Preparation method of polyaniline modified hydrophilic nanometer hollow microcapsule

Abstract

The application belongs to the technical field of carbon dioxide capture, and particularly relates to a preparation method of polyaniline modified hydrophilic nano hollow microcapsules, and the specific process comprises three steps of preparing hypercrosslinked hollow microcapsules (HCP-HC), preparing sulfonated HCP-HC (S-HCP-HC) and preparing PANI modified S-HCP-HC (PANI@S-HCP-HC). Based on the conductivity of polyaniline, the composite material has electrochemical activity. The S-HCP-HC has the advantages of hydrophilicity, adjustable structure, large specific surface area, good stability, diverse structure, low price, and can load other metals. The combination of PANI and sulfonated HCP-HC makes the hydrophilicity of S-HCP-HC make PANI enter the pore structure of S-HCP-HC, so that PANI@S-HCP-HC has good morphology and maintains high specific surface area. The principle is scientific and reliable, the operation process is simple, the reaction condition is mild, no special reaction equipment and expensive catalyst are needed, and the production cost is low.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon dioxide capture, and particularly relates to a preparation method of polyaniline modified hydrophilic nano hollow microcapsules for preparing a carbon capture electrode for electrochemical capture of CO2. BACKGROUND

[0002] With the deepening of industrialization, the concentration of greenhouse gases in the atmosphere is rising, especially CO2, global warming, the increase of extreme weather, and the emergence of energy crisis drive people to study the conversion of carbon dioxide. The overall strategy of carbon capture and utilization aims to convert carbon dioxide into economically valuable chemicals and then recycle, which has very important significance for protecting the ecological environment of the earth and promoting the sustainable development of human society.

[0003] At present, hollow organic microporous microcapsules have been widely used in catalysis, electrochemistry, and medical fields. For example, a preparation method of PLGA drug-loaded hollow microcapsules based on polyethylene glycol and folate grafted polyethyleneimine modification disclosed in Chinese patent 201310371108.7 includes: (1) dissolving folate FA in a solvent, adding N-hydroxysuccinimide NHS and carbodiimide EDC, then adding amino polyethylene glycol carboxylic acid NH2-PEG-COOH, and then stirring and reacting at 25-28°C for 2-3 days, dialysis, freeze-drying, re-dissolving in a solvent, adding N-hydroxysuccinimide NHS and carbodiimide EDC, then adding polyethyleneimine PEI, stirring and reacting at 25-28°C for 2-3 days, dialysis, freeze-drying, and obtaining PEI-PEG-FA polymer; (2) dissolving polylactic acid-glycolic acid copolymer PLGA in an organic solvent to obtain an oil phase; dissolving doxorubicin hydrochloride DOX·HCl in ultrapure water to obtain an aqueous phase; then mixing the oil phase and the aqueous phase, and ultrasonically treating in an ice water bath for 20-30s to obtain a water-in-oil W / O emulsion; (3) adding the above W / O emulsion into a polyvinyl alcohol PVA aqueous solution, and homogenizing under ice water bath conditions to obtain a water-in-oil-in-water W / O / W emulsion; (4) adding the above W / O / W emulsion into an isopropyl alcohol aqueous solution, stirring for 1-4h, centrifugal washing, and obtaining PLGA-DOX drug-loaded hollow microcapsules; (5) dispersing the above PLGA-DOX drug-loaded hollow microcapsules in water, adding a PEI-PEG-FA polymer aqueous solution, stirring for 15-30min, centrifugal washing, dispersing in water, and freeze-drying to obtain PLGA drug-loaded hollow microcapsules based on polyethylene glycol and folate grafted polyethyleneimine modification, which have good drug release performance and tumor cell targeting treatment effect, and provide a reference for the development of multifunctional targeted drug preparations.A porous polymer hollow microcapsule disclosed in Chinese patent 201210549671.4 is prepared by the following method: step one: adding nano-silica particles into anhydrous ethanol, ultrasonic dispersion, and adding ammonia water, then adding silane coupling agent 3-(methacryloyloxy) propyl trimethoxysilane to obtain a mixed solution, stirring for 12-36 hours for surface modification of the nano-silica particles, centrifuging the mixed solution, pouring off the supernatant, and washing 3-5 times with anhydrous ethanol or methanol to obtain surface-modified nano-silica particles; step two: ultrasonic dispersion of the surface-modified nano-silica particles in anhydrous ethanol, followed by addition of sodium dodecyl benzene sulfonate, sodium bicarbonate and water, ultrasonic stirring for 30-90 minutes, then adding monomer styrene and comonomer divinylbenzene to obtain a mixed solution, stirring at 40-60℃ for 30-90 minutes, heating to 70-90℃, adding an initiator and stirring for 1-5 hours, centrifuging the mixed solution, pouring off the supernatant, and washing 1-2 times with anhydrous ethanol or methanol, and drying to obtain poly(styrene-divinylbenzene) coated nano-silica core-shell particles; step three: stirring the poly(styrene-divinylbenzene) coated nano-silica core-shell particles, a crosslinking agent and an organic solvent at room temperature for 1-5 hours, magnetic stirring for 0.1-2 hours, then adding a Lewis acid as a catalyst, maintaining magnetic stirring, heating to 30-60℃, reacting at this temperature for 2-12 hours, then heating to 70-120℃, and reacting at this temperature for 10-72 hours to obtain a very viscous solid-liquid mixture, filtering the very viscous solid-liquid mixture to obtain a brown solid, washing the solid 1-5 times with diethyl ether and methanol to remove residual crosslinking agent, solvent and catalyst, and extracting the solid with methanol for 12-36 hours to remove the remaining catalyst Lewis acid, using hydrofluoric acid to remove the nano-silica particles, and drying to obtain a high molecular carrier for drug loading and release, catalyst loading or ion adsorbent: yellow-brown or purple porous polymer hollow microcapsule.

