CN107213877B - Synthetic method of imprinted mesoporous material with high selectivity to bisphenol A - Google Patents

Abstract

The invention provides a method for synthesizing an imprinted mesoporous material with high selectivity to bisphenol A, comprising the following steps: (1) uniformly mixing template molecule bisphenol A and functional monomers to obtain a preaction solution; (2) Dissolve cetyltrimethoxyammonium bromide in water, adjust the pH to 10.5-11.5 with sodium hydroxide solution, and stir for 50-70 minutes; add ethyl orthosilicate to the solution, and stir for 20-40 minutes; The preaction solution is added to the solution and stirred for 100-140 minutes; it is subjected to hydrothermal crystallization to obtain a mixture; (3) the mixture is dried, and then the template molecule bisphenol A is removed. The invention is easy to implement; the obtained imprinted mesoporous material not only has high selectivity to bisphenol A, but also has large adsorption capacity, good recycling performance and reproducibility.

Description

A kind of synthetic method of imprinted mesoporous material with high selectivity to bisphenol A

technical field

The invention belongs to the technical field of molecular imprinting, and mainly relates to a method for synthesizing molecularly imprinted mesoporous materials.

Background technique

Bisphenol A (BPA) is one of the most widely used industrial raw materials in the world, mainly used to produce various polymer materials and fine chemical products. At present, bisphenol A has been detected in water, sediment, soil, atmospheric environment and organisms. Bisphenol A is a low toxicity chemical and is also an environmental estrogen; trace or even trace amounts of bisphenol A can have adverse effects on the physiological status, reproductive system and fetal development of animals, and can adversely affect the endocrine, reproductive and fetal development of organisms. Nervous system produces a wide range of adverse effects. Governments at home and abroad have successively taken measures against the safety of bisphenol A in the consumption field, including restricting and reducing the amount of bisphenol A, and prohibiting its use in the production of some products such as baby milk. Therefore, the development of novel adsorbents with high selectivity to bisphenol A has become a research hotspot.

In 1994, Sellergren first reported the use of molecularly imprinted polymers as adsorbents in national phase extraction. Since then, molecularly imprinted-solid phase extraction technology has developed rapidly. Molecularly imprinted polymers have a "memory" effect on target molecules and can recognize target molecules in complex samples with high selectivity. Relevant research results show that molecularly imprinted polymers, as adsorbents for national phase extraction, not only have high selectivity, but also have the advantages of strong binding force, reusability and low cost.

In the prior art, magnetic molecularly imprinted polymers are prepared by using magnetic materials as carriers. However, some of the imprinted sites of the magnetic molecularly imprinted polymer are embedded in the polymer body, resulting in incomplete elution of the template molecule. In addition, the molecularly imprinted polymers in the prior art have significantly lower selective adsorption and adsorption capacity for bisphenol A in the aqueous phase.

It can be seen that it is necessary to develop a method for preparing molecularly imprinted materials with high selectivity to bisphenol A and large adsorption capacity.

SUMMARY OF THE INVENTION

In order to overcome the defects of the prior art, the present invention provides a method for synthesizing an imprinted mesoporous material with high selectivity to bisphenol A; the prepared imprinted mesoporous material not only has high selectivity to bisphenol A, but also adsorbs bisphenol A. Great capacity.

In order to solve the above problems, the present invention is realized according to the following technical solutions:

A method for synthesizing an imprinted mesoporous material with high selectivity to bisphenol A, comprising the following steps:

(1) mixing template molecule bisphenol A and functional monomer, stirring for 100-140 minutes to obtain a preaction solution;

(2) Dissolve hexadecyl trimethoxy ammonium bromide (CTAB) in water, adjust the pH value with sodium hydroxide solution to be 10.5-11.5, stir for 50-70 minutes; add ethyl orthosilicate ( TEOS), stirring for 20-40 minutes; adding the preaction solution to the solution, stirring for 100-140 minutes; subjecting it to hydrothermal crystallization to obtain a mixture;

(3) drying the mixture, and then removing the template molecule bisphenol A.

Preferably, the steps (1) to (3) are carried out at a temperature of 35-45°C.

Particularly preferably, the steps (1) to (3) are carried out at a temperature of 40°C. The inventors of the present application found that when the reaction temperature is 40°C, the reaction efficiency of each step can be improved.

