Supramolecular Coordination Framework Compounds and Their Preparation Methods, Nanoporous Membranes Modified with Supramolecular Coordination Frameworks and Their Applications

Abstract

The present invention belongs to the technical field of ion efficient separation materials, and specifically relates to a supramolecular coordination framework compound and a preparation method thereof, a supramolecular coordination framework modified nanochannel membrane and an application thereof. The present invention provides a supramolecular coordination framework compound having the structure shown in Formula 1. The supramolecular coordination framework compound provided by the present invention has a porphyrin group in its structure. When the supramolecular coordination framework compound is used as a sieving host and chemically modified in the nanochannels of the nanochannel membrane, there is a strong coordination interaction between the porphyrin group in the framework and divalent ions, thereby preventing the passage of divalent ions. Therefore, monovalent ions can be selectively passed through, forming a monovalent / divalent ion selective transport. The supramolecular coordination framework compound provided by the present invention shows significant ion sieving performance when used as a sieving host and modified in the nanochannels, and has excellent sieving performance for monovalent / divalent ions.

Description

Technical Field

[0001] The present invention belongs to the technical field of ion efficient separation materials, and particularly relates to a supramolecular coordination framework compound and a preparation method thereof, a nanochannel membrane modified with a supramolecular coordination framework, and an application thereof. Background Art

[0002] For decades, due to the importance of separating different-valence ions of sub-nanometer size in environmental science, chemistry, energy, and life science, it has attracted people's interest. Traditional methods (such as precipitation, ion exchange, and solvent extraction) are limited by high energy consumption and low separation efficiency. Membrane technologies have been developed to overcome these limitations. However, challenged by the similar sizes of ions, the ion sieve performance of membranes has always been limited.

[0003] In recent years, scientists have tried to simulate cell membranes and made more efforts on artificial membranes to achieve the construction of desired ion-selective nanochannels to meet the requirements of screening ions with high selectivity and high permeability.

[0004] Nanostructured materials and nanofabrication technologies have promoted the development of artificial nanochannel membranes with ion and molecule selectivity. However, the current screening performance of monovalent / divalent ion-selective nanochannel membranes is poor and cannot meet the needs of industrial practice. Summary of the Invention

[0005] The purpose of the present invention is to provide a supramolecular coordination framework compound and a preparation method thereof, a nanochannel membrane modified with a supramolecular coordination framework, and an application thereof. The supramolecular coordination framework compound provided by the present invention shows significant ion screening performance when used as a screening host to modify the nanochannel, and has excellent screening performance for monovalent / divalent ions.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a supramolecular coordination framework compound having the structure shown in Formula 1:

[0008]

[0009] The present invention provides a preparation method of the supramolecular coordination framework compound described in the above technical solution, including the following steps:

[0010] Carry out a coordination reaction on a metal ligand having the structure shown in Formula 2 and an organic ligand having the structure shown in Formula 3 in a polar solvent to obtain a supramolecular coordination framework compound having the structure shown in Formula 1;

[0011]

[0012] Preferably, the molar ratio of the metal ligand of the structure shown in Formula 2 to the organic ligand of the structure shown in Formula 3 is 2:1.

[0013] Preferably, the temperature of the coordination reaction is room temperature, and the time of the coordination reaction is 12 h.

[0014] The present invention provides a supramolecular coordination framework modified nanochannel membrane, which includes a nanochannel membrane and a supramolecular coordination framework compound chemically modified on the inner surface of the nanochannels of the nanochannel membrane; the supramolecular coordination framework compound is the supramolecular coordination framework compound described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method described in the above technical solution; the nanochannels penetrate through both surfaces of the nanochannel membrane.

[0015] Preferably, large-aperture ends and small-aperture ends are respectively formed on both surfaces of the nanochannel membrane;

[0016] The supramolecular coordination framework compound is chemically modified on the inner surface of the pore near the small-aperture end of the nanochannel.

[0017] Preferably, the material of the nanochannel membrane is polyethylene terephthalate polymer.