[0004] Polyaniline, as the earliest discovered conductive polymer, has the characteristics of low cost, easy synthesis, high conductivity, multiple oxidation states and high pseudo-capacitance, and is widely used in the fields of coatings, batteries, wave-absorbing materials, sensors and conductive fibers. In addition, it is found that the solid amine-based adsorbent has high adsorption capacity under low CO2 partial pressure, and the regeneration temperature is relatively low (less than 100℃), and the corrosion to the equipment is relatively small. Based on the interaction between CO2 and amino groups, the formation of carbamic acid, carbamate and bicarbonate, polyaniline has great potential in the application of capturing carbon dioxide. Therefore, the combination of polyaniline and hollow microcapsules is expected to obtain a cheap composite material with electrical activity and specific surface area, which can capture carbon dioxide and has positive social and economic value. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, and to design a polyaniline modified hydrophilic nanometer hollow microcapsule preparation method to solve the problems of polyaniline material itself without pore structure, small specific surface area, and poor conductivity of super-crosslinked polymer.

[0006] In order to achieve the above-mentioned purpose, the specific process of the polyaniline modified hydrophilic nanometer hollow microcapsule preparation method according to the present application includes three steps of preparing super-crosslinked hollow microcapsules (HCP-HC), preparing sulfonated HCP-HC (S-HCP-HC), and preparing PANI modified S-HCP-HC (PANI@S-HCP-HC):

[0007] (1) Preparation of HCP-HC

[0008] First, a mixture of KH-570 and ethanol with a volume ratio of 2:13 is dropped into a commercially available SiO2 nanoparticle ethanol dispersion solution, and the reaction is carried out for 24 hours. The obtained product is washed with methanol and centrifuged for 3 times, and then vacuum dried for 24 hours to obtain vinyl modified SiO2.

[0009] Among them, the particle size of SiO2 nanoparticles is 50-300 nm, and the ratio of ethanol to SiO2 nanoparticles is 25 mL:1 g.

[0010] Secondly, sodium dodecyl benzene sulfonate (SDBS) and NaHCO3 are dissolved in distilled water to obtain an aqueous solution, and the vinyl modified SiO2 is dispersed in ethanol and then added to the aqueous solution. Continuous stirring is carried out to obtain a stable emulsion. Styrene and divinylbenzene (DVB) are added to the emulsion, the temperature is raised to 85℃, and potassium persulfate (KPS) aqueous solution is added dropwise to obtain SiO2@PS-DVB.

[0011] Among them, the mass ratio of SDBS:NaHCO3 is 3:20, the volume of distilled water is 100 mL; the ratio of vinyl modified SiO2:ethanol is 3 mg:25 mL; the volume ratio of distilled water:ethanol:styrene is 10:1:1; the volume of DVB is 2-25% of the volume of styrene; the concentration of KPS aqueous solution is 0.1 g / mL;

[0012] Then, SiO2@PS-DVB is placed in a mixture of dichloroethane (DCE) and dimethoxymethane (FDA) for 1 hour, and FeCl3 is added at a temperature of 35℃. The temperature is raised to 45℃, and the reaction is carried out for 5 hours. The reaction product is heated to 80℃ and maintained for 19 hours. After washing and filtering, SiO2@HCPs is obtained.

