CN111363074B

CN111363074B - Preparation method of poly (styrene-co-oleic acid) nanoparticles with core-shell structure

Info

Publication number: CN111363074B
Application number: CN202010400834.7A
Authority: CN
Inventors: 郁梦佳; 周伟; 熊盛; 王亭芳; 符延和; 覃林娟
Original assignee: Shanghai Jiemen Biotechnology Co ltd
Current assignee: Shanghai Jiemen Biotechnology Co ltd
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2023-01-24
Anticipated expiration: 2040-05-13
Also published as: CN111363074A

Abstract

The invention relates to a preparation method of poly (styrene-co-oleic acid) nanoparticles with a core-shell structure. Specifically, the preparation method comprises a polymerization step of styrene monomer and a crosslinking step of polystyrene and a mixture containing the styrene monomer, oleic acid monomer and a crosslinking agent. The poly (styrene-co-oleic acid) nano-particles with the core-shell structure prepared by the method have the advantages of uniform particle size, high surface carboxyl content and the like.

Description

Preparation method of poly (styrene-co-oleic acid) nanoparticles with core-shell structure

Technical Field

The invention belongs to the field of preparation of carboxylated polystyrene nanoparticles, and particularly relates to a preparation method of poly (styrene-co-oleic acid) nanoparticles with a core-shell structure.

Background

The modified polystyrene is prepared by introducing other groups or substances through copolymerization, blending and other modes on the basis of easy polymerization and low cost of polystyrene (PSt), so as to achieve the purpose of improving physical and chemical properties. The carboxylated polystyrene nanoparticles are generally synthesized by copolymerizing styrene and an unsaturated vinyl monomer with a carboxyl functional group to obtain a target product. Studies by Sekerak N.M. et al have introduced that this class of carboxylated PSt nanoparticles can be prepared by emulsion polymerization, microemulsion polymerization, dispersion polymerization, suspension polymerization, and the like, with emulsion polymerization being the most widely used. According to literature introduction and operation experience of existing production, generally, after premixing a styrene monomer, an acrylic acid monomer, a persulfate initiator, a surfactant, a stabilizer and distilled water, heating the mixture to the decomposition temperature of the initiator in a nitrogen environment for a certain polymerization time to obtain carboxylated polystyrene nanoparticles, and washing the carboxylated polystyrene nanoparticles to be applied to the fields of biological immunodiagnosis and the like. Existing emulsion polymerization processes will generally have: persulfate and other water-soluble initiators are used, so that the nucleation period is long, and the particle size of the product is easy to be in multi-stage distribution; during the polymerization process, carboxyl is easy to gather into an organic phase, which causes the defects of low carboxyl content on the surface of a product and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of carboxylated polystyrene nanoparticles with uniform particle size and high carboxyl content on the surface of the particles.

In a first aspect, the present invention provides a method for preparing poly (styrene-co-oleic acid) nanoparticles having a core-shell structure, the method comprising the steps of:

(1) Firstly, mixing an emulsifier, a dispersant and water at room temperature in a nitrogen atmosphere; then adding styrene monomer into the mixture at 60 +/-5 ℃ for secondary mixing; then adding an initiator at the temperature of 80 +/-5 ℃ to carry out polymerization reaction, thereby obtaining a solution containing polystyrene;

(2) Adding an initiator and a pH regulator into the solution containing the polystyrene prepared in the step at 80 +/-5 ℃ in a nitrogen atmosphere for mixing; and then carrying out a crosslinking reaction on the mixture and a mixture containing a styrene monomer, an oleic acid monomer and a crosslinking agent at the temperature of 80 +/-5 ℃, and heating to 90 +/-5 ℃ to continue the reaction, thereby obtaining the poly (styrene-co-oleic acid) nano-particles with the core-shell structure.

In another preferred embodiment, the water is deionized water.

In another preferred embodiment, in step (1), the time for one mixing is 30 ± 10 minutes.

In another preferred example, in step (1), the time for the second mixing is 30 ± 10 minutes.

In another preferred embodiment, in step (1), the polymerization reaction time is 5 hours ± 30 minutes.

