CN106632828B - A kind of functional polymer microsphere and the preparation method and application thereof - Google Patents

Abstract

The invention discloses a kind of functional polymer microsphere, the mass percent of each element is as follows in the polymer microballoon: C:46.64%, H:7.93%, N:1.66%, O:39.3%, S:1.75%；Shown in the structural formula of the polymer microballoon such as formula (I).The features such as functional polymer microsphere prepared by the present invention has materials extensively, economic and environment-friendly, and easily modification and adsorption efficiency are high, compensates for the deficiency of presently commercially available solid phase extraction material；It is used for the core filler of solid phase extraction manipulations, the separation and concentration of 13 heavy metal species ions in environment water can be achieved at the same time, to copper, zinc, arsenic, cadmium, lead, mercury, tin, eight heavy metal species ion of bismuth adsorption rate 92% or more, while other heavy metal ion (vanadium, chromium, cobalt, antimony, barium) can also be reached 50% or more adsorption efficiency；Operation of the present invention is simple and convenient, and treatment effect is fast, and inorganic pollution separation analysis field has considerable application prospect in actual environment water body.

Description

A kind of functional polymer microsphere and its preparation method and application

technical field

The present invention relates to the technical field of separation and analysis of inorganic pollutants, in particular to a functional polymer microsphere and its preparation method and application, utilizing the characteristics of diversity, easy modification, environmental protection and economy of the functional polymer microsphere, the functional polymer microsphere The ball can simultaneously separate and enrich thirteen kinds of heavy metal ions in the environmental water.

Background technique

With the development of industrial production, the pollution of heavy metals in the environment is becoming more and more serious, which has affected the normal life of human beings, and most metal elements show different degrees of toxicity. Therefore, it is necessary to accurately analyze the content of trace metals in environmental water, especially heavy metal elements. is of great significance. However, in actual samples, the matrix effect will hinder the acquisition of chemical information, and the low concentration of the target substance will also make the characteristics of chemical information indistinct. With the help of effective separation and enrichment technology, eliminating interference matrix and increasing the concentration of target substances is an important way to accurately capture effective information. However, the theories and methods of sample separation and enrichment that can be provided at present are still difficult to meet the needs of various sample systems. Therefore, the establishment of new theories, new methods and detection technologies for sample pretreatment (separation and enrichment) is still one of the bottlenecks in the development of environmental analysis science. Solid phase extraction is an important sample pretreatment technology. Its basic characteristics are low reagent consumption, high enrichment factor, simple operation process, low cost, and more importantly, its easy automation, which has attracted widespread attention. and attention. It is an important development direction of new solid phase extraction technology to continuously develop new extraction materials and carry out appropriate modification on the basis of original materials in order to achieve better extraction effects.

Synthetic polymer materials are one of the symbols of human civilization, and tens of thousands of polymer materials have been synthesized so far. Synthetic polymer materials usually contain many functional groups, which can be combined with various metal ions by covalent bonds, ionic bonds, and van der Waals forces. Therefore, synthetic polymer materials are widely used in the separation and enrichment of heavy metal ions in water. Use the stable structure and chemical properties of polymer materials to improve the reutilization rate of adsorbents; combine polymer materials with other inorganic and organic materials to make adsorption materials with high specific surface area and high adsorption capacity; Synthesis conditions and the type and quantity of functional groups can achieve high selectivity and rapid adsorption of heavy metal ions, so as to achieve the maximum utilization of heavy metal resources in the simplest and most effective way. All of these will make polymer materials have high development potential and application value in the field of separation and analysis of heavy metal ions.

Among many polymer materials, cross-linked polymer beads can be widely used in many fields such as environmental protection, chromatographic separation, separation of biochemical and organic compounds, etc. Cross-linked polymer beads can be divided into gel type and macroporous type, in which macroporous cross-linked polymer beads have a permanent porous structure and have a large surface area even in a dry state, and macroporous cross-linked polymer beads The cross-linked polymer beads have stronger adsorption capacity than the gel-type cross-linked polymer beads, and it is easier to obtain a high rate of functional group introduction during chemical modification.

