Preparation method of polydivinylbenzene hollow microspheres based on sulfydryl-alkene click reaction

Abstract

The invention discloses a preparation method of polydivinylbenzene hollow microspheres based on sulfydryl-alkene click reaction, which comprises the following steps: adding n-amyl alcohol into a conical flask, putting into a water bath kettle, stirring, adding polyvinylpyrrolidone, absolute ethyl alcohol, ammonia water and deionized water to form a reversed-phase microemulsion system, adding tetraethyl silicate, stirring, filtering, washing, and drying to obtain the polydivinylbenzene hollow microspheres based on sulfydryl-alkene click reaction. Oscillating and shaking, standing, and centrifugally cleaning; absolute ethyl alcohol and deionized water are added, the water bath kettle is heated to 80 DEG C, trimethoxysilane is added for a reaction, and then centrifugal cleaning is conducted; then, absolute ethyl alcohol, polyvinylpyrrolidone, azodiisobutyronitrile, divinylbenzene and deionized water are added; heating and stirring in a water bath kettle, adding a NaOH solution, and centrifuging to obtain the polydivinylbenzene hollow microspheres. The PDVB hollow microspheres with different cavity sizes are successfully prepared by adjusting and controlling the size of the template, and the method has the advantages of good selectivity, high yield and the like, and provides a new way for preparing the high-performance hollow microspheres.

Description

Technical Field

[0001] The present invention relates to the field of polymer hollow microspheres, and particularly to a method for preparing polydivinylbenzene hollow microspheres based on thiol-ene click reaction. Background Art

[0002] With the rapid development of modern technology, the preparation and application of functional polymer microspheres have become a research hotspot in the field of materials science. There are various methods for preparing polymer hollow microspheres, and it is difficult to precisely control the process parameters, resulting in unstable product performance. Polydivinylbenzene (PDVB) microspheres have broad application prospects in the fields of molecular device materials, chemical modification and modification due to their unique physical and chemical properties. Especially the hollow microsphere structure shows great potential in energy storage, catalyst carriers and inertial confinement fusion research due to its low density, high specific surface area and excellent adsorption performance. Thiol-ene click reaction is an efficient organic chemical reaction with fast reaction speed, high yield, good tolerance to various functional groups, few by-products, in line with the principles of green chemistry, wide application range, and can be applied to the synthesis of polymer materials, surface modification, bioconjugation, medicinal chemistry, photoresists and microelectronics and other fields. Polydivinylbenzene hollow microspheres are prepared by thiol-ene click reaction. By precisely controlling the reaction conditions, microspheres with highly uniform spherical shapes and sizes can be prepared, thereby improving their structural stability and ensuring the stability and uniformity of the microsphere structure. As a common polymer material, polydivinylbenzene has good biocompatibility. The polydivinylbenzene hollow microspheres prepared by thiol-ene click reaction have the advantages of stable structure, diverse functions, good biocompatibility, flexible preparation and wide application. These advantages make polydivinylbenzene hollow microspheres have potential application value and development prospects in many fields. Summary of the Invention

[0003] The object of the present invention is to provide a method for preparing polydivinylbenzene hollow microspheres based on thiol-ene click reaction. It solves problems such as improving material properties, functional modification, enhancing preparation efficiency and expanding application fields. The present invention first uses the reverse microemulsion induction method, and by simply adjusting the condition parameters, polydivinylbenzene hollow microspheres with different particle size scales can be controllably prepared. Through the thiol-ene click reaction, thiols are introduced onto the surface of the polydivinylbenzene hollow microspheres, thereby changing their surface chemical properties, significantly improving the reaction efficiency, shortening the reaction time, increasing the yield, thus reducing the production cost, and having a broader application prospect. For example, in the biomedical field, it can be used as a drug carrier, cell culture matrix, etc.; in the field of materials science, it can be used as a catalyst carrier, adsorption material, etc.; in the field of environmental protection, it can be used for water treatment, air purification, etc.

