Preparation method and application of multi-element site regulation and control flexible ionic cross-linked polymer

Abstract

The invention discloses a preparation method and application of a multi-element site regulation and control flexible ionic cross-linked polymer. The method comprises the following steps: under the protection of N2 atmosphere, adding a cationic monomer 1H-benzotriazole and an anionic monomer halogenated xylene into an organic solvent 1, 2-dichloroethane solution, fully stirring to uniformly disperse the monomers, then adding a cross-linking agent dimethoxymethane and a catalyst anhydrous FeCl3 in sequence, carrying out catalytic induction of Friedel-Crafts alkylation and quaternization reactions, and carrying out solid-liquid separation, washing and drying to obtain the target product. The preparation method comprises the following steps: adding a cross-linking agent into a reaction kettle, stirring at 45-50 DEG C for 4-5 hours for pre-crosslinking, heating to 80-90 DEG C, reacting for 18-19 hours, and carrying out suction filtration, Soxhlet extraction activation and vacuum drying to finally obtain the flexible ionic cross-linked polymer. The flexible ionic cross-linked polymer prepared by the invention has a flexible ion / covalent / hydrogen bond multiple cross-linked network structure and abundant alkaline N cation and terminal group / free Cl anion active sites, and shows efficient synergistic adsorption performance on formaldehyde and CO2 in a high-humidity environment.

Description

Technical Field

[0001] The present invention belongs to the field of novel functional materials, and in particular relates to a method for preparing a flexible ionic cross-linked polymer for adsorbing and removing multi-component VOCs and CO2 in a high humidity environment. Background Art

[0002] With the development of modern society, the time humans spend in closed buildings and vehicles (such as vehicles, airplanes and other enclosed cabins) has increased significantly. This trend has led researchers to conduct extensive research on efficient cleaning technologies for gaseous pollutants in confined spaces. It is worth noting that volatile organic compounds (VOCs) derived from building materials such as coatings and adhesives, as typical pollutants, can seriously endanger human health even at low concentrations (<200ppm). In addition, if the carbon dioxide (CO2) exhaled by human activities in a confined space exceeds 1000ppm (about 4%), it may pose a direct risk to human health. Therefore, it is of vital importance to develop adsorbents with high adsorption and absorption capabilities to capture these ultra-low concentration gaseous pollutants.

[0003] Some studies have reported that porous adsorbents such as metal organic frameworks (MOFs), covalent organic frameworks (COFs) and hypercrosslinked polymers (HCPs) can effectively capture low concentrations of CO2, VOCs and other pollutants through their precisely designed pore structures and functional groups. At present, many researchers tend to focus only on the removal performance of adsorbents for single pollutants, while lacking systematic exploration of the synergistic adsorption mechanism and dynamic competition behavior of multi-component gaseous pollutants in a closed environment. Generally speaking, the strong competitive interactions between different components in a multi-component gas in a limited microporous space will weaken the adsorption force of each component on the adsorbent, thereby reducing its adsorption performance. In addition, the competitive adsorption of N2 and H2O molecules coexisting in the environment on the adsorbent also significantly reduces the adsorption capacity and adsorption rate of the adsorbent for pollutant species. Therefore, the construction of a new adsorbent material with both multi-pollutant adsorption capacity and humidity tolerance is still a scientific problem that needs to be solved urgently in the field of environmental functional materials.

[0004] In recent years, the development of new adsorbents with flexible structures has attracted widespread attention from researchers. Compared with traditional rigid adsorbents, they can interact with adsorbate molecules adsorbed in microspaces to adjust the pore structure or pore size of the adsorbent. Compared with the overall flexibility of MOFs materials that require strong perturbations of the filling molecules, HCPs assembled by interlayer chain structures show partial flexibility characteristics that are susceptible to molecular "microperturbations", which is expected to break the limitations of adsorption behavior in a single adsorption mechanism, and thus achieve the synergistic adsorption of multi-component VOCs and CO2 and other gas pollutant molecules in the same time and space. Summary of the invention

[0005] In view of the shortcomings of the current research on the adsorption and removal of multi-component VOCs and CO2 in actual environments, the present invention provides a preparation method and application of a flexible ionic cross-linked polymer. The H2O molecule synergistic adsorption strategy based on a flexible ionic cross-linked polymer (F-IHCP) with multiple adsorption sites realizes the synergistic adsorption of multi-component VOCs and CO2 in a high humidity environment. The technology of the present invention is achieved through the following technical solutions:

