO-67-MPPS.MSA, a obtained in example 5 _g SEM image of UiO-67-MPPS.MSA.

FIG. 24 is a differential scanning calorimetric diagram of the material UiO-67-MPPS.MSA obtained in example 7.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be interpreted that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Accordingly, the description herein is for the purpose of illustrating preferred examples only and is not intended to limit the scope of the invention, as it will be understood that other equivalent implementations and modifications may be made without departing from the spirit and scope of the invention.

The covalent organic framework material (COF-DHz-R) modified by the inner salt structure is prepared from C ₃ Symmetrical aldehyde monomers and C modified with an internal salt structure R ₂ Symmetrical hydrazide monomer (DHz-R) generalObtained by Schiff base condensation reaction, taking COF-DHz-APS and COF-DHz-MIMPS as examples, namely R is an sulfamic acid inner salt (APS) group (n=3) or an imidazole sulfonic acid inner salt (MIMPS) group (n=3), and the structural formula is as follows:

In the preparation method of the inner salt structure modified covalent organic framework material, the preparation method comprises the following steps:

(a) When the internal salt structure of the hydrazide monomer DHz-R is an ammonium salt, the DHz-R preparation chemistry is shown in equation 1 below:

the general chemical reaction is a hydrazide precursor DHz-NH modified by an amino group ₂ With sultone, dicyano vinyl acid lactone, or amino-modified hydrazide precursor DHz-NH ₂ Substitution and dealcoholization with different alkyl bromocarboxylate to prepare ammonium salt inner salt modified DHz-R.

The synthesis of specific ammonium propane sulfonate APS inner salt modified hydrazide monomer DHz-APS is exemplified by (n=3): dimethyl 2-aminoterephthalate (3.77 g,18 mmol) and liquid nitrogen cooled 1, 3-propane sultone (1494 ul,18 mmol) were sufficiently ground and uniformly mixed in a mortar, then transferred to a 20ml single-port bottle, reacted at 90-150 c, preferably 130 c for 1-8 hours, preferably 3 hours, after the reaction was completed, the reaction system was cooled, the resulting dark red solid was washed 2 to 4 times with acetic acid (17M), then washed twice with acetone, and dried to obtain white dimethyl terephthalate powder modified with an inner Ammonium Propane Sulfonate (APS) structure. And then placing the mixture and hydrazine hydrate solution in absolute ethyl alcohol in a molar ratio of 1:2, reacting at room temperature to 120 ℃, preferably 80 ℃ for 1-48 hours, preferably 36 hours, centrifuging to obtain precipitate, and drying the precipitate to obtain yellow APS inner salt structure modified hydrazide monomer DHz-APS.

(b) When the internal salt structure of the hydrazide monomer DHz is imidazole, pyridine salt, the chemical reaction is shown in the following reaction formula 2:

the general chemical reaction is a ring-opening reaction of imidazole/pyridyl modified hydrazide precursor with different sultone/dicyano vinyl acid lactone, or a substitution and dealcoholization reaction of imidazole/pyridyl modified hydrazide precursor with different alkyl bromocarboxylate.

Taking synthesis of specific MIMPS-modified hydrazide monomer DHz-MIMPS with the imidazole propyl sulfonate inner salt structure as an example (n=3): dimethyl 2- (imidazolylmethyl) biphenyl-4, 4' -dicarboxylate (2.0 g,5.71 mmol) was dissolved in acetone, and 1, 3-propanesultone (0.697 g,5.71 mmol) was slowly added. Stirring the solution at room temperature for 2-7 days, preferably 5 days, filtering, precipitating, washing with acetone, and drying to obtain white powder of dimethyl biphenyl-4, 4' -dicarboxylate modified by MIMPS of imidazole sulfonate inner group. And then placing the mixture and hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, reacting at the temperature of between room temperature and 120 ℃, preferably at the temperature of 80 ℃ for 1 to 48 hours, preferably 36 hours, centrifuging to obtain precipitate, and drying the precipitate to obtain white MIMPS inner salt structure modified hydrazide monomer DHz-MIMPS.

c modified with inner salt structure R obtained in step (1) ₂ Symmetrical hydrazide monomers (DHz-R) and corresponding C ₃ Placing symmetrical aldehyde monomer into mixed solvent, adding protonic acid to promoteAnd (3) carrying out ultrasonic mixing on the catalyst, vacuumizing, sealing the reaction system, reacting for 3-8 days at 120-130 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain precipitate, and washing, drying and activating the precipitate to obtain the covalent organic framework COF material (COF-DHz-R) with modified inner salt structure.

Preferably, in step (a) of step (1), the molar ratio of the amino-modified DHz precursor to the sultone (n=3, 4)/bromocarboxylate (n=3, 4, 5)/dicyano-vinyl lactone (n=2, 3) is 1:1 to 1:5, and the reaction temperature is 90 to 160 ℃.

Preferably, in step (1) of (b), the molar ratio of imidazole/pyridine modified hydrazide precursor DHz to sultone (n=3, 4)/bromocarboxylate (n=3, 4, 5)/dicyano vinyl lactone (n=2, 3) is 1:1 to 1:5, and the reaction temperature is from room temperature to 160 ℃.