[0018] The present invention provides a preparation method of the supramolecular coordination framework modified nanochannel membrane described in the above technical solution, including the following steps:

[0019] Dissolve the supramolecular coordination framework compound described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method described in the above technical solution in an organic solvent to obtain a supramolecular coordination framework compound solution;

[0020] Contact the surface of the supramolecular coordination framework compound solution with the nanochannel membrane, and heat for chemical modification to obtain the supramolecular coordination framework modified nanochannel membrane.

[0021] The present invention provides an application of the supramolecular coordination framework modified nanochannel membrane described in the above technical solution or the supramolecular coordination framework modified nanochannel membrane prepared by the preparation method described in the above technical solution in monovalent / divalent ion sieving.

[0022] Preferably, the monovalent ions in the monovalent / divalent ions include K + , Na + and Li + one or more of them; the divalent ions in the monovalent / divalent ions include Mg 2+ , Zn 2+ , Cu 2+ and Mn 2+ one or more of them.

[0023] The present invention provides a supramolecular coordination framework compound having the structure shown in Formula 1. The supramolecular coordination framework compound provided by the present invention has a porphyrin group in its structure. When the supramolecular coordination framework compound is used as a sieving host and chemically modified in the nanochannels of a nanochannel membrane, there is a strong coordination interaction between the porphyrin group in the framework and divalent ions, thereby preventing the passage of divalent ions. Therefore, monovalent ions can be selectively passed through, forming a monovalent / divalent ion selective transport. The supramolecular coordination framework compound provided by the present invention shows significant ion sieving performance when used as a sieving host and modified in the nanochannels, and has excellent sieving performance for monovalent / divalent ions.

[0024] The present invention provides a nanochannel membrane modified with a supramolecular coordination framework, comprising a nanochannel membrane and a supramolecular coordination framework compound chemically modified in the nanochannels of the nanochannel membrane; the supramolecular coordination framework compound is the supramolecular coordination framework compound described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method described in the above technical solution. When the nanochannel membrane modified with the supramolecular coordination framework provided by the present invention transports ions of different valences, since hydrated ions need to remove the bound water molecules to pass through the channel when passing through the sub-nanochannels, and compared with monovalent ions, the dehydration of divalent ions requires higher energy, and the coordination of the porphyrin group of the framework to divalent ions is stronger. Therefore, monovalent ions such as K + , Na + , Li + are more likely to pass through the channel, resulting in monovalent / divalent ion selective transport. The results of the examples show that: the nanochannel membrane modified with the supramolecular coordination framework provided by the present invention sieves a solution containing a mixture of monovalent and divalent ions, and after 24 hours of transport, the ion content of the transport solution is detected. The ion selectivities of K + / Mg 2+ , Na + / Mg 2+ , Li + / Mg 2+ reach 1015.5, 485.3, and 288.2 respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a preparation flow chart of the supramolecular coordination framework compound having the structure shown in Formula 1 provided by the embodiment of the present invention;

[0026] Figure 2 It is a preparation flow chart of the metal ligand having the structure shown in Formula 2 provided by the embodiment of the present invention;

[0027] Figure 3 It is the supramolecular coordination framework compound having the structure shown in Formula 1 provided by the embodiment of the present invention (Figure 3 The following figure in ) and the metal ligand of the structure shown in formula 2 ( Figure 3 The above figure in ) of the phosphorus spectrum;

[0028] Figure 4 The scanning electron microscope image of the nanochannel membrane provided by the embodiment of the present invention;

[0029] Figure 5 The monovalent / divalent ion sieving performance diagram of the supramolecular coordination framework modified nanochannel membrane for different monovalent and divalent mixed ions in the application example of the present invention;

[0030] Figure 6 The nuclear magnetic resonance hydrogen spectrum of the supramolecular coordination framework compound of the structure shown in formula 1 prepared in Example 1 of the present invention. Detailed implementation manners

[0031] The present invention provides a supramolecular coordination framework compound having the structure shown in formula 1:

[0032]

[0033] The present invention provides a preparation method of the supramolecular coordination framework compound described in the above technical solution, including the following steps:

[0034] Carry out a coordination reaction on the metal ligand of the structure shown in formula 2 and the organic ligand of the structure shown in formula 3 in a polar solvent to obtain the supramolecular coordination framework compound of the structure shown in formula 1;

[0035]

[0036] In the present invention, without special instructions, all preparation raw materials / components are commercially available products well-known to those skilled in the art.