[0013] Among them, the ratio of SiO2@PS-DVB:DCE:FDA is 1 g:20 mL:1.73 mL; the ratio of FeCl3:FDA is 3.32 g:1.73 mL.

[0014] Finally, etching SiO2@HCPs with hydrofluoric acid, cleaning after filtration, obtaining brown HCP-HC, drying in a vacuum environment at a temperature of 60 DEG C for 24h for standby;

[0015] (2) Preparation of S-HCP-HC

[0016] Stirring in concentrated sulfuric acid, stirring for 4h at a temperature of 35 DEG C, carefully washing with ethanol, drying in an environment at a temperature of 60 DEG C, obtaining S-HCP-HC;

[0017] Wherein, the ratio of concentrated sulfuric acid: HCP-HC is 10mL: 1g;

[0018] (3) Preparation of PANI@S-HCP-HC

[0019] Mixing concentrated hydrochloric acid and aniline, adding water, stirring for 3h at room temperature, adding S-HCP-HC and stirring for 6h, dropping into ammonium persulfate (APS) aqueous solution, reacting for 2h at room temperature, washing and filtering the obtained product with water and ethanol, drying in an environment at a temperature of 60 DEG C, obtaining PANI@S-HCP-HC;

[0020] Wherein, the ratio of S-HCP-HC: water is 0.2g: 1mL; the ratio of S-HCP-HC: aniline is 1g: 1-4mL; the volume ratio of concentrated hydrochloric acid: aniline is 4: 1; the ratio of APS: aniline is 0.12g: 1mL, and the volume of APS aqueous solution is 1mL.

[0021] The PANI@S-HCP-HC disclosed by the application is used for preparing an electrochemical carbon dioxide capturing material: PANI@S-HCP-HC carbon capture electrode, can improve the specific surface area of polyaniline, can adjust the pore size and conductivity of the electrochemical carbon dioxide capturing material by controlling the addition amount of aniline, and effectively promotes the electrochemical capture of carbon dioxide.

[0022] The specific preparation process is as follows: dispersing PANI@S-HCP-HC and carbon nanotubes in ethanol to obtain a dispersion liquid, adding polytetrafluoroethylene (PTFE) as a binder, ultrasonic mixing, and dropping on a polished glassy carbon electrode by using a micropipette gun, drying in an environment at a temperature of 60 DEG C for 1h, obtaining a PANI@S-HCP-HC carbon capture electrode; wherein, the mass percentage concentration of PTFE is 1%; the ratio of PANI@S-HCP-HC: carbon nanotube: PTFE is 4: 5: 1.

[0023] Compared with the prior art, the application has the advantages that the composite material has electrochemical activity based on the conductivity of polyaniline itself, the S-HCP-HC has hydrophilicity, adjustable structure, large specific surface area, good stability, diverse structure, low price, and can load other metals, etc., the PANI is combined with the S-HCP-HC after sulfonation, the hydrophilicity of the S-HCP-HC enables the PANI to enter the pore structure of the S-HCP-HC, the PANI@S-HCP-HC has good morphology and maintains high specific surface area, the principle is scientific and reliable, the operation is simple, the reaction condition is mild, no special reaction equipment and expensive catalyst are needed, and the production cost is low. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The cyclic voltammograms of the PANI@S-HCP-HC and the S-HCP-HC prepared in the embodiment of the application. DETAILED DESCRIPTION

[0025] The application will be further described below by means of embodiments and with reference to the drawings.

[0026] Embodiment 1

[0027] The specific process of the preparation method of the polyaniline modified hydrophilic nanohollow microcapsule involved in the embodiment is as follows:

[0028] The mixture of 500 mL of ethanol and 40 mL of TEOS was subjected to severe mechanical stirring, 40 mL of NH3·H2O was added, and after stirring for 24 h, a dispersion was obtained; a mixture of 4 mL of KH-570 and 26 mL of ethanol was dropped into the dispersion, and after reaction for 24 h, the reaction product was washed and centrifuged with methanol for 3 times, and vacuum dried for 24 h to obtain SiO2;

[0029] 0.036 g of SDBS and 0.24 g of NaHCO3 were dissolved in 100 mL of distilled water to obtain an aqueous solution, 1.2 mg of SiO2 was dispersed in 10 mL of ethanol, and then added to the aqueous solution, and continuous stirring was performed to obtain a stable emulsion, 10 mL of styrene and 5% of DVB based on the volume of styrene were added to the emulsion, the temperature was increased to 85℃, 1 mL of KPS aqueous solution with a concentration of 0.1 g / mL was added dropwise, and SiO2@PS-DVB was obtained;

