A covalent organic framework material for phthalate adsorption, its preparation method and application

Abstract

A covalent organic framework material for phthalate adsorption, a preparation method and an application thereof, which relates to a covalent organic framework material, a preparation method and an application thereof. It aims to solve the technical problems of the existing phthalate adsorbents having few types, long adsorption time and low adsorption amount. The basic structural unit of the covalent organic framework material of the present invention is as follows: it is obtained by reacting 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde. The covalent organic framework material is used as an adsorbent, and the content of phthalates in wastewater is detected by a standard curve method, which can be used in the field of phthalate detection.

Description

Technical Field

[0001] The invention relates to a covalent organic framework material and a preparation method and application thereof. Background Art

[0002] Phthalate esters (PAE) are mainly used in polyvinyl chloride materials to change polyvinyl chloride from hard plastic to elastic plastic, acting as a plasticizer. It is widely used in hundreds of products such as toys, food packaging materials, medical blood bags and hoses, vinyl floors and wallpapers, detergents, lubricants, personal care products (such as nail polish, hair spray, soap and shampoo), but these substances can pollute the environment through the environment (water, air and soil) or migrate from packaging materials, causing health problems due to their toxicity. Therefore, this type of compound has received widespread attention from environmental science, public health, the media and even the general public. Studies have shown that phthalates play a role similar to estrogen in humans and animals, can interfere with endocrine, and can cause testicular cancer in severe cases, making them the "culprit" of male reproductive problems. Among cosmetics, nail polish has the highest content of phthalates, and many cosmetics also contain this substance in their fragrance ingredients. This substance in cosmetics can enter the body through the female respiratory system and skin. If used excessively, it will increase the risk of breast cancer in women and harm the reproductive system of male babies they will give birth to in the future. Therefore, it is of great significance and extremely challenging to study materials that can effectively remove phthalates. Covalent Organic Frameworks (COFs) have broad application prospects in the field of adsorption due to their advantages such as orderly pore structure, large specific surface area, uniform porosity and good chemical stability. Therefore, they have become the focus of researchers.

[0003] At present, literature on the adsorption of ester substances by covalent organic framework materials has been reported one after another. In 2019, the Journal of Chromatography A, Issue 5, Volume 1525 reported that the nickel ions on the covalent triazine framework matrix were reduced in situ by solvothermal method to prepare magnetic CTFs / Ni composite materials. Under the optimal experimental conditions, the detection limits (LOD, S / N=3) of six PAEs were found to be in the range of 0.024-0.085 mg / kg. In 2022, the Journal of Chromatography A, Issue 15, Volume 45 reported that a magnetic covalent organic framework adsorbent with a coprecipitation structure was prepared using 4,4"-diaminoterphenyl and 1,3,5-trichlorobutanediol as monomers. Under optimized conditions, the detection limit of this method was 0.8-2.1 μg / L, and the recovery rate was 76.8%-99.2%. The adsorption of phthalates in milk was achieved, and as a composite material, the adsorption time of the dye was effectively reduced, but the material synthesis and separation process were complicated.

[0004] According to current literature reports, the existing functional materials for adsorbing phthalates have the following main defects:

[0005] 1. There are fewer types of materials used to absorb phthalates;

[0006] 2. Most materials require a long time to adsorb phthalates;

[0007] 3. The material has a low adsorption capacity for phthalates and the adsorption effect is poor;

[0008] 4. The materials required for adsorption of phthalates are complex to prepare. Summary of the invention

[0009] The present invention aims to solve the technical problems of the existing phthalate adsorbents, which have few types, long adsorption time and low adsorption amount, and provide a covalent organic framework material for phthalate adsorption and its preparation method and application. The covalent organic framework material has the advantages of short adsorption time and high adsorption amount for phthalate.

[0010] The basic structural unit of a covalent organic framework material for phthalate adsorption of the present invention is as follows:

[0011]

[0012] The above-mentioned covalent organic framework material for phthalate adsorption is obtained by reacting 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde. The specific preparation method is carried out according to the following steps:

[0013] 1. Add 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol, 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde, organic solvent I and acid into a pyrex tube in sequence, wherein the mass ratio of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol to 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde is 1:(1-5);

[0014] 2. Freeze, vacuumize and thaw the pyrex tube with liquid nitrogen, repeat the operation 4 to 5 times and seal it;

[0015] 3. Heat the pyrex tube to 100-180°C, react for 3-7 days, cool to room temperature after the reaction is completed, filter, wash the filter cake with organic solvent II, and vacuum dry to obtain a covalent organic framework material for phthalate adsorption.