[0037] In the present invention, the preparation method of the metal ligand of the structure shown in formula 2 includes the following steps:

[0038] React the compound of the structure shown in formula 4 with silver trifluoromethanesulfonate in an organic solvent, carry out solid-liquid separation on the obtained reaction feed liquid to obtain a liquid-phase product; remove the organic solvent from the liquid-phase product to obtain

[0039] The metal ligand of the structure described in formula 2;

[0040]

[0041] In the present invention, the molar ratio of the compound of the structure shown in Formula 4 to silver trifluoromethanesulfonate is preferably 1:2. The organic solvent is specifically preferably dichloromethane. The present invention has no special requirements for the amount of the organic solvent, and it is only necessary to ensure the smooth progress of the reaction. In the present invention, the reaction is carried out at room temperature, the reaction time is preferably 12 h, and the reaction is carried out under stirring conditions. In the present invention, the solid-liquid separation is preferably centrifugal separation. The specific implementation manner of removing the organic solvent is preferably vacuum evaporation.

[0042] The present invention has no special requirements for the source of the organic ligand of the structure shown in Formula 3, and both commercially available products and self-made products can be used.

[0043] In the present invention, the molar ratio of the metal ligand of the structure shown in Formula 2 to the organic ligand of the structure shown in Formula 3 is preferably 2:1. In the present invention, the polar solvent is preferably dimethyl sulfoxide. The present invention has no special requirements for the amount of the polar solvent, and it is only necessary to ensure the smooth progress of the coordination reaction.

[0044] In the present invention, the temperature of the coordination reaction is preferably room temperature, and the reaction time of the coordination reaction is preferably 12 h.

[0045] In the present invention, the coordination reaction gives a coordination reaction solution, and the present invention preferably performs post-treatment on the coordination reaction solution to obtain a supramolecular coordination framework of the structure shown in Formula 1. In the present invention, the post-treatment preferably includes the following steps: adding ether to the coordination reaction solution to precipitate a solid to obtain a supramolecular coordination framework of the structure shown in Formula 1.

[0046] The present invention provides a nanochannel membrane modified with a supramolecular coordination framework, comprising a nanochannel membrane and a supramolecular coordination framework compound chemically modified on the inner surface of the nanochannels of the nanochannel membrane; the supramolecular coordination framework compound is the supramolecular coordination framework compound described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method described in the above technical solution; the nanochannels penetrate through the two surfaces of the nanochannel membrane.

[0047] In the present invention, large-aperture ends and small-aperture ends are preferably formed on the two surfaces of the nanochannel membrane respectively; the supramolecular coordination framework compound is preferably chemically modified on the inner surface near the small-aperture end of the nanochannel.

[0048] In the present invention, the shape of the nanochannel in the nanochannel membrane is bullet-shaped, and the supramolecular coordination framework compound is preferably chemically modified on the bullet-shaped tip of the bullet-shaped nanochannel.

[0049] In the present invention, the material of the nanochannel membrane is polyethylene terephthalate polymer (PET).

[0050] In the present invention, the nanochannel membrane is preferably prepared by an asymmetric chemical track etching method. The specific implementation manner of the asymmetric chemical track etching is preferably as follows: A first etching is performed on one surface of the organic material using a first etching solution, and at the same time, a second etching is performed on the other surface of the organic material using a second etching solution, a large pore diameter end is formed on one surface of the organic material, and a small pore diameter end is formed on the other surface; A blocking solution is used to block on one surface and the other surface of the organic material to end the first etching and the second etching.

[0051] In the present invention, the thickness of the organic material is preferably 12 μm. The first etching solution is preferably a strong base solution, the strong base solution is preferably sodium hydroxide solution, and the molar concentration of the strong base solution is preferably 6 mol / L; The second etching solution is preferably a mixed solution of a strong base and a surfactant, the strong base is preferably sodium hydroxide, and the surfactant is preferably sodium dodecyl diphenyl ether disulfonate. In the second etching solution, the molar concentration of the strong base is preferably 6 mol / L, and the molar concentration of the surfactant is preferably 1.5 mmol / L.