Preferably, the preparation method of the functional monomer includes the following steps: dissolving 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) and KH-570 in ethanol, and adjusting the pH value with triethylamine solution To 7.5-8.5, under the condition of temperature of 35-45 ℃, stirring for 50-70 minutes to obtain functional monomer.

Particularly preferably, the preparation method of the functional monomer includes the following steps: dissolving 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) and KH-570 in ethanol, and adjusting the pH with triethylamine solution value to 8, and stirring for 60 minutes at a temperature of 40° C. to obtain a functional monomer.

Preferably, the molar ratio of the 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) to KH-570 is 1-2:1-2.

Particularly preferably, the molar ratio of the 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) and KH-570 is 1:1.

Preferably, the molar volume ratio mol:L of the 2-mercapto-4-methyl-5-thiazoleacetic acid (MMTA) and ethanol is 1:4.5-5.5.

Particularly preferably, the molar volume ratio mol:L of the 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) and ethanol is 1:5.

Preferably, the step (1) includes mixing the template molecule bisphenol A and the functional monomer, and vigorously stirring for 2 hours to obtain a preaction solution. The vigorous stirring is carried out under the condition that the rotating speed is 150-200 rpm, which can further form hydrogen bonds and π-π interaction between the template molecule bisphenol A and the functional monomer.

Preferably, the step (2) includes, at a temperature of 40°C, dissolving cetyltrimethoxyammonium bromide (CTAB) in water, adjusting the pH to 11 with sodium hydroxide solution, stirring 60 minutes; add ethyl orthosilicate dropwise to the solution and stir for 30 minutes; add the preaction solution dropwise to the solution and stir for 120 minutes; perform hydrothermal crystallization to obtain the product.

Preferably, the molar ratio of the template molecule bisphenol A to the functional monomer is 1:4.5-5.5.

Particularly preferably, the molar ratio of the template molecule bisphenol A and the functional monomer is 1:5.

Preferably, the molar ratio of the template molecule bisphenol A, cetyltrimethoxyammonium bromide (CTAB) and ethyl orthosilicate (TEOS) is 1:2.5-3.0:21.6-26.4.

Particularly preferably, the molar ratio of the template molecule bisphenol A, cetyltrimethoxyammonium bromide (CTAB) and ethyl orthosilicate (TEOS) is 1:2.74:24.

Preferably, the mass-to-volume ratio g:ml of the hexadecyltrimethoxyammonium bromide (CTAB) and water is 1:35-45.

Particularly preferably, the mass-to-volume ratio g:ml of the hexadecyltrimethoxyammonium bromide (CTAB) and water is 1:40.

Preferably, the water in step (2) is deionized water.

Preferably, the molar concentration of the sodium hydroxide solution is 8-12 mol/L.

Particularly preferably, the molar concentration of the sodium hydroxide solution is 10 mol/L.

Preferably, the hydrothermal crystallization is hydrothermal crystallization at a temperature of 80-90° C. for 70-74 hours.

Particularly preferably, the hydrothermal crystallization is hydrothermal crystallization at a temperature of 85° C. for 72 hours.

Preferably, the step of removing the template molecule bisphenol A is to perform Soxhlet extraction with a mixed solution of hydrochloric acid and ethanol.

Preferably, the Soxhlet extraction time is 88-104 hours.

Particularly preferably, the Soxhlet extraction time is 96 hours.

Preferably, the volume ratio of the hydrochloric acid and ethanol is 1:8.1-9.9.

Particularly preferably, the volume ratio of the hydrochloric acid and ethanol is 1:9.

The present invention has the following beneficial effects:

1. The imprinted mesoporous material prepared by the present invention has the morphology of a highly ordered and closely arranged hexagonal channel structure, and the particle distribution is relatively uniform; the average pore diameter of the imprinted mesoporous material is 3.6 nm, and the pore volume is 1.58 cm. ³ g ^-1 .

2. When the pH value is 6.5, the imprinted mesoporous material has the maximum adsorption capacity for bisphenol A. When the concentration of bisphenol A solution is 700mg/L, the imprinted mesoporous material can reach saturated adsorption equilibrium, and its adsorption capacity is 88.6 mg/g; it can be seen that the imprinted mesoporous material prepared by the present invention has a large adsorption capacity.

3. The imprinted mesoporous material prepared by the present invention has selective imprinting sites for bisphenol A, and has good selective recognition ability for bisphenol A.