[0030] 1 g of SiO2@PS-DVB was placed in a mixture of 20 mL of DCE and 1.73 mL of FDA, and swelled for 1 h, 3.32 g of FeCl3 was added at a temperature of 35℃, the temperature was increased to 45℃, and the reaction was performed for 5 h, the reaction product was heated to 80℃ and maintained for 19 h, and then washed and filtered to obtain SiO2@HCPs;

[0031] The SiO2@HCPs were etched with hydrofluoric acid, washed after filtration, and brown HCP-HC was obtained, which was dried in a vacuum environment at 60℃ for 24h;

[0032] 5mL of concentrated sulfuric acid was added to 0.5g of HCP-HC, and after stirring at 35℃ for 4h, the product was carefully washed and filtered with ethanol, and dried at 60℃ to obtain S-HCP-HC;

[0033] 0.2mL of concentrated HCl and 0.1mL of aniline were mixed, 1mL of water was added, and the mixture was stirred at room temperature for 3h, 0.2g of S-HCP-HC was added and stirred for 6h, 1mL of 0.012g / mL APS aqueous solution was added dropwise, and the mixture was reacted at room temperature for 2h, the product was washed and filtered with water and ethanol, and dried at 60℃ to obtain PANI@S-HCP-HC.

[0034] Example 2:

[0035] The process of the preparation method of PANI@S-HCP-HC in this example was the same as that in Example 1, except that the volume of concentrated HCl was 0.3mL, the volume of aniline was 0.07mL, and the concentration of APS aqueous solution was 0.016g / mL.

[0036] Example 3:

[0037] The process of the preparation method of PANI@S-HCP-HC in this example was the same as that in Example 1, except that the volume of concentrated HCl was 0.4mL, the volume of aniline was 0.05mL, and the concentration of APS aqueous solution was 0.024g / mL.

[0038] Example 4:

[0039] The CV curves of the working electrodes prepared from PANI@S-HCP-HC and S-HCP-HC in Examples 1, 2 and 3 were obtained at a scan rate of 100mV / s and a potential range of-0.2 to 0.8V, as shown in Figure 1 The CV curve area of PANI@S-HCP-HC increased compared with that of S-HCP-HC, indicating that PANI improved the electrochemical performance of S-HCP-HC; PANI@S-HCP-HC exhibited pseudo-capacitive characteristics, containing two pairs of redox peaks, where A / A’ was attributed to the conversion of emeraldine-pernigrainine, and B / B’ was attributed to the redox conversion of PANI between the semiconductor state and the conductive state, and the area of the CV curve increased with the increase of PANI.