[0004] To achieve the above-mentioned invention object, the present invention adopts the following technical solution: A preparation method of polydivinylbenzene hollow microspheres based on thiol-ene click reaction, the method comprising the following steps: S1. Add a certain amount of oily organic solvent to a conical flask, place it in a water bath at 30 °C and stir, and adjust the water bath to 50 °C; S2. When the water bath reaches 50 °C, add an appropriate amount of high molecular emulsifier to the conical flask and stir for 2 h; S3. After step (2) is completed, adjust the water bath to 30 °C, add anhydrous ethanol, ammonia water, and deionized water to the system, and stir for 40 min; S4. After completion, add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake for 2 - 3 min, and then place it in an oven at 30 °C and let it stand for 24 h; S5. Centrifuge and wash the solution obtained in step (4) to obtain a PDVB hollow microsphere template; S6. Add 100 mL of anhydrous ethanol and 30 mL of deionized water to the PDVB hollow microsphere template obtained in step (5), adjust the pH, stir at room temperature for 2 h, then heat the water bath to 80 °C, and add 2 mL of (3-mercaptopropyl)trimethoxysilane and stir for 15 h; S7. Centrifuge and wash the reaction system in step (6); S8. Add 45 mL of anhydrous ethanol and 2 g of polyvinylpyrrolidone to the washed template, stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene, and 5 mL of deionized water, stir for 2 h, and then heat the water bath to 50 °C and stir for 48 h; S9. Heat the water bath to 69 °C and stir for 10 h; S10. Heat the water bath to 79 °C and stir for 6 h, then add NaOH solution and stir for 4 h; S11. Centrifuge and remove impurities from the solution obtained in step (10) to obtain polydivinylbenzene hollow microspheres.

[0005] Preferably, the oily organic solvent in step S1 is n-pentanol, and its dosage is 50 mL.

[0006] Preferably, the high molecular emulsifier in step S2 is polyvinylpyrrolidone (pvp), and its dosage is 5 g.

[0007] Preferably, the volume ratio of anhydrous ethanol, ammonia water, and deionized water in step S3 is 10:3:6 - 12.

[0008] Preferably, in step S5, the centrifugal cleaning is carried out by centrifuging to the bottom once, washing with deionized water once, and washing with absolute ethanol twice, at a rotation speed of 10,000 rpm for 10 minutes.

[0009] Preferably, in step S6, the pH is adjusted to approximately 4.

[0010] Preferably, in step S7, the centrifugal cleaning is carried out by centrifuging to the bottom once and washing with absolute ethanol three times, at a rotation speed of 4,000 rpm for 10 minutes.

[0011] Preferably, in step S10, the mass ratio of the NaOH solution is 8% and its dosage is 50 mL.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention constructs polydivinylbenzene hollow microspheres based on inverse microemulsion induction, and this process shows the characteristics of high efficiency, greenness, and cleanliness; the polydivinylbenzene hollow microspheres prepared by thiol-ene click reaction have a stable structure and wide applications, and can be used as drug carriers, catalyst carriers, adsorption materials, water purification, etc.; by adjusting the volume of water in the inverse microemulsion system, the size of the hollow microspheres is successfully regulated, which can not only achieve precise design and performance optimization of the materials, but also expand their applications in the fields of energy, etc. This size regulation method provides important technical support for the development of functional materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the Fourier transform infrared spectrum (FTIR) corresponding to the substances generated in the preparation path of the polydivinylbenzene hollow microspheres in Example 1 of the present invention; Figures 2-5 It is the transmission electron microscope images (TEM) of the hollow microspheres with different scales after being etched by the alkaline etchant in Examples 1-4 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0015] Example 1 The present invention provides a low-cost method for preparing polydivinylbenzene hollow microspheres based on thiol-ene click reaction, which includes the following steps: S1. Use a graduated cylinder to measure 50 mL of n-pentanol and pour it into a conical flask. Place it in a water bath at 30 °C and stir. Adjust the water bath to 50 °C; S2. When the water bath reaches 50 °C, add 5 g of polyvinylpyrrolidone (pvp) to the conical flask and stir for 2 h to obtain a mixed solution; S3. After 2 h, adjust the water bath to 30 °C. Add 10 mL of absolute ethanol, 3 mL of ammonia water, and 6 mL of deionized water to the above mixed solution and stir for 40 min; S4. Add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake it for 2 - 3 min, and then place it in an oven at 30 °C and let it stand for 24 h; S5. Centrifuge and wash the solution in step (4). The centrifuge washing is to centrifuge until it settles to the bottom once, wash it with deionized water once, and wash it with absolute ethanol twice. The rotation speed is 10000 rpm and the time is 10 min; then obtain the PDVB hollow microsphere template; S6. Add 100 mL of absolute ethanol and 30 mL of deionized water to the PDVB hollow microsphere template obtained in step (5), adjust the pH≈4, stir at room temperature for 2 h, then heat the water bath to 80 °C, and add 2 mL of (3-mercaptopropyl)trimethoxysilane and stir for 15 h; S7. Centrifuge and wash the reaction system in step (6); the centrifuge washing is to centrifuge until it settles to the bottom once and wash it with absolute ethanol three times. The rotation speed is 4000 rpm and the time is 10 min; S8. Add 45 mL of absolute ethanol and 2 g of polyvinylpyrrolidone to the washed template, stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene, and 5 mL of deionized water and stir for 2 h. Heat the water bath to 50 °C and stir for 48 h; S9. Heat the water bath to 69 °C and stir for 10 h; S10. Heat the water bath to 79 °C and stir for 6 h, then add a NaOH solution with a mass ratio of 8% and a dosage of 50 mL based on the solution mass and stir for 4 h; S11. Centrifuge and remove impurities from the solution obtained in step (10) to obtain polydivinylbenzene hollow microspheres.

