阅读说明：本技术 一种巯基功能化自具微孔聚合物及其制备和应用 (Sulfydryl functionalized self-possessed microporous polymer and preparation and application thereof ) 是由 欧俊杰 徐俊文 叶明亮 于之渊 姜利 孙传盛 于 2019-09-18 设计创作，主要内容包括：本发明涉及一种巯基功能化自具微孔聚合物(PIM-1)的制备,并将其用于对汞离子的吸附。首先采用单体四氟对苯二腈和5,5’,6,6’-四羟基-3,3’,3,3’-四甲基-1,1’-螺双茚满聚合得到自具微孔聚合物PIM-1,然后将聚合物链上的腈基转化为羧基以便下一步巯基化修饰。最后的巯基化过程分为两步,先通过聚合物上的羧基和带二硫键的二胺键合,然后用二硫苏糖醇将二硫键打开暴露巯基,得到巯基功能化的自具微孔聚合物。该聚合物富含巯基,对汞离子有良好的亲和性,可以应用于汞离子的选择性吸附。(The invention relates to preparation of a sulfydryl functionalized self-provided microporous polymer (PIM-1) and application of the sulfydryl functionalized self-provided microporous polymer to adsorption of mercury ions. Firstly, monomers of tetrafluoroterephthalonitrile and 5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane are polymerized to obtain a polymer PIM-1 with micropores, and then nitrile groups on a polymer chain are converted into carboxyl groups so as to facilitate the next sulfhydrylation modification. The final sulfhydrylation process is divided into two steps, firstly, carboxyl on the polymer is bonded with diamine with disulfide bonds, and then, the disulfide bonds are opened by dithiothreitol to expose the sulfhydryls, so that the sulfhydrylsunctional self-possessed microporous polymer is obtained. The polymer is rich in sulfydryl, has good affinity to mercury ions, and can be applied to selective adsorption of the mercury ions.)

1. A sulfydryl functionalized self-possessed microporous polymer, the structure of which is shown as the following, the average molecular weight is 30000-60000,

2. a method of preparing the thiolated, self-supporting microporous polymer of claim 1, wherein:

1) polymerizing tetrafluoroterephthalonitrile and 5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane to obtain a polymer PIM-1 with micropores;

2) in order to improve the modifiable performance of the PIM-1, the PIM-1 is firstly carboxylated to obtain PIM-COOH, then a diamine containing a disulfide bond is introduced by utilizing the reaction of carboxyl and amino, and finally the disulfide bond is opened by dithiothreitol to obtain sulfhydrylated PIM-B and/or PIM-G, wherein the diamine containing the disulfide bond is cystamine dihydrochloride and/or 4,4' -dithiodiphenylamine.

3. The method of claim 2, wherein:

PIM-1 carboxylation: carrying out primary hydrolysis on PIM-1 by using 20-30 w% of potassium hydroxide ethanol/water (volume ratio is 1-1.5: 1) solution, wherein the reaction temperature is 100-120 ℃, and the reaction time is 10-20 h; and (3) deeply carboxylating the product of the primary hydrolysis by using a sulfuric acid/water/acetic acid (volume ratio is 2-2.5: 2: 1) solution, wherein the reaction temperature is 100-120 ℃, and the reaction time is 10-20 hours.

4. The method of claim 2, wherein:

sulfhydrylation to PIM-COOH: firstly, performing acetylation on PIM-COOH, adding 0.15-0.30 g of PIM-COOH into a mixed solution of 40-60 mL of dichloromethane and 5-10 mL of thionyl chloride, refluxing for 5-7 h at 50-70 ℃, and removing the solvent and the redundant thionyl chloride by adopting a rotary evaporation method. Then adding 30-50 mL of anhydrous DMF and 1.50-2.00 mmol of diamine with a disulfide bond (cystamine dihydrochloride or 4,4' -dithiodiphenylamine), and reacting for 10-20 h at 50-70 ℃ under the protection of argon; and finally adding 3-4 mmol of dithiothreitol, maintaining the original temperature, and reacting for 5-10 hours under the protection of argon.

5. Use of the thiolated, self-supporting microporous polymer of claim 1 in adsorption of mercury ions in solution.

6. Use according to claim 5, characterized in that: the pH value of the solution is 4-6.

Technical Field

The invention relates to preparation of sulfydryl functionalized self-contained microporous Polymers (PIMs) and application thereof in mercury ion adsorption.