The Metal organic framework MOF material modified by the inner salt structure forms a porous MOF-R material through coordination bonds by Metal ions (M) or Metal clusters (Metal clusters) and an inner salt modified dicarboxylic acid organic ligand (L-R), wherein the Metal organic framework MOF material takes UIO-66-APS as an example, and the structural formula is as follows: (wherein the polyhedron is represented by M ₆ O ₄ (μ ₃ -OH) ₄ Cluster structural units):

the preparation method of the inner salt structure modified metal organic framework material (MOF-R) comprises the following steps:

(a) Carboxylic acid organic ligands modified when internal salt structures(L-R) is an amino-modified ligand, the general chemical reaction for the preparation of L-R is: dicyano vinyl lactone/sultone is prepared by reacting a ligand precursor modified with an amino group (L-NH ₂ ) The ring-opening reaction or the substitution reaction of bromine by bromocarboxylic acid ester to prepare the dicarboxylic acid organic ligand with modified inner salt structure. L-NH ₂ The molar ratio of the reaction of the body and the sultone (n=3, 4)/bromocarboxylate (n=3, 4, 5)/dicyano vinyl acid lactone (n=2, 3) is 1:1-1:5, the reaction temperature is 90-160 ℃, and the chemical reaction for preparing the catalyst is shown in the following reaction formula 3:

In particular to terephthalic acid ligand H modified by amino propane sulfonate APS inner salt group (n=3) ₂ BDC-APS (n=3) for example, the synthesis proceeds as follows: the dimethyl 2-aminoterephthalate and 1, 3-propane sultone are homogeneously mixed in a molar ratio of 1:1 to 1:1.5, preferably 1:1. The reaction is carried out at 90-150 ℃, preferably 130 ℃ for 1-8 hours, preferably 3 hours, and the temperature of the reaction system is reduced after the reaction is finished. The solid product is washed 2 to 4 times with 1 to 17M acetic acid, preferably 3 times with 17M acetic acid. And (3) centrifugally drying to obtain dimethyl terephthalate with Ammonium Propane Sulfonate (APS) structure modification. Then placing the mixture and potassium hydroxide in a mixed solution of water and methanol according to a molar ratio of 1:4, reacting at room temperature to 120 ℃, preferably 80 ℃ for 8-24 hours, preferably 12 hours, then dropwise adding hydrochloric acid to acidify to pH=1-3, preferably pH=1, filtering to obtain a precipitate, and drying the precipitate to obtain the H modified with the APS inner salt structure ₂ BDC-APS。

(b) When the inner salt structure modified dicarboxylic acid organic ligand L-R is pyridinium ion + sulfonate/carboxylate/dicyano vinyl anion, the general chemical reaction is: the pyridyl modified dicarboxylic acid precursor (L-cy) is subjected to ring opening reaction with different sultone/dicyanovinyl lactone or substitution and dealcoholization reaction with different alkyl bromocarboxylate to prepare dicarboxylic acid organic ligand (L-R) with modified imidazole/pyridinium inner salt structure, wherein the molar ratio of the L-cy to the sultone (n=3, 4, 5)/bromocarboxylate (n=3, 4, 5)/dicyanovinyl lactone (n=2, 3) is 1:1-1:5, the reaction temperature is room temperature to 160 ℃, and the chemical reaction is shown in the following reaction formula 4:

Biphthalic acid ligand H modified with internal salt structure pyridine propyl sulfonate group MPPS (n=3) ₂ BPDC-MPPS synthesis is example (n=3): dimethyl 2- (picolyl) biphenyl-4, 4' -dicarboxylate and 1, 3-propane sultone were dissolved in acetone in a molar ratio of 1:3 to 1:8, preferably 1:8. The solution is stirred at room temperature for 2 to 7 days, preferably 5 days, the precipitate is filtered, washed with acetone and dried to obtain white diphenyl-4, 4' -dicarboxylic acid dimethyl ester powder modified by pyridine sulfonate internal salt group MPPS. Then placing the mixture and lithium hydroxide in a mixed solution of water and methanol according to a molar ratio of 1:2 to 1:4, preferably 1:4, reacting at room temperature to 120 ℃, preferably 80 ℃ for 8 to 24 hours, preferably 12 hours, then dropwise adding hydrochloric acid to acidify to pH=1 to 3, preferably pH=1, filtering to obtain a precipitate, and drying the precipitate to obtain the H with modified MPPS inner salt structure ₂ BPDC-MPPS(L)。

placing the inner salt modified dicarboxylic acid organic ligand (L-R) and the Metal salt corresponding to the Metal (Mtel) or the Metal cluster (Metal cluster) into a solvent, adding a protonic acid regulator, ultrasonically mixing, reacting in a polytetrafluoroethylene lining reaction kettle at 80-180 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain reaction precipitate, cleaning the precipitate, drying and activating to obtain the porous MOF-R material with the inner salt modified structure.