At present, commercial solid-phase extraction packings generally have shortcomings such as insufficient selectivity, poor reproducibility, and high price. The present invention utilizes cheap acrylate monomers and dialkylaminoethyl acrylate monomers as reactive monomers, acrylates as crosslinking agents, and simultaneously adds a certain proportion of porogens to prepare porous crosslinked polymers. The spheres are modified with propyl sultone to obtain functional polymer microspheres with uniform distribution of surface active sites. Using functional polymer microspheres as the core packing of the solid phase extraction column can quickly and effectively separate and enrich copper, zinc, arsenic, cadmium, lead, mercury, tin, bismuth, vanadium, chromium, cobalt, Thirteen heavy metal ions of antimony and barium.

Contents of the invention

In view of this, the object of the present invention is to propose a functional polymer microsphere, which has many advantages such as high efficiency, environmental protection, good selectivity and strong anti-interference ability, and can be used as the core of solid phase extraction column Packing, which can quickly and effectively separate and enrich the thirteen heavy metal ions of copper, zinc, arsenic, cadmium, lead, mercury, tin, bismuth, vanadium, chromium, cobalt, antimony and barium that may exist in the environmental water body. The application value is quite considerable.

Based on the above purpose, the present invention provides a functional polymer microsphere, the mass percentage of each element in the polymer microsphere is as follows: C: 46.64%, H: 7.93%, N: 1.66%, O: 39.3%, S: 1.75%; The structural formula of the polymer microsphere is as shown in formula (I):

The physical and chemical properties of the obtained functional polymer microspheres were analyzed, and the density was determined to be 0.98 by a densitometer. The mass percentages of C, H, N, O measured by elemental analyzer are C: 46.64%, H: 7.93%, N: 1.66%, O: 39.3%; the S content measured by inductively coupled plasma spectrometer is 1.75%. Fourier transform infrared spectrometer and scanning electron microscope (SEM) were used to characterize the structure and morphology of functional polymer microspheres. It can be seen from the infrared spectrum that 530cm ^-1 , 620cm ^-1 , 1068cm ^-1 and 1190cm ^-1 are The characteristic absorption peak of the sulfonic acid group, and the C=O stretching vibration absorption peak of the methacrylate at 1730cm ^-1 ; the scanning electron microscope (SEM) figure shows that the particle size distribution of the prepared functional polymer microspheres is uniform, in the micron class.

Further, the present invention also provides a method for preparing the functional polymer microspheres, comprising the following steps:

(1) Add a dispersant in a three-neck round bottom flask, start stirring after heating up, and ventilate nitrogen to remove oxygen;

(2) After mixing the monomer, crosslinking agent and porogen uniformly in a beaker, add the initiator to fully dissolve and prepare the monomer phase;

(3) under the condition of stirring, the monomer phase in the step (2) is added in batches in the dispersant after the deoxygenation in the step (1), and the nitrogen deoxygenation is carried out simultaneously in the process of adding in batches; the monomer Polymerization is carried out after addition to obtain polymer beads;

(4) Wash the obtained polymer beads with water for 2 to 3 times, then extract with acetone for 3 to 5 hours to remove uncrosslinked homopolymers, and then dry them in vacuum at 40°C to obtain porous crosslinked beads. polymer pellets;

(5) Use propyl sultone to modify the porous cross-linked polymer beads. After the modification, filter out the propyl sultone, wash with deionized water and methanol for 3 times, and then dry to finally prepare the functional polymer object microspheres.

In the present invention, preferably, the dispersant in step (1) is a polyvinyl alcohol aqueous solution with a volume fraction of 0.7%. min, and the time for purging nitrogen to remove oxygen is 15 min.

In the present invention, preferably, the monomer in step (2) includes monomer 1 and monomer 2, the monomer 1, the monomer 2, the crosslinking agent and the porogen The volume ratio is 1.5～2.5:5～7:3～5:3～5; the volume mass ratio of the cross-linking agent to the initiator is 3～5:0.25～0.35g, that is, every 3～5mL The cross-linking agent corresponds to 0.25-0.35 g of the initiator; the monomer 1 is an acrylate monomer, the monomer 2 is a dialkylaminoethyl acrylate monomer, and the cross-linking agent is an acrylate class, the porogen is n-hexane, and the initiator is benzoyl peroxide.