[0016] Example 2 S1. Use a graduated cylinder to measure 50 mL of n-pentanol and pour it into a conical flask. Place it in a water bath at 30 °C and stir. Adjust the water bath to 50 °C; S2. When the water bath reaches 50 °C, add 5 g of polyvinylpyrrolidone (pvp) to the conical flask and stir for 2 h to obtain a mixed solution; S3. After 2 h, adjust the water bath to 30 °C, add 10 mL of absolute ethanol, 3 mL of ammonia water, and 9 mL of deionized water to the above mixed solution, and stir for 40 min; S4. Add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake for 2 - 3 min, and then place it in an oven at 30 °C and let it stand for 24 h; S5. Centrifuge and wash the solution in step (4). The centrifugal washing is to centrifuge to the bottom once, wash with deionized water once, and wash with absolute ethanol twice, at a rotation speed of 10000 rpm for 10 min; then obtain the PDVB hollow microsphere template; S6. Add 100 mL of absolute ethanol and 30 mL of deionized water to the PDVB hollow microsphere template obtained in step (5), adjust the pH≈4, stir at room temperature for 2 h, then heat the water bath to 80 °C, and add 2 mL of (3 - mercaptopropyl) trimethoxysilane and stir for 15 h; S7. Centrifuge and wash the reaction system in step (6); the centrifugal washing is to centrifuge to the bottom once and wash with absolute ethanol three times, at a rotation speed of 4000 rpm for 10 min; S8. Add 45 mL of absolute ethanol and 2 g of polyvinylpyrrolidone to the washed template, stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene, and 5 ml of deionized water, stir for 2 h, and heat the water bath to 50 °C and stir for 48 h; S9. Heat the water bath to 69 °C and stir for 10 h; S10. Heat the water bath to 79 °C and stir for 6 h, then add a NaOH solution with a mass ratio of 8% and a dosage of 50 mL based on the solution mass, and stir for 4 h; S11. Centrifuge and remove impurities from the solution obtained in step (10) to obtain polydivinylbenzene hollow microspheres.