Take the preparation of UiO-66-APS modified with an amino propane sulfonate APS inner salt group as an example: zrCl was ultrasonically treated in a 40ml polytetrafluoroethylene-lined reactor ₄ (326 mg,1.39 mmol) and H ₂ BDC-APS is dissolved in 27ml super dry DMF at a molar ratio of 1:1 to 1:1.5, preferably 1:1, for about 5 to 10 minutes, preferably 10 minutes.45-100 equivalents of acetic acid regulator, preferably 75 equivalents, are added to the DMF solution, and the mixture is subjected to ultrasonic dispersion again for 5 minutes, and the static state of the reaction kettle is stored in an oven at 80-180 ℃ for 24-72 hours, preferably 120 ℃ for 24 hours. After cooling to room temperature in the oven, the solution is centrifuged and the resulting yellow (UiO-66-APS) precipitate is washed 2 to 5 times, preferably 3 times, with DMF and methanol, respectively, and finally soaked in methanol for 48 to 72 hours, preferably 72 hours, during which fresh methanol is changed every 24 hours. Finally, the obtained solid is centrifuged, and dried for 5 to 8 hours, preferably for 150 ℃ and 8 hours at 100 to 150 ℃ in a vacuum oven, so as to obtain the desolvated and activated UiO-66-APS sample.

Taking the preparation of UiO-67-MPPS modified with pyridine propyl sulfonate internal salt structure MPPS as an example: zrCl was ultrasonically treated in a 20ml polytetrafluoroethylene-lined reactor ₄ (56 mg,0.27 mmol) and H ₂ BPDC-MPPS is dissolved in 10ml of super-dry DMF at a molar ratio of 1:1 to 1:1.5, preferably 1:1, for about 5 to 10 minutes, preferably 10 minutes. Adding 35-75 equivalents of acetic acid regulator, preferably 45 equivalents, into the DMF solution, performing ultrasonic dispersion again for 5 minutes, and statically storing the reaction kettle in an oven at 80-180 ℃ for 24-72 hours, preferably 120 ℃ for 24 hours. After cooling to room temperature in the oven, the solution is centrifuged, and the resulting white (UiO-67-MPPS) precipitate is washed 2 to 5 times, preferably 3 times, with DMF and methanol, respectively, and finally immersed in methanol for 48 to 72 hours, preferably 72 hours, during which fresh methanol is replaced every 24 hours. Finally, the obtained solid is centrifuged, and dried for 5 to 8 hours, preferably for 150 ℃ and 8 hours at 100 to 150 ℃ in a vacuum oven, so as to obtain the desolvated and activated UiO-67-MPPS sample.

All features or conditions defined herein in terms of numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of a numerical range or percentage range should be considered to cover and specifically disclose all possible sub-ranges and individual values within the range, particularly integer values. For example, a range description of "1 to 8" should be taken as having specifically disclosed all sub-ranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, etc., particularly sub-ranges defined by all integer values, and should be taken as having specifically disclosed individual values such as 1, 2, 3, 4, 5, 6, 7, 8, etc. within the range. The foregoing explanation applies to all matters of the invention throughout its entirety unless indicated otherwise, whether or not the scope is broad.

If an amount or other numerical value or parameter is expressed as a range, preferred range, or a series of upper and lower limits, then it is understood that any range, whether or not separately disclosed, from any pair of the upper or preferred value for that range and the lower or preferred value for that range is specifically disclosed herein. Furthermore, where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

In this context, numerical values should be understood to have the accuracy of the numerical significance of the numerical values provided that the objectives of the present invention are achieved. For example, the number 40.0 is understood to cover a range from 39.50 to 40.49.

The following examples are merely illustrative of embodiments of the present invention and are not intended to limit the invention in any way, and those skilled in the art will appreciate that modifications may be made without departing from the spirit and scope of the invention. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products.

Example 1

The preparation of the COF-DHz-APS material comprises the following specific implementation steps:

dimethyl 2-amino terephthalate (3.77 g,18 mmol) and liquid nitrogen cooled 1, 3-propane sultone (1494 ul, 18 mmol) are fully ground and uniformly mixed in a mortar, then transferred into a 20ml single-port bottle, reacted for 3 hours at 130 ℃, after the reaction is finished, the reaction system is cooled, the obtained dark red solid is washed 2 to 4 times with acetic acid (17M), then washed twice with acetone, and dried to obtain white dimethyl terephthalate powder modified by Ammonium Propane Sulfonate (APS) structure. And then placing the mixture and hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, reacting for 36 hours at 80 ℃, centrifuging to obtain a precipitate, and drying the precipitate to obtain yellow APS inner salt structure modified hydrazide monomer DHz-APS.

0.15 mmole of DHz-APS and 0.10 mmole of 2,4, 6-trihydroxybenzene-1, 3, 5-trimethylaldehyde are placed in an 18ml heat-resistant glass tube, a mixed solvent of 2.7ml of mesitylene and 0.3ml of 1, 4-dioxane is heated in the heat-resistant glass tube, trifluoroacetic acid of 128 ul is added, ultrasonic dispersion is carried out for 10 minutes, three freezing-vacuumizing-nitrogen filling-thawing degassing circulation treatments are carried out in a double-row tube, the glass tube is sealed by flame after vacuumizing, reaction is carried out for 5 days at 120 ℃, after the temperature is reduced to room temperature, the reaction system is centrifuged, reaction precipitation is obtained, tetrahydrofuran (3X 10 ml) is adopted, acetone (3X 10 ml) is adopted for cleaning the precipitation, and the precipitation is dried for 8 hours at 60 ℃ in a nitrogen environment, so that brick red solid powder is obtained.