[0006] A method for preparing a flexible ion-type cross-linked polymer comprises the following steps:

[0007] (1) Swelling / dispersion of monomer molecules: Under the protection of N2 atmosphere, 1H-benzotriazole is added to the 1,2-dichloroethane solution, and then halogenated xylene is added. After sufficient stirring, the dimethoxymethane reagent is added to the mixed system to obtain a mixed solution;

[0008] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, anhydrous FeCl3 is added to the mixed solution of step (1), stirred at 45-50°C for 4-5h, and then heated to 80-90°C and maintained for 18-19h to catalyze and induce Friedel-Crafts alkylation and quaternization reactions. The mixture is then filtered and Soxhlet extracted for 20-24h, and vacuum dried to obtain a brown material, which is a flexible ionic cross-linked polymer (F-IHCP).

[0009] In the present invention, 1,2-dichloroethane is used as a solvent, 1H-benzotriazole with different functional groups and molecular sizes and α,α'-dichloro-p-xylene / α,α'-dibromo-p-xylene are used as monomers, dimethoxymethane is used as a crosslinking agent, and anhydrous FeCl3 is used as a catalyst.

[0010] As a preferred technical solution, in the step (1), the molar ratio of 1H-benzotriazole to halogenated xylene is 1:0.5-2; the halogenated xylene is α,α'-dichloro-p-xylene or α,α'-dibromo-p-xylene.

[0011] As a preferred technical solution, in step (1), the amount of 1,2-dichloroethane solution used is 5-25 L of 1,2-dichloroethane solution per mole of 1H-benzotriazole.

[0012] As a preferred technical solution, the molar ratio of 1H-benzotriazole to dimethoxymethane in step (1) is 1:1-4.

[0013] As a preferred technical solution, in step (1), the addition of 1H-benzotriazole and α,α'-dichloroparaxylene is fully stirred for 5-10 minutes.

[0014] Preferably as the technical solution, in the step (2), the molar ratio of anhydrous FeCl3 to dimethoxymethane is 1:0.25 - 1.

[0015] Preferably as the technical solution, in the steps (1) and (2), the stirring speed of the solution is 350 - 500 rpm.

[0016] Preferably as the technical solution, in the step (2), vacuum drying is carried out for 10 - 12 h.

[0017] The flexible ionic cross-linked polymer F-IHCP prepared by the present invention has a covalent / ionic / hydrogen bond multi-cross-linked network structure, and its BET specific surface area is 240 - 930 m 2 / g. The microstructure shows a honeycomb structure formed by the stacking of curved small sheet-like structures, and the average sheet thickness is about 10 nm.

[0018] The flexible ionic cross-linked polymer of the present invention can be applied to the simultaneous cooperative adsorption and removal of multi-component VOCs and CO2 in a high-humidity environment in the same time and space.

[0019] Principle of the present invention: Aiming at the deficiency in the research on the adsorption and removal of multi-component VOCs and CO2 in the actual environment, a H2O molecule cooperative adsorption strategy based on the flexible ionic cross-linked polymer F-IHCP with multiple adsorption sites is proposed. Through Friedel-Crafts alkylation polymerization and quaternization reactions, different anionic and cationic monomer molecules containing Cl / Br and basic N sites are used as structural units, and materials with high-density ionic sites are synthesized through their array-ordered self-assembly, constructing a central adsorption domain and a lateral adsorption domain with different adsorption characteristics for formaldehyde and CO2 molecules. Due to the existence of different ionic sites in these two adsorption regions, they can preferentially adsorb different adsorbate molecules and minimize the competitive adsorption between formaldehyde and CO2 molecules. On this basis, the strong interaction between formaldehyde and CO2 molecules and the flexible framework of F-IHCP leads to the pore swelling of the adsorbent and creates a new adsorption microenvironment for subsequent adsorbate molecules. In addition, in a high-humidity environment, the "hard base" H2O molecules can form new hydrogen bond interactions with the more acidic formaldehyde and CO2 molecules, and enhance the capture of formaldehyde and CO2 through the "formaldehyde-H2O-CO2" cooperative effect. These characteristics enable F-IHCP to achieve the cooperative adsorption of formaldehyde and CO2 mixtures at high humidity, realizing the reverse utilization of H2O molecules from competition to cooperation.