[0016] Furthermore, the preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol described in step 1 is carried out according to the following steps:

[0017] (1) Add 1 mL of 95% to 98% concentrated sulfuric acid and 2 to 10 mL of 62% to 65% concentrated nitric acid into a reaction container, mix thoroughly, cool to below 0° C., add 1 to 5 mg of 9,10-phenanthrenequinone, stir evenly, and obtain a reaction mixture; heat the reaction mixture to 80 to 140° C., react for 3 to 8 hours, cool to room temperature, pour into ice water, adjust the pH to neutral with 1% to 10% sodium hydroxide solution, collect a yellow solid, and dry it to obtain a dry yellow solid;

[0018] (2) 2 mg of dry yellow solid, 0.2-1.0 mg of ammonium acetate, 0.2-1.0 mg of 3-hydroxybenzaldehyde, 0.5-3 mL of acid and 5-20 mL of organic solvent III are added to a reaction container in sequence, reacted at a temperature of 80-120° C. for 10-24 hours, cooled to room temperature, adjusted the pH to neutral with a sodium hydroxide solution of 1%-10% by mass, collected a red solid, and dried it to obtain a dry red solid; the acid is any one of glacial acetic acid, trifluoroacetic acid, benzenesulfonic acid, p-toluenesulfonic acid, concentrated hydrochloric acid of 30%-37% by mass, and concentrated sulfuric acid of 95%-98% by mass; the organic solvent III is any one of N,N-dimethylformamide, benzene, ethanol, xylene, chlorobenzene, o-dichlorobenzene, acetic acid or n-butanol;

[0019] (3) Add 2 mg of dry red solid, 0.5-2 mg of Raney nickel, 10-30 mL of 45% by mass hydrazine hydrate and 5-20 mL of organic solvent IV to a reaction container in sequence, react at a temperature of 60-120° C. for 10-36 hours, cool to room temperature, filter, collect the gray solid, and dry to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol; the organic solvent IV is any one of ethanol, acetonitrile, tetrahydrofuran, o-dichlorobenzene, n-butanol, N,N-dimethylacetamide or acetone.

[0020] Furthermore, the organic solvent I described in step 1 is a mixture of any two solvents selected from mesitylene, tetrahydrofuran, o-dichlorobenzene, n-butanol, N,N-dimethylformamide, p-dimethylaminopyridine and dioxane.

[0021] Furthermore, the ratio of the mass of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol described in step 1 to the volume of organic solvent I is 1 mg:(1-4) mL.

[0022] Furthermore, the acid described in step 1 is one of glacial acetic acid, trifluoroacetic acid, benzenesulfonic acid, p-toluenesulfonic acid, concentrated hydrochloric acid with a mass percentage concentration of 30% to 37%, and concentrated sulfuric acid with a mass percentage concentration of 95% to 98%, or a combination of any two thereof.

[0023] Furthermore, the ratio of the mass of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol in step 1 to the volume of the acid is 1 mg: (0.05-1.0) mL.

[0024] Furthermore, the organic solvent II for washing the filter cake in step three is methanol, ethanol, acetonitrile, tetrahydrofuran, dichloromethane, chloroform, o-dichlorobenzene, n-butanol, N,N-dimethylacetamide or acetone.

[0025] The preparation process of the covalent organic framework material for phthalate adsorption of the present invention is represented by the following formula:

[0026]

[0027] The application of the above-mentioned covalent organic framework material for phthalate adsorption is to use the covalent organic framework material for phthalate adsorption as an adsorbent, detect the content of phthalate in wastewater by standard curve method, and perform quantitative analysis on phthalate in wastewater.