In another preferred embodiment, in the step (2), the time of the crosslinking reaction at 80. + -. 5 ℃ is 5 hours. + -. 30 minutes; the reaction time after the temperature is raised to 90 plus or minus 5 ℃ is 1 hour plus or minus 30 minutes.

In another preferred example, in the step (1), an ultrasonic step is further included between the end of the secondary mixing and the addition of the initiator: and (3) carrying out ultrasonic treatment on the mixture obtained after the secondary mixing at the temperature of 0 +/-5 ℃.

In another preferred embodiment, the time of the ultrasound is 10 minutes ± 5 minutes.

In another preferred embodiment, the emulsifier is sodium lauryl sulfate.

In another preferred embodiment, the dispersant is selected from the group consisting of: polyoxyethylene dodecyl ether and polyvinylpyrrolidone.

In another preferred embodiment, the initiator is an aqueous solution of potassium persulfate.

In another preferred embodiment, the initiator is a 2wt% aqueous solution of potassium persulfate.

In another preferred embodiment, the pH adjusting agent is selected from the group consisting of: aqueous sodium hydroxide solution, aqueous sodium bicarbonate solution.

In another preferred embodiment, the pH adjusting agent is selected from the group consisting of: 1wt% aqueous sodium hydroxide solution, 1wt% aqueous sodium bicarbonate solution.

In another preferred embodiment, the crosslinking agent is divinylbenzene.

In another preferred example, in the step (1), the volume-to-mass ratio (mL/g) of the initiator to the styrene monomer is 1 (1.3-3.4).

In another preferred example, in the step (1), the volume-to-mass ratio (mL/g) of the initiator to the styrene monomer is 1.

In another preferred example, in the step (1), the mass ratio of the emulsifier to the styrene monomer is 1 (57-400).

In another preferred example, in the step (1), the mass ratio of the emulsifier to the styrene monomer is 1.

In another preferred example, in the step (1), the mass ratio of the dispersing agent to the styrene monomer is 1 (20-2000).

In another preferred example, in the step (1), the mass ratio of the dispersing agent to the styrene monomer is 1.

In another preferred example, in the step (2), in the mixture containing the styrene monomer, the oleic acid monomer and the cross-linking agent, the mass ratio of the styrene monomer to the oleic acid monomer to the cross-linking agent is (0.8-5) to 1 (0.8-5).

In another preferred example, in the step (2), in the mixture containing the styrene monomer, the oleic acid monomer and the crosslinking agent, the mass ratio of the styrene monomer to the oleic acid monomer to the crosslinking agent is (1.25-3.125): 1 (1.25-3.125).

In another preferred embodiment, in the step (2), the volume ratio of the initiator to the pH regulator is 1 (1.25-2.5).

In another preferred example, the volume ratio of the initiator in step (1) to the initiator in step (2) is 5.

In another preferred example, the mass ratio of the styrene monomer in the step (1) to the styrene monomer in the step (2) is 8.

In another preferred embodiment, in the step (2), after the crosslinking reaction is finished, a solution containing the poly (styrene-co-oleic acid) nanoparticles with the core-shell structure is obtained;

firstly, washing the solution with deionized water until the pH value is neutral; then washing with ethanol, and finally drying in vacuum to obtain the poly (styrene-co-oleic acid) nano-particles with the core-shell structure.

The main advantages of the invention include:

1. the invention provides a preparation method of poly (styrene-co-oleic acid) nanoparticles with a core-shell structure. The method is an emulsion polymerization method with sample adding in batches, and the polymerization process is more controllable, so that a series of problems of nonuniform particle size, low carboxyl content on the surface of particles, poor monodispersity and the like of carboxylated polystyrene nanoparticles are solved.

2. The poly (styrene-co-oleic acid) nano-particles with the core-shell structure prepared by the preparation method take polystyrene particles with uniform diameters as a core layer; introducing the mutual action of oleic acid molecules and hydrophilic groups in a water phase into the surfaces of polystyrene particles to obtain the high-orientation uniformly-distributed microsphere surface carboxylated polystyrene nanoparticles.

It is to be understood that within the scope of the present invention, the above-described features of the present invention and those specifically described below (e.g., in the examples) may be combined with each other to form new or preferred embodiments. Not to be repeated herein, depending on the space.