[0017] Example 3 S1. Measure 50 mL of n - pentanol with a measuring cylinder and pour it into a conical flask, place it in a water bath at 30 °C and stir, and adjust the water bath to 50 °C; S2. When the water bath rises to 50 °C, add 5 g of polyvinylpyrrolidone (pvp) to the conical flask and stir for 2 h to obtain a mixed solution; S3. After 2 h, adjust the water bath to 30 °C, add 10 mL of absolute ethanol, 3 mL of ammonia water, and 10 mL of deionized water to the above mixed solution, and stir for 40 min; S4. Add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake for 2 - 3 min, and then place it in an oven at 30 °C and let it stand for 24 h; S5. Centrifuge and wash the solution in step (4). The centrifuge washing is to centrifuge to the bottom once, wash with deionized water once, and wash with absolute ethanol twice, at a rotation speed of 10,000 rpm for 10 min; then a PDVB hollow microsphere template is obtained. S6. Add 100 mL of absolute ethanol and 30 mL of deionized water to the PDVB hollow microsphere template obtained in step (5), adjust the pH to approximately 4, stir at room temperature for 2 h, then heat the water bath to 80 °C, and add 2 mL of (3-mercaptopropyl)trimethoxysilane and stir for 15 h. S7. Centrifuge and wash the reaction system in step (6). The centrifuge washing is to centrifuge to the bottom once and wash with absolute ethanol three times, at a rotation speed of 4,000 rpm for 10 min. S8. Add 45 mL of absolute ethanol and 2 g of polyvinylpyrrolidone to the washed template, stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene, and 5 mL of deionized water, stir for 2 h, and heat the water bath to 50 °C and stir for 48 h. S9. Heat the water bath to 69 °C and stir for 10 h. S10. Heat the water bath to 79 °C and stir for 6 h, then add a NaOH solution with a mass ratio of 8% and a volume of 50 mL based on the solution mass, and stir for 4 h. S11. Centrifuge and remove impurities from the solution obtained in step (10) to obtain polydivinylbenzene hollow microspheres. Example 4 S1. Measure 50 mL of n-pentanol with a graduated cylinder and pour it into a conical flask, place it in a water bath at 30 °C and stir, and adjust the water bath to 50 °C; S2. When the water bath reaches 50 °C, add 5 g of polyvinylpyrrolidone (pvp) to the conical flask and stir for 2 h to obtain a mixed solution. S3. After 2 h, adjust the water bath to 30 °C, add 10 mL of absolute ethanol, 3 mL of ammonia water, and 12 mL of deionized water to the above mixed solution and stir for 40 min. S4. Add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake for 2 - 3 min, and then place it in an oven at 30 °C and let it stand for 24 h. S5. Centrifuge and wash the solution in step (4). The centrifuge washing is to centrifuge to the bottom once, wash with deionized water once, and wash with absolute ethanol twice, at a rotation speed of 10,000 rpm for 10 min; then a PDVB hollow microsphere template is obtained. S6. Add 100 mL of absolute ethanol and 30 mL of deionized water to the PDVB hollow microsphere template obtained in step (5), adjust the pH to approximately 4, stir at room temperature for 2 h, then heat the water bath to 80 °C and add 2 mL of (3-mercaptopropyl)trimethoxysilane and stir for 15 h; S7. Centrifuge and wash the reaction system in step (6); the centrifuge washing is to centrifuge to the bottom once and wash with absolute ethanol three times, with a rotation speed of 4000 rpm and a time of 10 min; S8. Add 45 mL of absolute ethanol and 2 g of polyvinylpyrrolidone to the washed template, stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene and 5 mL of deionized water and stir for 2 h, heat the water bath to 50 °C and stir for 48 h; S9. Heat the water bath to 69 °C and stir for 10 h; S10. Heat the water bath to 79 °C and stir for 6 h, then add a NaOH solution with a mass ratio of 8% based on the solution mass and a dosage of 50 mL and stir for 4 h; S11. Centrifuge and remove impurities from the solution obtained in step (10) to obtain polydivinylbenzene hollow microspheres.

[0018] Table 1 is a summary table of the masses of the added materials in Examples 1-4;

[0019] It should be noted that the procedures of Examples 1-4 are basically the same, only the ratios of some reagents are different. The preparation process of the product of Example 1 is taken as an example for illustration below.

[0020] I. For the Fourier transform infrared spectra of the substances generated in the preparation route of polydivinylbenzene hollow microspheres, see Figure 1 ; Figure 1It is the Fourier transform infrared spectroscopy (FTIR) spectrum of the substances generated in the preparation process of polydivinylbenzene hollow microspheres. The substances generated during the preparation process are: mercaptopropyltrimethoxysilane (MPTS)-modified silica templates (MPTS-modified SiO2) obtained by mercapto-functionalizing silica dispersed in a water-alcohol system with mercapto silane coupling under acidic conditions; mercapto-modified silica-polydivinylbenzene core-shell microspheres (SiO2@PDVB core-shell microspheres) constructed by thiol-ene click reaction by introducing crosslinking monomers and azo radical initiators; and hollow polydivinylbenzene microspheres (Hollow PDVB microspheres) with confined cavities finally obtained by etching the mercapto-modified silica-polydivinylbenzene core-shell microspheres (SiO2@PDVB core-shell microspheres) by the template etching method.

[0021] Among them, characteristic peaks of Si-O-Si, Si-OH, and Si-O appear in the Fourier transform infrared spectroscopy (FTIR) spectra of both the mercaptopropyltrimethoxysilane (MPTS)-modified silica templates (MPTS-modified SiO2) and the mercapto-modified silica-polydivinylbenzene core-shell microspheres (SiO2@PDVB core-shell microspheres), while they do not appear in the Fourier transform infrared spectroscopy (FTIR) spectrum of the hollow polydivinylbenzene microspheres (Hollow PDVB microspheres); characteristic peaks of methylene (-CH2-), carbon-carbon double bond (C=C), and hydrocarbon group (C-H) appear in the Fourier transform infrared spectroscopy (FTIR) spectra of both the mercapto-modified silica-polydivinylbenzene core-shell microspheres (SiO2@PDVB core-shell microspheres) and the hollow polydivinylbenzene microspheres (Hollow PDVB microspheres), while they do not appear in the Fourier transform infrared spectroscopy (FTIR) spectrum of the mercaptopropyltrimethoxysilane (MPTS)-modified silica templates (MPTS-modified SiO2), thus confirming the successful preparation of the hollow polydivinylbenzene microspheres.