In the present invention, it is further preferred that the acrylate monomer is methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, methyl acrylate, ethyl methacrylate, methyl butyl acrylate or isooctyl methacrylate; the dialkylaminoethyl acrylate monomer is dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diisooctyl acrylate Aminoethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or diisooctylaminoethyl methacrylate; the acrylates are Triethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyvinyl alcohol diacrylate, or triethanolamine triacrylate; the monomer 1. The volume ratio of the monomer 2, the cross-linking agent to the porogen is 2:6:4:4; the volume-to-mass ratio of the cross-linking agent to the initiator is 4:0.30g , that is, every 4 mL of the cross-linking agent corresponds to 0.30 g of the initiator.

In the present invention, the monomer 1 is an acrylate monomer from which a polymerization inhibitor has been removed, and a polymerization inhibitor is an industrial auxiliary agent usually used to prevent the progress of polymerization. Inhibitor molecules react with chain free radicals to form non-free radical substances or low-activity free radicals that cannot be initiated, thereby terminating polymerization. In order to avoid polymerization of the monomer during storage and transportation, a small amount of polymerization inhibitor is often added to the monomer and removed before use.

In the present invention, preferably, the speed of stirring in step (3) is 490 to 510 rpm/min, the time for adding in batches is 30 min, the time for passing nitrogen to remove oxygen is 15 min, and the polymerization reaction For constant temperature reaction at 90° C. for 3.5-4.5 hours, the volume ratio of the dispersant to the cross-linking agent is 100:3-5.

In the present invention, it is further preferred that the polymerization reaction in step (3) is a constant temperature reaction at a temperature of 90° C. for 4 hours and then cooling to end the polymerization reaction; the volume ratio of the dispersant to the crosslinking agent is 100 :4.

In the present invention, the stirring speed in the step (3) is the same as that in the step (1). In order to ensure good monomer dispersion, nitrogen gas is used to remove oxygen for 15 minutes in this step.

In the present invention, preferably, the specific step of using propyl sultone to modify the porous cross-linked polymer beads described in step (5) is: mix propyl sultone with the porous cross-linked polymer beads According to the mass ratio of 1:1, it was dissolved in the mixed solution of methanol and tetrahydrofuran, stirred at 50°C for 48 hours, filtered to remove propyl sultone, washed with deionized water and methanol for 3 times, and dried to obtain the functional polymer wherein the volume ratio of methanol to tetrahydrofuran in the mixed solution is 1:1, and the volume-to-mass ratio of the mixed solution to the porous crosslinked polymer beads is 25-35:2.0-3.0, that is, every 25-35 mL of the mixed solution corresponds to 2.0-3.0 g of the porous cross-linked polymer beads.

In the present invention, propyl sultone is used to modify porous cross-linked polymer beads to obtain functional polymer microspheres with uniform distribution of surface active sites.

In the present invention, it is further preferred that the volume-to-mass ratio of the mixed solution to the porous cross-linked polymer pellet is 30:2.5, that is, every 30 mL of the mixed solution corresponds to 2.5 g of the porous cross-linked polymer pellet. ball.

The preparation method of the functional polymer microsphere of the present invention mainly includes the preparation and modification of cross-linked polymers. The preferred steps are: first in a beaker, the ethyl methacrylate that has removed the polymerization inhibitor, diethylaminoethyl methacrylate, triethylene glycol dimethacrylate and n-hexane are mixed homogeneously, Add benzoyl peroxide (BPO) to fully dissolve and prepare a monomer phase; add polyvinyl alcohol aqueous solution into a three-necked round bottom flask, and after heating up, stirring, and purging nitrogen to remove oxygen, keep stirring speed, and the prepared single Add the bulk phase to a three-neck round bottom flask in batches to ensure good monomer dispersion, pass nitrogen gas to remove oxygen, and then react at 90°C for about 4 hours to end the polymerization reaction and remove uncrosslinked homopolymers. After vacuum drying Obtain porous cross-linked polymer beads; finally, mix porous cross-linked polymer beads with an equal amount of propyl sultone in 30 mL of equal-volume mixed methanol and tetrahydrofuran solutions, stir and filter to remove unreacted propyl groups The sultone was washed with deionized water and methanol respectively, and then dried to obtain functional polymer microspheres, which were ready for use.