FIG. 1 is an X-ray powder diffraction pattern of the material COF-DHz-APS obtained in example 1; strong characteristic diffraction peaks were shown at 3.55 °, 7.62 ° and 9.73 °, and weak broad characteristics at 26.66 °, corresponding to the (100), (200), (120), (001) planes, respectively. Comparing the experimental data with the PXRD curve (including AA stack, AB stack) of COF-DHz-APS calculated by the Material studio simulation, the COF-DHz-APS was found to fit well with the AA stack pattern, indicating successful synthesis of COF-DHz-APS.

FIG. 2 is an infrared spectrum of the material COF-DHz-APS obtained in example 1, from which it can be seen that after polymerization, the aldehyde group characteristic peak (1643) of the monomer TFP (triallylmethoglucinol) disappeared, indicating complete consumption of the reactant. And c=o (1636 cm) ^-1 )，C＝C(1616cm ^-1 )，C-N(1258cm ^-1 )，S＝O(1041cm ^-1 ) And the like, which indicates that the material is successfully synthesized and belongs to covalent organic framework materials connected by beta-ketoenamine.

Example 2

The preparation of the COF-DHz-MIMPS material comprises the following specific implementation steps:

dimethyl 2- (imidazolylmethyl) biphenyl-4, 4' -dicarboxylate (2.0 g,5.71 mmol) was dissolved in acetone, and 1, 3-propanesultone (0.697 g,5.71 mmol) was slowly added. Stirring the solution at room temperature for 5 days, filtering, precipitating, washing with acetone, and drying to obtain white powder of dimethyl biphenyl-4, 4' -dicarboxylate modified by MIMPS. And then placing the mixture and hydrazine hydrate solution in absolute ethyl alcohol according to the molar ratio of 1:2, reacting for 36 hours at 80 ℃, centrifuging to obtain precipitate, and drying the precipitate to obtain white MIMPS inner salt structure modified hydrazide monomer DHz-MIMPS.

Placing 0.15mmol of DHz-MIMPS and 0.10mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-trimethylaldehyde in a 18ml heat-resistant glass tube, heating a mixed solvent of 2ml of o-dichlorobenzene and 2.0ml of n-butanol in the heat-resistant glass tube, adding 400ul of acetic acid, performing ultrasonic dispersion for 10 minutes, performing three freezing-vacuumizing-nitrogen filling-thawing degassing circulation treatment in a double-row tube, vacuumizing, sealing the glass tube by flame, reacting for 5 days at 130 ℃, centrifuging a reaction system after the temperature is reduced to room temperature, obtaining reaction precipitate, cleaning the precipitate by adopting tetrahydrofuran (3X 10 ml) and acetone (3X 10 ml), and drying for 8 hours at 60 ℃ in a nitrogen environment to obtain brick red solid powder.

FIG. 9 is an X-ray powder diffraction pattern of the material COF-DHz-MIMPS obtained in example 2; wherein a strong characteristic diffraction peak is shown at 4.8 deg., and a weak broad characteristic is shown at 22.1 deg., corresponding to the (100), (001) planes, respectively. The small angle of the peak shows successful synthesis of COF-DHz-MIMPS.

FIG. 10 is an infrared spectrum of the material COF-DHz-MIMPS obtained in example 2, from which it can be seen that after polymerization, the aldehyde group characteristic peak (1639) of monomeric TFP (triallylmethoglucinol) disappeared, indicating complete consumption of the reactants. And c=o (1637 cm) ^-1 )，C＝C(1618cm ^-1 )，C-N(1280cm ^-1 )，S＝O(1174，104,3cm ^-1 ) And the like, which indicates that the material is successfully synthesized and belongs to covalent organic framework materials connected by beta-ketoenamine.

Example 3

COF-DHz-APS·MSA、COF-DHz-APS·ESA、a _g COF-DHz-APS·MSA、 a _g The preparation of the COF-DHz-APS-ESA material comprises the following specific implementation steps:

10mg of the COF-DHz-APS material prepared in example 1 was taken in a mortar, pulverized to be fluffy, and 1.5ul of MSA or 1.8ul of ESA was quantitatively removed and dropped into the mortarGrinding in a mortar until the powder is completely and uniformly absorbed by the COF-DHz-APS material, collecting the powder, sealing and storing in a drying oven to obtain the COF-DHz-APS-MSA and the COF-DHz-APS-ESA. Heating on heating plate at 120-130deg.C for 3-5min to obtain glassy product a with fluidity _g COF-DHz-APS-MSA and a _g COF-DHz-APS·ESA。

FIG. 3 is a schematic diagram of the materials COF-DHz-APS-MSA, COF-DHz-APS-ESA, a obtained in example 3 _g COF-DHz-APS·MSA，a _g X-ray powder diffraction pattern of COF-DHz-APS. ESA; the diffraction peaks of COF-DHz-APS.MSA, COF-DHz-APS.ESA and COF-DHz-APS are similar, and good crystallinity is shown, so that the material is structurally stable in organic acid MSA and ESA; after heating and melting, a _g COF-DHz-APS·MSA，a _g The COF-DHz-APS.ESA diffraction peak disappeared, and an amorphous pattern was exhibited.