[0028] The covalent organic framework material used for phthalate adsorption was used as an adsorbent, and a standard curve was drawn using high performance liquid chromatography. The content of phthalates in wastewater was detected by high performance liquid chromatography against the standard curve. The specific method is as follows:

[0029] 1. Prepare aqueous solutions of phthalates with concentrations of 10 mg / L, 20 mg / L, 30 mg / L, 40 mg / L, 50 mg / L, 60 mg / L, 70 mg / L, 80 mg / L, 90 mg / L and 100 mg / L respectively;

[0030] 2. Using high performance liquid chromatography to measure the retention time and absorption peak intensity of the above phthalate solutions of different concentrations; recording the absorption peak intensities at the respective retention times corresponding to the different concentrations of phthalates, and drawing a standard curve of phthalate concentration-absorption peak intensity;

[0031] 3. Take 10 mL of wastewater containing phthalates, add 1 to 3 mg of covalent organic framework material for phthalate adsorption to the wastewater, mix well, and obtain a test solution;

[0032] 4. Determine the HPLC of the solution to be tested and record the absorption peak intensity of the phthalate ester at the corresponding retention time, which is recorded as I A ;

[0033] 5. Find I by comparing with the standard curve A The corresponding concentration of phthalate esters is obtained to obtain the concentration of phthalate esters in the test solution.

[0034] Furthermore, the phthalate aqueous solution in step 1 is any one of deionized water, high-purity water or double distilled water;

[0035] Furthermore, the phthalates are dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) or di(2-ethylhexyl) phthalate (DEHP).

[0036] The covalent organic framework material for phthalate adsorption of the present invention has a simple, efficient and easy-to-operate adsorption method for phthalate, and the adsorption equilibrium time for dimethyl phthalate is 90 minutes, and the maximum adsorption amount is 167 mg·g -1 The adsorption equilibrium time of diethyl phthalate was 70 min, and the maximum adsorption capacity was 136 mg·g -1 The adsorption equilibrium time of dibutyl phthalate was 60 min, and the maximum adsorption capacity was 106 mg·g -1 The adsorption equilibrium time of di(2-ethylhexyl) phthalate was 100 min, and the maximum adsorption capacity was 105 mg·g -1 , the adsorption effect is good. It can be used in the field of phthalate detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is an infrared spectrum of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of Example;

[0038] Figure 2 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of Example 1 HNMR spectrum;

[0039] Figure 3 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of Example 13 CNMR spectrum;

[0040] Figure 4 This is an infrared spectrum of the covalent organic framework material for phthalate adsorption prepared in Example 1;

[0041] Figure 5 This is a nitrogen adsorption-desorption curve diagram of the covalent organic framework material for phthalate adsorption prepared in Example 1;

[0042] Figure 6 It is a covalent organic framework material used for the adsorption of phthalates. The adsorption isotherms of phthalate solutions with different concentrations were detected by high performance liquid chromatography.

[0043] Figure 7 This is a graph showing the adsorption kinetics of phthalates by the covalent organic framework material for phthalate adsorption prepared in Example 1. DETAILED DESCRIPTION

[0044] The beneficial effects of the present invention are verified by the following examples:

[0045] Example 1: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0046] 1. First, prepare 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol. The specific method is carried out according to the following steps:

[0047] (1) Add 1 mL of 98% by mass concentrated sulfuric acid and 5 mL of 65% by mass concentrated nitric acid into a reaction container, mix thoroughly, cool to below 0° C., add 2 mg of 9,10-phenanthrenequinone, stir evenly, and obtain a reaction mixture; heat the reaction mixture to 100° C., react for 6 hours, cool to room temperature, pour into ice water, adjust the pH to neutral with 5% by mass sodium hydroxide solution, collect a yellow solid, and dry it to obtain a dry yellow solid;

[0048] (2) 2 mg of dry yellow solid, 0.5 mg of ammonium acetate, 0.5 mg of 3-hydroxybenzaldehyde, 2 mL of glacial acetic acid and 20 mL of N,N-dimethylformamide were added to a reaction container in sequence, reacted at 100° C. for 20 h, cooled to room temperature, adjusted the pH to neutral with 5% by mass sodium hydroxide solution, collected the red solid, and dried it to obtain a dry red solid;