Furthermore, the present invention also provides the application of the functional polymer microspheres in the preparation of solid phase extraction column fillers.

In the present invention, preferably, the solid phase extraction column filler is used to separate and enrich copper, zinc, arsenic, cadmium, lead, mercury, tin, bismuth, vanadium, chromium, cobalt, antimony, barium present in the environmental water body Thirteen heavy metal ions.

The functional polymer microspheres prepared in the present invention are made into core packing of a solid phase extraction column, and then the solid phase extraction column is connected with a high-pressure infusion pump for separation and enrichment of heavy metal ions in environmental water. The solid-phase extraction method (SPE) generally needs to adjust the pH value of the general filler, the target analyte is few and the separation and enrichment efficiency is low, and the functional polymer microspheres of the present invention are made into the core filler of the solid-phase extraction column. A method for rapidly separating and enriching heavy metal ions in environmental water under mild neutral conditions is provided. This method does not need any external reagents, and it only takes 8 minutes to realize the rapid adsorption of copper, zinc, arsenic, cadmium, lead, mercury, tin, and bismuth eight heavy metal ions, and the adsorption rates are all above 92%. adsorption efficiency. At the same time, it can also achieve an adsorption efficiency of more than 50% for other heavy metal ions (vanadium, chromium, cobalt, antimony, barium).

Compared with the prior art, the method of the present invention has the following beneficial effects:

The functional polymer microspheres prepared by the present invention have the characteristics of wide selection of materials, economical and environmental protection, easy modification and high adsorption efficiency, which makes up for the shortage of currently commercially available solid phase extraction materials; it can be used as the core filler for solid phase extraction operations. At the same time, the separation and enrichment of thirteen kinds of heavy metal ions in the environmental water body are realized, and the adsorption rates of eight kinds of heavy metal ions of copper, zinc, arsenic, cadmium, lead, mercury, tin and bismuth are all above 92%, and other heavy metal ions ( Vanadium, chromium, cobalt, antimony, barium) can also reach an adsorption efficiency of more than 50%; the present invention is simple and convenient to operate, has fast treatment effect, and has considerable application prospects in the field of separation and analysis of inorganic pollutants in actual environmental water bodies.

Description of drawings

The accompanying drawings illustrate the process trend in detail in conjunction with the specific process implementation.

Fig. 1 is the infrared spectrogram of functional polymer microsphere of the present invention;

Fig. 2 is the scanning electron micrograph of functional polymer microsphere of the present invention;

Figure 3 is the influence of flow rate on the adsorption effect of target heavy metal ions;

Fig. 4 is the impact of sample volume on the recovery rate of heavy metal ions;

Figure 5 is a comparison chart of environmental standard samples before and after solid-phase extraction adsorption.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The preparation of embodiment 1 functional polymer microsphere

In this embodiment, ethyl methacrylate is used as monomer 1, diethylaminoethyl methacrylate is used as monomer 2, and triethylene glycol dimethacrylate is used as crosslinking agent to carry out the formation of functional polymer microspheres. Synthesis, the synthesis path is as follows:

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 2mL of ethyl methacrylate (monomer 1), 6mL of diethylaminoethyl methacrylate (monomer 2), 4mL of triethylene glycol diethylene glycol, which has been removed from the polymerization inhibitor After mixing methacrylate (crosslinking agent) and 4mL n-hexane (porogen) evenly, add 0.30g benzoyl peroxide (BPO) (initiator) to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 4 hours and then cool down to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 2.5 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 30 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The preparation of embodiment 2 functional polymer microspheres

In this embodiment, ethyl methacrylate is used as monomer 1, diethylaminoethyl methacrylate is used as monomer 2, and triethylene glycol dimethacrylate is used as crosslinking agent to carry out the formation of functional polymer microspheres. synthesis.