[0052] In the present invention, the temperature of the first etching is preferably 60 °C, and the time of the first etching is preferably 4 min. The temperature of the second etching is preferably 60 °C, and the time of the second etching is preferably 4 min.

[0053] In the present invention, the blocking solution is preferably an aqueous mixed solution of formic acid and potassium chloride. In the blocking solution, the molar concentration of formic acid is preferably 1 mol / L, and the molar concentration of potassium chloride is preferably 1 mol / L. In the present invention, the temperature for blocking with the blocking solution is preferably 60 °C, and the blocking time with the blocking solution is preferably 30 min.

[0054] The present invention provides a method for preparing a nanochannel membrane modified with a supramolecular coordination framework as described in the above technical solution, including the following steps:

[0055] Dissolve the supramolecular coordination framework compound as described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method as described in the above technical solution in an organic solvent to obtain a supramolecular coordination framework compound solution;

[0056] Bring the supramolecular coordination framework compound solution into contact with the surface of the nanochannel membrane, and heat for chemical modification to obtain the supramolecular coordination framework modified nanochannel membrane.

[0057] The supramolecular coordination framework compound described in the above technical solution or the supramolecular coordination framework compound prepared by the preparation method described in the above technical solution is dissolved in an organic solvent to obtain a supramolecular coordination framework compound solution. In the present invention, the organic solvent is preferably dimethyl sulfoxide. The mass concentration of the supramolecular coordination framework compound solution is preferably 2.5 mg / mL.

[0058] After obtaining the supramolecular coordination framework compound solution, the present invention contacts the supramolecular coordination framework compound solution with the surface of the nanochannel membrane and heats it for chemical modification to obtain the supramolecular coordination framework-modified nanochannel membrane. In the present invention, the supramolecular coordination framework compound solution preferably contacts the surface of the nanochannel membrane with the small pore diameter end. The contact is preferably coating the supramolecular coordination framework compound solution on the surface of the nanochannel membrane with the small pore diameter end. In the present invention, the temperature of the chemical modification is preferably 60 °C, and the heat preservation time of the chemical modification is preferably 24 h.

[0059] In the present invention, during the chemical modification, since the inner surface of the etched nanochannel has carboxyl groups, at 60 °C, the metal ligand of the supramolecular coordination framework coordinates with the carboxyl groups to achieve the purpose of modification.

[0060] The present invention provides the application of the supramolecular coordination framework-modified nanochannel membrane described in the above technical solution or the supramolecular coordination framework-modified nanochannel membrane prepared by the preparation method described in the above technical solution in the screening of monovalent / divalent ions.

[0061] In the present invention, the monovalent ions in the monovalent / divalent ions preferably include K + 、Na + and Li + One or more of them, more preferably K + 、Na + or Li + .

[0062] In the present invention, the divalent ions in the monovalent / divalent ions preferably include Mg 2+ 、Zn 2+ 、Cu 2+ and Mn 2+ One or more of them, more preferably Mg 2+ .

[0063] In the present invention, the application is preferably carried out under the condition of voltage drive. When applying, the drive voltage is preferably 2 V.

[0064] In the present invention, the specific implementation method of the application is preferably as follows: a monovalent / divalent metal ion solution is placed on one side modified by the supramolecular coordination framework, water is added to the other side modified by the supramolecular coordination framework, and monovalent / divalent metal ion sieving is carried out under the condition of an applied voltage. In the present invention, the monovalent / divalent metal ion solution preferably contacts the surface of the small-aperture end modified by the supramolecular coordination framework. In the present invention, the molar concentration of the monovalent / divalent metal ion solution is preferably 0.1 mol / L for both. In the present invention, the applied voltage is preferably 2 V. In the present invention, the time for monovalent / divalent metal ion sieving is preferably 24 h.