[0049] (3) 2 mg of dry red solid, 1 mg of Raney nickel, 20 mL of 45% by mass hydrazine hydrate and 20 mL of N,N-dimethylacetamide were added to a reaction container in sequence, reacted at 100° C. for 24 h, cooled to room temperature, filtered, collected the gray solid, and dried to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0050] 2. Add 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 2 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde to a mixture of 1 mL of mesitylene and 1 mL of N,N-dimethylformamide, add the mixture to a pyrex tube, add 0.2 mL of glacial acetic acid as a catalyst, mix well by ultrasonication, and obtain a reaction mixture;

[0051] 3. Perform liquid nitrogen freezing, vacuuming and thawing cycles on the pyrex tube, repeat the operation 4 times and seal it;

[0052] 4. Heat the pyrex tube to 120°C and react for 72 hours; after the reaction is completed, cool to room temperature to obtain a reaction product;

[0053] 5. The reaction product was filtered, and the filter cake was repeatedly washed with ethanol and methanol in turn, and vacuum dried to obtain a covalent organic framework material for phthalate adsorption. The yield of the covalent organic framework material was calculated to be 86%.

[0054] The infrared spectrum of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of this example is as follows: Figure 1 As shown, IR (KBr, cm –1 ):3354,1625,1521,1477,1268,950,815,712.

[0055] The 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of this example 1 H NMR spectrum Figure 2 As shown, 1 H NMR(600MHz,DMSO-d6)δ13.02(s,1H),9.67(s,1H),8.24(d,J=11.6Hz,2H),7.79–7.66(m, 3H), 7.58 (s, 1H), 7.46 (s, 1H), 7.35 (t, J = 7.8Hz, 1H), 6.86 (d, J = 9.1Hz, 4H), 5.27 (s, 5H).

[0056] The 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol prepared in step 1 of this example 13 C NMR spectrum Figure 3 As shown, 13C NMR(151MHz,DMSO-d6)δ158.18(s),148.52(s),146.52(d,J=37.5Hz),137.36–135.56(m),132.55(s),130.30(s),127.98(s),127.1 1 (s), 123.89 (d, J = 47.5Hz), 122.40 (s), 120.08 (d, J = 60.6Hz), 117.27 (s), 116.38 (s), 115.19 (d, J = 65.6Hz), 113.29 (s), 104.34 (s).

[0057] From the results of infrared and nuclear magnetic resonance tests, we can know that the structural formula of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is:

[0058] In order to more clearly determine the structure of the covalent organic framework material for phthalate adsorption, the covalent organic framework material prepared in Example 1 was subjected to infrared spectroscopy testing, and the obtained infrared spectrum is as follows: Figure 4 As shown, the test results are analyzed. Figure 4 It can be seen that the covalent organic framework is at 1685cm -1 and 1604cm -1 There are two characteristic peaks at 1465cm, which belong to the asymmetric and symmetric vibration of the C=O group on the imine ring. The C=O group comes from 4,4',4"-(phenyl-1,3,5-triyl) tribenzaldehyde. -1 The peak at is the stretching vibration of the CNC bond. The imide bond is generated by the condensation reaction of -NH2 on 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 4,4',,4"-(phenyl-1,3,5-triyl)tribenzaldehyde. According to the infrared data analysis, the covalent organic framework material was successfully prepared in Example 1.

[0059] Figure 5 This is a graph of nitrogen adsorption-desorption curves of the covalent organic framework material for phthalate adsorption prepared in Example 1. The nitrogen adsorption curve shows that the nitrogen adsorption amount increases rapidly in the relative pressure range of 0.1 to 0.3, and the nitrogen adsorption amount increases sharply at higher relative pressures (0.8 to 1.0). According to the IUPAC classification, the nitrogen adsorption-desorption isotherm of the covalent organic framework material for phthalate adsorption prepared in this example is a type IV curve, indicating that this material has a mesoporous structure, and it can be explained that this pore structure is highly ordered.