Drawings

FIG. 1 is a Scanning Electron Microscope (SEM) photograph of poly (styrene-co-oleic acid) nanoparticles 1 prepared in example 1.

FIG. 2 is a Scanning Electron Microscope (SEM) photograph of the poly (styrene-co-oleic acid) nanoparticles 2 prepared in example 2.

FIG. 3 is a Scanning Electron Microscope (SEM) photograph of poly (styrene-co-oleic acid) nanoparticles 3 prepared in example 3.

Fig. 4 is a Scanning Electron Microscope (SEM) photograph of comparative nanoparticle 1 prepared in comparative example 1.

Fig. 5 is a Scanning Electron Microscope (SEM) photograph of comparative nanoparticle 3 prepared in comparative example 3.

Detailed Description

The invention provides a preparation method of poly (styrene-co-oleic acid) nanoparticles with a core-shell structure.

Firstly, preparing polystyrene particles with uniform particle size as a core layer; when preparing the core layer, the inventor adds a nonionic polymer surfactant as a dispersing agent in addition to an emulsifier required by emulsion polymerization, so that the condition of secondary nucleation is effectively reduced, and polystyrene particles with more uniform and non-adhesive particle sizes can be prepared.

The method then crosslinks oleic acid monomers on the surfaces of polystyrene particles to obtain a copolymer of polystyrene and oleic acid as a shell layer, namely a polystyrene-oleic acid copolymer layer. In preparing the shell layer, the inventors copolymerized styrene monomers and oleic acid monomers by putting a certain ratio of styrene monomers and oleic acid monomers into a solution containing polystyrene nanoparticles. The oleic acid after copolymerization modification mainly exists in three modes of freeness, surface combination and embedding, if the proportion of the embedded acid is too large, the carboxyl is gathered in an organic phase in the reaction process, the surface charge density is reduced, the stability of liquid drops is reduced, and the particle size distribution is influenced. In order to ensure that carboxyl exists mainly in the form of surface-bound acid, the pH value of a reaction system is increased by adding a certain amount of pH regulator into a water phase under the condition of not influencing a crosslinking reaction, so that the surface-bound acid is increased.

The inventor unexpectedly finds that the carboxyl distribution on the surface of the particle modified by oleic acid is more uniform, the self-polymerization of the monomer is not obvious, and the particle size distribution of the final nanoparticle is more uniform compared with the particle modified by acrylic acid monomer.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out under conventional conditions or conditions recommended by the manufacturers. Unless otherwise indicated, percentages and parts are by weight.

Reagents or materials for laboratory or instruments

Experimental reagent: styrene, potassium persulfate (KPS), oleic acid, acrylic acid, divinylbenzene, sodium lauryl sulfate, polyoxyethylene lauryl ether (EMULGEN 1150S-60), sodium hydroxide, sodium bicarbonate, sodium azide, ethanol, deionized water, etc.;

an experimental instrument: a 250mL three-neck flask, an electric stirrer, a reflux condenser, a thermometer, a constant temperature water bath, a Buchner funnel, a vacuum pump, a nitrogen bottle, a Scanning Electron Microscope (SEM), a high-resolution zeta potential and laser particle size analyzer (ELSZ-2000), an electronic pH meter and the like;

styrene is dried by alkali washing and is distilled under reduced pressure for standby: under the protection of nitrogen, styrene monomer soaked by calcium hydride is subjected to vacuum rectification at 40-50 ℃ in an oil bath, and middle distillate is taken for the following steps.

Deionized water was subjected to RO membrane filtration and used in the following steps.

And (3) recrystallizing the potassium persulfate for later use: heating a small amount of ethanol to boil, condensing and refluxing, and adding potassium persulfate into the hot ethanol; continuously adding ethanol/water until the potassium persulfate to be treated is completely dissolved; cooling the mixture and separating out potassium persulfate; and (4) carrying out suction filtration to obtain potassium persulfate crystals, washing with ethanol, and carrying out vacuum cooling and drying for the following steps.

As used herein, "room temperature" means 20-30 ℃.