[0020] Compared with the prior art, the advantages of the present invention are as follows:

[0021] (1) The multi - elemental site - regulated flexible ionic hypercrosslinked polymer prepared in the present invention is obtained by a template - free one - step method through Friedel - Crafts alkylation polymerization and quaternization reactions. In an oily solvent, the ionic bonds and hydrogen bonds between monomer molecules endow the F - IHCP material with a unique honeycomb - like pore structure stacked by sheet - like structures.

[0022] (2) The multi - elemental site - regulated flexible ionic hypercrosslinked polymer prepared in the present invention has a high specific surface area, a flexible covalent / ionic / hydrogen - bond multi - crosslinked network structure, and abundant basic N and terminal / free Cl active sites, and can rapidly adsorb atmospheric pollutants such as formaldehyde and CO2 with high capacity.

[0023] (3) The flexible ionic hypercrosslinked polymer prepared in the present invention constructs a central adsorption domain and a lateral adsorption domain with different adsorption characteristics for formaldehyde and CO2 molecules through the interaction between basic N cations and terminal / free Cl anion active sites. These two adsorption regions can preferentially adsorb different adsorbate molecules and minimize the competitive adsorption between formaldehyde and CO2 molecules.

[0024] (4) The strong adsorption force of the flexible ionic hypercrosslinked polymer prepared in the present invention for formaldehyde and CO2 molecules deforms its backbone structure, increases the adsorption capacity, creates a new adsorption micro - environment for subsequent adsorbate molecules, and greatly enhances the binding energy for formaldehyde and CO2, thus realizing the synergistic adsorption enhancement for the formaldehyde / CO2 mixture.

[0025] (5) The present invention proposes a H2O molecule synergistic adsorption strategy based on the flexible ionic hypercrosslinked polymer. In a high - humidity environment, "hard base" H2O molecules can form new hydrogen - bond interactions with more acidic formaldehyde and CO2 molecules, and enhance the capture of formaldehyde and CO2 in a high - humidity environment through the "formaldehyde - H2O - CO2" synergistic effect.

[0026] (6) The preparation method of the present invention is simple, easy to operate, and has a low cost, and is suitable for large - scale industrial production. Description of the Drawings

[0027] Figure 1 Schematic diagram of the synthesis principle of the flexible ionic hypercrosslinked polymer F - IHCP prepared in Example 1.

[0028] Figure 2 SEM and TEM images of the flexible cationic hypercrosslinked polymer in Comparative Example 1 and the flexible zwitterionic hypercrosslinked polymer F - IHCP prepared in Examples 1 - 2.

[0029] Figure 3 TEM and EDS images of the flexible zwitterionic hypercrosslinked polymer F - IHCP prepared in Example 1.

[0030] Figure 4 XRD patterns of the rigid cross-linked polymer of Comparative Example 1 and the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Examples 1-2.

[0031] Figure 5 N2 adsorption / desorption isotherms and pore size distribution curves of the flexible cationic hyper-crosslinked polymer of Comparative Example 1 and the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Examples 1-2.

[0032] Figure 6 Adsorption isotherms of CO2 and N2 for the flexible cationic hyper-crosslinked polymer of Comparative Example 1 and the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Examples 1-2.

[0033] Figure 7 Adsorption isotherm of water vapor for the flexible cationic hyper-crosslinked polymer of Comparative Example 1 and the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Examples 1-2.

[0034] Figure 8 Adsorption kinetic curves and comparison diagrams of adsorption capacity / rate for the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Example 1 for single components (S) of formaldehyde and CO2 and a mixed component (M) of formaldehyde / CO2.

[0035] Figure 9 Adsorption kinetic curves and comparison diagrams of adsorption capacity / rate for water in single components (S) of formaldehyde and CO2 and a mixed component (M) of formaldehyde / CO2 for the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Example 1.

[0036] Figure 10 Breakthrough curves and corresponding Yoon-Nelson model fitting curves for the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Example 1 for single components of formaldehyde and CO2 and a mixed component of formaldehyde / CO2.

[0037] Figure 11 Diagram of the 5-cycle adsorption performance of the flexible zwitterionic hyper-crosslinked polymer F-IHCP prepared in Example 1 for a formaldehyde / CO2 mixed component. Detailed implementation manners

[0038] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the scope of protection required by the present invention is not limited to the scope of protection of the embodiments. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention all fall within the scope of protection of the present invention. The specific process parameters and the like in the following examples are only examples within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific values in the following examples.