[0060] The covalent organic framework material used for phthalate adsorption was used as an adsorbent, and a standard curve was drawn using high performance liquid chromatography. The content of phthalates in wastewater was detected by high performance liquid chromatography against the standard curve. The specific method is as follows:

[0061] 1. Prepare dimethyl phthalate (DMP) aqueous solutions with concentrations of 10 mg / L, 20 mg / L, 30 mg / L, 40 mg / L, 50 mg / L, 60 mg / L, 70 mg / L, 80 mg / L, 90 mg / L and 100 mg / L respectively;

[0062] 2. Using high performance liquid chromatography to measure the retention time and absorption peak intensity of the above dimethyl phthalate solutions of different concentrations. Record the absorption peak intensity of dimethyl phthalate of different concentrations at their respective retention times, and draw standard curves of dimethyl phthalate concentration-absorption peak intensity;

[0063] 3. Take 10 mL of wastewater containing dimethyl phthalate, add 1 to 3 mg of covalent organic framework material for phthalate adsorption to the wastewater to obtain a test solution;

[0064] 4. Determine the HPLC of the solution to be tested and record the absorption peak intensity of dimethyl phthalate at the corresponding retention time, which is recorded as I A ;

[0065] 5. Find I by comparing with the standard curve A The corresponding concentration of dimethyl phthalate is recorded as the concentration of dimethyl phthalate in the test solution;

[0066] 6. Replace dimethyl phthalate (DMP) with diethyl phthalate (DEP), dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP), respectively, and repeat the above test.

[0067] Using the formula q e =V(c0-c e ) / m to calculate the equilibrium adsorption amount of phthalates by covalent organic framework materials for phthalates adsorption, where q e (mg·g -1 ) represents the equilibrium adsorption amount of phthalates by the covalent organic framework material for phthalates adsorption, q e The unit is mg·g -1 ; V represents the volume of the solution containing phthalates to be tested in step 4, and its unit is L; c0 represents the initial concentration of phthalates, and its unit is mg·L -1 ;c eIt indicates the equilibrium concentration of phthalates when adsorption reaches equilibrium, and its unit is mg·L -1 ; m represents the mass of the covalent organic framework material used for phthalate adsorption, and its unit is g.

[0068] Figure 6 The adsorption isotherms of covalent organic framework materials for phthalate adsorption of different concentrations of phthalate, the horizontal axis is the concentration of phthalate in the solution when the adsorption equilibrium is reached, and the vertical axis is the equilibrium adsorption amount. Figure 6 It can be seen that the equilibrium adsorption amount of phthalates by the covalent organic framework material for phthalate adsorption increases with the increase of phthalate concentration. When the equilibrium adsorption concentration is 300 mg / L, the adsorption equilibrium is reached, and the equilibrium adsorption amount of dimethyl phthalate can reach 155 mg·g -1 ; The equilibrium adsorption capacity of diethyl phthalate can reach 125 mg·g -1 ; The equilibrium adsorption capacity of dibutyl phthalate can reach 122 mg·g -1 ; The equilibrium adsorption capacity of di(2-ethylhexyl) phthalate can reach 106 mg·g -1 These results indicate that the covalent organic framework material for phthalate adsorption provided in this embodiment can reach adsorption equilibrium for phthalates in a relatively short time, and has a relatively high equilibrium adsorption amount, and can be used for the determination of phthalate concentration in wastewater.

[0069] Figure 7 The adsorption kinetics curve of phthalates by the covalent organic framework material for phthalate adsorption prepared in Example 1 is shown in FIG. Figure 7 It can be seen that with the increase of adsorption time, the adsorption amount of phthalates by the covalent organic framework material for phthalate adsorption gradually increases. Within 0-60 minutes, it shows rapid adsorption with a high adsorption rate; from 60 to 90 minutes, the adsorption rate slows down; when the adsorption time is 90 minutes, the adsorption reaches a saturated state. After that, the adsorption time continues to increase, and the adsorption amount remains basically constant. This adsorption phenomenon is mainly attributed to the intermolecular hydrogen bonding between the hydroxyl functional groups in the covalent organic framework material for phthalate adsorption and phthalates.

[0070] Example 2: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0071] 1. The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is the same as that in Example 1 to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0072] 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 4 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde were added to a mixture of 1 mL of dioxane and 2 mL of N,N-dimethylformamide, and the mixture was added to a pyrex tube, and 0.5 mL of benzenesulfonic acid was added as a catalyst, and ultrasonic mixing was performed to obtain a reaction mixture;

[0073] Second, freeze the pyrex tube with liquid nitrogen, evacuate and thaw it in a cycle, repeat the operation 4 times and seal it;

[0074] 3. Heat the pyrex tube to 100°C and react for 80 hours; after the reaction is completed, cool it to room temperature to obtain a reaction product;

[0075] Fourth, the reaction product was filtered, and the filter cake was repeatedly washed with acetonitrile and tetrahydrofuran in turn, and vacuum dried to obtain a covalent organic framework material for phthalate adsorption, with a yield of 79%.