Background

Environmental pollution is an increasingly serious threat facing today's society. The removal of contaminants from air and water is an important aspect of environmental pollution remediation. Among all the contaminants, heavy metal ions, especially mercury ions, can cause serious damage to the human body (document 1.Nolan et al, "Tools and Tactics for the Optical Detection of Mercuric Ion", Chemical Reviews, 2008, 108, 3443-. The development of corresponding adsorbents is a relatively important field in scientific research. In order to find mercury ion adsorbing materials with high efficiency, high capacity and high selectivity, scientists test various porous materials, including zeolite, mesoporous silicon, Metal Organic Framework (MOF), Covalent Organic Framework (COF), pottery clay and the like, and find a lot of materials with excellent performance.

As an important branch of porous organic polymers, self-microporous Polymers (PIMs) were obtained by the scientist Budd et al since 2004 (reference 2, Bud)The long-term development has been achieved after synthesis of "Solution-Processed, organic Membrane Derived from a Polymer of Intrasic Microporosity", Advanced Materials, 2004, 16, 456-459 ". PIMs have their distinctive and distinct characteristics in porous organic polymers. As a mostly linear polymer, it is very uncommon for PIMs to have micropores in the solid state. The micropores of PIMs are derived from their unique molecular structure, and their molecular chains are rigidly twisted, and such molecular chains cause space not to be effectively occupied when stacked, and the space not effectively occupied becomes the micropores of PIMs (document 3, buddy et al, "expansion of internal Microporosity in Polymer-Based Materials", Macromolecules, 2010, 43, 5163-. Owing to their linear structure, PIMs are soluble in partially organic solvents (e.g., dichloromethane, chloroform, tetrahydrofuran, etc.) and can be formed into thin films. Films made from PIMs have very good properties in Gas separation and storage (document 4, "Gas separation membranes from polymers of intrinsic microporosity", "Journal of Membrane Science, 2005, 251, 263-269), and are widely used for the separation of important Gas pairs, for example CO₂/CH₄、 CO₂/N₂、H₂/N₂、H₂/CH₄And O₂/N₂And the like. In addition to their main gas separation applications, PIMs have been used in catalysis, sensors, energy conversion, chiral separation, and dye adsorption (reference 5, buddy et al, "Polymers of Intrinsic Microporosity (PIMs): organic materials for membrane separations, xenogeneous catalysts and hydrostorage", Chemical Reviews, 2006,35,675-683), but PIMs have not been developed for heavy metal adsorption applications. The invention aims to develop the application of PIMs in the aspect of heavy metal adsorption. PIMs, the most important representative of PIMs, are prepared by polymerizing monomers of tetrafluoroterephthalonitrile and 5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane. The invention develops a method for functionalizing PIM-1 sulfydryl and applying the method to selective adsorption of mercury ions. PIM-1 is highly hydrophobic in itself and cannot be sufficiently dispersed in the aqueous phase, so that it has little effect on adsorption of mercury ions. The method has the advantages that the PIM-1 is subjected to sulfhydrylation, the hydrophobic property which is not possessed by the PIM-1 is not possessed by light, and the PIM-1 also has good mercury ion affinity and can be used for selective adsorption of mercury ions.

Disclosure of Invention

The invention aims to provide a preparation method of sulfydryl functionalized self-micropore Polymers (PIMs), which is shown as the following,

the sulfhydrylation endows the PIMs with good hydrophilicity and mercury ion affinity, so that the PIMs can be used for selective adsorption of mercury ions.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

(1) preparation of PIM-1

The polymer PIM-1 with micropores is obtained by polymerization of tetrafluoroterephthalonitrile and 5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane, and has an average molecular weight of 20000-40000 and a specific surface area of 600-1000 m²Per g, the aperture is 0.02-0.1 nm;

specifically, tetrafluoroterephthalonitrile (1.80g,9.00mmol),5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane (3.06g,9.00mmol) and anhydrous potassium carbonate (4.98g, 36mmol) are added to 50mL of anhydrous DMF, and reacted at 65 ℃ for 72h under the protection of argon. After the reaction was completed, the reaction was poured into deionized water, and then suction filtration was carried out to obtain yellow powder. The obtained crude product is subjected to soxhlet extraction and washing by using ethanol to obtain a final product.

(2) Carboxylation of PIM-1

To fully carboxylate PIM-1, the process was carried out in two steps. Firstly, carrying out primary hydrolysis on PIM-1 by using 20-30 w% ethanol/water (volume ratio is 1-1.5/1) solution of potassium hydroxide, wherein the heating temperature is 100-120 ℃, and the time is 10-20 h. After the reaction is completed, the alkalinity is neutralized by excessive acetic acid, and the reaction product is washed by methanol after suction filtration. And drying the obtained product at the temperature of 60-80 ℃ by using a vacuum drying oven. Further hydrolyzing with sulfuric acid/water/acetic acid (volume ratio is 2-2.5/2/1) solution, heating at 100-120 deg.C for 10-20 h. After cooling to room temperature, the mixture was poured into excess water, filtered, and washed thoroughly with methanol to give a green powder. And (3) drying the powder in a vacuum drying oven at the temperature of 60-80 ℃ to obtain a final product PIM-COOH.