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 1.5mL of ethyl methacrylate (monomer 1), 5mL of diethylaminoethyl methacrylate (monomer 2), and 3mL of triethylene glycol were placed in a 50mL beaker. After dimethacrylate (crosslinking agent) and 3mL n-hexane (porogen) were mixed evenly, 0.25g of benzoyl peroxide (BPO) (initiator) was added to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 3.5 hours and then cool to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 2.0 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 25 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The preparation of embodiment 3 functional polymer microspheres

In this embodiment, ethyl methacrylate is used as monomer 1, diethylaminoethyl methacrylate is used as monomer 2, and triethylene glycol dimethacrylate is used as crosslinking agent to carry out the formation of functional polymer microspheres. synthesis.

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 2.5mL of ethyl methacrylate (monomer 1), 7mL of diethylaminoethyl methacrylate (monomer 2), and 5mL of triethylene glycol were placed in a 50mL beaker. After dimethacrylate (crosslinking agent) and 5mL n-hexane (porogen) were mixed uniformly, 0.35g of benzoyl peroxide (BPO) (initiator) was added to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 4.5 hours and then cool to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 3.0 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 35 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The preparation of embodiment 4 functional polymer microspheres

In this example, ethyl acrylate was used as monomer 1, dimethylaminoethyl acrylate was used as monomer 2, and polyvinyl alcohol diacrylate was used as a crosslinking agent to synthesize functional polymer microspheres.

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 2mL of ethyl acrylate (monomer 1), 6mL of dimethylaminoethyl acrylate (monomer 2), and 4mL of polyvinyl alcohol diacrylate (cross-linked) were placed in a 50mL beaker. After mixing evenly with 4mL n-hexane (porogen), add 0.30g benzoyl peroxide (BPO) (initiator) to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 4 hours and then cool down to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 2.5 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 30 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The preparation of embodiment 5 functional polymer microspheres

In this example, isooctyl acrylate is used as monomer 1, diisooctylaminoethyl methacrylate is used as monomer 2, and ethylene glycol diacrylate is used as a crosslinking agent to synthesize functional polymer microspheres.

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 1.5mL of isooctyl acrylate (monomer 1), 5mL of diisooctylaminoethyl methacrylate (monomer 2), and 3mL of ethylene glycol dimethacrylate were placed in a 50mL beaker. Acrylate (crosslinking agent) and 3mL n-hexane (porogen) were mixed evenly, and then 0.25g of benzoyl peroxide (BPO) (initiator) was added to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 3.5 hours and then cool to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 2.0 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 25 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The preparation of embodiment 6 functional polymer microspheres

In this embodiment, methyl methacrylate is used as monomer 1, diisooctylaminoethyl acrylate is used as monomer 2, and triethanolamine triacrylate is used as crosslinking agent to synthesize functional polymer microspheres.

Specifically include the following steps:

(1) Add 100mL of polyvinyl alcohol aqueous solution with a volume fraction of 0.7% in a three-neck round bottom bottle with a volume of 250mL as a dispersant, heat up to 69-71°C, start stirring, and the stirring speed is 490-510rpm/min. Nitrogen deoxygenation for 15 minutes;

(2) In a 50mL beaker, 2.5mL of methyl methacrylate (monomer 1), 7mL of diisooctylaminoethyl acrylate (monomer 2), and 5mL of triethanolamine triacrylate were placed in a 50mL beaker. (Crosslinking agent) and 5mL n-hexane (porogen) are mixed evenly, add 0.35g benzoyl peroxide (BPO) (initiator) to fully dissolve and prepare the monomer phase;

(3) Maintain the stirring speed, the stirring speed is 490-510rpm/min, add the prepared monomer phase into the three-neck round bottom flask in batches within 30 minutes, to ensure good monomer dispersion, and deoxygenate with nitrogen for 15 minutes; After the addition, continue to react at a constant temperature of 90°C for 4.5 hours and then cool to end the polymerization reaction to obtain polymer beads;

(4) After washing the obtained polymer beads with water for 2 to 3 times, extract them with acetone for 3 to 5 hours in a Soxhlet extractor to remove uncrosslinked homopolymers, and then vacuum them at 40°C. Dry to obtain porous cross-linked polymer beads;

(5) Mix 3.0 g of porous cross-linked polymer beads and an equal amount of propyl sultone in 35 mL of an equal volume of mixed methanol and tetrahydrofuran solution, stir at 50°C for 48 hours, and filter out the propyl sultone The ester, deionized water and methanol were washed three times and then dried to obtain functional polymer microspheres.