[0022] II. Transmission electron microscopy (TEM) images of polydivinylbenzene hollow microspheres with different scales are shown in Figures 2-5 ; Mercapto-modified silica-polydivinylbenzene core-shell microspheres (SiO2@PDVB core-shell microspheres) were constructed by thiol-ene click reaction by introducing crosslinking monomers and azo radical initiators into the reaction system, and then they were etched by the template etching method to finally obtain hollow polydivinylbenzene (PDVB) microspheres with confined cavities. Figures 2-5They are the transmission electron microscopy images of polydivinylbenzene hollow microspheres at the same magnification corresponding to 6 ml, 9 ml, 10 ml, and 12 ml of deionized water in sequence. It can be seen from the figures that obvious hollow structures exist, and the cavity sizes increase in sequence, indicating that PDVB hollow microspheres with different cavity sizes are successfully prepared.

[0023] In addition, it should be understood that the above-described embodiments are only used to explain the present invention in detail, but the present invention is not limited to the above detailed methods. For those skilled in the art, any improvement to the present invention, the equivalent replacement of each raw material of the products of the present invention, the selection of specific methods, etc., should be covered within the protection scope and the disclosure scope of the present invention.

Claims

1. A method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction, characterized in that: The method comprises the following steps: S1. Add a certain amount of oily organic solvent into a conical flask and place it in a 30 ℃ water bath with stirring, and adjust the water bath to 50 ℃; S2. When the water bath temperature rises to 50°C, add an appropriate amount of polymer emulsifier into the conical flask and stir for 2 h. S3. After step (2), adjust the water bath to 30°C, add anhydrous ethanol, ammonia water and deionized water to the system in step (2), and stir for 40 min; S4. After completion, add 3.5 mL of tetraethyl orthosilicate (TEOS) to the system in step (3), shake for 2-3 min, and then place in a 30 °C oven for 24 h; S5, centrifugally washing the solution obtained in step (4) to obtain a polydivinylbenzene (PDVB) hollow microsphere template; S6. Add 100 mL of anhydrous ethanol and 30 mL of deionized water to the polydivinylbenzene (PDVB) hollow microsphere template obtained in step (5), adjust the pH, stir for 2 h, heat the water bath to 80 °C, add 2 mL of (3-mercaptopropyl)trimethoxysilane and stir for 15 h; S7, centrifugally washing the reaction system in step (6); S8, add 45 mL of anhydrous ethanol and 2 g of polyvinyl pyrrolidone to the cleaned template and stir at room temperature for 2 h, then add 0.2 g of azobisisobutyronitrile, 4 g of divinylbenzene and 5 ml of deionized water and stir for 2 h, then heat the water bath to 50 °C and stir for 48 h; S9, heat the water bath to 69 °C and stir for 10 h; S10, heat the water bath to 79 °C and stir for 6 h, then add NaOH solution and stir for 4 h; S11, centrifuging the solution obtained in step (10) to remove impurities and obtain polydivinylbenzene hollow microspheres.

2. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: The oily organic solvent in step S1 is n-pentanol, and the amount used is 50 mL.

3. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: In step S2, the polymer emulsifier is polyvinyl pyrrolidone (pvp), and the amount used is 5 g.

4. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: In step S3, the volume ratio of anhydrous ethanol, ammonia water and deionized water is 10:3:6-12.

5. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: The centrifugal washing in step S5 is centrifugal sedimentation once, deionized water washing once, and anhydrous ethanol washing twice, with a rotation speed of 10000 rpm and a time of 10 min.

6. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: In step S6, pH is adjusted to 4.

7. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: The centrifugal washing in step S7 is centrifugal sedimentation once, and washing with anhydrous ethanol three times, with a rotation speed of 4000 rpm and a time of 10 minutes.

8. The method for preparing hollow polydivinylbenzene microspheres based on thiol-ene click reaction according to claim 1, characterized in that: The mass ratio of the NaOH solution in step S10 is 8%, and the dosage is 50 mL.

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