Example 1

A1.250 mL three-necked flask was charged with 150mL deionized water, and then 0.2g of sodium lauryl Sulfate (SDB), which is an emulsifier, and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60), which is a dispersant, were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. The mixture was heated in a water bath to 60 ℃ and after temperature equilibration 20g of styrene monomer (St) were added and stirring was continued for 30 minutes. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture was again heated to 80 ℃ and after temperature equilibration 10mL of an aqueous solution of initiator potassium persulfate (2 wt%) was added and the reaction was carried out for 5 hours to obtain a polystyrene solution.

2. Adding 2mL of potassium persulfate aqueous solution (2 wt%) and 2.5mL of sodium hydroxide aqueous solution (1 wt%) as a pH regulator into the polystyrene solution prepared in the previous step under the atmosphere of 80 ℃ water bath nitrogen, fully mixing, slowly and dropwise adding a mixture of 2.5g of styrene monomer (St), 2g of oleic acid monomer (OA) and 2.5g of crosslinking agent Divinylbenzene (DVB) for reacting for 5 hours, raising the temperature of the water bath to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano particles.

3. And washing the solution of the nanoparticles obtained in the above steps with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the poly (styrene-co-oleic acid) nanoparticles 1 with the core-shell structure.

The poly (styrene-co-oleic acid) nanoparticle 1 was examined to have a SEM diameter of 100nm, a hydrated particle size of 104nm, and a dispersion of 0.001. The Scanning Electron Microscope (SEM) photograph thereof is shown in FIG. 1.

Example 2

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60) as a dispersant were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. Heating in water bath to 60 deg.C, adding 20g styrene monomer after temperature balance, and stirring for 30 min. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture was again heated to 80 ℃ and after temperature equilibration 10mL of aqueous solution of initiator potassium persulfate (2 wt%) was added and the reaction was carried out for 5 hours to obtain polystyrene solution.

2. And (2) adding 2mL of potassium persulfate aqueous solution (2 wt%) and 2.5mL of sodium hydroxide aqueous solution (1 wt%) as a pH regulator into the polystyrene solution prepared in the step under the atmosphere of water bath nitrogen at the temperature of 80 ℃, slowly dropwise adding a mixture of 2.5g of styrene monomer, 0.8g of oleic acid monomer and 2.5g of cross-linking agent divinylbenzene, reacting for 5 hours, raising the water bath temperature to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano particles.

3. And washing the solution of the nanoparticles obtained in the step with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the poly (styrene-co-oleic acid) nanoparticles 2 with the core-shell structure.

Detection shows that the poly (styrene-co-oleic acid) nanoparticle 2 has a SEM diameter of 180nm, a hydrated particle size of 198nm, and a dispersion of 0.004. The Scanning Electron Microscope (SEM) photograph thereof is shown in FIG. 2.

Example 3

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of emulsifier sodium lauryl sulfate and 1g of dispersant polyvinylpyrrolidone (PVP) were added thereto, and stirred at room temperature for 30 minutes under a nitrogen purge. Heating in water bath to 60 deg.C, adding 20g styrene monomer after temperature balance, and stirring for 30 min. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture was again heated to 80 ℃ and after equilibration the 10mL aqueous solution (2 wt%) of initiator potassium persulfate was added and the reaction proceeded for 5 hours to give a polystyrene solution.

2. Adding 2mL of potassium persulfate aqueous solution (2 wt%) and 2.5mL of sodium hydroxide aqueous solution (1 wt%) as a pH regulator into the polystyrene solution prepared in the previous step under the atmosphere of 80 ℃ water bath nitrogen, fully mixing, slowly and dropwise adding a mixture of 2.5g of styrene monomer, 2g of oleic acid monomer and 2.5g of cross-linking agent divinylbenzene, reacting for 5 hours, raising the water bath temperature to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano-particles.

3. And washing the solution of the nano-particles obtained in the step with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the poly (styrene-co-oleic acid) nano-particles 3 with the core-shell structure.

Through detection, the diameter of the SEM of the poly (styrene-co-oleic acid) nano-particles 3 is 250nm, and the particle size is larger. The Scanning Electron Microscope (SEM) photograph thereof is shown in FIG. 3.

Example 4

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60) as a dispersant were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. Heating in water bath to 60 deg.C, adding 20g styrene monomer after temperature balance, and stirring for 30 min. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture was again heated to 80 ℃ and after temperature equilibration 10mL of an aqueous solution of initiator potassium persulfate (2 wt%) was added and the reaction was carried out for 5 hours to obtain a polystyrene solution.