4. The recovery rate of the imprinted mesoporous materials (MIPs) prepared by the present invention can be kept above 98.0% after repeated use for 5 times, indicating that the imprinted mesoporous materials (MIPs) have good recycling performance.

5. The imprinted mesoporous materials (MIPs) prepared by the present invention have good reproducibility. At different times, 5 batches of imprinted mesoporous materials (MIPs) synthesized by the technical solution of the present invention were used for adsorption experiments, and the relative standard deviation of the adsorption amount of bisphenol A by 5 batches of imprinted mesoporous materials (MIPs) (RSD) was only 1.1%.

Description of drawings

Fig. 1 is the synthetic route diagram of the present invention;

Fig. 2 is the infrared spectrum before and after Soxhlet extraction of imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

3 is a small-angle XRD diffractogram of the imprinted mesoporous material (MIPs) prepared in Example 1 of the present invention;

4 is a scanning electron microscope (SEM) image of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

5 is a perspective electron microscope (TEM) image of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

6 is a graph of nitrogen adsorption and desorption curves of imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

7 is a pore size distribution diagram of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

8 is a graph showing the effect of pH on the adsorption capacity of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

9 is an adsorption curve diagram of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

10 is a graph showing the adsorption kinetics of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention;

FIG. 11 is a graph of the repeatability experimental data of the imprinted mesoporous materials (MIPs) prepared in Example 1 of the present invention.

Detailed ways

Below in conjunction with embodiment, the technical scheme of the present invention is further described:

Example 1:

1) Preparation of functional monomers:

In a 10 ml flask, 1.0 mmol of 2-mercapto-4-methyl-5-thiazole acetic acid (MMTA) and 1.0 mmol of KH-570 were dissolved in 5 ml of ethanol, and the pH of the solution was adjusted to 8 with triethylamine. Under the condition of temperature of 40°C, stirring was carried out for 2 hours; the light yellow liquid was obtained as functional monomer, which was sealed and stored.

2) Preparation of imprinted mesoporous materials with high selectivity to bisphenol A:

(1) Mix 0.25 mol of template molecule bisphenol A with 1.0 mmol of functional monomer, and stir vigorously for 2 hours under the condition of a water bath temperature of 40° C. to obtain a preaction solution.

(2) Under the condition that the temperature of the water bath is 40°C, take another 1.0g of cetyltrimethoxyammonium bromide (CTAB) and dissolve it in 40mL of deionized water, and adjust the pH with 10mol/L sodium hydroxide solution value to 11.0 and stir for 1 hour. Add 5.2g of tetraethyl orthosilicate (TEOS) dropwise to the solution and stir for 30 minutes; add the preaction solution dropwise to the solution and stir for 2h; move it to a hydrothermal reaction kettle, at a temperature of 85 Under the condition of °C, hydrothermal crystallization was carried out for 72 hours to obtain a mixture.

(3) after the mixture is dried by suction filtration, use a hydrochloric acid and ethanol mixed solution with a volume ratio of 1:9, under the condition that the water bath temperature is 40 ° C, carry out Soxhlet extraction for 96 hours, remove the template molecule bisphenol A, and simultaneously Cetyltrimethoxyammonium bromide (CTAB) was also removed, and the resulting product was dried to obtain imprinted mesoporous materials (MIPs).

Attached:

1) synthetic route map, see Fig. 1;

2) Experimental reagents and experimental instruments, see Table 1 and Table 2.

Table 1 Experimental reagents

Table 2 Experimental equipment

laboratory apparatus model Manufacturer Electromechanical agitator JJ-1A Jiangsu Jincheng Guosheng Experimental Instrument Factory Water bath HH-S11 Shanghai Yuefeng Instrument Co., Ltd. Soxhlet extractor HH-S11 Shanghai Yuefeng Instrument Co., Ltd. Analytical Balances OOS Sartorius Electric blast drying oven DGG-9070DA2 Shanghai Senxin Experimental Instrument Co., Ltd. infrared spectrometer DRX-400 American Varian Company Nitrogen adsorption instrument ASAP-2020 American Micromeritics X-ray diffractometer D8Advance Bruker, Germany Transmission Electron Microscope Analyzer JEM-2100HR JEOL Corporation of Japan Field Emission Scanning Electron Microscope ZEISS Ultra55 Carl Zeiss, Germany oven controlled oscillator THZ82 Jiangsu Taicang Experimental Equipment Factory high-speed centrifuge TG16-W Guangzhou Guangyi Scientific Instrument Co., Ltd. Ultrasound SK250H Shanghai Keda Ultrasonic Instrument Co., Ltd. Microcentrifuge TG16-W Changsha Xiangyi Centrifuge Instrument Co., Ltd.