[0039] Example 1

[0040] A preparation method of a Cl-based flexible zwitterionic hypercrosslinked polymer Cl / N-IHCP includes the following steps:

[0041] (1) Swelling of monomer molecules: Under the protection of N2 atmosphere, first add 50 ml of 1,2-dichloroethane solution into a 250 ml three-necked flask, then add 5 mmol of 1H-benzotriazole and 5 mmol of α,α'-dichloro-p-xylene in sequence. After stirring well for 5 - 10 min, slowly drop 10 mmol of dimethoxymethane into the mixed solution and make it mix evenly under magnetic stirring at 400 rpm;

[0042] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, quickly add 20 mmol of anhydrous FeCl3 into the above mixed solution, place it in a water bath at 45 °C and stir magnetically for 5 h (rotation speed 400 rpm), then raise the temperature to 80 °C and keep it for 19 h; after reacting for 19 h, stop heating, add 30 ml of methanol solution into the three-necked flask to quench the reaction. The obtained solution is filtered by suction and Soxhlet extracted for 24 h to remove impurities, and then dried at 70 °C at room temperature and dried in vacuum at 80 °C for 12 h. Finally, a brown product is obtained, which is the Cl-based flexible zwitterionic hypercrosslinked polymer (Cl / N-IHCP).

[0043] Example 2

[0044] A preparation method of a Br-based flexible zwitterionic hypercrosslinked polymer Br / N-IHCP includes the following steps:

[0045] (1) Swelling of monomer molecules: Under the protection of N2 atmosphere, first add 50 ml of 1,2-dichloroethane solution into a 250 ml three-necked flask, then add 5 mmol of 1H-benzotriazole and 5 mmol of α,α'-dibromo-p-xylene in sequence. After stirring well for 5 - 10 min, slowly drop 10 mmol of dimethoxymethane into the mixed solution and make it mix evenly under magnetic stirring at 400 rpm;

[0046] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, 20 mmol of anhydrous FeCl3 was quickly added to the above mixed solution, and it was placed in a water bath at 45 °C and magnetically stirred for 5 h (rotation speed 400 rpm), then the temperature was raised to 80 °C and maintained for 19 h; after reacting for 19 h, heating was stopped, 30 ml of methanol solution was added to the three-necked flask to quench the reaction, and the obtained solution was filtered by suction and Soxhlet extracted for 24 h to remove impurities. After drying at 70 °C at room temperature and vacuum drying at 80 °C for 12 h, a brown product was finally obtained, which was the Br-based flexible zwitterionic hypercrosslinked polymer (Br / N-IHCP).

[0047] Comparative Example 1

[0048] A preparation method of a flexible cationic hypercrosslinked polymer N-IHCP includes the following steps:

[0049] (1) Swelling of monomer molecules: Under the protection of N2 atmosphere, first add 50 ml of 1,2-dichloroethane solution to a 250 ml three-necked flask, then add 10 mmol of 1H-benzotriazole, and after stirring well for 5 - 10 min, slowly drop 10 mmol of dimethoxymethane into the mixed solution and mix it evenly under magnetic stirring at 400 rpm;

[0050] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, 20 mmol of anhydrous FeCl3 was quickly added to the above mixed solution, and it was placed in a water bath at 45 °C and magnetically stirred for 5 h (rotation speed 400 rpm), then the temperature was raised to 80 °C and maintained for 19 h; after reacting for 19 h, heating was stopped, 30 ml of methanol solution was added to the three-necked flask to quench the reaction, and the obtained solution was filtered by suction and Soxhlet extracted for 24 h to remove impurities. After drying at 70 °C at room temperature and vacuum drying at 80 °C for 12 h, a brown product was finally obtained, which was the flexible cationic hypercrosslinked polymer (N-IHCP).