[0076] Example 3: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0077] 1. The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is the same as that in Example 1 to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0078] 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 6 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde were added to a mixture of 2 mL of chlorobenzene and 1 mL of isoquinoline, and the mixture was added to a pyrex tube, and 0.3 mL of trifluoroacetic acid was added as a catalyst, and ultrasonic mixing was performed to obtain a reaction mixture;

[0079] Second, freeze the pyrex tube with liquid nitrogen, evacuate and thaw it in a cycle, repeat the operation 4 times and seal it;

[0080] 3. Heat the pyrex tube to 130°C and react for 90 hours; after the reaction, cool to room temperature to obtain a reaction product;

[0081] Fourth, the reaction product was filtered, the filter cake was repeatedly washed with dichloromethane, and vacuum dried to obtain a covalent organic framework material for phthalate adsorption, with a yield of 70%.

[0082] Example 4: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0083] 1. The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is the same as that in Example 1 to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0084] 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 8 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde were added to a mixture of 2 mL of n-butanol and 2 mL of N,N-dimethylformamide, and the mixture was added to a pyrex tube, and 1.0 mL of p-toluenesulfonic acid was added as a catalyst, and ultrasonic mixing was performed to obtain a reaction mixture;

[0085] Second, freeze the pyrex tube with liquid nitrogen, evacuate and thaw it in a cycle, repeat the operation 4 times and seal it;

[0086] 3. Heat the pyrex tube to 160°C and react for 100 hours; after the reaction is completed, cool to room temperature to obtain a reaction product;

[0087] Fourth, the reaction product was filtered, the filter cake was repeatedly washed with ethanol and methanol in turn, and vacuum dried to obtain a covalent organic framework material for phthalate adsorption, with a yield of 82%.

[0088] Example 5: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0089] 1. The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is the same as that in Example 1 to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0090] 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 10 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde are respectively added to a mixture of 2 mL of nitrogen methyl pyrrolidone and 3 mL of N,N-dimethylformamide, and the mixture is added to a pyrex tube, and then 0.5 mL of concentrated hydrochloric acid with a mass percentage concentration of 30% to 37% is added as a catalyst, and ultrasonic mixing is performed to obtain a reaction mixture;

[0091] Second, freeze the pyrex tube with liquid nitrogen, evacuate and thaw it in a cycle, repeat the operation 4 times and seal it;

[0092] 3. Heat the pyrex tube to 180°C and react for 120 hours; after the reaction, cool to room temperature to obtain a reaction product;

[0093] Fourth, the reaction product was filtered, the filter cake was repeatedly washed with ethanol and methanol in turn, and vacuum dried to obtain a covalent organic framework material for phthalate adsorption, with a yield of 68%.

[0094] Example 6: The preparation method of the covalent organic framework material for phthalate adsorption in this example is carried out according to the following steps:

[0095] 1. The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol is the same as that in Example 1 to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol;

[0096] 2 mg of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol and 10 mg of 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde are respectively added to a mixture of 2 mL of nitrogen methyl pyrrolidone and 2 mL of isoquinoline, and the mixture is added to a pyrex tube, and then 0.5 mL of concentrated sulfuric acid with a mass percentage concentration of 95% to 98% is added as a catalyst, and ultrasonic mixing is performed to obtain a reaction mixture;

[0097] Second, freeze the pyrex tube with liquid nitrogen, evacuate and thaw it in a cycle, repeat the operation 4 times and seal it;

[0098] 3. Heat the pyrex tube to 160°C and react for 150 hours; after the reaction is completed, cool to room temperature to obtain a reaction product; 4. Filter the reaction product, wash the filter cake repeatedly with ethanol and methanol in turn, and vacuum dry to obtain a covalent organic framework material for phthalate adsorption, with a yield of 65%.