Structural characterization of the imprinted material prepared in Example 1:

A. Infrared Spectral Characterization:

It can be seen from FIG. 2 that the three absorption peaks at 1040 cm ^-1 , 960 cm ^-1 , and 791 cm ^-1 are characteristic peaks of the mesoporous material (silicon-based material). Imprinted mesoporous materials (MIPs) before Soxhlet extraction have sharp absorption peaks in the 2800-3000 cm ^-1 region representing the symmetric and asymmetric vibrations of CH, which is due to the porogen cetyltrimethoxyammonium bromide (CTAB) presence. After Soxhlet extraction with ethanol:hydrochloric acid (9:1=V/V), the characteristic absorption peak of CH disappeared, indicating that CTAB had been eluted. The absorption peaks at 1640 cm ^-1 of the imprinted mesoporous materials (MIPs) before and after elution are the stretching vibration absorption peaks of C=O, indicating that the functional monomers have successfully participated in the framework synthesis of mesoporous materials.

B. Small angle XRD characterization:

It can be seen from Figure 3 that three distinct characteristic peaks are (100), (110) and (200) crystal planes, respectively. The characterization results of small-angle XRD indicate that the imprinted mesoporous materials (MIPs) have highly ordered MCM-41 mesoporous materials. The characteristic structure of the hole.

C. Electron Microscopy Characterization:

It can be seen from Figure 4 that the synthesized imprinted mesoporous materials (MIPs) have relatively uniform particle distribution.

It can be seen from Fig. 5 that the imprinted mesoporous materials (MIPs) have the morphology of highly ordered and closely arranged hexagonal channel structure.

D. Characterization of nitrogen adsorption and desorption:

The pore size and pore volume of imprinted mesoporous materials (MIPs) were determined by nitrogen adsorption and desorption experiments.

As shown in Figure 6, the nitrogen adsorption-desorption isotherm of imprinted mesoporous materials (MIPs) is a type IV curve, which is a typical nitrogen adsorption-desorption isotherm of mesoporous materials. Using the Bnmauer-Enunett-Teller (BET) method, the specific surface area of the material was calculated to be 960.5m ² g ^-1 , and the pore volume was 1.58cm ³ g ^-1 , which indicated that the imprinted mesoporous materials (MIPs) had larger The specific surface area and pore volume are favorable for the mass distribution of imprinted sites and the resorption process.

It can be seen from Figure 7 that the pore size distribution of the imprinted mesoporous materials (MIPs) is uniform, with a relatively concentrated and sharp peak distribution, mainly between 3.4-3.9 nm, which proves that the material has a high degree of order. The average pore size of the material obtained by the Barrett-Joyner-Halenda (BJH) method is 3.6 nm.

Experiments to investigate the adsorption properties of the imprinted materials prepared in Implementation 1:

In order to investigate the adsorption properties of the imprinted materials, two physical quantities, the adsorption amount and the adsorption rate, can be used to characterize them. The adsorption capacity reflects the adsorption capacity of the adsorbent to a certain concentration of substrate, and is a very important thermodynamic parameter.

The calculation formula (1-1) of the adsorption capacity is as follows:

Q=(C _O -C _t )V/M (1-1)

In the formula, Q—the amount of adsorption at time t (mg/g);

_CO ——the initial concentration of the substance to be adsorbed (mg/L);

C _t ——the concentration of the substance to be adsorbed at time t (mg/L);

M - adsorbent mass (mg);

V—volume of reaction solution (mL).

A. Effect of pH value on adsorption performance A of imprinted mesoporous materials (MIPs):

The adsorption effect of imprinted mesoporous materials (MIPs) on the target molecule bisphenol A was investigated under different pH conditions (pH=5-8). 10 mg of imprinted mesoporous materials (MIPs) were added to the bisphenol A solution with a volume of 3 mL and a concentration of 200 mg/L under different pH conditions (pH=5-8), and after shaking at room temperature for 4 h, centrifuged, and then used The concentration of bisphenol A in the filtrate was detected by high performance liquid chromatography. Substitute into Equation 1-1 to calculate the adsorption capacity of the imprinted mesoporous materials (MIPs), thereby obtaining the effect of pH on the adsorption capacity.