2. And (2) adding 2mL of potassium persulfate aqueous solution (2 wt%) and 5mL of pH regulator sodium bicarbonate aqueous solution (1 wt%) into the polystyrene solution prepared in the previous step under the atmosphere of 80 ℃ water bath nitrogen, fully mixing, slowly and dropwise adding a mixture of 2.5g of styrene monomer, 2g of oleic acid monomer and 2.5g of crosslinking agent divinylbenzene, reacting for 5 hours, raising the water bath temperature to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano particles.

3. And washing the solution of the nanoparticles obtained in the step with deionized water until the pH value is neutral, washing with ethanol, and drying in vacuum to obtain the poly (styrene-co-oleic acid) nanoparticles 4 with the core-shell structure.

Example 5

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60) as a dispersant were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. Heating to 60 ℃ in a water bath, adding 20g of styrene monomer after the temperature is balanced, and continuing stirring for 30 minutes. The mixture was heated to 80 ℃ and after equilibration the initiator potassium persulfate solution (2% by weight) was added in 10mL and the reaction was allowed to proceed for 5 hours to give a polystyrene solution.

2. Adding 2mL of potassium persulfate aqueous solution (2 wt%) and 2.5mL of pH regulator sodium hydroxide aqueous solution (1 wt%) into the polystyrene solution prepared in the step under the atmosphere of 80 ℃ water bath nitrogen, fully mixing, slowly dropwise adding a mixture of 2.5g of styrene monomer, 2g of oleic acid monomer and 2.5g of cross-linking agent divinylbenzene, reacting for 5 hours, raising the water bath temperature to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano particles.

3. And washing the solution of the nanoparticles obtained in the above steps with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the poly (styrene-co-oleic acid) nanoparticles 5 with the core-shell structure.

Comparative example 1

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60) as a dispersant were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. Heating to 60 ℃ in a water bath, adding 20g of styrene monomer after the temperature is balanced, and continuing stirring for 30 minutes. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture was again heated to 80 ℃ and after temperature equilibration 10mL of aqueous solution of initiator potassium persulfate (2 wt%) was added and the reaction was carried out for 5 hours to obtain polystyrene solution.

2. Adding 2mL of potassium persulfate aqueous solution (2 wt%) and 2.5mL of pH regulator sodium hydroxide aqueous solution (1 wt%) into the polystyrene solution prepared in the above step under the atmosphere of 80 ℃ water bath nitrogen, fully mixing, slowly dropwise adding a mixture of 2.5g of styrene monomer, 2g of acrylic acid monomer and 2.5g of cross-linking agent divinylbenzene, reacting for 5 hours, raising the water bath temperature to 90 ℃, and continuing to react for 1 hour to obtain the solution of the polystyrene-co-oleic acid core-shell nano particles.

3. And washing the solution of the nanoparticles obtained in the above step with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the comparative nanoparticles 1.

The comparative nanoparticle 1 was examined to have a SEM diameter of 150nm, a hydrated particle size of 185nm, and a dispersion of 0.074. The Scanning Electron Microscope (SEM) photograph thereof is shown in FIG. 4. From the electron micrograph, it is found that the particle size is not uniform.

Compared with the modification by adopting acrylic acid monomers, the surface carboxyl distribution of the particles modified by adopting oleic acid is more uniform, the self-polymerization of the monomers is not obvious, and the particle size distribution of the final nanoparticles is more uniform.

Comparative example 2 one-step sample application

A1.250 mL three-necked flask was charged with 150mL deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier and 1g of polyoxyethylene lauryl ether (EMULGEN 1150S-60) as a dispersant were added thereto, and the mixture was stirred at room temperature for 30 minutes under a nitrogen purge. The bath was heated to 60 ℃ and a mixture of 22.5g of styrene monomer, 2g of oleic acid monomer and 2.5g of the crosslinker divinylbenzene was added after temperature equilibration and stirring was continued for 30 minutes. The mixture solution was ultrasonically dispersed in an ice-water bath at 0 ℃ for 10 minutes to prevent prepolymerization. The mixture is heated to 80 ℃ again, 10mL of aqueous solution (2 wt%) of initiator potassium persulfate is added after the temperature is balanced, and the polystyrene-co-oleic acid nanoparticle solution can be obtained after the reaction is continuously carried out for 8 hours.