The physical and chemical properties of the functional polymer microspheres prepared in Examples 1-6 were analyzed, and the density was measured to be 0.98 by a densitometer. The percentages of C, H, N, and O measured by the elemental analyzer are C: 46.64%, H: 7.93%, N: 1.66%, O: 39.3%; the S content measured by the inductively coupled plasma spectrometer is 1.75% %.

Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the functional polymer microspheres. The infrared spectrum and SEM morphology are shown in Figure 1 and Figure 2, respectively. It can be seen from Figure 1 that the characteristic absorption peaks of sulfonic acid groups are at 530cm ^-1 , 620cm ^-1 , 1068cm ^-1 and 1190cm ^-1 , while the C=O stretching vibration absorption of methacrylate is at 1730cm ^-1 Peak; Figure 2 shows that the prepared functional polymer microspheres have a uniform particle size distribution and are at the micron level.

Test Example 1 Separation and Enrichment of Heavy Metal Ion Standards Using Functional Polymer Microspheres as SPE Column Packing

1.1 Establishment and verification of solid phase extraction method

Specific steps are as follows:

1) Weigh 430 mg of the functional polymer microspheres prepared in Example 1, and evenly add them into a stainless steel empty chromatographic column with a specification of 50×4.6 mm, and make a self-made SPE enrichment column. Use PEEK tubing to connect the SPE enrichment column to the STI high-pressure infusion pump. At a flow rate of 1 mL/min, wash the enrichment column with 5% methanol solution and pure water respectively until the pressure of the high-pressure pump is stable.

2) Prepare a series of mixed standards of copper, zinc, arsenic, cadmium, lead, mercury, tin and bismuth with concentrations of 0.2ng/mL, 0.5ng/mL, 1.0ng/mL, 2.0ng/mL and 5.0ng/mL solution.

3) In the range of flow rate 1-7mL/min, the influence of the flow rate of the high-pressure infusion pump on the adsorption efficiency of target heavy metal ions was investigated. It can be seen from Figure 3 that as the flow rate increased to 5 mL/min, the adsorption efficiency did not change significantly, however when the flow rate continued to increase, the recovery rate began to decrease. The reason may be that the too high flow rate will cause incomplete contact between the target substance and the active site of the enrichment column.

4) Prepare a series of mixed standard solutions with volumes of 10mL, 20mL, 30mL, 40mL, 50mL and 60mL, and investigate the influence of sample volume on the recovery rate of target heavy metal ions, as shown in Figure 4. When the loading volume was higher than 40mL, the recovery rate began to decrease, which may be due to the saturation of the adsorption capacity of the enrichment column.

6) Through the optimization of experimental conditions, at a flow rate of 5mL/min, an online solid phase extraction operation was performed on the above-mentioned mixed standard solution with a volume of 40mL. After the sample adsorption was completed, the target substance was eluted with 2% _HNO3 solution. For each concentration gradient, three parallel adsorption and elution operations were performed with a process blank.

7) Inductively coupled plasma mass spectrometry (ICPMS) was used to detect the content of the mixed solution of heavy metal ions before and after solid phase extraction and adsorption, and the concentration before and after adsorption was compared to calculate the adsorption efficiency.

8) Simultaneously measure the target ions in the eluent, and calculate the adsorption efficiency and enrichment factor.

The adsorption effect and elution efficiency of the above established method on mixed standard solutions of heavy metal ions with different concentration gradients were investigated. The results show that for the mixed standard solutions of heavy metal ions (copper, zinc, arsenic, cadmium, lead, mercury, tin, bismuth) with different concentration gradients, the adsorption effect and elution efficiency of more than 92% can be realized. The gradient mixed standard solution of heavy metal ions (vanadium, chromium, cobalt, antimony, barium) can also achieve an adsorption efficiency of more than 50%.

The solid-phase extraction method (SPE) generally needs to adjust the pH value of the general filler, the target analyte is few and the separation and enrichment efficiency is low, and the functional polymer microspheres of the present invention are made into the core filler of the solid-phase extraction column. A method for rapidly separating and enriching heavy metal ions in environmental water under mild neutral conditions is provided. The method does not need any external reagents, and only needs 8 minutes to realize the rapid adsorption of heavy metal ions that may exist in environmental water.