Claims

1. A covalent organic framework material for phthalate adsorption, characterized in that The basic structural units of this material are as follows:

2. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 1, characterized in that The method is carried out in the following steps:

1. Add 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol, 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde, organic solvent I and acid into a pyrex tube in sequence, wherein the mass ratio of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol to 4,4',4"-(phenyl-1,3,5-triyl)tribenzaldehyde is 1:(1-5); 2. Freeze, vacuumize and thaw the pyrex tube with liquid nitrogen, repeat the operation 4 to 5 times and seal it; 3. Heat the pyrex tube to 100-180°C, react for 3-7 days, cool to room temperature after the reaction is completed, filter, wash the filter cake with organic solvent II, and vacuum dry to obtain a covalent organic framework material for phthalate adsorption.

3. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that The preparation method of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol described in step 1 is carried out according to the following steps: (1) Add 1 mL of 95% to 98% concentrated sulfuric acid and 2 to 10 mL of 62% to 65% concentrated nitric acid into a reaction container, mix thoroughly, cool to below 0° C., add 1 to 5 mg of 9,10-phenanthrenequinone, stir evenly, and obtain a reaction mixture; heat the reaction mixture to 80 to 140° C., react for 3 to 8 hours, cool to room temperature, pour into ice water, adjust the pH to neutral with 1% to 10% sodium hydroxide solution, collect a yellow solid, and dry it to obtain a dry yellow solid; (2) 2 mg of dry yellow solid, 0.2-1.0 mg of ammonium acetate, 0.2-1.0 mg of 3-hydroxybenzaldehyde, 0.5-3 mL of acid and 5-20 mL of organic solvent III are added to a reaction container in sequence, reacted at a temperature of 80-120° C. for 10-24 hours, cooled to room temperature, adjusted the pH to neutral with a sodium hydroxide solution of 1%-10% by mass, collected a red solid, and dried it to obtain a dry red solid; the acid is any one of glacial acetic acid, trifluoroacetic acid, benzenesulfonic acid, p-toluenesulfonic acid, concentrated hydrochloric acid of 30%-37% by mass, and concentrated sulfuric acid of 95%-98% by mass; the organic solvent III is any one of N,N-dimethylformamide, benzene, ethanol, xylene, chlorobenzene, o-dichlorobenzene, acetic acid or n-butanol; (3) Add 2 mg of dry red solid, 0.5-2 mg of Raney nickel, 10-30 mL of 45% by mass hydrazine hydrate and 5-20 mL of organic solvent IV to a reaction container in sequence, react at a temperature of 60-120° C. for 10-36 hours, cool to room temperature, filter, collect the gray solid, and dry to obtain 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol; the organic solvent IV is any one of ethanol, acetonitrile, tetrahydrofuran, o-dichlorobenzene, n-butanol, N,N-dimethylacetamide or acetone.

4. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that The organic solvent I described in step 1 is a mixture of any two solvents selected from mesitylene, tetrahydrofuran, o-dichlorobenzene, n-butanol, N,N-dimethylformamide, p-dimethylaminopyridine and dioxane.

5. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that: The ratio of the mass of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol described in step 1 to the volume of organic solvent I is 1 mg:(1-4) mL.

6. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that: The acid described in step 1 is one of glacial acetic acid, trifluoroacetic acid, benzenesulfonic acid, p-toluenesulfonic acid, concentrated hydrochloric acid with a mass percentage concentration of 30% to 37% and concentrated sulfuric acid with a mass percentage concentration of 95% to 98%, or a combination of any two thereof.

7. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that: The ratio of the mass of 3-(5,10-diamino-1H-phenanthro[9,10-d]imidazol-2-yl)phenol described in step 1 to the volume of the acid is 1 mg: (0.05-1.0) mL.

8. A method for preparing a covalent organic framework material for phthalate adsorption according to claim 2, characterized in that: The organic solvent II for washing the filter cake in step 3 is methanol, ethanol, acetonitrile, tetrahydrofuran, dichloromethane, chloroform, o-dichlorobenzene, n-butanol, N,N-dimethylacetamide or acetone.

9. The use of the covalent organic framework material for phthalate adsorption according to claim 1, characterized in that The application is to use the covalent organic framework material for phthalate adsorption as an adsorbent, detect the content of phthalate in wastewater by the standard curve method, and conduct quantitative analysis of phthalate in wastewater.

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