As shown in Fig. 8, the adsorption amount of imprinted mesoporous materials (MIPs) changed with pH. When pH=5.5-6.5, as the pH increased, the adsorption amount of imprinted mesoporous materials (MIPs) also increased. This may be because too strong acidity will reduce the π-electron cloud density of the negative electrons on the aromatic ring, thereby weakening the π-π interaction between the rings and reducing the adsorption capacity. At pH=6.5-8, with the increasing alkalinity of the solution, the hydroxyl groups in bisphenol A and the carboxyl groups of functional monomers are partially deprotonated, resulting in a decrease in the intermolecular hydrogen bond force, which further leads to a decrease in the adsorption capacity. Therefore, when pH=6.5, the interaction force between the template molecule bisphenol A and the functional monomer is the strongest, and the corresponding adsorption amount reaches the maximum. The maximum adsorption amount was 15.6 mg/g.

B. Determination of saturation adsorption curve:

10 mg of imprinted mesoporous materials (MIPs), non-imprinted mesoporous materials (NIPs) and mesoporous materials (MCM-41) were added to a series of concentrations of 50-1000 mg/L bilayer in a volume of 10 mL at pH 6.5. In the phenol A solution, after shaking for 4 hours, centrifuge separation, and then use high performance liquid chromatography to detect the concentration of bisphenol A in the filtrate, and substitute it into formula 1-1 to calculate the imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials respectively. (NIPs) and mesoporous materials (MCM-41).

As shown in Figure 9, the adsorption curves of imprinted mesoporous materials (MIPs), non-imprinted mesoporous materials (NIPs) and mesoporous materials (MCM-41) in a series of bisphenol A solutions with a concentration of 50-1000 mg/L; The imprinted mesoporous materials (MIPs) exhibited larger adsorption capacity compared with the non-imprinted mesoporous materials (NIPs) and mesoporous materials (MCM-41). The imprinted mesoporous materials (MIPs) reached saturated adsorption equilibrium when the concentration of bisphenol A solution was 700 mg/L, and the adsorption capacity was 88.6 mg/g. At the same concentration of bisphenol A solution, the adsorption capacities of non-imprinted mesoporous materials (NIPs) and mesoporous materials (MCM-41) were 39.3 mg/g and 30.2 mg/g, respectively. The maximum adsorption amount of the imprinted mesoporous materials (MIPs) indicated that the imprinting effect increased the specific surface area and pore volume of the mesoporous materials. This is beneficial to increase the contact opportunity and time of action between bisphenol A molecules and imprinted holes in the polymer, and enhance the adsorption of bisphenol A by imprinted mesoporous materials (MIPs).

Attached:

1) Synthesis method of non-imprinted mesoporous materials (NIPs): It is basically the same as the synthetic method of imprinted mesoporous materials (MIPs), the only difference is that the template molecule bisphenol A is not added in step (1).

2) Synthesis method of mesoporous material (MCM-41): Dissolve 1.0 g of cetyltrimethoxyammonium bromide (CTAB) in 40 mL of deionized water, stir for 1 hour at a temperature of 40 °C, and use The NaOH solution of 10mol/L was adjusted to pH 11.0; after stirring for 1.0 hours, 5.2g of ethyl orthosilicate was added dropwise, stirred for 24 hours, and transferred to the hydrothermal reactor, at a temperature of 85°C , hydrothermally crystallized for 72 hours, the product was dried by suction filtration, extracted with a mixed solution of hydrochloric acid: ethanol (v:v=1:9) Soxhlet for 7 days, removed hexadecyltrimethoxyammonium bromide ( CTAB), drying the obtained product to obtain mesoporous material (MCM-41).

C. Adsorption kinetics experiment:

10 mg of imprinted mesoporous materials (MIPs) were added to the bisphenol A solution with a concentration of 60 mg/L, 800 mg/L, pH value of 6.5, and a volume of 3 mL, and shaken at room temperature. Every 5 minutes, the solid was centrifuged, and the concentration of bisphenol A in the filtrate was detected by high performance liquid chromatography, and the adsorption amount of bisphenol A by imprinted mesoporous materials (MIPs) was calculated by substituting into formula 1-1, and then to study its dynamics.