2. And washing the solution of the nanoparticles obtained in the above step with deionized water until the pH value is neutral, washing with ethanol, and vacuum-drying to obtain comparative nanoparticles 2.

Comparative example 3

A1.250 mL three-necked flask was charged with 150mL of deionized water, and 0.2g of sodium lauryl sulfate as an emulsifier was added thereto, followed by stirring at room temperature for 30 minutes under a nitrogen purge. Heating in water bath to 60 deg.C, adding 20g styrene monomer after temperature is balanced, stirring for 30 min, and ultrasonic dispersing in ice water bath at 0 deg.C for 10min to prevent prepolymerization. The mixture was again heated to 80 ℃ and after temperature equilibration 10mL of aqueous solution of initiator potassium persulfate (2 wt%) was added and the reaction was carried out for 5 hours to obtain polystyrene solution.

3. And washing the solution of the nanoparticles obtained in the above step with deionized water until the pH value is neutral, washing with ethanol, and then drying in vacuum to obtain the comparative nanoparticles 3.

The comparative nanoparticle 3 was examined to have a SEM diameter of 200nm, a hydrated particle size of 207nm, and a dispersion of 0.055. The Scanning Electron Microscope (SEM) photograph thereof is shown in FIG. 5.

Test example

Antibody coating method:

the nanoparticles prepared in the above examples or comparative examples were dispersed in deionized water to prepare a 5wt% nanoparticle solution, and 0.1wt% sodium azide was added for further use.

To 0.5mL of 5wt% aqueous nanoparticle solution was added 150. Mu.L of 1-ethyl- (3-dimethylaminopropyl) carbodiimide (EDC) aqueous solution (33.33 wt%), mixed for 10min, centrifuged at 6000r,10min, and the supernatant was discarded. Adding 1mL MES buffer solution with pH5.5, resuspending the nanoparticles, and ultrasonic dispersing for 1min. To the suspension was added 200. Mu.L of rabbit anti-human BMG antibody (10 mg/mL), mixed well for 2 hours, centrifuged 6000r,10min, and the supernatant was discarded. 1mL of PBS buffer (pH 7.4) containing bovine white (10 wt%), resuspending, and ultrasonically dispersing for 1min. After mixing for 1 hour, the mixture was centrifuged at 8000r and 10min, and the supernatant was discarded. 2mL of latex stock solution was added, re-suspended, and ultrasonically dispersed for 10min. According to the nano particle solution: volume of diluent 1:10, diluting to obtain the reagent working solution.

The following parameters or properties were tested, respectively: appearance, linearity, hook effect, sensitivity, accuracy, stability.

Testing an instrument: hitachi 7180

Testing parameters: 3/150/30;18-34;600nm

Taking blood-BMG at concentrations of 0mg/mL, 5mg/mL, 10mg/mL, 50mg/mL, 80mg/mL, 200mg/mL, 400mg/mL as examples, the results are as follows:

appearance: the latex solution after binding the antibody was a uniform white liquid.

Linearity: the serum is in the linear range of [ 0.4-80 ] mg/L, and the correlation coefficient r is more than or equal to 0.990.

Hook effect: at a sample concentration of 400mg/L, the value was found to be 80mg/L above the upper limit of the linear range.

Sensitivity: at the concentration of 2.25mg/L, the absorbance value is more than or equal to 0.02.

Accuracy: the relative deviation does not exceed +/-10%.

Stability: no precipitation appears after standing and placing, and the sensitivity change does not exceed +/-10%.

The specific test results are shown in table 1.

TABLE 1

In the above table, the first and second sheets are shown,

in the appearance test results, a indicates a white solution with a uniform appearance, with no visible precipitate.

In the linear test result, AA represents that the correlation coefficient is more than or equal to 0.998; a represents that the correlation coefficient is more than or equal to 0.990; b represents that the correlation coefficient is more than or equal to 0.975; c represents a correlation coefficient of < 0.975.