[0051] Example 3

[0052] A preparation method of a Cl-based flexible zwitterionic hypercrosslinked polymer Cl / N-IHCP includes the following steps:

[0053] (1) Swelling of monomer molecules: Under the protection of N2 atmosphere, first add 125 ml of 1,2-dichloroethane solution to a 250 ml three-necked flask, then add 5 mmol of 1H-benzotriazole and 5 mmol of α,α'-dichlorop-xylene in sequence. After stirring well for 5 - 10 min, slowly drop 20 mmol of dimethoxymethane into the mixed solution and mix it evenly under magnetic stirring at 500 rpm;

[0054] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, 20 mmol of anhydrous FeCl3 was rapidly added to the above mixed solution, and the mixture was magnetically stirred in a water bath at 50 °C for 4 h (rotation speed 500 rpm), then heated to 90 °C and maintained for 18 h. After 18 h of reaction, heating was stopped, and 30 ml of methanol solution was added to the three-necked flask to quench the reaction. The obtained solution was filtered by suction and Soxhlet extracted for 24 h to remove impurities, and then dried at 70 °C at room temperature and 80 °C under vacuum for 12 h. Finally, a brown product was obtained, which was the Cl-based flexible zwitterionic hypercrosslinked polymer (Cl / N-IHCP).

[0055] Example 4

[0056] A preparation method of a Br-based flexible zwitterionic hypercrosslinked polymer Br / N-IHCP includes the following steps:

[0057] (1) Swelling of monomer molecules: Under the protection of N2 atmosphere, first add 25 ml of 1,2-dichloroethane solution to a 250 ml three-necked flask, then sequentially add 5 mmol of 1H-benzotriazole and 5 mmol of α,α'-dibromo-p-xylene, and stir well for 5 - 10 min. Then, slowly drop 5 mmol of dimethoxymethane into the mixed solution and mix it evenly under magnetic stirring at 350 rpm;

[0058] (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, 20 mmol of anhydrous FeCl3 was rapidly added to the above mixed solution, and the mixture was magnetically stirred in a water bath at 45 °C for 5 h (rotation speed 400 rpm), then heated to 80 °C and maintained for 19 h. After 19 h of reaction, heating was stopped, and 30 ml of methanol solution was added to the three-necked flask to quench the reaction. The obtained solution was filtered by suction and Soxhlet extracted for 20 h to remove impurities, and then dried at 70 °C at room temperature and 80 °C under vacuum for 10 h. Finally, a brown product was obtained, which was the Br-based flexible zwitterionic hypercrosslinked polymer (Br / N-IHCP).

[0059] Material property detection

[0060] The products prepared in Comparative Example 1 and Examples 1 - 2 of the present invention were subjected to structural and property characterization and analysis.

[0061] (I) Microstructural characterization of crosslinked polymers

[0062] The microstructure of N-IHCP prepared in Comparative Example 1 and Cl / N-IHCP and Br / N-IHCP prepared in Examples 1-2 of the present invention was characterized using a Hitachi SU8020 scanning electron microscope (SEM) and a JEOL JEM-2100F transmission electron microscope (TEM, acceleration voltage: 200 kV), and the corresponding elemental maps were characterized by energy-dispersive X-ray spectroscopy (EDS), as Figure 2 and 3 shown. Figure 2 a-c are SEM images of N-IHCP of Comparative Example 1 and Cl / N-IHCP and Br / N-IHCP prepared in Examples 1-2, respectively. It can be clearly seen that N-IHCP exhibits a petal-like structure assembled from larger flakes with a wrinkled surface, and its thickness and width are approximately ~15 nm and 1.2 μm, respectively ( Figure 2 a). Compared with cationic N-IHCP, the sizes of the flaky structures of zwitterionic Cl / N-IHCP and Br / N-IHCP are significantly reduced ( Figure 2 b, c). Among them, Cl / N-IHCP has a framework structure formed by the stacking and assembly of flaky structures, and the average lamellar thickness is about 10 nm ( Figure 2 d). Figure 3 The elemental map shows that N and Cl elements are uniformly distributed on the surface of Cl / N-IHCP, indicating the successful reaction of 1H-benzotriazole and α,α'-dibromo-p-xylene monomer molecules.

[0063] (II) XRD Characterization of Polymers

[0064] The crystal structures of N-IHCP prepared in Comparative Example 1 and Cl / N-IHCP and Br / N-IHCP prepared in Examples 1-2 of the present invention were characterized using a Rigaku SMARTLAB3KW powder X-ray diffractometer (PXRD) with CuKα radiation in the range of 2θ = 5-60°, as shown. It can be clearly seen that the three polymers only show characteristic amorphous graphite carbon peaks (black marks), which belong to the (101) crystal plane of hexagonal graphite, indicating their amorphous nature with a certain degree of graphitization. Figure 4

[0065] (III) Characterization of Nitrogen Adsorption / Desorption Isotherms and Pore Structure Parameters of Polymers

[0066] The specific surface area and pore structure of N-IHCP prepared in Comparative Example 1 and Cl / N-IHCP and Br / N-IHCP prepared in Examples 1-2 of the present invention were characterized using a Micromeritics ASAP 2460 specific surface area and porosity analyzer at 77 K, and the characterization results are as​Figure 5 As shown in Table 1, Example 1 is the material with the optimal parameters.