FIG. 4 is a differential scanning calorimeter of the materials COF-DHz-APS, COF-DHz-APS. MSA obtained in examples 1 and 3; from a review of FIG. (a), it can be seen that COF-DHz-APS shows no endothermic or exothermic peaks during the heating and cooling cycles at 0 to 180℃indicating that COF-DHz-APS has no structural change. In the first heating step of the COF-DHz-APS MSA in the graph (b), an endothermic peak appears at 145℃and is assigned to the melting temperature T in combination with the heating phenomenon _m . The jump in plateau was seen at 102℃during the second temperature increase, corresponding to the glass transition temperature Tg of the sample. Notably T _g /T _m ＝102/145＝0.70>2/3，T _g /T _m Representing the glass forming ability, it is generally considered that when T _g /T _m >2/3, the system has higher glass forming capacity, T _g /T _m The larger the material, the faster the viscosity increases with decreasing temperature as it cools and solidifies from the molten state, the less quickly the molecules are displaced to the lowest capacity state and the crystallization process can be inhibited.

FIG. 5 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g COF-DHz-APS·MSA， a _g COF-DHz-APS-ESA, and reference polycarbonate, silica glass plateSAXS diagram; tests have shown that in the q=0.025-0.25 range, the heated material shows a similar trend to that of polycarbonate PC, silica glass plate, indicating a _g COF-DHz-APS·MSA，a _g COF-DHz-APS ESA shows a uniform state, no particles exist, the crystal form disappears, and the glass is successfully converted from a crystalline state to an amorphous state.

FIG. 6 is a material a obtained according to example 3 _g Polarized light microscopy of COF-DHz-APS.MSA. Polarized light microscopy is used to identify whether a substance is single refractive (isotropic) or birefringent (anisotropic), with birefringence being a fundamental property of a crystal. When the lens barrel is rotated, the visual field is dark under the condition that the light rays are orthogonal, the visual field becomes bright if the detected object is anisotropic, and the visual field is still dark if the detected object is isotropic. In the figure, under the condition of 90 degrees orthogonality, the field of view is dark, which shows that the detected object has isotropy and accords with the characteristics of glassy substances.

FIG. 7 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g SEM image of COF-DHz-APS.MSA; from the figure it can be seen that the COF-DHz-APS powder exhibits a uniform globular shape with a size of about 150nm; after heating and melting, a _g The surface of the COF-DHz-APS.MSA is smooth, flat and defect-free.

FIG. 8 is the COF-DHz-APS, a of the materials obtained in examples 1 and 3 _g Conductivity diagram of COF-DHz-APS-MSA; from the figure it can be seen that the electrical conductivity of the heated material is always higher than that of the unheated material, reaching 1.2X10 s at 80℃ ^-2 (S·cm ^-1 ) The COF material in the glass state is shown to eliminate the grain boundary resistance and realize higher conductivity.

Example 4

COF-DHz-MIMPS·MSA、COF-DHz-MIMPS·ESA、a _g COF-DHz-MIMPS·MSA、 a _g The preparation of the COF-DHz-MIMPS-ESA material comprises the following specific implementation steps:

10mg of the COF-DHz-MIMPS material prepared in example 2 was taken in a mortar, and pulverized to a powder fluffy state, 1.2ul of MSA or 1.5ul of ESA was quantitatively taken respectively, and dropped into the mortar, and the pulverization was continued until it was completely and uniformly pulverized by the COF-DHz-MIMPSAbsorbing the material, collecting the powder, sealing, and storing in a drying oven to obtain COF-DHz-MIMPS.MSA and COF-DHz-MIMPS.ESA. Heating on heating plate at 120-130deg.C for 3-5min to obtain glassy product a with fluidity _g COF-DHz-MIMPS MSA and a _g COF-DHz-MIMPS·ESA。

FIG. 11 is a photomicrograph of the material COF-DHz-MIMPS. MSA obtained in examples 2 and 4 before and after heating, (a) shows that COF-DHz-MIMPS. MSA is in a powder state at room temperature, and (b) shows that a _g COF-DHz-MIMPS.MSA is a transparent bulk solid.

In the figure, under the condition of 90 degrees orthogonality, the field of view is dark, which shows that the detected object has isotropy and accords with the characteristics of glassy substances.

FIG. 13 is the COF-DHz-MIMPS, a of the materials obtained in examples 2 and 4 _g Conductivity map of COF-DHz-MIMPS-MSA; from the figure it can be seen that the electrical conductivity of the heated material is always higher than that of the unheated material, reaching 2.0X10 at 30℃ ^-2 (S·cm ^-1 ) The COF material in the glass state is shown to eliminate the grain boundary resistance and realize higher conductivity.