[0065] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0066] Example 1

[0067] According to Figure 2 the preparation flow chart of the metal ligand with the structure shown in Formula 2:

[0068] The compound with the structure shown in Formula 4 and silver trifluoromethanesulfonate (molar ratio 1:2) were stirred and reacted in dichloromethane for 12 h. The precipitate after the reaction was removed by centrifugation, and the organic solvent in the liquid phase product after the reaction was removed under vacuum to obtain the metal ligand with the structure shown in Formula 2.

[0069] According to Figure 1 the preparation flow chart of the supramolecular coordination framework compound with the structure shown in Formula 1:

[0070] 4 mg of the metal ligand with the structure shown in Formula 2 and 1 mg of the organic ligand with the structure shown in Formula 3 were respectively dissolved in 1 mL of dimethyl sulfoxide solvent. The obtained metal ligand solution with the structure shown in Formula 2 (0.003 mM) and the organic ligand solution with the structure shown in Formula 3 (0.0015 mM) were mixed. Among them, the molar ratio of the metal ligand shown in Formula 2 to the organic ligand with the structure shown in Formula 3 was 2:1, and the reaction was carried out under stirring conditions at room temperature for 12 hours. After the reaction was completed, an ether solvent was added to precipitate a solid product, and the solid-liquid separation was carried out to obtain the supramolecular coordination framework compound with the structure shown in Formula 1.

[0071] Figure 6 1H NMR spectrum of the supramolecular coordination framework compound with the structure shown in Formula 1 prepared in Example 1 of the present invention, with deuterated DMSO as the solvent. Figure 3 For the supramolecular coordination framework compound with the structure shown in Formula 1 provided in the example of the present invention ( Figure 3 the lower figure in Figure 3 and the phosphorus spectrum of the metal ligand with the structure shown in Formula 2 (

[0072] Example 2

[0073] The PET membrane was subjected to asymmetric chemical track etching. The specific method of asymmetric chemical track etching was as follows: The PET membrane was placed in an electrolytic cell, and bullet-shaped nanochannels were etched through an etching solution. A 6M NaOH solution was used as the first etching solution on one surface of the PET membrane (with a thickness of 12 μm), while a mixed solution of 6M NaOH and 1.5 mM dodecyl diphenyl ether disulfonate was used as the second etching solution on the other surface of the PET membrane. It was heated to 60 °C for etching, and the etching time was 4 min. A large pore diameter end was formed on one surface of the PET membrane, and a small pore diameter end was formed on the other surface. The first etching solution and the second etching solution were removed, and then a mixed solution of 1M HCOOH and 1M KCl was used as a blocking solution and added to one surface and the other surface to end the etching. A nanochannel membrane with bullet-shaped nanochannels was obtained.

[0074] The supramolecular coordination framework compound prepared in Example 1 was dissolved in dimethyl sulfoxide to obtain a 2.5 mg / mL supramolecular coordination framework compound solution.

[0075] The supramolecular coordination framework compound solution was placed on the surface of the small pore end of the nanochannel membrane and reacted at 60 °C for 24 hours to obtain a supramolecular coordination framework-modified nanochannel membrane.

[0076] From Figure 4 observing the changes at the small pore end before and after the modification of the bullet-shaped nanochannel membrane, Figure 4 the upper figure in Figure 4 is the electron microscopy image of the nanochannels of the bullet-shaped nanochannel membrane, and Figure 4 the lower figure in

[0077] Application Example 1

[0078] The supramolecular coordination framework-modified nanochannel membrane prepared in Example 2 was used as a molecular sieve to screen monovalent / divalent metal ion solutions. Ion screening was carried out by applying a voltage to the modified nanochannel membrane. Three electrolyte solutions were added to the small pore end of the nanochannel membrane respectively. The monovalent metal ions in the three electrolyte solutions were K + , Li + or Na + , and the corresponding divalent metal ions were all Mg 2+ . The molar ratio of monovalent ions to divalent ions in the electrolyte solution was 1:1, the molar concentration of monovalent metal ions was 0.1M, and Mg 2+The molar concentration is 0.1 M; deionized water is added to the other end, and it is transported for 24 hours under the drive of a 2V voltage. Applying a voltage is beneficial for driving ion transport. The hydrated ions passing through the sub-nanometer channels need to remove the bound water molecules to pass through the channels. Compared with monovalent ions, the dehydration of divalent Mg 2+ requires more energy, and the porphyrin groups of the coordination framework have a stronger effect on divalent Mg 2+ . Therefore, monovalent ions such as K + , Na + , Li + are more likely to pass through the nanochannels, resulting in the selective transport of monovalent / divalent ions.