[0067] Table 1 Specific surface area and pore structure parameters of flexible ionic hypercrosslinked polymer materials

[0068]

[0069] (4) Adsorption kinetic performance analysis of cationic and zwitterionic crosslinked polymers on single components.

[0070] The CO2, N2 and water vapor adsorption isotherms of N-IHCP prepared in Comparative Example 1 and Cl / N-IHCP and Br / N-IHCP prepared in Examples 1-2 of the present invention were measured using a Micromertics 3Flex surface characterization analyzer in the United States, as Figure 6 and 7 shown.

[0071] In Figure 6 , the adsorption capacity of Cl / N-IHCP for CO2 at 298K is the highest, up to 2.43 mmol / g, significantly higher than that of N-HCP (0.95 mmol / g) and Br / N-IHCP (1.93 mmol / g). On the contrary, the N2 adsorption capacity of Cl / N-IHCP (0.079 mmol / g) is lower than that of Br / N-IHCP (0.14 mmol / g). The adsorption difference between CO2 and N2 indicates that Cl / N-IHCP has a strong adsorption selectivity for CO2 and is more conducive to purifying CO2 in indoor environments or enclosed spaces.

[0072] In Figure 7 , the water adsorption isotherms of N-HCP, Cl / N-IHCP and Br / N-IHCP show different upward trends with the increase of pressure. When the relative pressure < 0.4, the water adsorption of the three polymers increases relatively slowly (< 3 mmol / g). It is worth noting that compared with N-IHCP, Cl / N-IHCP and Br / N-IHCP show a certain degree of reduction in water absorption rate, which is attributed to the smaller micropores with benzene ring skeletons on the polymer hindering the rapid entry of H2O molecules.

[0073] When the relative pressure > 0.4, due to the condensation of water in mesopores, the water vapor adsorption capacities of the three polymers increase rapidly until reaching adsorption saturation at a relative pressure of 0.94. Compared with N-HCP, the water adsorption amounts of Cl / N-IHCP and Br / N-IHCP increase faster in the range of relative pressure 0.4 - 0.6 and finally reach higher saturated adsorption capacities, which are 12.3 and 15.0 mmol / g respectively, about 24% and 50% higher than that of N-HCP respectively. This is attributed to the stronger adsorption force of the introduced Cl and Br ion sites on H2O molecules, as well as the higher BET specific surface area and mesopore volume of Cl / N-IHCP and Br / N-IHCP.

[0074] (V) Adsorption Kinetics Performance Analysis of Flexible Zwitterionic Crosslinked Polymers for Single and Mixed Components of Formaldehyde and CO2

[0075] The adsorption kinetics of Cl / N-IHCP prepared in Example 1 of the present invention for single and mixed components of formaldehyde and CO2 was measured using a Finnish GASERA ONE photoacoustic spectroscopy multi-gas analyzer, as Figure 8 shown.

[0076] In Figure 8 a-b, the adsorption kinetics (points) of Cl / N-IHCP for formaldehyde and CO2 reach equilibrium within 50 min and show a good pseudo-first-order kinetic trend (R 2 > 0.99). Different from the adsorption of single components of CO2 and formaldehyde, the adsorption kinetics of Cl / N-IHCP for its mixed components can be divided into three stages. In Stage Ι and Stage ΙΙ, Cl / N-IHCP shows an adsorption process similar to that of single-component adsorption for formaldehyde. However, its adsorption behavior for CO2 is different, with almost no adsorption in the initial Stage Ι and then a rapid increase in Stage ΙΙ. In addition, the adsorption of both CO2 and formaldehyde by Cl / N-IHCP reaches equilibrium in Stage ΙΙΙ.