Example 5

The preparation of the UiO-66-APS comprises the following specific steps:

dimethyl 2-aminoterephthalate and 1, 3-propane sultone are uniformly mixed according to a ratio of 1:1. Reacting for 3 hours at 130 ℃, and cooling the reaction system after the reaction is finished. The solid product was washed 3 times with 1-17M acetic acid. And (3) centrifugally drying to obtain dimethyl terephthalate with Ammonium Propane Sulfonate (APS) structure modification. Then placing the mixture and potassium hydroxide in a mixed solution of water and methanol according to a molar ratio of 1:4, reacting for 12 hours at 80 ℃, then dropwise adding hydrochloric acid to acidify to pH=1, filtering to obtain a precipitate, and drying the precipitate to obtain the H with the modified APS inner salt structure ₂ BDC-APS。

ZrCl was ultrasonically treated in a 40ml polytetrafluoroethylene-lined reactor ₄ (326mg，1.39 mmol) and acetic acid regulator (6 ml,105 mmol) were dissolved in 27ml super dry DMF for about 5 minutes. By reacting organic ligand H ₂ BDC-APS (474 mg,1.39 mmol) was dissolved in the clear solution and after ultrasonic dispersion for about 5 minutes was stored statically in an oven at 120℃for 24 hours. After cooling to room temperature in the oven, the solution was centrifuged, the resulting yellow (UiO-66-APS) precipitate was washed 3 times with DMF and methanol, respectively, and finally immersed in methanol for 72 hours to remove unreacted organic ligand and metal salts, and further dried under vacuum at 80 ℃ for 8 hours, and the desolvated activated sample was stored in a glove box.

Example 6

The preparation of the UiO-66-APS-MSA, uiO-66-APS-ESA, agUiO-66-APS-MSA and agUiO-66-APS-ESA materials comprises the following specific implementation steps:

50mg of activated UiO-66-APS was taken and ground with 28ul of methanesulfonic acid (MSA) or 28ul of ethanesulfonic acid (ESA) in a mortar for 2 minutes, after which the sample was ground in a vacuum oven at 50℃for 6 hours, so that the methanesulfonic acid or ethanesulfonic acid was homogeneously diffused in the UiO-66-APS and thoroughly mixed, to give pale yellow solid powders, designated UiO-66-APS. MSA and UiO-66-APS. ESA, respectively. The process is carried out under the protection of inert gas in a glove box, so that the water vapor in the air is avoided being absorbed. Heating at 120-150deg.C for 30min to obtain glass body a with fluidity _g UiO-66-APS.MSA and a _g UiO-66-APS·ESA。

FIG. 14 is a diagram of materials UiO-66, uiO-66-APS. MSA, uiO-66-APS. ESA, a according to examples 5-6 _g UiO-66-APS.MSA and a _g Powder X-ray diffraction pattern of UiO-66-APS. ESA; uiO-66-APS has the same Bragg diffraction peak position as UiO-66, and the lower angles of 7.35 DEG and 8.54 DEG are diffraction of (1, 1) and (2,0,0) crystal planes respectively, and have relatively strong diffraction, which indicates that the ligand (H) with an aminopropanesulfonic acid side chain ₂ BDC-APS) produced UiO-66-APS has the same framework structure as the parent UiO-66. After UIO-66-APS-MSA and UIO-66-APS-ESA are supported methanesulfonic acid or ethanesulfonic acid, the overall diffraction line is widened, the diffraction intensity of the original crystalline MOF is reduced due to the relative disorder of guest molecules, but the frame crystal of the materialThe lattice structure remains. a, a _g UiO-66-APS.MSA and a _g UiO-66-APS-ESA is a sample after melt quenching, the original Bragg diffraction peak disappears, and only a diffuse scattering signal in a glass state indicates that the sample is in the glass state after melt quenching.

FIG. 15 is an optical micrograph of materials UiO-66-APS-MSA and UiO-66-APS-ESA obtained in example 6 before and after heating, (a) and (c) show that UiO-66-APS-MSA and UiO-66-APS-ESA respectively show powder state at room temperature, and (c) and (d) show a _g UiO-66-APS.MSA and a _g UiO-66-APS-ESA is a transparent bulk vitreous.

FIG. 16 Material a according to example 6 _g The UIO-66-APS-MSA and the UIO-66-APS-ESA are pictures under the conditions that the polarization microscope performs parallel polarization analysis, and the upper and lower analyzers form an angle of 45 degrees and orthogonal polarization analysis. Under parallel polarization analysis, the upper and lower analyzers are parallel to each other, the field of view is brightest, and a transparent sample can be seen; the upper and lower analyzers are at 45 degrees to darken the field of view, and the sample also appears darkened; under orthogonal polarization analysis, the upper and lower analyzers are perpendicular to each other, the field of view is darkest, and darkening of the sample along with the glass slide indicates that the melt quenched sample does not have a crystalline structure, but is an isotropic glass body.

FIG. 17 is a diagram of materials UiO-66-APS. MSA, uiO-66-APS. ESA, a according to example 6 _g UiO-66-APS.MSA and a _g SEM image of UiO-66-APS. ESA; as can be seen from the figure, the morphology of UiO-66-APS.MSA and UiO-66-APS.ESA are spherical particles, and after the particles are heated and melted, a _g UiO-66-APS.MSA and a _g The surface of the UiO-66-APS.ESA is smooth, flat and defect-free.