(3) Thiolation of PIM-COOH

0.15-0.30 g of PIM-COOH is added into 40-60 mL of dichloromethane, and then 5-10 mL of thionyl chloride is added. And refluxing the mixed solution at 50-70 ℃ for 5-7 h, and then carrying out rotary evaporation on the solvent and the redundant thionyl chloride. Adding 30-50 mL of anhydrous DMF and 1.50-2.00 mmol of diamine with disulfide bonds (cystamine dihydrochloride or 4,4' -dithio diphenylamine) into a flask containing the product, and reacting at 50-70 ℃ for 10-20 h under the protection of argon. And finally adding 3-4 mmol of dithiothreitol, maintaining the original conditions, and reacting for 5-10 h to open a disulfide bond. And pouring the reaction solution into excessive 1-5M hydrochloric acid, and centrifuging to obtain a crude product. And fully washing the crude product with 1-3M hydrochloric acid, and drying in vacuum at 60-80 ℃ to obtain the final product.

The polymer is rich in sulfydryl, has good affinity to mercury ions, and can be applied to selective adsorption of the mercury ions.

The invention has the beneficial effects that:

1. the invention prepares a sulfydryl functionalized self-possessed microporous Polymer (PIMs) which can be used for selective adsorption of mercury ions.

2. The PIMs prepared by the method have hydrophilicity which is not possessed by common PIMs, and can be well dispersed in a water phase.

3. The PIMs obtained by the method contain rich sulfydryl, have good affinity to mercury ions, and have good selectivity to mercury ion adsorption.

4. The PIMs obtained by the invention have fluorescence property and better affinity to mercury ions, and can be developed to be applied to the aspect of mercury ion detection.

Drawings

FIG. 1 is a schematic diagram of a process for the preparation of thiolated PIMs;

FIG. 2 is a Fourier transform infrared spectrum of PIM-1, PIM-COOH and PIM-G, PIM-B. In the infrared spectrum of PIM-1, it was observed that the peak intensity was at 2240cm^-1A peak belonging to C.ident.N, which is not observed in a spectrum of PIM-COOH, and C.ident.O (1724 cm)^-1) Absorption peaks can be observed. PIM-G and PIM-B showed C ═ O absorption peaks (1654 cm) comparable to PIM-COOH^-1) A shift occurred indicating that the carbonyl was amidated. The successful performance of the thiolation was demonstrated by the observation of the addition of a characteristic absorption peak for the thiol group at around 2600 wave numbers.

FIG. 3 shows PIM-1 (a), PIM-COOH (B), PIM-G (c), and PIM-B (d)¹H NMR spectrum. (e) PIM-1, (f) PIM-COOH, (G) PIM-G¹³C NMR spectrum. Comparison of nuclear magnetic hydrogen spectra of PIM-1 and PIM-COOH revealed that a proton hydrogenation chemical shift signal (14ppm) attributed to carboxyl groups could be observed in the PIM-COOH spectrum, whereas it was not observed in the PIM-1 spectrum, confirming the occurrence of carboxylation. In the hydrogen spectra of PIM-G and PIM-B, amide hydrogen chemical shift signals (about 8 ppm) were observed, but the chemical shift signals attributed to carboxyl proton hydrogenation did not completely disappear, indicating that the thiolation did not proceed completely. Chemical shift signals (around 1.95 ppm) for sulfhydryl hydride can be found in the nuclear magnetic hydrogen spectra of PIM-G and PIM-B, directly demonstrating the occurrence of sulfhydrylation. Comparison of the nuclear magnetic carbon spectra of PIM-G, PIM-B and PIM-COOH revealed that the chemical shift signal attributed to the carbonyl group was changed, confirming amidation of PIM-COOH, indirectly verifying the occurrence of thiolation.

FIG. 4 surface water contact angles of four PIMs: (a) PIM-1(99.4 °), (B) PIM-COOH (89.9 °), (c) PIM-G (70.2 °), and (d) PIM-B (84.1 °). The larger contact angles of PIM-1 and PIM-COOH indicate stronger hydrophobicity, while the smaller contact angles of thiolated PIM-G and PIM-B are both lower than 90, indicating stronger hydrophilicity.

FIG. 5(a) SEM images of PIM-G and (B) PIM-B; (c) SEM images of the adsorbed PIM-G and (d) PIM-B. (e) Transmission electron micrographs of PIM-G and (f) PIM-B; (g) transmission electron micrographs after adsorption of PIM-G and (h) PIM-B. Transmission electron and scanning electron micrographs showed that the thiolated PIMs were amorphous. Comparing the transmission electron microscope images before and after adsorption, the transmission electron microscope image after adsorption has small points which are the adsorbed mercury salt pictures.