As shown in FIG. 10 , the adsorption kinetic curve of the imprinted mesoporous material (MIPs) is the result of the kinetic adsorption experiment of the imprinted mesoporous material (MIPs). In this experiment, two different concentrations of bisphenol A solutions were selected, 60 mg/L and 800 mg/L, respectively. The pH value of the solution was 6.5. With the increase of the concentration of bisphenol A in the solution, the time for the adsorption to reach equilibrium also increased, which were 15 and 25 min, respectively. It can be seen that the adsorption kinetic time of the imprinted mesoporous materials (MIPs) prepared in Example 1 is much faster than that of ordinary molecularly imprinted materials, benefiting from the large pore size and specific surface area of the imprinted mesoporous materials.

D. Selectivity Analysis of Imprinted Mesoporous Materials (MIPs):

Selectivity experiments on imprinted mesoporous materials (MIPs) using 4-cinnamylphenol, bisphenol F, catechol, and phenol as structural analogs. Prepare bisphenol A, 4-cinnamyl phenol, phenol, bisphenol F, and catechol solutions with molar concentrations of 0.6 mmol/L, and mix 10 mg of imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials (NIPs), respectively Add to the above solution in a volume of 10 mL. After shaking at room temperature for 4 h, the imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials (NIPs) were separated by centrifugation, and then bisphenol A, 4-cinnamic phenol, bisphenol F, phthalate were detected by university liquid chromatography. The concentrations of phenol and phenol were substituted into Equation 1-1 to calculate the adsorption capacity of imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials (NIPs). The relative selectivity coefficients of imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials (NIPs) for the five compounds are shown in Table 3.

K represents the distribution coefficient, R _IF represents the relative impact factor, and the calculation formula is as follows:

K=Q/Ce,

R _IF =R _MPs /K _NIPs .

where Q is the adsorption amount of template molecules or their analogs by imprinted mesoporous materials (MIPs) or non-imprinted mesoporous materials (NIPs);

Ce is the remaining concentration of template molecules or their analogs in the adsorbed solution;

K _MIPs is the partition coefficient of imprinted mesoporous materials (MIPs); K _NIPs is the partition coefficient of non-imprinted mesoporous materials (NIPs).

Table 3 Relative selectivity coefficients of imprinted mesoporous materials (MIPs) and non-imprinted mesoporous materials (NIPs) for five compounds

It can be seen from Table 3-1 that the relative imprinting factor ranges from 1.06 to 3.20, which indicates that MIPs have better selective recognition ability for bisphenol A, and there are selective imprinting sites for BPA. The values of K _NIPs are relatively small and relatively similar, which indicates that NIPs do not have specific selectivity for the adsorption of BPA, because there is no imprinting site that can selectively recognize BPA.

E. Repeated adsorption and reproducible performance studies of imprinted mesoporous materials (MIPs):

In order to investigate the reusability of imprinted mesoporous materials (MIPs), 10 mg of imprinted mesoporous materials (MIPs) were added to a bisphenol A solution with a volume of 3 mL, a concentration of 200 mg/L, and a pH value of 6.5, and the solution was shaken at room temperature for 25 min. After centrifugation, the imprinted mesoporous materials (MIPs) were eluted and separated with a volume of 2 mL of hydrochloric acid, and the concentration of bisphenol A in the filtrate was detected by high performance liquid chromatography, and the recovery rate was calculated. The imprinted mesoporous materials (MIPs) were washed several times with deionized water and dried for the next use. The imprinted mesoporous materials (MIPs) were recycled 5 times.

As shown in Figure 11, after the imprinted mesoporous materials (MIPs) were reused for 5 times, the adsorption capacity decreased to a certain extent with the increase of the number of cycles, but the recovery rate of the imprinted mesoporous materials (MIPs) was still It is maintained above 98.0%, indicating that the material has good recycling performance.

To test the reproducibility of MIPs, adsorption experiments were performed using 5 batches of imprinted mesoporous materials (MIPs) synthesized by the synthesis method of Example 1 at different times. The experimental data are shown in Table 4.