FIG. 18 is a differential scanning calorimetry plot of the materials UiO-66-APS-MSA and UiO-66-APS-ESA obtained in example 6, showing that UiO-66-APS-MSA is the end point of the endothermic peak at 138℃during the first heating, which we attribute to the melting temperature T in combination with the heating phenomenon _m . During the second heating up, a jump in plateau was seen at 77℃corresponding to the glass transition temperature T of the sample _g . UiO-66-APS-ESA sample, endothermic peak end point temperature of 134 ℃ corresponding to melting temperature T _m In the followingThe second warming procedure sees a glass transition point T at 48 ℃ _g It is believed that this is a gradual increase in viscosity during sample cooling, which is a slow phase change process, as opposed to UiO-66-aps·msa, which is not apparent.

FIG. 19 is a material a obtained according to example 6 _g UiO-66-APS.MSA and a _g Electric conductivity map of UiO-66-APS. ESA, glass samples MOFs excellent in proton conductivity, a, can be obtained by melt quenching _g UiO-66-APS.MSA reaches 10 at 10 DEG C ^-3 S/cm, has high potential application value.

Example 7

The preparation of the UiO-67-MPPS comprises the following specific steps:

dimethyl 2- (picolyl) biphenyl-4, 4' -dicarboxylate and 1, 3-propane sultone were dissolved in acetone at a 1:8 molar ratio. The solution was stirred at room temperature for 5 days, the precipitate was filtered, washed with acetone and dried to give white powder of dimethyl diphenyl-4, 4' -dicarboxylate modified with pyridine sulfonate internal salt group MPPS. Then placing the mixture and lithium hydroxide in a mixed solution of water and methanol according to a molar ratio of 1:4, reacting for 12 hours at 80 ℃, then dropwise adding hydrochloric acid to acidify to pH=1, filtering to obtain precipitation, and drying the precipitation to obtain the H modified with MPPS inner salt structure ₂ BPDC-MPPS。

ZrCl was ultrasonically treated in a 40ml polytetrafluoroethylene-lined reactor ₄ (56 mg,0.27 mmol) and acetic acid regulator (0.695 ml,13 mmol) were dissolved in 10ml super-dry DMF for about 5 minutes. By reacting organic ligand H ₂ BPDC-MPPS (119 mg,0.27 mmol) was added to the clear solution for dissolution, and after ultrasonic dispersion for about 5 minutes, it was stored statically in an oven at 120℃for 24 hours. After cooling to room temperature in the oven, the solution was centrifuged, the resulting white (UiO-67-MPPS) precipitate was washed 3 times with DMF and methanol, respectively, and finally immersed in methanol for 72 hours to remove unreacted organic ligand and metal salts, and further dried under vacuum at 80 ℃ for 8 hours, and the desolvated activated sample was stored in a glove box.

Example 8

UiO-67-MPPS.MSA and a _g Preparation of UiO-67-MPPS.MSA MaterialThe preparation method comprises the following specific implementation steps:

80mg of activated UiO-67-MPPS was taken and ground with 32ul of methanesulfonic acid in a mortar for 2 minutes, and the ground sample was placed in a vacuum oven at 60℃for 6 hours, so that the methanesulfonic acid was uniformly dispersed and thoroughly mixed in the UiO-67-MPPS, and a white solid powder was obtained, designated UiO-67-MPPS.MSA. The process is carried out under the protection of inert gas in a glove box, so that the water vapor in the air is avoided being absorbed. Heating at 120-150deg.C for 30min to obtain glass body a with fluidity _g UiO-67-MPPS·MSA。

FIG. 21 is an optical microscope photograph of the material UiO-67-MPPS.MSA obtained in example 7 before and after heating, (a) shows the powder state of UiO-67-MPPS.MSA at room temperature, respectively, (b) shows a _g UiO-67-mpps·msa is a transparent bulk glass body.

FIG. 22 is a photograph of the material UiO-67-MPPS.MSA obtained in examples 7 and 8 under an optical microscope before and after heating, and under parallel and orthogonal polarization analyses by a polarized light microscope. Under parallel deviation analysis, the upper and lower analyzers are parallel to each other, the field of view is brightest, and a transparent sample can be seen; under orthogonal polarization analyzer, the upper and lower analyzers are perpendicular to each other, the field of view is darkest, and the sample darkens as with the slide.

FIG. 23 is a diagram of the material UiO-67-MPPS.MSA, a obtained according to example 8 _g SEM image of UiO-67-MPPS.MSA; from the figure, it can be seen that the UiO-67-MPPS.MSA changed from particles to smooth and flat surfaces and blocky planes after being heated and melted.

FIG. 24 is a differential scanning calorimetric diagram of the material UiO-67-MPPS. MSA obtained in example 8, showing that during the first heating of UiO-67-MPPS. MSA an endothermic peak occurs at 138.3℃which, in combination with the heating phenomenon, we attribute it to the melting temperature T _m . During the second heating up, a jump in plateau was seen at 123.5℃corresponding to the glass transition temperature T of the sample _g 。