[0077] Figure 8 c-d shows the comparison of the adsorption capacities and kinetics of Cl / N-IHCP for CO2 and formaldehyde in single and mixed components. As can be seen from Figure 8 c, compared with single-component adsorption, the equilibrium adsorption amounts of Cl / N-IHCP for CO2 (62.5 mg / g) and formaldehyde (27.3 mg / g) in the mixed components increase by about 45% and 70% respectively. This illustrates the existence of the synergistic effect between CO2 and formaldehyde molecules and promotes the adsorption of both by Cl / N-IHCP. For the adsorption of mixed components, the adsorption rates of Cl / N-IHCP for CO2 and formaldehyde show interrelated changes in Stage Ι and Stage ΙΙ. Compared with only adsorbing CO2 (0.093 min -1) and formaldehyde (0.165 min -1 ), compared with formaldehyde, the adsorption rate of Cl / N-IHCP for formaldehyde in Stage Ι and Stage ΙΙ increased significantly (0.246 min-1), while its adsorption rate for CO2 decreased first within a very short time (0.0013 min -1 ), and then increased significantly by about 270 times, reaching 0.350 min -1 ( Figure 8 d). In Stage Ι, the adsorption rate of Cl / N-IHCP for formaldehyde was about 190 times higher than that for CO2, while in Stage ΙΙ, it was exactly the opposite (k CH2O = 0.246 min -1 < k CO2 = 0.350 min -1 ). These adsorption kinetic results indicate that, compared with the single-component adsorption of CO2 and formaldehyde, the coexistence of CO2 and formaldehyde molecules promoted the adsorption of both by Cl / N-IHCP.

[0078] (VI) Analysis of the adsorption kinetic performance of water in single and mixed components of formaldehyde and CO2 by flexible zwitterionic cross-linked polymers

[0079] The Cl / N-IHCP prepared in Example 1 of the present invention was used to conduct the adsorption kinetic determination of water in single and mixed components of formaldehyde and CO2 by using a Finnish GASERA ONE type photoacoustic spectroscopy multi-gas analyzer, as Figure 9 shown.

[0080] From Figure 9 a, it can be seen that different from the adsorption kinetics of water in single components of CO2 and formaldehyde, the adsorption kinetics of water in the formaldehyde / CO2 mixed component by Cl / N-IHCP also has three stages. Among them, the adsorption of water by Cl / N-IHCP increased slowly in Stage Ι, then increased rapidly in Stage ΙΙ, and reached equilibrium in Stage ΙΙΙ. Figure 9 b shows the comparison of the adsorption capacity and adsorption rate of water in single and mixed components of CO2 and formaldehyde by Cl / N-IHCP. The results show that the equilibrium adsorption amount of water in the mixed component by Cl / N-IHCP (52.7 mg / g) is 2.7 and 7.6 times the adsorption amounts of water in the two single components (19.7 and 6.9 mg / g), respectively. For the adsorption rate, the adsorption rates of water by Cl / N-IHCP in the two single-component systems (0.086 and 0.157 min -1 ) are lower than those for CO2 (0.093 min -1 ) and formaldehyde (0.165 min -1 ), indicating that its adsorption force for CO2 and formaldehyde is stronger than that for water molecules. Therefore, compared with the adsorption of CO2 and formaldehyde ( Figure 8a), The adsorption of Cl / N-IHCP on the mixed component water shows a certain hysteresis. However, it is worth noting that while the adsorption of CO2 and formaldehyde in the mixed component is enhanced, the adsorption of water by Cl / N-IHCP is also enhanced synchronously.

[0081] (VII) Analysis of breakthrough curves of flexible zwitterionic cross-linked polymers for single and mixed components of formaldehyde and CO2

[0082] Using a multi-component adsorption breakthrough curve analyzer (BSD-MAB), the breakthrough curves of formaldehyde and CO2 in single and mixed components of Cl / N-IHCP prepared in Example 1 of the present invention were measured at 298K, as Figure 10 shown.