Table 4 Reproducibility experiments of imprinted mesoporous materials (MIPs)

Table 4 shows the adsorption capacity of bisphenol A for 5 batches of imprinted mesoporous materials (MIPs). According to this data, the relative standard deviation (RSD) of the adsorption amount of bisphenol A for 5 batches of imprinted mesoporous materials (MIPs) was calculated to be 1.1%, which proved that the imprinted mesoporous materials (MIPs) prepared in Example 1 had a relative standard deviation (RSD) of 1.1%. ) with very good reproducibility.

F. Actual sample adsorption experiment:

The water of Yangmei Water Plant in Gaoming District, Foshan, Guangdong was selected as the sample solution to test the actual sample adsorption capacity of imprinted mesoporous materials (MIPs). The sample solution was first filtered with a 0.45-micron filter to remove solid impurities. The content of bisphenol A in the samples was determined by liquid chromatography in colleges and universities, and the content was 0.031 mg/L. In the sample solution with a volume of 30ml, 20mg, 40mg, 60mg, 80mg, 100mg of imprinted mesoporous materials (MIPs) were added respectively, shaken at room temperature for 4 hours, and the imprinted mesoporous materials (MIPs) were centrifuged to separate the imprinted mesoporous materials (MIPs). The concentration of bisphenol A in the filtrate was measured and substituted into formula 1-1 to calculate the adsorption amount of imprinted mesoporous materials (MIPs). The experimental results are shown in Table 5.

Table 5 Adsorption of different amounts of imprinted mesoporous materials (MIPs) to real samples

As shown in Table 5, the adsorption study was carried out on the actual samples by inputting different amounts of imprinted mesoporous materials (MIPs). (GB5749-2006, 0.01mg/L). Therefore, the amount of MIPs required to treat Yangmei water plant water is about 4.0 g/L.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Therefore, without departing from the content of the technical solutions of the present invention, any changes made to the above embodiments according to the technical essence of the present invention Simple modifications, equivalent changes and modifications still fall within the scope of the technical solutions of the present invention.

Claims (4)

1. A synthetic method of imprinted mesoporous material with high selectivity to bisphenol A is characterized by comprising the following steps:

(1) mixing template molecule bisphenol A and functional monomer, stirring for 100-140 min to obtain pre-acting solution; the mole ratio of template molecule bisphenol A to functional monomer is 1: 4.5-5.5;

the preparation method of the functional monomer comprises the following steps: dissolving 2-mercapto-4-methyl-5-thiazoleacetic acid and KH-570 in ethanol, adjusting pH value to 7.5-8.5 with triethylamine solution, and stirring at 35-45 deg.C for 50-70 min to obtain functional monomer; the molar ratio of the 2-mercapto-4-methyl-5-thiazoleacetic acid to the KH-570 is 1-2: 1-2; the mol ratio of the 2-mercapto-4-methyl-5-thiazole acetic acid to the ethanol is as follows: l is 1: 4.5-5.5;

(2) dissolving hexadecyl trimethoxy ammonium bromide in water, adjusting the pH value to 10.5-11.5 by using a sodium hydroxide solution, and stirring for 50-70 minutes; adding tetraethoxysilane into the solution, and stirring for 20-40 minutes; adding the pre-acting solution into the solution, and stirring for 140 minutes; carrying out hydrothermal crystallization on the mixture, wherein the hydrothermal crystallization is carried out for 70-74 hours at the temperature of 80-90 ℃ to obtain a mixture;

(3) drying the mixture, and removing template molecule bisphenol A, wherein the step of removing template molecule bisphenol A is to perform Soxhlet extraction for 88 to 104 hours by using a mixed solution of hydrochloric acid and ethanol, and the volume ratio of the hydrochloric acid to the ethanol is 1: 8.1-9.9.

2. The method for synthesizing imprinted mesoporous material with high selectivity to bisphenol a according to claim 1, wherein the mole ratio of template molecules bisphenol a, hexadecyl trimethoxy ammonium bromide and ethyl orthosilicate is 1: 2.5-3.0: 21.6-26.4.

3. The method for synthesizing imprinted mesoporous material with high selectivity to bisphenol A according to claim 2, wherein the mass-to-volume ratio of cetyl trimethoxy ammonium bromide to water is g: the ml ratio is 1: 35-45.

4. The method for synthesizing imprinted mesoporous material with high selectivity to bisphenol A according to claim 1, wherein the steps (1) to (3) are performed at a temperature of 35-45 ℃.

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