Test example 1

COF-DHz-APS、a _g COF-DHz-APS·MSA、COF-DHz-MIMPS、 a _g COF-DHz-MIMPS·MSA、a _g UiO-66-APS·MSA、a _g UiO-66-APS. ESA and a _g The specific implementation steps of the measurement of the conductivity of the UiO-67-MPPS.MSA material are as follows:

ac impedance testing methods using electrochemical workstations the ac impedance values of the materials were tested at a temperature in the range of-60 ℃ to 130 ℃ and the resulting Nyquist patterns (not shown). Based on the Nyquist pattern, COF-DHz-APS and a can be obtained _g The conductivity of COF-DHz-APS. MSA is shown in FIG. 8; obtaining COF-DHz-MIMPS and a _g The conductivity of COF-DHz-MIMPS.MSA is shown in FIG. 13; a, a _g UiO-66-APS·MSA、a _g The electrical conductivity of UiO-66-APS. ESA is shown in FIG. 19.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A meltable material prepared from an internal salt structure modified covalent organic framework material, wherein the meltable material is prepared by reacting an internal salt structure modified covalent organic framework material with a bronsted acid, wherein the bronsted acid is selected from the group consisting of: any one of methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, bistrifluoromethanesulfonimide, phosphoric acid and sulfuric acid;

In the preparation of the inner salt structure modified covalent organic framework structure meltable material, grinding the inner salt structure modified covalent organic framework material and Bronsted acid until the inner salt structure modified covalent organic framework material and Bronsted acid are uniformly mixed, heating for 30-40 min at a medium temperature of 100-250 ℃ to obtain a melt, and cooling and quenching to obtain a glassy product, wherein the molar ratio of the inner salt structure modified covalent organic framework material to the Bronsted acid is 1:1-1:10;

the covalent organic framework material modified by the inner salt structure is formed by C ₃ Symmetrical aldehyde monomers and C modified with an internal salt structure R ₂ Symmetrical hydrazide monomers are obtained by schiff base condensation reaction, wherein C ₃ Symmetrical aldehyde monomers and C modified with an internal salt structure R ₂ The molar ratio of the symmetrical hydrazide monomers is 2:3;

the C modified with an internal salt structure R ₂ The symmetrical hydrazide monomer is selected from the compounds shown below:

wherein R is selected from the following structures:

wherein n is an integer of 2, 3, 4 or 5;

when R is selected fromWhen n is an integer of 3, 4 or 5;

when R is selected from When n is an integer of 3 or 4.

2. The meltable material prepared from an internal salt structure modified covalent organic framework material of claim 1, wherein the molar ratio of internal salt structure modified covalent organic framework material to bronsted acid is 1:1.

3. The meltable material prepared from an internal salt structure modified covalent organic framework material of claim 1, wherein the preparation process of the internal salt structure modified covalent organic framework material is performed as follows:

(1) C modified with inner salt Structure R ₂ Preparation of symmetrical hydrazide monomers:

by C ₂ The symmetrical amino/imidazole/pyridyl modified hydrazide monomer is subjected to ring opening reaction with sultone/dicyano vinyl acid lactone, or the amino/imidazole/pyridyl modified hydrazide precursor is subjected to substitution and dealcoholization reaction with different alkyl bromocarboxylic acid esters, so that C modified with an inner salt structure R is obtained ₂ Symmetrical hydrazide monomers;

c modified with inner salt structure R obtained in step (1) ₂ Symmetrical hydrazide monomers and corresponding C ₃ Placing symmetrical aldehyde monomers in a mixed solvent, adding a proton acid catalyst, carrying out ultrasonic mixing, vacuumizing, sealing a reaction system, reacting for 3-8 days at 120-130 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain a precipitate, cleaning, drying and activating the precipitate to obtain the covalent organic framework COF material modified by an inner salt structure.

4. A meltable material prepared from an internal salt structure modified covalent organic framework material according to claim 3, characterized in that the corresponding internal salt of the R structure is selected from the group consisting of an internal salt of aminopropanesulfonic acid, an internal salt of aminobutanesulfonic acid, an internal salt of imidazolium propane sulfonic acid and an internal salt of imidazolium butane sulfonic acid.

5. A meltable material prepared from an inner salt structure modified covalent organic framework material according to claim 3, characterized in that in step (2) the mixed solvent is mesitylene and 1, 4-dioxane in a volume ratio of 9:1 or o-dichlorobenzene and n-butanol in a volume ratio of 1:1;

the protonic acid catalyst in the step (2) is trifluoroacetic acid or acetic acid aqueous solution.

6. The method of preparing a meltable material of claim 1, comprising the steps of:

taking a certain amount of covalent organic framework material modified by an inner salt structure, grinding the covalent organic framework material into powder to be fluffy, quantitatively transferring different types of Bronsted acids, continuously grinding the Bronsted acids until the Bronsted acids are uniformly mixed, heating the mixture at a medium temperature of 100-250 ℃ for 30-40 min to obtain a melt, and cooling and quenching the melt to obtain a glassy product a _g COF-DHz-R·HA；

The molar ratio of the covalent organic framework material modified by the inner salt structure to the Bronsted acid is 1:1 to 1:10;

The Bronsted acid is any one of methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, bistrifluoromethanesulfonimide, phosphoric acid and sulfuric acid.

7. The method of claim 6, wherein the molar ratio of the internal salt structure modified covalent organic framework material to the bronsted acid is 1:1.

8. The meltable material of claim 1 prepared from the inner salt structure-modified covalent organic framework material as H ⁺ 、Li ⁺ 、Na ⁺ 、K ⁺ Ion(s)Use of conductive materials, optical devices, multifunctional glasses, gas adsorption separation membranes.