Claims

1. A method for preparing polyaniline modified hydrophilic hollow microcapsules, the process comprising three steps of preparing super-crosslinked hollow microcapsules, preparing sulfonated HCP-HC and preparing PANI modified S-HCP-HC, characterized in that: (1) preparing HCP-HC firstly, a mixture of KH-570 and ethanol is dropped into SiO2 nanoparticle ethanol dispersion, and the obtained product is washed with methanol, centrifuged and vacuum dried to obtain vinyl modified SiO2; secondly, sodium dodecyl benzene sulfonate and NaHCO3 are dissolved in distilled water to obtain an aqueous solution, and the vinyl modified SiO2 is dispersed in ethanol and then added to the aqueous solution, and continuous stirring is performed to obtain a stable emulsion, styrene and divinyl benzene are added to the emulsion, and an aqueous solution of potassium persulfate is added dropwise at a high temperature to obtain SiO2@PS-DVB; then, SiO2@PS-DVB is swelled in a mixture of dichloroethane and dimethoxymethane, FeCl3 is added, and the reaction product is heated, washed and filtered to obtain SiO2@HCPs; finally, HCP-HC is obtained by etching SiO2@HCPs with hydrofluoric acid, washing and filtering, and drying in a vacuum environment; (2) preparing S-HCP-HC HCP-HC is stirred in concentrated sulfuric acid, washed with ethanol, filtered and dried to obtain S-HCP-HC; (3) preparing PANI@S-HCP-HC concentrated hydrochloric acid and aniline are mixed, water is added, stirring is performed, S-HCP-HC is added and stirred, an aqueous solution of ammonium persulfate is added dropwise, the obtained product is washed with water and ethanol, and dried to obtain PANI@S-HCP-HC; PANI@S-HCP-HC is used for preparing an electrochemical carbon dioxide capture material: a PANI@S-HCP-HC carbon capture electrode, by controlling the amount of aniline added, the pore size and conductivity of the electrochemical carbon dioxide capture material are adjusted. The specific process is as follows: (1) preparing HCP-HC firstly, a mixture of KH-570 and ethanol in a volume ratio of 2:13 is dropped into commercially available SiO2 nanoparticle ethanol dispersion, and the obtained product is washed with methanol, centrifuged three times and vacuum dried for 24 h to obtain vinyl modified SiO2; secondly, sodium dodecyl benzene sulfonate and NaHCO3 are dissolved in distilled water to obtain an aqueous solution, and the vinyl modified SiO2 is dispersed in ethanol and then added to the aqueous solution, and continuous stirring is performed to obtain a stable emulsion, styrene and divinyl benzene are added to the emulsion, and an aqueous solution of potassium persulfate is added dropwise at a temperature of 85℃ to obtain SiO2@PS-DVB; then, SiO2@PS-DVB is swelled in a mixture of dichloroethane and dimethoxymethane for 1 h, FeCl3 is added at a temperature of 35℃, the temperature is increased to 45℃, and the reaction is performed for 5 h, the reaction product is heated to 80℃ and kept for 19 h, and then washed and filtered to obtain SiO2@HCPs; ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The method for preparing polyaniline modified hydrophilic nanohollow microcapsules according to claim 1, characterized in that, ​ ​ ​ ​ ​ Finally, etching SiO2@HCPs with hydrofluoric acid, cleaning after filtration, obtaining brown HCP-HC, drying in a vacuum environment at a temperature of 60℃ for 24h for standby; (2) Preparation of S-HCP-HC Stirring HCP-HC in concentrated sulfuric acid, stirring for 4h at a temperature of 35℃, carefully cleaning with ethanol after filtration, drying in an environment at a temperature of 60℃, obtaining S-HCP-HC; (3) Preparation of PANI@S-HCP-HC Mixing concentrated hydrochloric acid and aniline, adding water, stirring for 3h at room temperature, adding S-HCP-HC, stirring for 6h, dropping into aqueous ammonium persulfate solution, reacting for 2h at room temperature, cleaning the obtained product with water and ethanol, drying in an environment at a temperature of 60℃, obtaining PANI@S-HCP-HC.

3. The method for preparing polyaniline modified hydrophilic nanohollow microcapsules according to claim 1 or 2, characterized in that, In step (1), the particle size of SiO2 nanoparticles is 50-300 nm, the ratio of ethanol to SiO2 nanoparticles is 25mL:1g; the mass ratio of SDBS:NaHCO3 is 3:20, the volume of distilled water is 100mL; the ratio of vinyl modified SiO2:ethanol is 3mg:25mL; the volume ratio of distilled water:ethanol:styrene is 10:1:1; the volume of DVB is 2-25% of the volume of styrene; the concentration of KPS aqueous solution is 0.1g / mL; the ratio of SiO2@PS-DVB:DCE:FDA is 1g:20mL:1.73mL; the ratio of FeCl3:FDA is 3.32g:1.73mL.

4. The method for preparing polyaniline modified hydrophilic nanohollow microcapsules according to claim 1 or 2, characterized in that, In step (2), the ratio of concentrated sulfuric acid:HCP-HC is 10mL:1g.

5. The method for preparing polyaniline modified hydrophilic nanohollow microcapsules according to claim 1 or 2, characterized in that, In step (3), the ratio of S-HCP-HC:water is 0.2g:1mL; the ratio of S-HCP-HC:aniline is 1g:1-4mL; the volume ratio of concentrated hydrochloric acid:aniline is 4:1; the ratio of APS:aniline is 0.12g:1mL, and the volume of APS aqueous solution is 1mL.

6. The method for preparing polyaniline modified hydrophilic nanohollow microcapsules according to claim 1 or 2, characterized in that, The specific preparation process is as follows: dispersing PANI@S-HCP-HC and carbon nanotubes in ethanol to obtain a dispersion liquid, adding a binder, ultrasonicating, dropping on a glassy carbon electrode, and drying for 1h to obtain a PANI@S-HCP-HC carbon capture electrode.

7. The method according to claim 6, wherein the method is characterized by, The binder is polytetrafluoroethylene.

8. The method according to claim 6, wherein the method is characterized by, Drying in an environment at a temperature of 60℃.

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