1.2 Separation and enrichment of heavy metal ion environmental standards by the above solid phase extraction method

Environmental standard samples GSBZ50009-88 (water quality copper, lead, zinc, cadmium) and GSB07-3171-2014 (water quality arsenic) were used as analysis objects to verify the feasibility and accuracy of the method. Due to the relatively high initial concentration of the target substance in the standard samples, they were diluted 200 times and 20 times respectively before solid-phase extraction, and the blank control and parallel samples were analyzed at the same time. ICP-MS detection adopts KED analysis mode to improve the signal-to-background ratio. When the helium flow rate is 4.091mL/min, the influence of doubly charged interference ions can be effectively eliminated, and the background signal is significantly reduced. Under the optimized experimental conditions, that is, at a flow rate of 5mL/min, the above-mentioned mixed standard solution with a volume of 40mL was subjected to online solid-phase extraction operation. After the sample adsorption was completed, the target substance was eluted with 2% _HNO3 solution. Three parallel adsorption and elution operations were carried out for each concentration gradient, and with a process blank, the adsorption efficiency of more than 92% could be achieved for the five heavy metal ions in the environmental standard sample, as shown in Figure 5.

Test Example 2 Separation and Enrichment of Environmental Water Samples Using Functional Polymer Microspheres as Solid Phase Extraction Column Packing

Lake water and river water were collected from Fujian Province and Zhejiang Province respectively, and the principle of multi-point sampling was followed in the sampling process to ensure the representativeness and uniformity of sampling. During the collection process, large algae and particulates were first removed with a filter, and immediately sent to the laboratory for analysis after acidification (preserved with ice packs during transportation). Before on-line separation and enrichment, the sample was first filtered through a cellulose acetate filter membrane with a pore size of 0.22 μm, and then transferred to a clean brown bottle. For the environmental water sample with a volume of 40mL, each sample was analyzed 3 times in parallel at a pump speed of 5mL/min, and 3 process blank samples were taken at the same time. The ICP-MS device was used to detect and compare the concentration changes before and after solid phase extraction separation and enrichment, and calculate the adsorption efficiency of each heavy metal ion, all of which were above 92%, and a satisfactory separation and enrichment effect was obtained. Finally, the as-prepared polymer material and the solid-phase extraction method were verified by spike recovery experiments. The results show that the adsorption rate of eight heavy metal ions of copper, zinc, arsenic, cadmium, lead, mercury, tin and bismuth is above 92%, and it can also reach five heavy metal ions of vanadium, chromium, cobalt, antimony and barium. More than 50% adsorption efficiency.

In summary, the functional polymer microspheres prepared by the present invention have the characteristics of wide selection of materials, economical and environmental protection, easy modification and high adsorption efficiency, which makes up for the shortcomings of currently commercially available solid phase extraction materials; it can be used for solid phase extraction operations The core filler can realize the separation and enrichment of thirteen kinds of heavy metal ions in environmental water at the same time, and the adsorption rate of copper, zinc, arsenic, cadmium, lead, mercury, tin and bismuth eight kinds of heavy metal ions are all above 92%. It can also achieve an adsorption efficiency of more than 50% for other heavy metal ions (vanadium, chromium, cobalt, antimony, barium); the invention is simple and convenient to operate, has fast treatment effect, and has considerable application in the field of separation and analysis of inorganic pollutants in actual environmental water bodies prospect.

Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is exemplary only, and is not intended to imply that the scope of the present disclosure (including claims) is limited to these examples; under the idea of the present invention, the above embodiments or Combinations between technical features in different embodiments are also possible, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, equivalent replacements, improvements, etc. within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A functional polymer microsphere, characterized in that, the mass percent of each element in the polymer microsphere is as follows: C:46.64%, H:7.93%, N:1.66%, O:39.3%, S: 1.75%; The structural formula of the polymer microsphere is as shown in formula (I): 2. a preparation method of functional polymer microspheres according to claim 1, is characterized in that, comprises the following steps: (1) Add a dispersant in a three-neck round bottom flask, start stirring after heating up, and ventilate nitrogen to remove oxygen; (2) After mixing the monomer, crosslinking agent and porogen uniformly in a beaker, add the initiator to fully dissolve and prepare the monomer phase; (3) under the condition of stirring, the monomer phase in the step (2) is added in batches in the dispersant after the deoxygenation in the step (1), and the nitrogen deoxygenation is carried out simultaneously in the process of adding in batches; the monomer Polymerization is carried out after addition to obtain polymer beads; (4) Wash the obtained polymer beads with water for 2 to 3 times, then extract with acetone for 3 to 5 hours to remove uncrosslinked homopolymers, and then dry them in vacuum at 40°C to obtain porous crosslinked beads. polymer pellets; (5) Use propyl sultone to modify the porous cross-linked polymer beads. After the modification, filter out the propyl sultone, wash with deionized water and methanol for 3 times, and then dry to finally prepare the functional polymer object microspheres. 3. The preparation method of functional polymer microspheres according to claim 2, is characterized in that, the dispersant described in step (1) is the polyvinyl alcohol aqueous solution that volume fraction is 0.7%, and described warming up is warming up to 69 ~71°C, the stirring speed is 490-510rpm/min, and the time for passing nitrogen to remove oxygen is 15min. 4. the preparation method of functional polymer microsphere according to claim 2 is characterized in that, described monomer in step (2) comprises monomer 1 and monomer 2, and described monomer 1, described monomer 2. The volume ratio of the crosslinking agent to the porogen is 1.5 to 2.5:5 to 7:3 to 5:3 to 5; the volume to mass ratio of the crosslinking agent to the initiator is 3 to 5: 0.25-0.35g, that is, every 3-5mL of the cross-linking agent corresponds to 0.25-0.35g of the initiator; the monomer 1 is ethyl methacrylate, and the monomer 2 is diethyl methacrylate Amino ethyl ester, the crosslinking agent is triethylene glycol dimethacrylate, the porogen is n-hexane, and the initiator is benzoyl peroxide. 5. the preparation method of functional polymer microsphere according to claim 4 is characterized in that, the volume ratio of described monomer 1, described monomer 2, described crosslinking agent and described porogen is 2 :6:4:4; the volume mass ratio of the crosslinking agent to the initiator is 4:0.30g, that is, every 4mL of the crosslinking agent corresponds to 0.30g of the initiator. 6. the preparation method of functional polymer microsphere according to claim 2 is characterized in that, the speed of stirring described in step (3) is 490～510rpm/min, and the time of described adding in batches is 30min, so The time for passing nitrogen to remove oxygen is 15 minutes, the polymerization reaction is a constant temperature reaction at a temperature of 90° C. for 3.5 to 4.5 hours, and the volume ratio of the dispersant to the crosslinking agent is 100:3 to 5. 7. the preparation method of functional polymer microsphere according to claim 2 is characterized in that, the concrete step of adopting propyl group sultone to modify porous cross-linked polymer microsphere described in step (5) is: Propyl sultone and porous cross-linked polymer beads were dissolved in a mixed solution of methanol and tetrahydrofuran at a mass ratio of 1:1, stirred at 50°C for 48 hours, filtered to remove propyl sultone, and deionized water washed with methanol for 3 times and then dried to obtain functional polymer microspheres; wherein the volume ratio of methanol to tetrahydrofuran in the mixed solution is 1:1, and the volume ratio of the mixed solution to the porous cross-linked polymer beads The volume-to-mass ratio is 25-35:2.0-3.0, that is, every 25-35 mL of the mixed solution corresponds to 2.0-3.0 g of the porous cross-linked polymer beads. 8. the preparation method of functional polymer microsphere according to claim 7, is characterized in that, the volume-to-mass ratio of described mixed solution and described porous crosslinked polymer bead is 30:2.5, promptly every 30mL described The mixed solution corresponds to 2.5 g of the porous cross-linked polymer beads. 9. The application of functional polymer microspheres according to claim 1 in the preparation of solid phase extraction column packing. 10. the application of functional polymer microspheres according to claim 9 in the preparation of solid-phase extraction column packing, is characterized in that, described solid-phase extraction column packing is used for separating copper, zinc, zinc, Arsenic, cadmium, lead, mercury, tin, bismuth, vanadium, chromium, cobalt, antimony, barium thirteen heavy metal ions.