[0079] The transport solution was detected, and the ion content in the transport solution was detected by an inductively coupled plasma optical emission spectrometer (ICP-OES). The results are as Figure 5 shown, Figure 5 This is the monovalent / divalent ion sieving performance diagram of the supramolecular coordination framework modified nanochannel membrane of the present invention. Figure 5 is the ion selectivity calculated according to the transport rate. The transport rates of K + , Na + , Li + , Mg 2+ are 3.5 mol·m -2 ·h -1 , 1.67 mol·m -2 ·h -1 , 9.93×10 -1 mol·m -2 ·h -1 , 3.45×10 -3 mol·m -2 ·h -1 . From Figure 5 it can be concluded that the bullet-shaped nanochannel membrane modified with the supramolecular coordination framework prepared in Example 2 has selectivity for monovalent ions. Therefore, the bullet-shaped nanochannel membrane modified with the supramolecular coordination framework prepared in Example 2 exhibits excellent monovalent / divalent ion sieving performance and has important applications in the field of ion sieving.

[0080] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all embodiments. Other embodiments can also be obtained based on this embodiment without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A supramolecular coordination framework compound, characterized in that It has the structure shown in Formula 1:

2. The preparation method of the supramolecular coordination framework compound according to claim 1, characterized in that, It includes the following steps: Carry out a coordination reaction of a metal ligand with the structure shown in Formula 2 and an organic ligand with the structure shown in Formula 3 in a polar solvent to obtain a supramolecular coordination framework compound with the structure shown in Formula 1; 3. The preparation method according to claim 2, characterized in that, The molar ratio of the metal ligand with the structure shown in Formula 2 to the organic ligand with the structure shown in Formula 3 is 2:

1.

4. The preparation method according to claim 2, wherein The temperature of the coordination reaction is room temperature, and the time of the coordination reaction is 12 h.

5. A supramolecular coordination framework modified nanochannel membrane, characterized in that, It includes a nanochannel membrane and a supramolecular coordination framework compound chemically modified on the inner surface of the nanochannels of the nanochannel membrane; the supramolecular coordination framework compound is the supramolecular coordination framework compound described in Claim 1 or the supramolecular coordination framework compound prepared by the preparation method described in any one of Claims 2 to 4; the nanochannels penetrate through both surfaces of the nanochannel membrane.

6. The supramolecular coordination framework-modified nanochannel membrane according to claim 5, characterized in that, The nanochannels form a large pore diameter end and a small pore diameter end on both surfaces of the nanochannel membrane respectively; The supramolecular coordination framework compound is chemically modified on the inner surface of the pore near the small pore diameter end of the nanochannel.

7. The supramolecular coordination framework modified nanochannel membrane according to claim 5, characterized in that, The material of the nanochannel membrane is polyethylene terephthalate polymer.

8. The preparation method of the supramolecular coordination framework-modified nanochannel membrane according to any one of claims 5 to 7, characterized in that, It includes the following steps: Dissolve the supramolecular coordination framework compound described in Claim 1 or the supramolecular coordination framework compound prepared by the preparation method described in any one of Claims 2 to 4 in an organic solvent to obtain a supramolecular coordination framework compound solution; Contact the supramolecular coordination framework compound solution with the surface of the nanochannel membrane and heat it for chemical modification to obtain the supramolecular coordination framework-modified nanochannel membrane.

9. Application of the supramolecular coordination framework-modified nanochannel membrane described in any one of Claims 5 to 7 or the supramolecular coordination framework-modified nanochannel membrane prepared by the preparation method described in Claim 8 in the screening of monovalent / divalent ions.

10. The application according to claim 9, wherein The monovalent ions in the monovalent / divalent ions include K + , Na + and Li + or one or more of them; the divalent ions in the monovalent / divalent ions include Mg 2+ , Zn 2+ , Cu 2+ and Mn 2+ or one or more of them.

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