[0083] As Figure 10 shown in a, compared with the adsorption of single CO2 and formaldehyde, the working adsorption time (t w ) and equilibrium adsorption time (t e ) of Cl / N-IHCP for CO2 and formaldehyde in the mixed component are both significantly increased, indicating that the adsorption capacity for the two in the mixed component is greater than that for the single component. It is worth noting that in the later stage of the breakthrough experiment for single-component CO2, the C / C0 value of the CO2 concentration is greater than 1. This is attributed to the fact that the adsorption of Cl / N-IHCP on single-component CO2 is more likely to reach saturation, and after reaching saturation, argon (Ar) in the system will carry out the adsorbed CO2 molecules in the sample, resulting in an increase in the CO2 concentration in the pipeline. Figure 10 Figure b shows the diffusion rates of CO2 and formaldehyde on Cl / N-IHCP under different adsorption systems calculated by the Y-N model, and shows a good fitting trend (R 2 > 0.99). Compared with the single component, the breakthrough rate constant (k) of Cl / N-IHCP for CO2 in the mixed component decreases from 1.56 to 0.497×10 -1 min·g -1 , while the k value for formaldehyde increases from 0.046 to 0.064×10 - 1 min·g -1 . This shows that in the initial stage of adsorption (<5 min), the adsorption force of Cl / N-IHCP for formaldehyde is stronger than that for CO2, inhibiting the adsorption of CO2, thus showing an adsorption phenomenon of increasing adsorption rate for formaldehyde and decreasing adsorption rate for CO2.

[0084] (VIII) Analysis of cyclic adsorption performance of flexible zwitterionic cross-linked polymers for formaldehyde / CO2 mixed components

[0085] Figure 11Shows the 5 consecutive adsorption / desorption cycles of Cl / N-IHCP for the formaldehyde / CO2 mixed component (black represents formaldehyde and blue represents CO2). For the adsorption of formaldehyde by Cl / N-IHCP, the first adsorption amount is 27.3 mg / g, and the fifth adsorption amount still reaches 26.7 mg / g; for the adsorption of CO2 by Cl / N-IHCP, the first adsorption amount is 62.5 mg / g, and the fifth adsorption amount still reaches 60.4 mg / g. It shows the excellent adsorption stability and repeatability of Cl / N-IHCP for the formaldehyde / CO2 mixed component.

[0086] The examples given in the present invention are not intended to limit the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a flexible ion-type cross-linked polymer, characterized in that: The steps include: (1) Swelling / dispersion of monomer molecules: Under the protection of N2 atmosphere, 1H-benzotriazole is added to the 1,2-dichloroethane solution, and then halogenated xylene is added. After sufficient stirring, the dimethoxymethane reagent is added to the mixed system to obtain a mixed solution; (2) Polymerization of monomer molecules: Under the protection of N2 atmosphere, anhydrous FeCl3 is added to the mixed solution of step (1), stirred at 45-50°C for 4-5h, and then heated to 80-90°C and maintained for 18-19h to catalyze and induce Friedel-Crafts alkylation and quaternization reactions. The mixture is then filtered and Soxhlet extracted for 20-24h, and vacuum dried to obtain a brown material, which is a flexible ionic cross-linked polymer.

2. The method for preparing a flexible ionomer according to claim 1, characterized in that: In the step (1), the molar ratio of 1H-benzotriazole to halogenated xylene is 1:0.5-2; the halogenated xylene is α,α'-dichloro-p-xylene or α,α'-dibromo-p-xylene.

3. The method for preparing a flexible ionomer according to claim 1, characterized in that: In the step (1), the amount of 1,2-dichloroethane solution used is 5-25 L of 1,2-dichloroethane solution added to each mole of 1H-benzotriazole.

4. The method for preparing a flexible ionomer according to claim 1, characterized in that: In the step (1), the molar ratio of 1H-benzotriazole to dimethoxymethane is 1:1-4.

5. The method for preparing a flexible ionomer according to claim 1, characterized in that: In the step (1), the addition of 1H-benzotriazole and α,α'-dichloroparaxylene is fully stirred for 5-10 minutes.

6. The method for preparing a flexible ionomer according to claim 1, characterized in that: The molar ratio of anhydrous FeCl3 to dimethoxymethane in the step (2) is 1:0.25-1.

7. The method for preparing a flexible ionomer according to claim 1, characterized in that: In the step (2), vacuum drying is performed for 10-12 hours.

8. The method for preparing a flexible ionomer according to claim 1, characterized in that: The stirring speed of the solution in steps (1) and (2) is 350-500 rpm.

9. The flexible ion-type cross-linked polymer prepared by the method according to any one of claims 1 to 8, characterized in that: The BET specific surface area of ​​the flexible ion-type cross-linked polymer is 240-930 m 2 / g, the microstructure is a honeycomb structure formed by the stacking of small curved platelets.

10. The use of the flexible ionomer according to claim 9, characterized in that: Application of flexible ionic cross-linked polymers in the adsorption and removal of VOCs and CO2 in high humidity environments.

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