FIG. 6(a) PIM-G and (B) PIM-B PXRD spectrograms; (c) PIM-G and (d) PXRD spectrum after PIM-B adsorption. Diffraction peaks belonging to mercury salts can be observed in the spectrum of the sulfhydrylation PIMs after adsorption, and the adsorption effect on mercury ions is verified.

FIG. 7 fluorescent chromatograms of PIM-G and PIM-B. Under the excitation of light with the wavelength of 309nm, the maximum emission wavelength of PIM-G is 496nm, and the maximum emission wavelength of PIM-B is 509 nm.

FIG. 8(a) mercury ion adsorption equilibrium curves for PIM-G and (c) PIM-B; (b) PIM-G and (d) Mercury ion adsorption kinetics curves.

Detailed Description

Example 1

1. Into a 100mL three-necked flask were added tetrafluoroterephthalonitrile (1.80g,9.00mmol),5,5 ', 6,6 ' -tetrahydroxy-3, 3 ', 3,3 ' -tetramethyl-1, 1 ' -spirobiindane (3.06g,9.00mmol) and anhydrous potassium carbonate (4.98g, 36.0 mmol).

2. To the flask was added 50.0mL of anhydrous DMF.

3. The system is reacted for 72 hours at 65 ℃ under the protection of argon.

4. After cooling to room temperature, the reaction mixture was poured into excess deionized water and the product was obtained by suction filtration.

5. The product obtained in the step 4 is subjected to soxhlet extraction and washing by using ethanol, and then is subjected to vacuum drying at 60 ℃ for 12 hours to obtain a final product PIM-1, wherein the average molecular weight of the product is 20000-40000, and the specific surface area is 600-1000 m²The pore diameter is 0.02-0.1 nm.

6. 1.50g of PIM-1 powder was weighed into a 250mL flask, followed by addition of 75.0mL of water, 75.0mL of ethanol, and 33.8g of potassium hydroxide.

7. The system was refluxed at 100 ℃ for 12 h.

8. And cooling to room temperature, pouring the system into 500mL of deionized water, neutralizing with acetic acid to be neutral, performing suction filtration, and collecting a filter cake to obtain a crude product.

9. Washing the product obtained in the step 8 with methanol for 3 times, and then drying in vacuum at 60 ℃ for 12 h.

10. The product from step 9 was transferred to a 250mL flask and 45.0mL sulfuric acid, 45.0mL water and 15.0mL acetic acid were added.

11. The above system was refluxed at 105 ℃ for 12 h.

12. The mixture was poured into 500mL, filtered with suction, washed three times with water, and then 3 times with methanol.

13. And (3) drying the green solid obtained in the step (12) at 60 ℃ in vacuum for 12h to obtain PIM-COOH.

14. 0.200g of PIM-COOH was added to a 100mL flask.

15. 50.0mL of methylene chloride and 2.00mL of thionyl chloride were added.

16. Refluxing was carried out at 60 ℃ for 6h, followed by rotary evaporation to remove dichloromethane and excess to give thionyl chloride.

17. The product from step 16 was dissolved in 40mL of anhydrous DMF and transferred to a 100mL three-necked flask.

18. 1.60mmol of a disulfide-bonded diamine (cystamine dihydrochloride or 4,4' -dithiodiphenylamine, respectively) was added.

19. The reaction is carried out for 12h at 60 ℃ under the protection of argon.

20. 0.494g of dithiothreitol is added and the reaction is continued for 6h under argon protection.

21. After cooling to room temperature, the above system was poured into 400mL of 2M hydrochloric acid and centrifuged.

22. The product obtained in step 21 was washed five times with 1M hydrochloric acid.

23. And (3) drying the product obtained in the step (22) at 60 ℃ for 12h in vacuum to obtain PIM-G or PIM-B respectively.

24. Adding 5mg of sulfhydrylation PIMs into 20mL of a series of mercury ion solutions with pH value of 5 (the concentrations are respectively (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100mg/L), measuring the mercury ion concentrations after shaking for 12h at 25 ℃, respectively calculating the mercury ion adsorption amounts under different concentrations, drawing a material mercury ion adsorption equilibrium curve according to the mercury ion concentrations and the corresponding mercury ion adsorption amounts, and respectively setting the maximum mercury ion adsorption amounts of PIM-G and PIM-B under the selected conditions to be 136mg/L and 127 mg/L.

25. 20mg of the adsorbent was added to 80mL of a mercury ion solution (15mg/L) having a pH of 5, stirred at room temperature, and sampled every 30 seconds to measure the concentration of mercury ions. And drawing an adsorption kinetic curve according to the measured concentration of the mercury ions.