In the Hook effect test results, when 400mg/L of the sample was tested, the following values were found: AA is more than or equal to 100; a is more than or equal to 80; b is more than or equal to 75 and less than 80; c is less than 75.

In the sensitivity test results, at a concentration of 2.25mg/L, absorbance value: a is more than or equal to 0.02; b is more than or equal to 0.015; c is less than 0.015.

In the accuracy test result, A represents that the relative deviation of the reagent does not exceed +/-10%; b means that the relative deviation of the reagents is more than + -10%.

In the stability test result, A represents that the sensitivity change is less than or equal to 5 percent at 4 ℃ for 14 days and less than or equal to 5 percent at 37 ℃ for 7 days; b represents that the sensitivity change is less than or equal to 10 percent at 4 ℃ for 14 days and less than or equal to 10 percent at 37 ℃ for 7 days; c indicates a sensitivity change of > 10% at 4 ℃ for 14 days and a sensitivity change of > 10% at 37 ℃ for 7 days.

As can be seen from the test results, the poly (styrene-co-oleic acid) nanoparticles with the core-shell structure obtained by the preparation method have generally good performances.

All documents mentioned in this application are incorporated by reference in this application as if each were individually incorporated by reference. Furthermore, it should be understood that various changes and modifications of the present invention can be made by those skilled in the art after reading the above teachings of the present invention, and these equivalents also fall within the scope of the present invention as defined by the appended claims.

Claims

1. A method for preparing poly (styrene-co-oleic acid) nanoparticles having a core-shell structure, the method comprising the steps of:

(2) Adding an initiator and a pH regulator into the solution containing the polystyrene prepared in the step at 80 +/-5 ℃ in a nitrogen atmosphere for mixing; then, carrying out a crosslinking reaction on the mixture and a mixture containing a styrene monomer, an oleic acid monomer and a crosslinking agent at the temperature of 80 +/-5 ℃, and heating to the temperature of 90 +/-5 ℃ to continue the reaction so as to obtain the poly (styrene-co-oleic acid) nano-particles with the core-shell structure;

the emulsifier is sodium dodecyl sulfate; the dispersant is selected from the group consisting of: polyoxyethylene lauryl ether, polyvinylpyrrolidone, or a combination thereof; each of the initiators is independently an aqueous solution of potassium persulfate; the pH regulator is selected from the group consisting of: sodium hydroxide aqueous solution, sodium bicarbonate aqueous solution; the crosslinking agent is divinylbenzene.

2. The method of claim 1, wherein the step (1) further comprises an ultrasonic step between the end of the second mixing and the addition of the initiator: and (3) carrying out ultrasonic treatment on the mixture obtained after the secondary mixing at the temperature of 0 +/-5 ℃.

3. The method according to claim 1, wherein in the step (1), the mass ratio of the emulsifier to the styrene monomer is 1 (57-400).

4. The method according to claim 1, wherein in the step (1), the mass ratio of the dispersant to the styrene monomer is 1 (20-2000).

5. The process according to claim 1, wherein the initiator is a 2wt% aqueous solution of potassium persulfate.

6. The method of claim 1, wherein the pH adjusting agent is selected from the group consisting of: 1wt% aqueous sodium hydroxide solution, 1wt% aqueous sodium bicarbonate solution.

7. The method according to claim 1, wherein in the step (1), the volume-to-mass ratio of the initiator to the styrene monomer is 1.

8. The preparation method according to claim 1, wherein in the step (1), the volume-to-mass ratio of the initiator to the styrene monomer is 1 (1.3-3.4) mL/g.

9. The method according to claim 1, wherein in the step (2), the mixture containing the styrene monomer, the oleic acid monomer and the crosslinking agent has a mass ratio of (0.8-5) to 1 (0.8-5) of the styrene monomer, the oleic acid monomer and the crosslinking agent.

10. The preparation method according to claim 1, wherein in the step (2), after the crosslinking reaction is finished, a solution containing poly (styrene-co-oleic acid) nanoparticles having a core-shell structure is obtained;

firstly, washing the solution by deionized water until the pH value is neutral; then washing with ethanol, and finally drying in vacuum to obtain the poly (styrene-co-oleic acid) nano-particles with the core-shell structure.